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A couple of people have recently asked 'what is capping'. Being no expert at all on this i thought i'd post this video.
NOTE: Just to be clear, BCA Insurance DOES NOT cover this activity! see: 64 Q: Is the use of Hilti caps covered? A: No. While it is an open question as to whether the technique is actually legal or not, the fact remains that the experience to date indicates that the technique is simply not safe enough to be considered as an acceptable risk in the context of caving in general. It may be that individuals have identified equipment and procedures which leave them satisfied that the technique is safe enough for their own purposes, but this is still a long way from being able to accept the risk of a claim from an untrained and inexperienced individual. Over time, we may be able to define procedures, training and equipment which allow the use of Hilti caps to be seen as low enough risk that they can be included in the PL scheme, but this point has not yet been reached and therefore we must regretfully conclude that the scheme cannot cover this activity whoever undertakes it. |
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Tim Watts
Last Edit: 12 years 2 weeks ago by timwatts.
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that could have blown his fuckin balls off. he should have only used ONE hilti cap for a rock that size
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what a prick ..wont go under ground with him
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mike leahy wrote:
that could have blown his fuckin balls off. he should have only used ONE hilti cap for a rock that size Having never done this, I am assuimng that should one fail to do the job, You can repeat in the same hole with 2 caps? |
You want me to go down *there*? On a bloody *rope*?
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best practice is to drill another hole alongside un-expoded cap and repeat. if you put another cap in the same hole you are in danger of the second cap squashing against the first cap as it is a softer material than the rock. one hole one cap other wise you end up like that fool , most capping is done in confined places as well as close proximity to the object/rock. if it make a dull thud you know it's done the job
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He may as well have taken a bazooka to it .
Still an informative clip, cheers Tim |
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bunch off poofs! chuck a handfull in just to make sure! I was expecting an exploaion when I posted the clip. mike didn't let me down.
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Tim Watts
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What's with the Colour coding of the Hilti caps? Graded according to how powerful they are? If so, what ones would you get? Are some too powerful for use in a confined space?
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You want me to go down *there*? On a bloody *rope*?
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NewStuff wrote:
What's with the Colour coding of the Hilti caps? Graded according to how powerful they are? If so, what ones would you get? Are some too powerful for use in a confined space? if i remember correctly the weakest ones are yellow then red then black, the yellow's are not really up for the job for us . you must remember that they are't desighed for this lark. |
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TimWatts wrote:
I was expecting an exploaion when I posted the clip. mike didn't let me down. your just getting cheeky cos your on your holiday home in the north sea.i'll give you explosion when you get back |
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just found a site for dexpan try it out:blink:
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No link in your post, but a search reveals a most interesting product.
I presume it's for use where surroundings are too unstable to use stuff that goes Boom? |
You want me to go down *there*? On a bloody *rope*?
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NewStuff wrote:
No link in your post, but a search reveals a most interesting product. I presume it's for use where surroundings are too unstable to use stuff that goes Boom? ye but there is no fun if it does'nt go BOOM |
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Having spent some of my Teenage years in the US, I'll agree wholehertedly with that. Seeing a full stick of TNT go up is something else. I wasn't so keen on the Dirt-shower that followed shortly afterwards though!
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You want me to go down *there*? On a bloody *rope*?
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heres a slightly more realistic - in action - version.
Major risks that i am aware of.... Firing the rod back at you like a bullet fragments coming back up the hole at you (fragments of the metal cap that is) hence the heavy piece of matting - some claim thick rubber off a conveyor or similar is a must along with a large diameter washer on the striker rod too. I've a pot of 100 'reds' if anyone wants to play with them. What is interesting that i've heard the the shape of the striker rod is important in a way i'd never before realized. |
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Tim Watts
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for long term ref - i thought i'd chuck the following that was ripped from elsewhere on here....
