Best Drill Bit For Gummy Aluminum?


The shooting club I belong to uses aluminum clips to hold cardboard
target backers to wooden target frames. The clips are made from soft
aluminum roll flashing, and are held to the frames by a pair of aluminum
nails. Over time, the frames & clips get shot up, and we have to keep
building new frames & making more clips. I've made some jigs to help
mass produce the clips. Part of the process is to drill a stack of the
blanks to make holes for the nails. The jig I made has two 3/32" steel
drill bushings for this purpose.
The problem is the drilling. Roll flashing is typical soft aluminum, and
wants to stick to the drill & stick to itself. It also wants to fuse
together rather than cut. I'd like to just be able to zip through a
stack of 10 or more blanks, but if I'm in the least bit impatient, I end
up welding the stack together at the holes. I also end up with stringy
chips stuck in the drill flutes. To minimize mess, I'm doing this dry,
with no cutting lube. It slows things down considerably if I have to
keep peeling chips out of the drill flutes, and pry all the blanks apart
at the end of the drilling process.
I started with some fast twist bits from McMaster Carr, on the theory
that they would pull the chips out better. They have a bright finish,
and I'm not convinced that they are any better than normal drill bits.
Rumor has it that black oxide finished will help prevent the chips
sticking to the drill bit. I'm wondering if there is anything else
special I should look for. Split points might be helpful, but I'm not
sure anyone bothers for drill bits this small.
Ideas or suggestions would be appreciated. I don't mind spending a few
bucks on fancy drill bits if it will speed up the process considerably.
Thanks!
Doug White
Reply to
Doug White
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One cheap and easy thing to try is spraying the drill bits with a moly-disulfide spray. One of the top coatings used in very fancy multi-coated tools, specifically to prevent chips from sticking or welding to the tool, is straight moly disulfide.
Since this is not a high-temperature application, any hardware spray would be worth a try, including the ones that combine moly with Teflon. You might try spraying it around the spots on the aluminum sheets where you're going to drill, too. It may help keep them from sticking.
Good luck.
Reply to
Ed Huntress
Normal drills work fine. Use diesel as a lube and make certain the drill is sharp. Steve
Reply to
Steve Lusardi
You might want to try the wood bits with the spurs or regrind a regular bit with the same configuration.
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And I REALLY like a punch for such things. $55 for punch, $80 for the kit. I keep two of them in the lab with different punch sets loaded
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Doug White wrote:
Reply to
RoyJ
Doug White fired this volley in news:Xns9D10A2027FBB6gwhitealummitedu@69.16.186.50:
Doug, it would probably be a lot faster to punch those holes with something like a Roper-Whitney bench-top punch. You can buy a Chinalloy version for about $30. It should be able to handle four sheets at a time.
LLoyd
Reply to
Lloyd E. Sponenburgh
Just nail through the @#$% metal?
Reply to
Tim Wescott
$19.95 Hand punch
or
$24.95 Deep throat hand punch
$9.95 Mounting base for heavy duty punch
I got the last two recently for $17.95 for the punch, and $1 for an 'open box' mounting base.
Reply to
Michael A. Terrell
"Lloyd E. Sponenburgh" wrote in news:Xns9D10A6D394E5Clloydspmindspringcom@216.168.3.70:
I have a Roper Whitney punch, and drilling is a LOT faster because I can set up a much thicker stack and the drill bushings make locating the holes effortless. Even with prying them apart, drilling is a win. The goal is also to provide the Club with idiot proof tooling so I don't have to do this in the future. The drill jig is something anyone with an electric drill can use.
I found that McMaster Carr has split point parabolic drills in 3/32". I can get them bright, black oxide or TiN. I suspect they will work better than the plain point fast twist drills I have now. I found one source that says black oxide is no good for aluminum, so I will probably try TiN. I can try coating the drill with a spritz of lube as Ed Huntress suggested. That will help keep the mess under control.
Doug White
Reply to
Doug White
The nice thing about the moly is that it dries. No mess. And it wipes off easily.
Reply to
Ed Huntress
"Tim Wescott" wrote in message
Roofers nail aluminum flashing all day with aluminum nails and it certainly didn't take jigs, tooling, or much training to get even the newest hires doing this. Art
Reply to
Artemus
Try reducing the rpm of the drill. If that doesn't work, do it again. I've this to be usually effective.
Hul
Doug White wrote:
Reply to
dbr
Can you just nail through the material? RR
Reply to
Randall Replogle
TiN coating (the gold-looking drill bits) is intended to keep aluminum from sticking. There's also a lubricant wax available that you can keep by the drill press; a touch of the wax on a drill bit tip lubes the next deep hole you drill. Castrol "Stick wax" and LPS "Edge" are brands in my old Enco catalog.
Reply to
whit3rd
It's not the bit, you'll get build up on just about anything when drilling that stuff dry. Lots of stuff will work to keep the chips from welding, some healthier than others to use. Tap lube made for aluminum comes up top, runs through various oils, even milk!. Tap wax will work, you can just jab the drill into an end as needed.
Best design for a publically-used target holder I've seen used pipes stuck in the berm horizontally, end on to the shooters, each pair spaced 2' or so and had Vs cut in facing sides to hold the cardboard backers. They didn't get shot up, no richocet problem, you just had to have cardboard cut to the right size. Used about 1 1/2" pipe.
Stan
Reply to
stans4
"Artemus" wrote in news:hk2dho$4p6$ snipped-for-privacy@news.eternal- september.org:
They are nailing small clips to the edge of a 1x3, and without the holes, they make a mess of it. Don't ask me how, I don't know. I need to make this completely idiot proof so I don't have to deal with it in the future.
Doug White
Reply to
Doug White
whit3rd wrote in news:6a853d70-1f49-4a9d-b8ff- snipped-for-privacy@t1g2000vbq.googlegroups.com:
The stick stuff is a good idea, but I think I'll start with TiN & see how that goes. I can get split point TiN drills pretty cheap. These will eventually get left at the range house, and the fewer pieces the better. If I buy some stick lube, it will go walkabout in no time. The drill bits are small enough that they should last a while.
Doug White
Reply to
Doug White
snipped-for-privacy@prolynx.com wrote in news:6c323785-aac6-457c-bbd7- snipped-for-privacy@h2g2000yqj.googlegroups.com:
Our range has 25 yard targets in front of 50 yard targets, and the 25 yard targets are on a turning system for matches. It's all a bit complicated, but it's been working well for the 35 years I've shot there.
Doug White
Reply to
Doug White
"Ed Huntress" wrote in news:4b64b774$0$31279$ snipped-for-privacy@cv.net:
I have a couple of options to try, but they are both greases that may be a bit messier than what you suggest. I have a tube of mil spec moly grease for torquing AR-15 barrel nuts, as well as some really high moly content assembly grease. The tube of mil spec stuff will last a dozen life times, and is cheaper, so if I go the moly route, I may start with that. Is there a specific moly spray that you would recommend that dries?
Doug White
Reply to
Doug White
Sorry, but I don't have a recommendation. I haven't had the industrial stuff for a couple of decades, but it was great stuff.
There are several manufacturers. Here's one, for example:
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You probably can find one at any good hardware store, although the ones I've been are diluted with graphite or Teflon. Still, I don't think that would be a problem drilling soft aluminum.
Reply to
Ed Huntress
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't drill. Punch, instead.
Reply to
Stormin Mormon

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