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Joe Ponto
01-12-2008, 02:39 PM
Folks, I have a Zeiss riflescope and would like to know how to safely remove epoxy / adhesive from the exterior objective bell. The original German mount was glued to the scope objective and has since been removed. Now I would like to remove the epoxy without damaging the scope body......

Regards,

Joe

dokey
01-12-2008, 04:21 PM
There are 3 ways it can be done:
1) use acetone
2) scrape or sand it off but might damage finish
3) apply heat sparingly to the area with a tiny torch (I use one used for making creme boulee). Epoxy gets soft at around 300* F

Joe Ponto
01-12-2008, 04:34 PM
I am a bit afraid to apply heat although done carefully, I suspect it should work. Well try that one last.

I have some acetone so I'll give that a try. Still hoping for a sure a thing....

Thanks again.

Joe

koginam
01-12-2008, 06:21 PM
Adding heat will more then likely damage your scope, Their is a delicate balance of pressure within the tube, heat will increase it and you will lose the inert gas that keeps it fog free, do not use it.

Dennis Sorensen
01-12-2008, 06:39 PM
Contact Zeiss! Forget about doing it yourself until they respond..

Butch Lambert
01-12-2008, 06:44 PM
Do you believe that Koginam? I'm speaking of the gas issue.
Butch

Big Al
01-12-2008, 07:34 PM
I have used paint remover with not a problems on aluminum before (jelly type) no problems with the original finish. Just used a rough terry cloth wash rag (dry) after it softens to remove. Takes several apps, but works safely.

Joe Ponto
01-12-2008, 11:23 PM
Big Al, any idea what brand?

Big Al
01-13-2008, 10:58 AM
Yes, the cheapest on sell brand at the paint store I could find. All the stuff does is soften the material you want to remove. That's why you need to use a rough wash rag to get it off. I think the most I've had to apply was three applications to get it all off. MAKE sure you get the jelly kind.

Joe Ponto
01-14-2008, 10:14 AM
Any other suggestions?

Gave acetone a whirl, but it didn't seem like it really affected the cured epoxy/adhesive.... Any other suggestions?

Big Al
01-14-2008, 01:41 PM
Joe, if you are reluctant to try jelly paint remover, try it on a piece of junk metal like a Weaver base or on an old blued rifle barrel. I have yet to see the finish on aluminum or steel effected by the stuff. I use it on rifle barrels that get bedding compound on them often and scope bases more than just a few times. (makes you wonder what people were thinking)?

No Joe, it ain't sexy stuff, vary low tech. It just works!

Joe Ponto
01-14-2008, 01:46 PM
I am a bit hesitant. The scope finish appears to be paint or baked on paint.

I don't think it would remove bluing or anodizing (much tougher and part of the Aluminum).

I will be trying your suggestion as soon as I can pick up some gel remover...

dennisinaz
01-14-2008, 07:40 PM
I would use methylene chloride-won't hurt the anodized finish and should soften the epoxy enough to scrape it off with a popsicle stick.

Dennis

Joe Ponto
01-14-2008, 07:50 PM
Hi Dennis.

Not sure where I would get methylene chloride and I think its one of those chemicals that has to be used very carefully from a health prospective.

If I can find some, I'll give it a try. The scope is a pre-anodized scope from europe.....paint of some sort which makes it even worse from a damage prospective...

Thanks for your help....hope I can do it without damaging the finish..

dennisinaz
01-15-2008, 10:20 AM
The Methylene Chloride that I have comes in aerosol cans and is kind of thick- almost a gel. It will burn you skin if you leave it on more than a few seconds so wear gloves and do it outside. I had a Burris scope that had been camo painted with epoxy paint. I taped the lenses and sprayed it down, once softened, I used and old toothbrush to scrape off the loose paint. I sold the scope to someone and they never knew it had been camo painted previously.

Dennis

Joe Ponto
01-15-2008, 10:48 AM
Contact Zeiss! Forget about doing it yourself until they respond..


Dennis, perhaps you have never dealt with Zeiss or the Germans. No insult intended, but that is too funny. Several attempts have resulted in absolutely zero gains.......anyone surprised!

Dennis Sorensen
01-15-2008, 10:58 AM
Dennis, perhaps you have never dealt with Zeiss or the Germans. No insult intended, but that is too funny. Several attempts have resulted in absolutely zero gains.......anyone surprised!

No insult taken... I have not dealt with Zeiss ... but considering the quality of the scope and the high possibility that claw mounts have been installed and removed from Zeiss scopes in the past, I would think Zeiss would have some knowledge about this...

Unfortunately you may be contacting them about refinishing a tube... I guess you could alway sand it off and spray paint it... :(

brickeyee
01-15-2008, 01:41 PM
MEK (methyl ethyl ketone) from the paint section at a paint store will attack even cured epoxy.
It is actualy a pretty safe solvent, just keep it out of your eyes.

We used it for years to dissolve the epoxy potting on electronics to 'work' on them. You had to be careful though, or a typical printed wiring board would be reduced to fiberglass and copper.