burrencrawler: Hi Guys, Some of us have a caving talk coming up for irish students in Kilfenora. Thought it would be a good idea to show them how to cap rock, here is a new video fresh out, hope you like it: * link removed * mmilner: Cool video, thanx! Presumably then, the caps are set off by being hit round the rim and not in the centre? Brains: The caps are rimfire not crntre fire,the pin wil be like a phillips scredriver with the middle ground ou to leave a crown of points. Ois nabdy to have your friends wear catcher mitts to help get the bits berore they get you 2!. Good video Ed W: Good to see some infor being shared - isn't it about time that those of us using caps regularly got together to compare techniques? I don't want to sound like a moaning minnie, but it is worth pointing out that capping is an inherently risky technique. After having used caps extensively (several thousand of them) and seen several accidents (including being on the receiving end myself) there are several points that I might argue with in this video. I am sure that there are others out there who in turn would suggest that the way I am doing things could be improved. The big difference in the way I do things is to place the pin in a heavy rod which is struck rather than the pin directly. This has two effects, firstly moving you further away from the business end of the capping and secondly the extra mass means that if the pin does "jump" it does so much more slowly than just the very lightweight pin. Anyone who has seen a naked pin shoot back out of the hole at high speed will know what potential it has to cause injury. The other often overlooked accident is from fragments of the cap making their way between the mat (I use eavy rubber sheeting such as conveyor belt matting or heavy workshop flooring material after seeing what these fragments can penetrate). In order to prevent this I use a large diameter washer on the pin on top of the mat - since using this I have yet to see a fragment injury. The techniques I use have evolved over time with a group of friends that I dig with regularly. Given the somewhat unsurprising reluctance of some to talk openly about the technique we have learned only from our own mistakes, I think it would be really great to get as many active cappers as possible together to compare notes. It is after all far less painfull to learn from other peoples mistakes, and personally I would absolutely hate to end up having an accident and someone else say "same thing happened to me"! Capping is a really useful technique, but I believe that there is still a long way to go in evolving safer techniques and spreading the word as widely as possible. This post is not intended to slag off teh above video, I think it is great that someone has stuck their head above the parapet. I am just appealing to make sure that as a community we make sure that lessons are learned from our experiences. All the best, Ed Ed W: Hopefully this video will illustrate my techniques a little better than my ramble above! Bone Hole 20 Nov 2010 Mr Mike: Surely burrencrawler forgot his ball protectors? AndyF: Sorry, but POOR SAFETY TECHNIQUES in this video Prodding and cleaning the hole WITH the caps in risks setting them off. The way this chap was doing it risked the cleaning rod being shot out right up and into his arm. The injury would be appaling. If you need to clean the hole (and if you have the right sized bar you don't need to) then use a babies bottle brush or rifle barrel cleaning brush. He even says it would be better to clean the hole first before putting the caps in!...ermm yes it would! NEVER NEVER have any part of your body over a charged hole, especially not your face/head Bob Smith: I agree that shoving the cap down with your hand over the back of the tamping rod may be a little foolish, but i didn't hear him say anything about cleaning the hole. Andy can you give me a time stamp for that part? Rhys: I'm well aware that there's more than one way to skin a cat; people are all doing things differently and view various parts of the procedure as more risky than others. People's own experience shapes these techniques. However, personally I would strongly advise against the vigorous prodding and poking of the cap in the hole before putting on safety kit (goggles, gloves and long sleeves - the latter two weren't used at all). Hole cleaning with a blow tube is very helpful when using Hilti branded caps as they're a tight fit in an 8mm hole. Spit branded caps are a smaller diameter and slide nicely into the hole without lots of cleaning or poking. I'd also say you were quite lucky to avoid a good kick in the balls or at least a bruised knee cap from one of those chunks of rock. A good starting point though Quentin! Rhys Bob Smith: Sorry Andy, just spotted that I was watching the wrong video.... :chair: burrencrawler: Hi Guys, Thanks for all the feedback. I have blown more than a few thousand caps myself especially in the last two years. Where I do not claim this to be a textbook execution it is however how I do things. The exception to this is that I forgot to clean the hole with the rod before putting in the caps. The reason i did this was simply because the caps I use are not Hilti (I dont like them), and fall in without the need to push them down with a rod at all, and so I forgot to do this, and thought I would pretend to push the caps down with the rod for the sake of the video. As for the chap with the washer around the pin well that's fine, I use a thick plastic disc with a tight fit hole and some