how to brake an epoxy bond

[kbstenberg]

I used some Loctite 2 part epoxy to bond an aluminum scope base (I also used the provided screws) to the barrel of a single shot rifle. Both the scope base and rifle came from the same manufacturer. So i assumed they would fit together.
I got everything tightened down with the screws. And the epoxy was cured.
When I was starting to mount the scope it didn't look correct. It looked like the scope was sitting at an angle. The front being high. LSS the fold down sight didn't fold down far enough. An the scope base that sat suspended above the barrel was tight on the sight.
My question. What is the easiest and safest way to break the epoxy bond between the aluminum mount and the steel barrel?

[georgerkahn]

I have had mixed -- sometimes it works, sometimes it doesn't -- success using liquid nitrogen poured on the epoxy -- quick freeze -- and whacking with a ball peen hammer driven chisel or punch. (My last, I used a rivet-setter punch) If you try this, make sure you are wearing gloves (the nitrogen will freeze your skin almost instantly!) and, of course, safety glasses. Good luck, whatever you try! If the cold doesn't work, you may try heat -- e.g., the tip of an Ungar-type soldering iron -- while being cognizant of both potential toxic fume hazard as well as altering temper of metals joined.
geo

[JimB..]

https://www.tedpella.com/technote_html/Reworking_Cured_Epoxy.pdf

[country gent]

Most epoxies are temperature sensitive and the other is the different expansion rates of the materials. Cooling the blocks with dry ice will shrink the aluminum steel and actual epoxy at different rates breaking the bond, Heat will also work the same but these may take several applications.

[Misery-Whip]

Once apart, the epoxy is going to be stuck to one surface or the other. Hopefully the scope mount. If heat or a penetrating oil wont get under the remaining epoxy, your going to have to find a mechanical method of removing it. Sanding, scraping.

Good luck.

[skrapyard628]

I used quite a few different brand 2 part epoxys for bonding gemstones to brass dops for faceting. My normal release method is just heating the brass dop with a propane torch. Not heating the epoxy directly. Then I use a bit of acetone to soften the bits of leftover epoxy and clean things up. Works great for me!

[MostlyLeverGuns]

Most epoxies fail around 250*F so a LITTLE heat from a propane torch will/should break down the epoxy. There are some epoxies with much higher heat strength, J-B Weld, Bisonite bedding, others. I have become more selective in epoxy and bedding compound use because of this, especially if it is something I might want to change. 250*F +/- is pretty easy to reach without damaging 'stuff' while the 600*F +/- of J-B Weld can be tricky. There are some 'paint removers' that will dissolve epoxy but again care is needed to avoid damage to other 'stuff' like plastic parts and finishes.

[Shawlerbrook]

Heat !

[pietro]

.

Heat x3 ! !

Just be sure to remove any stock wood near the area, like the forend.

[Winger Ed.]

If it's the real good stuff, and is the chemical like JB weld, it turns to ashes at about 400 degrees.

[15meter]

A commercial heat gun like this:

https://www.northerntool.com/shop/tools/product_200195474_200195474

may be your best bet, no open flame to oxidize the surface or start the epoxy on fire. Several heat/cool cycles may be required.

Heat it up then set an ice cube on it to try and shock it off.

Good luck, may want to check if you can rent a heat gun/paint stripper. May be able to rent a good one as opposed to buying it for what is potentially a one time use.

[colchester]

A clothes iron set on the scope base will work as well

[deltaenterprizes]

A clothes iron set on the scope base will work as well

That worked for me!