Dissolving Cured Epoxy - Bolt Gun Painted Shut

[Somebody]

What is everybody's favorite chemical for removing cured epoxy?

I've picked up a complete, but poor condition Greene bolt action in a trade. For reasons unknown, a previous owner painted all the metal with a silver flake epoxy, including all the seams around the bolt and lugs. The coating looks very much like Pettit Trailercoat, which is an aluminized urethane epoxy. I have managed to strip all the surface coating, and free every single moving part, except for the bolt, which has no handle and remains stuck shut. I have located a spare bolt handle, but I must remove the current bolt. After a few days of experimentation, here is what I have tried and my thoughts on each approach.

Clean Strip Premium Stripper - Half hour soak softens the surface enough for a bronze brush to scrub surfaces clean.
Acetone - Half hour soak softens enough for a bronze brush to scrub surfaces clean. It evaporates too quickly for brush application, but immersion worked well for the small parts.
Xylene - About as effective as acetone, but more useful - the slower evaporation rate allows for useful brush work, and wrapping the work in tinfoil greatly enhances the soak time.
Methyl Ethyl Ketone - Seems about as effective and useful as Xylene. Evaporation rate somewhere between Xylene and Acetone.
Heat - Epoxy should soften around 400°F, but that is well into the tempering range of modern steels. I have no idea if it would harm 1860s alloys, nor do I know if such alloys would respond to modern re-heat treat methods. Photos of other rifles show the bolts as either bright or blued, not case-hardened.

NONE of the chemicals have succeeded in softening more than a thin layer of epoxy, even after 24 hours. This isn't a problem when you are scrubbing accessible surfaces, but now I must penetrate into the inaccessible bolt lugs and races. I have soaked the action overnight in each of the above solvents, and the bolt remains firmly stuck. This evening will be day 2 of the MEK soak, but I don't expect it to be any better than day one.

*Edit - I am aware that there is a button that must be pressed to unlock the bolt. That locking system has been removed for cleaning, and is not the source of the bolt remaining stuck.

So, if you need to remove thin coats of cured epoxy, any of the above chemicals will do nicely. If you have ever succeeded in softening thicker layers, I would love to hear your thoughts and experiences!

[country gent]

While not a solvent, you might try heating and cooling cycles. Pack in ice for a while then heat with a heat gun. Most epoxies dont hold up to expansion. try several cycles of this

[Nobade]

That's a neat rifle, well worth taking the time to bring it back!
Is there a hole where the bolt handle goes that you can get a lever into? That and a heat gun ought to do it. I wouldn't worry about annealing the metal, you won't be soaking it through and most likely there's not much that can be changed anyway. If it is hardened anywhere it's going to be a case. I've been able to remove bedding and pillars from McMillan stocks this way without damaging them, just get on it and cool things off as soon as you get it apart.

[cwtebay]

What an awesome rifle with a tragic story!
Definitely not the same, but I had a pre 64 Model 70 that someone had tried to bed - slopped the bedding compound into the action and into the magazine. I believe I paid $20 for it. I tried everything that I could think of with zero success. What did finally work was placing the rifle in a vice, holding a piece of oak against the action and using an air hammer on the block, I had to move it around the area for total success - but it worked!
I would love to see some pictures of your rifle!

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[36g]

Dimethylformamide appears to be the most commonly recommended solvent. There are some MSDS cautions to be aware of.

[LAGS]

I have never glued a receiver shut.
But did have a barrel that got stuck to the stock when glass bedding the barrel.
I left the barrel and stock in a freezer over night.
It popped loose in the morning.
To remove epoxy bedding used to bed stocks to refinish them.
I just used paint / epoxy stripper.
It doesn't liquify the epoxy.
But it softens it up so it is gummy and can be removed easily.

[M-Tecs]

Real MEK works but it's not available in most states. I have a soak tank and it will dissolve solid chunks of epoxy in a couple of days.

[cwtebay]

Dimethylformamide is difficult to get, I tried dimethylsulfoxide in my case unsuccessfully in the action opening. It did help with the stripping of the epoxy once it was open.