tractor tyre inner tubing on the other side of the mat, same thing. I did not want to do an overly long video about this, just merely something for people to get started on so they can get a 'feel' for it themselves. I used to use the heavy rod too, and sometimes still do, that's why the end of my pins are hex bolts. There is a fine line between total safety and getting anything done. I like getting things done safely. I use two drills at the same time when drilling to cut down on time spent hanging around, then I cap them all one by one in a matter of minutes. The other reason why this rock blew so dramatically was because I picked up a piece of stone around my house which I later discovered to be sandstone=> would prefered to have had a block of Limestone which behaves itself much more. (It took just under two minutes to drill!!) as opposed to 30 seconds. Keep the feedback coming, its just my way now. AndyF: --- Quote from: Rhys on April 20, 2011, 11:24:43 am --- Hole cleaning with a blow tube is very helpful when using Hilti branded caps as they're a tight fit in an 8mm hole. --- End quote --- Correct, which is why we drill for capping with 9mm drill bit! They are easily obtained mail order... 8mm is just a bit too tight. SamT: JESUS WEPT This video should be re-titled how NOT to perform capping. I cringed my way though most of it. --- Quote from: burrencrawler link=topic=11865.msg153770#msg153770 date=1303306718 ---Where I do not claim this to be a textbook execution --- End quote --- Damned right - Well why bother going to the effort of making a video and publicising if your going to make a cock up of it. Prating around broddling/cleaning/tapping etc with caps down hole, no matting/gloves/anything. :wall: Matting woefully small. :wall: Pin a bit too small, not convinced by the mole grips to be honest - proper capping bar/slide hammer would be better. And most worryingly - Bollocks fully exposed to blast. Forget the goggles - you needed to be wearing a box!! I'm sure you've capped a million boulders etc, fine, but its your limbs/eyes/bollocks your putting on the line, but videoing 'the way you it' and all your bad habits and poor techniques get passed on from generation to generation etc. Ed's video is better. I mate of mine ended up in hospital under a general having brass shrapnel from the cap removed from between his ribs, dangerously close to his lung, because a crappy bit of carpet was used. He wasn't even the one firing and was sat a good 6 feet away and behind the firer. The matting IMO should provide a barrier between rock and human, it doesn't have to be huge, just provide a line of sight barrier. I also doubt the wisdom of spreading the knowledge of capping out on the WWW. Its been debated a few times on this site and the consensus has always been that its best kept word of mouth and low key. However, I appreciate that poor word of mouth leads to chinese whispers thus poor technique and bad habits get passed on. Perhaps there does need to be access to some sort of ratified code of practice however I'm fairly certain that Vimeo and YouTube are not the place for it. Previous discussion on this here... ukcaving.com/board/index.php?topic=10997.0 If folks insist on having something on vimeo/youtube - I suggest quents vid ought to be taken off vimeo for the time being whilst a decent one is made. burrencrawler: Hi sam, I suggest more time spent caving and less time spent posting, it will cure you and make you less negative. Maybe we do things different in this country. Nobody said we all had to be the same. bubba: Haha, somebody accusing Sam of not doing enough caving There's nothing wrong with having good capping information online but if it's done like this with glaring safety issues then it's better kept to yourselves. Link removed, topic locked. bubba: I've unlocked this as perhaps discussion is best There's an article on capping on the wiki: ukcaving.com/wiki/index.php/Capping Please feel free to submit a video that has proper safety precautions included. SamT: --- Quote from: burrencrawler on April 20, 2011, 11:36:07 pm ---Hi sam, I suggest more time spent caving and less time spent posting, it will cure you and make you less negative. --- End quote --- What ever :shrug: --- Quote from: burrencrawler on April 20, 2011, 11:36:07 pm ---Maybe we do things different in this country. Nobody said we all had to be the same. --- End quote --- I'm not suggesting we have to do things the same, lets just try to do them safetly eh?? I apologise for the tone of my post, it was late, I was tired and irritable etc etc but seeing bad capping practice really gets my goat. Let alone when its a video running under the guise of "how to cap". Off the top of my head, I know of 5 potentially serious capping injuries. 3 of which could easily have been fatal. 