You may need to wrap some cheese cloth around the area with the epoxy, then get it wet with MEK and wrap in aluminum foil and let it sit a while.
Warm MEK works faster but you need to be VERY careful heating the stuff.
Electric heat only, no sparks or flames, etc.

zzuric
01-15-2008, 08:55 PM
Better be careful about that heat. Delamination of the lens can and DOES happen when too much heat is applied...and that point cannot be pre-determined.

BJS6
01-15-2008, 10:57 PM
I used some paint stripper gel on a Browning alloy shotgun action once to remove the residual gold in the emblem that was half falling out anyway.

It certainly bamaged the finish, not badly but you could see where it had been, a distinct line at the edge where the stripper had contacted the finish.

Joe Ponto
01-17-2008, 10:13 PM
I'll try a few of the strippers and the MEK. I am told the acetone would do but perhaps I wasn't patient enough. I was thinking of turning most of it off in the lathe...................

Cerakote makes an air dry paint that could be used, but I don't want to lose the "Zeiss" labels!

koginam
01-18-2008, 02:20 AM
Butch sorry to get back to you so late, yea I just had a customers scope returned from Leopold, he had it to close to a heater in the camper and it built up enough pressure to leak the nitrogen out, it fogged up first time he went out. Doesn't take much heat to build up pressure enough for it to leak out.

Butch Lambert
01-18-2008, 10:35 AM
koginam,
It has been explained to me that they are purged with nitrogen or it is blown through. I don't think that it stays in the scope. There are several hundred modified scopes out there that have no nitrogen. None of mine ever fogged.
Butch

chino69
01-18-2008, 12:36 PM
koginam,
It has been explained to me that they are purged with nitrogen or it is blown through. I don't think that it stays in the scope. There are several hundred modified scopes out there that have no nitrogen. None of mine ever fogged.
Butch

Butch,
This caught my interest so I called Leupold Technical Support. The scopes are inerted and slightly pressurized with nitrogen so heating the tube could damage the integrity of the O-ring seals.
Chino69

Butch Lambert
01-18-2008, 12:46 PM
I believe what you are saying on heat, but I doubt that the nitrogen stays in the scope for a long period of time.
Butch

Big Al
01-18-2008, 02:09 PM
FYI, nitrogen is a dryer. It removes damp air and replaces with dry nitrogen. It does not need to last after evacuation of the vessel that has been purged of moist air.

Remember that the external pressure would have to exceed 14.2 lbs gage, before any other gas could replace the nitrogen.

So what does the scope contain after it has been purged? It's easier to say it contains no moisture.

chino69
01-18-2008, 02:46 PM
FYI, nitrogen is a dryer. It removes damp air and replaces with dry nitrogen. It does not need to last after evacuation of the vessel that has been purged of moist air.

Remember that the external pressure would have to exceed 14.2 lbs gage, before any other gas could replace the nitrogen.

So what does the scope contain after it has been purged? It's easier to say it contains no moisture.

Yes,
Nitrogen is used as a moisture replacer. Once the interior is inerted with nitrogen, it will remain that way until the seals are damaged and moisture is allowed to creep back in.
Chino69

koginam
01-18-2008, 10:47 PM
I'm not sure what pressure if any is in the scope, it just has a nitrogen environment inside the scope, but if it is heated what ever is in there will expand and can blow the seal, allowing moisture in. Most top quality scopes that I have played with use O-rings for sealing as well as grease on the threads. cheaper scopes use just grease.

Butch Lambert
01-18-2008, 11:52 PM
Where is Wally Seibert when we need him.
Butch

brickeyee
01-21-2008, 01:31 PM
"Remember that the external pressure would have to exceed 14.2 lbs gage, before any other gas could replace the nitrogen."

Not exactly.
The partial pressure of nitrogen at sea level is only around 11 PSI.
While a gauge shows the pressure of ALL the gases in a container, the individual gases also have their own pressure fractions and leak/diffuse in (& out) based on the partial pressures.
Oxygen is trying to get INTO the scope at about 3.7 PSI (if it has 100% notrogen fill) no matter what other gasses are present and the pressure they have.

Scopes are NOT hermeticaly sealed since they use rubber to allow for focusing and movement.

Big Al
01-21-2008, 06:56 PM
"Remember that the external pressure would have to exceed 14.2 lbs gage, before any other gas could replace the nitrogen."

Not exactly.
The partial pressure of nitrogen at sea level is only around 11 PSI.
While a gauge shows the pressure of ALL the gases in a container, the individual gases also have their own pressure fractions and leak/diffuse in (& out) based on the partial pressures.
Oxygen is trying to get INTO the scope at about 3.7 PSI (if it has 100% notrogen fill) no matter what other gasses are present and the pressure they have.

Scopes are NOT hermeticaly sealed since they use rubber to allow for focusing and movement.

The 14.2 lbs is absolute pressure of air at sea level. So the reading is 14.2 lbs gage absolute. And no air @ 21% O2 and the balance of nitrogen is going to leak into the scope. It is not in a vacuum, it is not under any more pressure than atmospheric pressure. By that, I mean pressure ambient to the scope body.