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[15meter]

Try a lower temp to heat to. West System epoxy recommends ~ 121C, no where near the 400F you are quoting.

https://www.westsystem.com.au/epoxy-handling/clean-up/

I trust their recommendations, I've been using their products for almost a half a century. It's good stuff backed up with full lab testing.

[Somebody]

Is there a hole where the bolt handle goes that you can get a lever into?
The stub of the handle remains, which is just enough meat to get some purchase with a pipe wrench. A previous owner tried that, but didn’t care to pad the wrench jaws. It should buff out. The rear of the bolt is free and springs slightly under torque. It is just up front where the lugs are that is remains stuck.

[Somebody]

Real MEK works but it's not available in most states. I have a soak tank and it will dissolve solid chunks of epoxy in a couple of days.
I have a gallon of real MEK. Since the action happens to be soaking in it right now, I’ll leave it for another few days before trying again. My soak tank is a tall spray can with aluminum foil wrapped tightly around the opening.

[Somebody]

Brief update: heat and 56 hours of soaking in MEK still have not freed the bolt.

[15meter]

Put the whole thing in an electric oven(if it will fit) for and hour or two to get the heat to soak all the way through? Oven set to 210? Probably a Craigslist freebie set out side.


Or a craigslist toaster oven with a hole punched in the side for the barrel to stick out?

[Somebody]

I suspect that there might be a fair bit of rust at the bolt head keeping things locked up. I don’t have a cleaning rod long enough to reach the chamber!
It’s back in the soak tank, but the next step will be pouring an ounce of Kroil down the bore.

[LAGS]

I worked in construction for many years.
We did several types of Epoxy Flooring.
If we had to shave out defects or remove epoxy from things like metal beams , we used heat.
We would just use a heat gun or propane torch.
Heat up the area and then scrape off the epoxy with a scraper or chisel.
If the finish that you have is not softened but heat between 400 or 600 degrees.
Then it might not be epoxy.
Maybe it is something like Ceracoat.
You might have to try bead blasting some areas and see if that will remove that finish enough to break it open

[popper]

https://generalchem.com/category/epoxy-paint-strippers

[ulav8r]

400 degrees should not harm the heat treatment of the metal. Heat to that, then apply as much force as you dare. If it doesn't move put it in the freezer for 24 hours, remove, tap on the bolt with a leather, wood, or deadblow hammer a few times and try to open. Tap in all directions to rotate open and closed and on the rear of the bolt and the front with a long rod. If that doesn't work, heat it again.

[M-Tecs]

Heat treatment should not be an issue with this one.

https://www.thefirearmblog.com/blog/2017/06/27/powder-goes-front-bullet-curious-case-greene-underhammer/

https://collegehillarsenal.com/Fine-Scarce-Greene-Bolt-,Action-Rifle#:~:text=The%20Greene%20Rifle%20was%20a%20tru ly%20revolutionary%20design,operated%20twice%20in% 20order%20to%20load%20the%20gun.

[375RUGER]

Jasco Premium Paint and Epoxy Remover for thick epoxy layers. Have used it successfully to unpot electronics, very thick epoxy. I remove it in stages, let it dissolve some and remove the dissolved material then reapply, keep repeating.
From the sounds of it though I don't think this is what you need. I'm surprised that the 56 hour soak in MEK didn't do it. Long soak in MEK is what I would have done myself.

[cwtebay]

What an awesome rifle with a tragic story!
Definitely not the same, but I had a pre 64 Model 70 that someone had tried to bed - slopped the bedding compound into the action and into the magazine. I believe I paid $20 for it. I tried everything that I could think of with zero success. What did finally work was placing the rifle in a vice, holding a piece of oak against the action and using an air hammer on the block, I had to move it around the area for total success - but it worked!
I would love to see some pictures of your rifle!