2 of which lead to hospitalizations. It'll happen one day, and as a result the caving world will have a world of legislation and law heaped upon it, along with perhaps a knock on effect to other 'techniques'. Why risk it upsetting the apple cart by posting it all over the web. The wiki page is a start and can be peer reviewed/altered I guess (though the capping mat is still too small IMHO). AndyF: Yes I watched it a gain and got to agree with the points Sam picked up on. For us some useful pointers are: 9mm drill bit not 8mm We use dome head coach bolts for strikers. Cheap, hardened, don't matter if you bend them just get another out the box and the dome head allows for mis-strikes better. Conveyor belt material for the "carpet" Full face mask, not just goggles. - Paintball masks are quite good as an intermediate. Get your mate to actually do the hitting.... ;D NigR: Firstly, let me make it clear that (unlike Quentin, Ed and some of the other posters) I have no firsthand experience of hilti capping whatsoever and have not the slightest inclination to ever alter this situation. Having spent the last thirty years ensuring that I am as far away as possible before boulders shatter into numerous fragments I am not going to deliberately reverse my basic survival instincts now. However, I do not think that the link to the original (Quentin's) video should have been removed. Doing so was pointless in any case as all anyone has to do is go to Youtube or Vimeo, type in 'Hilti Capping' and there it is! Far better to make it readily available to use as a starting point for further discussion and (hopefully) education. burrencrawler: Hi Guys, You may not like my methods, but I am not inexperienced nor am i ignorant of everything you have said. I have tried it all at some stage and arrived at what I do from thousands of caps spent. Back to discussing pros and cons of stuff you have been mentioning. 1)9mm vs 8mm bits: No thanks, the area to be drilled (If you use the Pi X Radius squared) quite clearly gives you one third extra battery power for 8mm bits. Also in UK you may have more materials and gauges available to you than we do here in Ireland. I had one set of 9mm rods + bits, and i will never do it again. First its impossible to order standard 9mm stuff here and i need to get it 'off the shelf' without especially ordering. Next the caps I use are 7.5mm and super short; with a 9mm hole they sometimes go in on their side==> not very safe because if it dont go off and you put in more, you are causing an unnecessarily big bang. When i cap I am usually drilling between 20 to thirty holes a session, so let's see how far your batteries go on 9mm holes. 2)The carpet: My carpet is thicker than conveyor belt material even though it may not have looked so on the video, its just 'carpeted' on one side. you may think its small, but its bigger than I need and it fits in my capping box with ALL my stuff including two drill batteries. 3)The cleaning rod: I mean for gods sake, someone said it was unsafe to tap down the caps BY HAND when i have done this regularly (when using the larger Hilti caps which I dont normally use) with a lump hammer. THIS is why the god-damned ends of them are rounded off, the firing bit is one edges of the caps, remember? 4)The firing pin: yeah someone else said "I put a heavy thicker steel rod to be further away and take up the recoil" or something like that. Well you keep on doing it, pal. I got sick of it personally and now I dont do it. If I still want to i can screw it on and its still in my capping box. I dont put my face in the way of the firing pin, its impossible or you would smash it with the hammer as you hit it. 5)'My goggles are shit' well whatever, as I PM'd someone earlier I use to use diving tempered glass goggles and i got sick of that too, If you REALLY want to know I rarely use goggles at all (eat that, capping police), and i out my feet on the rock i am going to cap to keep it from hopping up. 6)'Lacking body protection' or some other lame way of saying it. Yeah sure I ended up getting hit by rocks at least once every two capping sessions, for me its part of the job, a bruise for a day or two, and we get on with it. 7)'No gloves' well i did mention 'some people' like to wear gloves. I hate gloves for any aspect of caving that is digging, capping SRT or plain normal stuff, who cares? Sure i end up with some minor capping scrapes and 'sand shrapnel' but in a couple of days its gone. Remember guys that when I am taking time off to do some capping far from an entrance and a lot need to be done, I want a small load to carry, no danger of my batteries running out, and for my equipment to TODALLY rock. I am not trying to make out that i am hard, (you obviously call it 'stupid' and that's fine by me) but experience is the only thing that will teach you where you can cut back on certain things. If you didnt like the video thats cool, but despite what you think, in my mind I am in full control of my own :idea:safety issues. Ed W: Firstly, I think it is very good that this thread has been unlocked and that we can have an adult discussion about capping. Although others have hinted at it, NiGR hits the nail (or pin?) on the head when pointing out that the achilles heel of the technique is the need for the caver to be in close proximity to where the action is happening (and yes NiG, I must get my arse in gear and come and place myself close to soem fragmenting boulders with you in S Wales now that my heart seems to be beating properly again - and no it wasn't the last capping session with you that caused it to go funny in the first place either). Having said that it has many worthwhile advantages over other techniques in certain circumstances (I am sure someone will list them all out at some point). Burrencrawler is also spot on with his sentiments of balancing safety with effect (especially in terms of dragging kit a long way through a cave). After all, this is something we all do on every caving trip - how many of us prefer to free climb a 20ft drop rather than carry kit to descend it with far less risk... Just for a few more details of my kit. I drill 8mm holes, I do not clean them out other than to brush/blow away any dust from around the hole mouth. Again Burrencrawler is spot on about