Magnetize Drill Bit to Avoid Loose Chips?

I need to drill out a small steel sleeve that is inside a dead plastic
firing seal in a competition CO2 pistol (Czech Tau-7). The normal
approach for seal replacement involves yanking it out with a brass wood
screw, but this is a very early one. The older seals have a small tube
inside that needs to be drilled out so the woodscrew can dig into the
seal.
I really don't want loose metal chips floating around inside. That is a
guaranteed way to end up with a leak, or worse, to chew up the new seal.
There isn't much metal to remove. The sleeve is only 15-20 mils thick,
~0.2" in diamter, and about 1/8" long. I've been planning on doing it
upside down so the chips will fall out of the action, and I can park a
vacuum nearby to try to encourage that. There are a couple of small
pasageways the chips could get into. Although I will clean it as best I
can, there's only so much I can do without completely disassembling the
trigger, firing mechanism and removing the sights. I will hose down the
inside with solvent first, to remove any oil that might attract chips.
I was thinking that if I magnetized the drill bit, the chips would stick
to that, and not float around inside. The possible downside is that if
the chips get magnetized and get loose, they will then stick to the
inside of the pistol, which could be worse than just having them loose.
Any thoughts?
Thanks!
Doug White
Reply to
Doug White
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Doug White fired this volley in news:XnsA5759719AFA99gwhitealummitedu@69.16.179.42:
That seems like the best solution. If you're expending all that effort just to keep the chip contamination low, why not do that work 'up front' and eliminate all the back-end problems?
L
Reply to
Lloyd E. Sponenburgh
Can you fill the area with something like wax, grease... first? Something to block all the passages and then heat it up/remove the foreign substance once done. If you use wax though you'll have to be careful not to get it too warm whilst doing the job...
Just a wild ass suggestion ;-)
Reply to
Leon Fisk
Can you pressurize it with shop air coming down the barrel? That would blow the chips away from the internals. Plus coat the drill with grease.
Or heat up a piece of rod that will fit inside the sleeve and melt it enough that the sleeve will pull free.
Reply to
Steve W.
"Lloyd E. Sponenburgh" wrote in news:XnsA5759F0D17060lloydspmindspringcom@216.168.4.170:
Taking off all the other pieces is very tricky, and not something I've done before. Replacing the seal if it gets damaged is far easier, especially if I use a new seal without the sleeve.
Doug White
Reply to
Doug White
Leon Fisk wrote in news:n54fc5$nlt$2@dont- email.me:
It might work, but grease would be better than wax. At least if I leave a little grease in it, it's no big deal. My concern is heating up the whole pistol to melt the stuff out. I can remove a few of the O-rings, but I'm not sure what else would be affected.
The region I would want to fill is where my drill & drill guide will fit. I'll have to think about that.
Thanks!
Doug White
Reply to
Doug White
"Steve W." wrote in news:ZXjdy.1083$ snipped-for-privacy@fx39.iad:
With the valve removed (that goes up against the seal), there are a couple of passages that would have to be plugged. One is easy, one is nearly impossible, and one woudl mererly be tricky.
The grease on the bit idea is good. I may try that. I could still end up with sticky chips, but squirting solvent in should flush them out. Magnetized chips might not be so abliging.
The seal is over an inch down inside a hole. I think getting the sleeve out is still job one. The seal is basically a cylinder, and the sleeve may be to provide some support so the press fit of the seal inside doesn't cold flow & leak over time. I think they decided that was unnecessary, because only the earliest ones have the sleeve.
Doug White
Reply to
Doug White
Doug White fired this volley in news:XnsA575B21A3B11Egwhitealummitedu@69.16.179.42:
Even if you get chips into other passages, as you noted earlier could be a problem? Then, you'd have to fully dismantle the piece, anyway.
"Tricky" doesn't mean you cannot do it right. If you do it once, 'should be a piece of cake the next time. And if you're shooting it enough to wear it out, you just might have a "next time".
Lloyd
Reply to
Lloyd E. Sponenburgh
Doug White fired this volley in news:XnsA575B3E68A36gwhitealummitedu@69.16.179.42:
Or they chose a different plastic for it, eliminating the _need_ for the metal liner. This might be another reason to fully dismantle it. You might be better-off making a new seal body.
Lloyd
Reply to
Lloyd E. Sponenburgh
How about
1) inserting a syringe with lithium grease into the seal hole 2) filling the chamber with grease 3) drilling out the tube 4) removing the seal 5) then swab out the grease and chips, now that you have access. The small amount of clean grease left should be acceptable, or blow it out with compressed air.