Sent from my Pixel 5 using TapatalkJust an FYI - I was not implying that you beat the ever lovin out of your action. Merely to induce vibration with the air hammer on the block of wood.
(After I re read my post I realized I was encouraging near blasphemy)

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[Somebody]

Cwtebay, the sins against this action are already unforgivable, so a little blasphemy cannot harm its soul any further.

However, I am stumped. I can snake a piece of welding wire through one lug recess, under the bolt, and back out the opposite side. The epoxy is gone, yet the bolt remains stuck.

I purchased a longer cleaning rod, and was able to remove a fair amount of rust from the chamber. It is now sitting with an ounce of Kroil in the bore. If it fails to creep past the bolt head, then I can only assume that it is sealed tight by epoxy, rust …or a bullet.

The bore is clear past the nipple, but the rod goes thump instead of clang when it bottoms out.

[cwtebay]

Cwtebay, the sins against this action are already unforgivable, so a little blasphemy cannot harm its soul any further.

However, I am stumped. I can snake a piece of welding wire through one lug recess, under the bolt, and back out the opposite side. The epoxy is gone, yet the bolt remains stuck.

I purchased a longer cleaning rod, and was able to remove a fair amount of rust from the chamber. It is now sitting with an ounce of Kroil in the bore. If it fails to creep past the bolt head, then I can only assume that it is sealed tight by epoxy, rust …or a bullet.

The bore is clear past the nipple, but the rod goes thump instead of clang when it bottoms out.I'm going to ask this though you addressed it adequately in your post. Are you sure that the bolt disconnect is inactive? I wholeheartedly apologise if it is, but that's a serious hurdle if you have done all of the above.
Dang it, now I want that rifle!

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[Somebody]

It’s a very fair question. Unless there is more to the lock than this, it should be quite free.
320663
That flat spring is going to be a pain to duplicate too. One hurdle at a time.

[cwtebay]

It’s a very fair question. Unless there is more to the lock than this, it should be quite free.
320663
That flat spring is going to be a pain to duplicate too. One hurdle at a time.Is that pan head screw holding anything up?

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[Somebody]

The pan head is the bolt release button. It is a very loose clearance fit with the tang, but I cannot remove it without removing the bolt first.

Up front on the recoil lug is the remains of a nipple. That is about 1.5” forward of the bolt head, so there is no interference there either.

[W.R.Buchanan]

I would soak it in MEK over night or for a few days if necessary in a Closed Container. That way the stuff doesn't evaporate. If you can't get MEK then Acetone is the next most volatile substance down the Petroleum Ladder.

Maybe that stuff in a Vibrasonic Cleaner Tank? would get better penetration?

If that doesn't work, then heat is your only other option.

Randy

[Hannibal]

At this point I do not think you're dealing with an epoxy locking up the bolt.

I'd consider a mechanical interference of some sort.

And the epoxy was applied as an 'excuse' for whatever is actually locking it up.

I do not envy your situation. Unknown can 'o worms.

[Somebody]

You may be right, Hannibal. The chamber has been soaking in Kroil all weekend, and not a drop has crept past the bolt head. The only thing I can think of moving forward is applying more heat. It might be solder, or one doozy of a rust joint keeping things shut tight.

[Hannibal]

You may be right, Hannibal. The chamber has been soaking in Kroil all weekend, and not a drop has crept past the bolt head. The only thing I can think of moving forward is applying more heat. It might be solder, or one doozy of a rust joint keeping things shut tight.

After reading your original post, and given what you've tried already, I'd start considering some unpleasant possibilities.

Such as, the bolt was locked up and someone forced the bolt handle from the bolt body trying to rotate the locked bolt.

Then the epoxy was applied later.

So consider what will be required to remove a siezed bolt. That's the course of action to follow going forward I think.