the number of holes drilled. I generally use only one cap, but occasionally two (nearly always blacks or reds). In general I tend to try and use the minimum I can to do the job, to my mind if bits of rock are flying around I've done too much. I like to leave stuff cracked so that it falls apart with a gentle tickle of a crowbar. I "drift" caps down the hole (one at a time if I go double) with a 6mm brass rod, then end of which has been filed to an approximate hemisphere. This ensures that the rod only touches the centre of the cap. The rod is mounted in a steel handle (25mm diameter) about 200mm long which also has a wide (100mm) disc welded to it. This allows the cap to be pushed firmly down an 8mm hole. I have never had this rod initiate the cap. The only time I have seen this happen was with a similar handle equipped with an 8mm steel drift rod which had simply been cut and not profiled. There was no injury (except maybe to laundry bill) of the person in question). I find that if the caps are drifted to the bottom of the hole before introducing the pin, then the whole operation is far more reliable (I suspect that the shape of the pin can damage the cap if used to drift down the hole). Also drifting with the pin risks initiation near the top of the hole and causing superficial fragmentation at the top of the hole - in other words it makes lots of small fast bits. My view is that speed is the dangerous thing. I now use 7.5mm pins, made of un hardened silver steel. 7.5mm was chosen in order to prevent jamming of the pin in the hole, something that happened far too regularly with 8mm pins. I have noticed no difference in end effect between 7.5 and 8mm pins. I have mucked about with various profiles to the end of the pin, but to be honest simpler is better. In the past I have used hardened steel, but have noticed fracturing of the profiled end. I am yet to bend one of these pins. The pin is held in a "heavy" rod. I have several and chose the most appropriate for the site I am working in at the time. Typically these are made of 20 - 25mm black steel between 600 and 900mm long. The pin pushes into an 8mm hole at one end, and is secured by an 8mm bolt in a tapped hole to the side (this is one point where I do need to find an improvement, too often the pin comes loose). The rod not only absorbs recoil, but also provides a secure hand hold (I have considered making a separate hand guard for the rod, but not got round to it). As mentioned before, I place a large washer over the pin before the mat (I also have one mat where I have rivetted washers to either side of it). This was in response to the cap fragments mentioned before. This seems to occur when small cracks are created in the mat around the pin hole. The washers seem to prevent this effect very effectively indeed (to date). For the record, I wear eye protection (wrap around safety specs, though I should point out that my worst capping injury was from thumping my hand with a lump hammer due to muddy specs) and ear defenders. My kit (including drill) fits into one peli case and a small tackle bag. This is compact enough for me (a fat unfit sort of caver) to take quite long distances in to caves to dig (c.2.5 hours to West Passage in Upper Flood for instance). Once again, I make no claims that this is the right way to do things, but it works for me. And as said before, I would love to learn from other's mistakes before I repeat them! Ed AndyF: This is what we use for strikers... You need a vernier to measure the body diameter, different brands vary. Get the rigth one then buy a few dozen for about 50p a go. Cut the thread off and you have a lot of strikers. Get assorted lengths so you can choose one so the dome head sits just out of the hole, this helps avoids bending them. The dome allows atriking at odd angles which can be useful at times. I usually tie a bit of cord around the top and tie off to something so you can find the thing after the bang. If you loose or bend one, your day is not over as you have 5 more in your box. ;D As for tapping down the caps being hazardous. Well yes it is, but in 9mm holes they drop straight down. Never had a problem with ones going sideways, though they may, they always seem to "go off"... Alex: I did not think these cap's where that powerful and by the sounds of it they are not if "burrencrawler" is repeatably hit with rocks and only comes away with bruises. Does this cleaning rod fit the hole exactly, if not I cannot see how this is danger as all it would do if it set off is go bang and waste a cap as the explosive force would be dissipated around it? I can see how if it did fit exactly though it would act like a cannon but with such a small charge anything in there would not come out with enough force to do any real damage would it? I speak not from experience as only rock smashing I have ever done is with a hammer and chisel. But is this not the case of yet again health and safety gone mad? Buttencrawler has been clearly doing it a long time? Or are you guys saying he is an accident waiting to happen? Has he been lucky thousands of times as the odds of that being the case would be low. Maybe an experiment should be set up and we could see how much damage something shot out of a hole with a hilti cap could be. Perhaps something for Mythbusters? Bob Smith: Ask Mike Willet about the neat hole through his hand after a particularly nasty bit of debris decided that was a good route to pass.... burrencrawler: Hi Ed, Very good post (one of the better ones i think). I agree with a lot of what you