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

Doug White fired this volley in
:

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.

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

On Sat, 19 Dec 2015 19:51:14 GMT
Doug White wrote:

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?

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 ;-)

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

Doug White wrote:
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

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.

--
Steve W.

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
. 4.170:

Doug White fired this volley in
:

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.

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?

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

Leon Fisk wrote in news:n54fc5$nlt$2@dont-
email.me:

On Sat, 19 Dec 2015 19:51:14 GMT
Doug White wrote:

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?

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 ;-)

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

"Steve W." wrote in
:

Doug White wrote:
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

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.

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.

Or heat up a piece of rod that will fit inside the sleeve and melt it
enough that the sleeve will pull free.

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

Doug White fired this volley in
:

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.

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

Doug White fired this volley in
:

I think they decided that was
unnecessary, because only the earliest ones have the sleeve.



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

On Sat, 19 Dec 2015 22:30:30 GMT, Doug White
wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
.4.170:

Doug White fired this volley in
:

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.

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?

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.

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

--
Creativity is allowing yourself to make mistakes.
Art is knowing which ones to keep.
-- Scott Adams, 'The Dilbert Principle'

On Sat, 19 Dec 2015 22:30:30 GMT, Doug White
wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
.4.170:

Doug White fired this volley in
:

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.

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?

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

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

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
. 4.170:

Doug White fired this volley in
:

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.

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.

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.

"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".

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

Pete Keillor wrote in
:

On Sat, 19 Dec 2015 22:30:30 GMT, Doug White
wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
8.4.170:

Doug White fired this volley in
:

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.

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?

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

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.

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

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
. 4.170:

Doug White fired this volley in
:

I think they decided that was
unnecessary, because only the earliest ones have the sleeve.



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.

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

Doug White fired this volley in
:

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

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

"Doug White" wrote in message
...

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.


How about super gluing a small rod to the seal to pull it out? If it fails
you can still drill it out.


Robert

"Robert" wrote in
:

"Doug White" wrote in message
...

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.

How about super gluing a small rod to the seal to pull it out? If it
fails you can still drill it out.

Robert

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

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in
. 4.170:

Doug White fired this volley in
:

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

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

I thought about that, but the wall of the sleeve is only ~ 10 mils
thick.

Doug White

On Sat, 19 Dec 2015 19:51:14 GMT, Doug White
wrote:

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

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.
--
cheers,

John B.

On 2015-12-20, Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Doug White fired this volley in
:

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

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.

Or perhaps a roll tap -- no chips, as long as you have a hole of
the right size to thread into.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

John B. wrote in
:

On Sat, 19 Dec 2015 19:51:14 GMT, Doug White
wrote:

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

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.
--
cheers,

John B.

I'm going to try the superglue approach suggested in another post, but I
will first need to remove some burrs left from the failed attempt with
the wood screw. I'm going to use grease in the drill bit flutes to try
to keep the chips under control from that process.

I've drawn up the critical dimensions for the superglue puller, but I
doubt I will get a chance to try it out until well after New Years. I'm
looking forward to reporting success with that. Fingers crossed...

Doug White

On Thu, 24 Dec 2015 03:38:15 GMT, Doug White
wrote:

John B. wrote in
:

On Sat, 19 Dec 2015 19:51:14 GMT, Doug White
wrote:

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

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.
--
cheers,

John B.

I'm going to try the superglue approach suggested in another post, but I

Don't let it drip!


will first need to remove some burrs left from the failed attempt with
the wood screw. I'm going to use grease in the drill bit flutes to try
to keep the chips under control from that process.

It likely won't be enough. I'd fill the chamber with grease to
prevent it, just in case.


I've drawn up the critical dimensions for the superglue puller, but I
doubt I will get a chance to try it out until well after New Years. I'm
looking forward to reporting success with that. Fingers crossed...

G'luck!


--
Creativity is allowing yourself to make mistakes.
Art is knowing which ones to keep.
-- Scott Adams, 'The Dilbert Principle'

Doug White wrote in
:

John B. wrote in
:

On Sat, 19 Dec 2015 19:51:14 GMT, Doug White
wrote:

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

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.
--
cheers,

John B.

I'm going to try the superglue approach suggested in another post, but
I
will first need to remove some burrs left from the failed attempt with
the wood screw. I'm going to use grease in the drill bit flutes to
try
to keep the chips under control from that process.

I've drawn up the critical dimensions for the superglue puller, but I
doubt I will get a chance to try it out until well after New Years.
I'm
looking forward to reporting success with that. Fingers crossed...

Doug White

Well, I figured I should report back on this adventure. I made a Delrin
guide, and successfully bored out the burrs in the metal sleeve. I
greased the bit, and that did a good job of collecting the shavings.

I then made a tight fitting pin on the end of a cap screw, which I super
glued into the sleeve. I used a nut on the screw to try to jack the
sleeve & seal out. That popped loose very quickly. Attempts to drill
out the metal sleeve just spun it inside the plastic seal.

The final solution was to make a hollow core drill that I used to cut
out the middle of the plastic seal. That got rid of the metal sleeve,
and reduced the thickness of the plastic so that the press fit was
weakened considerably. I made a brass hook tool, and succeeded in
pulling what was left of the seal out of the pistol.

I'm going to give the inside of the pistol a thorough cleaning & oiling
to prevent future rust, and then install a new seal. I'm reasonably
condfident that all will be well after that.

Thansks for all the feedback & ideas.

Doug White

On Thu, 25 Feb 2016 17:35:25 GMT, Doug White
wrote:

Doug White wrote in
2:

John B. wrote in
:

On Sat, 19 Dec 2015 19:51:14 GMT, Doug White
wrote:

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

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.
--
cheers,

John B.

I'm going to try the superglue approach suggested in another post, but
I
will first need to remove some burrs left from the failed attempt with
the wood screw. I'm going to use grease in the drill bit flutes to
try
to keep the chips under control from that process.

I've drawn up the critical dimensions for the superglue puller, but I
doubt I will get a chance to try it out until well after New Years.
I'm
looking forward to reporting success with that. Fingers crossed...

Doug White

Well, I figured I should report back on this adventure. I made a Delrin
guide, and successfully bored out the burrs in the metal sleeve. I
greased the bit, and that did a good job of collecting the shavings.

I then made a tight fitting pin on the end of a cap screw, which I super
glued into the sleeve. I used a nut on the screw to try to jack the
sleeve & seal out. That popped loose very quickly. Attempts to drill
out the metal sleeve just spun it inside the plastic seal.

The final solution was to make a hollow core drill that I used to cut
out the middle of the plastic seal. That got rid of the metal sleeve,
and reduced the thickness of the plastic so that the press fit was
weakened considerably. I made a brass hook tool, and succeeded in
pulling what was left of the seal out of the pistol.

I'm going to give the inside of the pistol a thorough cleaning & oiling
to prevent future rust, and then install a new seal. I'm reasonably
condfident that all will be well after that.

Thansks for all the feedback & ideas.

Doug White

Thanks for reporting back.

Pete