[georgerkahn]

Not to be a sourpuss -- but I have been a bit startled by the repeated posts re use of Methyl Ethyl Ketone (MEK)! I was "taught" some solvents (e.g., carbon tet -- which we used to use "everyday/for everything" -- hazards are over-rated), while MEK (we used it as an additive to epoxies) was really nasty stuff: Not to get a drop on your skin; or, to breathe even a slight whiff! Forget eye contact -- irreversible damage!
OK if you use the stuff and it works -- PLEASE EXERCISE DUE CAUTION!!! You can (please do) read all about MEK at https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/mek.html .
I've had minimal experience in softening epoxies, having used Acetone with marginal success as my one and only.
Again, please be careful with MEK!!!
geo

[Somebody]

Georgerkahn, MEK came up so often because it’s the big gun up against something designed to be permanent. Before epoxy cures, even ordinary alcohol cleans it up easily. It’s a different animal once it cures.

Acetone is my bread and butter solvent, but it just wasn’t sticking around long enough to be useful for long soaks.

[siamese4570]

You might try sticking the action in a pot of boiling water for 15-20 min. That will put a lot of heat into the action without having to worry about ruining the temper. Did this once on a screw that was green loctited.
Siamese4570

[StrawHat]

Automatic transmission fluid is a good penetrant.

Kevin

[JDHasty]

Get a couple cans of computer duster. Put straw on. Turn the can upside down and spray Carbon Dioxide onto the epoxied parts trying to get it in, under and over and build up a good inch thick layer of pseudo dry ice and then put it in a chest freezer so the dry ice will evaporate more slowly and suck as much energy as possible out of the deeper areas in the steel before the Carbon Dioxide completely evaporates. This usually contracts the heck out of the steel and breaks the bond between the epoxy and steel and will allow solvents to penetrate in between. Then by giving small areas of epoxy the dry ice treatment again it will become brittle and can be snapped off using a brass chisel and picks.

WEAR GLOVES! Good gloves.

[405grain]

So far, lots of good advise regarding the action being locked up by epoxy. If that's the case continue proceeding. If however it's a rust/corrosion problem, then none of the chemical solvent solutions are going to give much relief. If the action is frozen because of rust an electrolysis cleaning might be a good option. Chemical rust removers might be too harsh on the action, but electrolysis is gentler, yet effective. There are lots of video tutorials on this process, and it usually takes little more than a bucket, a small battery charger, some wire and household chemicals. If the epoxy removal methods don't work, an electrolysis cleaning may work, but even if it doesn't there's not much to loose. If there's something mechanical locking the action closed (weld, silver solder, pin or screw), then that's going to be something else all together.

[DougGuy]

Get a couple cans of computer duster. Put straw on. Turn the can upside down and spray Carbon Dioxide onto the epoxied parts trying to get it in, under and over and build up a good inch thick layer of pseudo dry ice and then put it in a chest freezer so the dry ice will evaporate more slowly and suck as much energy as possible out of the deeper areas in the steel before the Carbon Dioxide completely evaporates. This usually contracts the heck out of the steel and breaks the bond between the epoxy and steel and will allow solvents to penetrate in between. Then by giving small areas of epoxy the dry ice treatment again it will become brittle and can be snapped off using a brass chisel and picks.

WEAR GLOVES! Good gloves.

This sounds like the more advantageous method of using temperature to break the epoxy bond. If it gets the epoxy cold enough it just may break it with a sharp impact.


The stub of the handle remains, which is just enough meat to get some purchase with a pipe wrench.

Being a welder by trade, I would find a nut that will slip over the stub, leave enough of the center of the nut that you can fill it with weld and weld it, preferably with a TiG torch and fill the nut up with weld metal which will attach a grip point to the bolt, AND heat the bolt enough to soften the epoxy.

[JDHasty]

On of my gunsmith buddy's sons is a doctor. He gave him some sort of device that is used w/liquid nitrogen to freeze off skin lesions. After seeing that thing in action on loctited and rusted scope base screws and such I started flipping the cans of electronics duster to see if I could achieve the same and it has worked pretty doggone well. One other thing I came up with is to keep the broken and blunted points for your Starrett Automatic Center punch and grind them to fit screw slots and grind a ball end on one and a flat end on another. The sharp impact blow on stuck screws works really well in getting Kroil to penetrate and finally give way. I have six or eight that I have reshaped and they have been a Godsend.