say. There are some things that in Ireland are difficult to obtain. These are non standard gauge steel/bits. I like your 7.5mm idea, again batteries would go according to my calculations 12% further than 8mm bits. The way I have made 8mm bits 'work for me' is after drilling the hole I lift the drill up and down the length of the hole while bending the drill bit into the sides north south east and west, this enlarges the hole a little bit all the way down. Then i clean it with the 8mm screw rod, this smooths the walls all the way down to the caps. By the time the caps have 'fallen in' without the need to tap them down. (And incidentally i have never seen a cap go off with a cleaning rod even with some fairly heavy hammer taps). What I like about this situation is: 1)The hole is quite snug with the firing pin without it being tight or loose. 2)To my mind i think the tighter the fit the more the impact goes straight into the rock as opposed to getting 'wasted' by blowing back up the hole, also the less that blows up the hole the safer it is., ie. the bang is more efficient. The only times i had caps go on their side was with 9mm holes -the caps i always use are american, very short, powerful, and only 7.5mm diameter) there was a picture of them on the video, and you saw what only two of these would do. I use these because they are Muhamad Ali like. The better the caps work the less i have to drill the more battery power i keep, blah blah blah. I do not like silver steel for the reason that a)Its very expensive b)it rusts making the fit tighter than i would like sometimes and i get bored having to steel wool it down every time i am going to use it. c)it bends very easily. My preferred steel is 8mm 316 grade stainless steel rod (304 grade if there is none, but 316 is better) I have the head of an old hammer that I welded a bolt on to. I sometimes attach this to my firing pin if its in closer proximity than i would like, that way the hammer head absorbs some of the recoil, and its very difficult to miss as a target. AndyF: I like your idea of the strikers you use, except for the length, I use three lengths of strikers depending on how deep i have drilled the hole, this keeps the bending of the pins down to a minimum. But for my 'short' striker i like your one a lot, especially if i can cut the screw section off, The 'head' is cool. (This is proof that i am not the only one around here that doesn't attach the heavy gauge screw on to the end of their firing pins.) I will look out for these next time i am at my hardware store. Thanks There has been ample time to experiment with caps here on the Burren as i have capped in EVERY single cave that has been found and explored in the last ten years here. Keep the arguments coming as I am finding this very interesting. Some great ideas from people here. graham: --- Quote from: burrencrawler on April 22, 2011, 12:18:17 pm --- ...as i have capped in EVERY single cave that has been found and explored in the last ten years here. --- End quote --- Hmm. Whelan's Quarry Cave? or doesn't that count as being on the Burren? Burt: Hey, Burrencrawler- Don't get too wound up on it mate, there's a million opinions out there and generally, the feedback is aimed at keeping you and us alive - aint that a good thing? For the record, I've capped a little bit and so far been OK, but I'm very aware that stuff like eyes and bollox are pretty much irreplaceable..... Bob Smith: I dunno tho' Burt, you can often find an awful lot of bollox knocking around here.... Roger W: That's true, Bob... The problem comes in successfully transplanting the required amount to replace some you've managed to lose! AndyF: --- Quote from: burrencrawler on April 22, 2011, 12:18:17 pm ---Hi Ed, Very good post (one of the better ones i think). I agree with a lot of what you say. There are some things that in Ireland are difficult to obtain. These are non standard gauge steel/bits. --- End quote --- You can the 9mm bits from Amazon... Im sure Amazon deliver to Ireland! --- Quote --- AndyF: I like your idea of the strikers you use, except for the length, --- End quote --- You can get these in any length up to about 300mm quite easily. They tend to come in two types, BZP (bright zinc plate - "shiny" ones) which are usually softer and hardened ones (usually black) which don't bend but are harder to cut. Different brands vary in length of thread etc. and you have to experiment, but once you've got a source that works a tenners worth will last a long time! ian.p: --- Quote ---I speak not from experience as only rock smashing I have ever done is with a hammer and chisel. --- End quote --- well that's pretty apparent from your post once you've fired a few caps you will probably start to appreciate that being right on top what is effectively of a blank .22 round when it goes of does funnily enough present a few hazards! the forces involved are significant and if you cock it up there's the potential to get really badly hurt i dont know about the phisics but ive seen a few accidents and had a few very close shaves! I used to use coach bolt strikers in toad hole before I acquired a proper bar i also used to use cary mat as blast matting and stick carry mat in my ears instead of wearing ear defenders non of the above works very well!! I learnt that carry matt is crap for blast matting when I fired a charge that hadn't been drilled far enough and sent a load of gravel flying back at me which went strait through the mat and missed my hand by centimetres. I lernt that bits of carry matt as ear plugs