Then again, if you're going to be working with these pistols again, why not learn how to disassemble them NOW?
DISASSEMBLE? Noooooooooooooooooo! --#9
Reply to
Larry Jaques
Are you the guy maintaining a bunch of these for a school shooting program? It might help to learn the disassembly tricks. Sometimes a special jig or tool can make it much easier, like a trigger rebound spring tool for a Smith & Wesson. I made one of those when I had a Smith.
Good luck in any case.
Pete Keillor
Reply to
Pete Keillor
"Lloyd E. Sponenburgh" wrote in news:XnsA575D4BC63757lloydspmindspringcom@216.168.4.170:
Taking it apart doesn't give much better access to the passages, it only gets them out of the way so they won't get damaged by heat or solvents. I mostly need to make sure the chips aren't behind the seal, where they could cause seal damage and/or a leak. After the seal isn't quite so crucial. Dirt on that side of things will get blown out with each shot.
Taking the trigger & firing assembly apart is probably an hour, plus an hour or more to put it all back together & readjust it. The rear sight should at least come off as an assembly. I can open one of these pistols up & replace the seal in only a half an hour.
I help coach a collegiate team, and I have 15 of this design to keep working. If it was my pistol, I might want to tear it down fully. I just don't have the time to do that with every problem child that comes along. I've got 5 other air pistols of various flavors in my shop right now, waiting for me to get this one off the bench. They are all non-US made, and frequently require that I make parts for them.
Doug White
Reply to
Doug White
Pete Keillor wrote in news: snipped-for-privacy@4ax.com:
That's me, and thanks! Yes, I'm constantly making dummy pins, special fixtures & tools for these things, as well as detailed photos & documentation for every repair. I have a K-38 S&W that I also made a rebound spring tool for (somewhere...).
I thought I had the seal replacement process down pretty good until I hit this one. I've done about 5 in the past. The Tau-7's are 15 to 20 years old, and still shoot great. If I can get the seals replaced, they should last until it's the the next guys problem. He will at least have notes & tools to work with.
Doug White
Reply to
Doug White
"Lloyd E. Sponenburgh" wrote in news:XnsA575D52DADBC9lloydspmindspringcom@216.168.4.170:
Although it took some luck & about 4 years of searching, I now have a Czech buddy who can get me parts. I have a good supply of the new seals without the sleeves.
Before that, I had some success making my own seals from nylon rod stock. It's just a short thick tube that press fits down inside the pistol. There's a steel valve stem with a conical face that seats against it.
Doug White
Reply to
Doug White
Doug White fired this volley in news:XnsA57663328F59Fgwhitealummitedu@69.16.179.43:
What about just coating a spiral tap with a heavy grease, then threading it into the seal, in order to draw it out all in one piece? The spiral tap will draw chips UP into the grease, where they'll be held.
Lloyd
Reply to
Lloyd E. Sponenburgh
How about super gluing a small rod to the seal to pull it out? If it fails you can still drill it out.
Robert
Reply to
Robert
"Robert" wrote in news:n56jba$24j$ snipped-for-privacy@dont-email.me:
OHHH! I like that idea! The seal is plastic, but if I can get a good glue joint on the inner steel sleeve, that could work slick. The sleeve actually has an enlarged boss on the far side, so it will definitely pull the seal with it.
I'll have to think about making a longish tool that will giude itself down into the sleeve, and also have a way to get a good grip to pull it out. I can always get the old sleeve off with acetone, so a re-useable tool with a T-handle would be perfect. I've also thought about adding a threaded section with a nut to jack out the seal.
The nice thing, as you say, is that if it doesn't work, I'm no worse off, other than the time to make the puller.
Thanks!
Doug White
Reply to
Doug White
"Lloyd E. Sponenburgh" wrote in news:XnsA57668CE22D83lloydspmindspringcom@216.168.4.170:
I thought about that, but the wall of the sleeve is only ~ 10 mils thick.
Doug White
Reply to
Doug White
We once had a Tech Order compliance on the Boeing C-135 (Boeing 707) that involved drilling a small hole in the alternator drive into the accessory drive housing which allowed oil to leak out of the drive and lubricate the alternate drive splines that had been failing.
The Order specified to pack the drill flutes with grease to prevent getting chips in the accessory drive housing. Might work on your air pistol.
Reply to
John B.
Or perhaps a roll tap -- no chips, as long as you have a hole of the right size to thread into.
Good Luck, DoN.
Reply to
DoN. Nichols

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