don't work very well when upside down in a 4ft deep pit capping a bolder in the bottom of the pit. id placed two black caps I then bent two out of three pins bent the third smacked the bent pin on the bend not really expecting it to fire it did with an almighty bang (the drill I was using at the time was crap and the battery would usually run out before I could get more than two holes to a sensible depth so the charges where often shallow) and one of my earplugs had fallen out. the bang left me completely disorientated with no idea which way up i was and my mate who was holding on to my heels had to pull me out. I find capping with a proper bar is A. shit loads quicker as your not faffing around with bent pins B. more effective good long firing pin means you can drill deeper holes and split more rock of with each charge C. an awfull lot safer its not just the risk of the pin flying youre also further away from the bang and any fly rock or bits of cap that might come back I drill 8mm holes and drift the cap down using the firing pin ive never had a cap go of prematurely and even when set i usually find that the cap requires quite a hefty wack to fire it this may in part be due to the snug fit of the bar. I can see the advantages of using a 9mm bit especialy in mudy caves and that it might make capping quicker and the bar less likley to jam but with the drill I use battery economy is a bit of a priority... mike barnes: Interesting thread. Burrencrawler, your nonchalant attitude as the rock explodes is superb. There's also a film on Youtube from 'Mindlessminer' doing a similar thing, 3 caps in a smallish piece of gritstone. But a cap surely has a definite amount of stored energy, and that these 2 vids simply show that too many caps in a small piece of stone will always produce such dramatic, and dangerous results, irrespective of stone type. Ed's film seems to show how the right amount of cap produces just enough force to crack the rock. There was another film called 'explosive archeology'!?? which showed 2 spanish guys breaking numerous bits of boulders with minimal force. So I'm wondering, breaking boulders seems fairly straight forward, but what about shaving some rock of tight passages. If you drilled a 12 cm deep hole into 1 side at say a 30 degree angle, would a cap blow off a lump of rock with the cap position being the deepest point of hopefully a bowl shaped hole. Then you could do the next hole a short way along the side of the 'bowl' and continue in the same fashion until it enlarged or you gave up. And I wonder if some short of better shield would be required to prevent any ricochet rock flying about, bouncing off the opposite wall. Maybe a small piece of thin plywood? AndyF: In my experience nothing short of HE is much use for widening a solid rock passage. Get the angle wrong and the re is a high risk of "Blowout" too. The reason seems to be that with a loose rock, ALL the stress from the blast makes its way to the surface, but with a solid wall maybe 70% is absorbed in the rock itself. Shock going inwards doesn't do anything useful... It can be done with SLB type charges, but gets rather expensive. langcliffe: I agree with AndyF. Capping bedrock is a tedious process. It took us six long trips to widen an almost vertical rift for a couple of metres by about 10 cm. With HE, it would have taken a couple of quick trips. Ed W: I disagree with Langcliffe and Andy F. I have successfully used caps to widde narrow passages on several occasions, yes there are other techniques available, but it is a case of choosing the most appropriate technique for your situation. The most recent success was opening "The Nitpicker" in Rod's Pot. 3 two hour sessions to open a 2.5m long too tight passage. Other techniques would still have taken at least two trips due to fumes, which would also have been a bad idea in a very popular cave. Saying this, capping solid is a very different game to breaking boulders. As Andy F says, it is all to do with the air surfaces - i.e. all around a boulder and only on one side (typically) of solid. NigR: I can back Ed up on this 'cos I've seen him do it! Very impressive and very effective. However, I also agree with Andy F and Langcliffe that long term 'mining' operations in solid rock are probably best tackled with more traditional techniques, particularly if there is a favourable draught to mitigate the problems caused by fumes. Depending on the site, my own preferred approach would be a combination of the two: do as much as you can with hilti caps then drill longer holes for a 'parting gesture' before you leave. In fact, there's an ongoing project here in West Wales that fits the bill perfectly - I'm just waiting for Ed to contact me to pay his Garimpeiro subs for this year! Ed W: Nig, OK the subtle hint has worked I'll cough up - but to be fair I think I owe last year's too! Funnily enough I was waiting for you to contact me for my annual outing to Wales... Ed NigR: Thanks, Ed. Got a bit of new passage today and can see into more but (surprise, surprise!) it needs making bigger! I agree, it's time for your annual foray across the border. What are you doing next weekend? Cheers, Nig Ed W: Nig - I'm already committed next weekend, how about the one after (Sat 25th)? NigR: Ed - will PM or phone you. Just to get back on topic...... Another way to combine hilti capping with more traditional enlarging techniques is as follows: Have your thin men 'mousehole' it as they go, then make it big enough for normal people with hilti caps afterwards. This works very well. Of course, it acts as an added incentive if your hilti capping expert is too large to get anywhere near the sharp end in the first place! mike barnes: So my first box of red hilti caps has just arrived and now I'm looking for something to demolish! But I've put a accurate vernier gauge on, and the rim is 8.1mm wide. So Ed, you've stated that you drift them into a 8mm hole with a rounded brass rod. Does that require a fair old bit of whacking to get them to the bottom. The rim is very thin and I can see how it will easily burr over once it starts going down a too tight hole. Sadly, you didn't show in your film the cap going in. Andy, if you're drilling 9mm holes, what diameter firing pin are you using. I guess something about 8.5mm would be tight enough without the risk of it jamming. I thought of the possibility of getting a 9mm drill bit, them filing or grinding down the carbide tip to make it 8.3/8.4mm ish. Or is that completely unnecessary? I don't yet know how easy it would be to grind, it must be pretty tough stuff. I can't see how a cap can go in sideways in a 9mm hole as they are 10.7mm long. mrodoc: Wear ear plugs or muffs when you are capping. Standing next to Burrencrawler when he is firing caps is deafening I decamped for the rest of my filming. Unfortuately the video clips the bang so it doesn't sound impressive. Will edit the Gonzo movie when I have a moment and post it on Youtube. AndyF: --- Quote from: mike barnes on June 15, 2011, 12:51:49 pm --- Andy, if you're drilling 9mm holes, what diameter firing pin are you using. I guess something about 8.5mm would be tight enough without the risk of it jamming. I thought of the possibility of getting a 9mm drill bit, them filing or grinding down the carbide tip to make it 8.3/8.4mm ish. Or is that completely unnecessary? I don't yet know how easy it would be to grind, it must be pretty tough stuff. I can't see how a cap can go in sideways in a 9mm hole as they are 10.7mm long. --- End quote --- Just use a 9mm drill.... its not the fine art you think. Don't know what the diameter rod I use, not measured but we don't get blow out. It doesn't matter if the cap goes down the hole at any angle any way, the rod will still crush it and set it off. |
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Tim Watts
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some of these comments are right, clean the shot hole BEFORE you put the cap in and NEVER use the back of your hand to drive the priming rod in. but a better vid the most
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Personally, I don't like capping.. BUT it is quick, cheap and fairly efficient. We tend to use a 'chisel' type tipped threaded bar screwed into an extension bar around 2foot long for firing. ALWAYS stand to side, or just don't look. A peice of carpet or similar will deflect most of blow and then a small square piece of rubber to stop it cracking and flying too far. Three knocks should do it usually. Clear the hole once drilled then pack in (for most cases) 3 reds and a black. 99% of the time it will fire, if it doesn't turn rod and try again.
I have seen capping gone wrong twice, once took a slice of somebody's ear off and the other landed a huge boulder (just blown up) on his foot... clever. alternatives are, of course, Snappers (Then you are at least a few metres away) but if no draft if fills the place with fumes. Plug and feathers, basically expansion technique like a chisel. and 'bang'/ debtcord which needs a license for storing and a license to use... but wow does it do some damage! |
The trees have ears, the hills have eyes. Trust no one... but the sheep.
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horses for courses tom
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Hi Guys
Just to throw some light on the subject its all about keeping the gas in the hole and of course trying different methods,I have been hilti capping for over 20 years and have now got a system thats good. hilti caps as you are awarw ring fired i.e not the centre, so if you take an 8 mm titainum screwdriver acut the end of so you have a straight 8mm face,you then cut a cross in it dipping it in water you then have 4 pertruding tips at the ringside of the hilt cap any one of these 4 will fire the cap,if you burn the handle off you will see the screwdriver has pertuding sides this will fit in a 10mm socket attach this to the handle of the socket now you have a solid wieghted handle to twat with your hand being well away from the firing rod, before pushing the rod down fit on the rubber ring that you get to protect your drill from getting dust in push this down onto the rock face this is to keep as much of the gas in,if gas escspes then the charge will be weaker its the gas that forces its self into the weak parts of the rock forcing it apart.heavy rubber or carpet over this keeps bits from flying,the same size screw driver with a flat face is used to push the hilt cap down with a slight tap down intill you hear a change of tone, i,e, from low to highyou are now ready to fire you can squash the hilti cap a little bit it won,t fire ,use a lump hammer and hit the top of the socket hard holding it down and following it through with the hammer head .note a firing rod will only fly out if it is not held down in the hole. a 9 inch deep hole with tight gas fit will fracture a bolder 3 ft square,hope this helps a bit and this does work,I will demonstrate this on thursday at MS2 dig if the weather is good Mick |
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