I bought a like-new, used Win M70 with Weaver bases already mounted. I didn't bother to remove bases prior to sale. Evidently, previous owner needed bases permanently attached.

Even if I wanted to use Weaver mounts, I would have removed the bases to ensure they are attached the way I want. I found the rear three screws have epoxy on them, and were fairly difficult to remove. The front screw on the receiver ring is stuck.

I have slowly heated the screw area with a propane torch, bare thumb as thermometer, to "as hot as I can stand it" level. I don't want to go hotter. I have broken three hollow-ground 3/16" screw driver bits; I've been lucky, so far. One option is to replace other base and screws, go with Weaver, but that is not the system I want to use.

Will a solvent remove or weaken the epoxy, such as acetone?
Is low level (non-temper removing) heat even effective for loosening epoxy?

I'm out of acetone and other solvents, and have no decent Weaver style rings in stock. I want to choose carefully before I start buying more "stuff".

Acetone and heat work well in breaking down Loctite. However, epoxy is more resistant. I would soak it in acetone to see if it help. It may take some time.

350 degrees to break down epoxy sticks in my mind somehow, and that's a lot hotter than you can touch.

Of course it would have to be applied carefully so as not to compromise heat treated steel. Might be best to have a pro do it, or at least consult on the job.

For a single screw I'd just use a soldering iron, and not worry about it.

Paul

What about using a hammer type impact driver?

Something like this .....

http://www.amazon.com/Tool-Aid-SGT14950-Impact-Driver/dp/B000I1X6RU

I used to work with removing epoxy a bunch. There's no chemicals (that I know of) that will disolve it. Soften it a little - maybe - and that includes extremely harsh epoxy paint strippers and a specialty expoxy solvent that I tried. The other problem is nothing chemical is going to penetrate down into the threads.

I'd say gentle heat along with an impact driver and a quality screw driver bit would be the best way to go. Hopefully you won't strip or break off the screw head in the process. A little dab of water based coarse valve grinding compound on the tip of the screwdriver bit will help prevent it from slipping.

Good luck.

Another option is to heat a screw driver tip pretty hot, the put in in the screw slot. Let heat transfer for a few minutes, they try to break the screw loose while it is hot.

Some epoxys will withstand the heat of boiling water, so you may need to get it above 212 degrees.

The hot screwdriver tip should not transfer too much heat to the receiver, even if you get it red hot and just hold it on the screw head long enough to heat the screw 4 or 5 hundred degrees.

Heat will cause the screw to expand, possibly making it tighter. If the screw will not come out after heating and trying to unscrew while hot, let it cool to room temperature and try again.

No offense but, I don't think you'd get enough heat transfer from a hot screwdriver tip. The action and scope mount will soak up what little heat there is. You'd also risk losing the temper in the screwdriver tip/bit.

I'm thinking Paul39's idea of using a soldering iron to heat the screw along with my suggestions is the way to go.

Although, it's only because I'm egotistical and opinionated.

"Although, it's only because I'm egotistical and opinionated."

No more than me.

Soldering iron and hold it on the screw. Been there...it works.

I tried the red hot screwdriver thing once just to see - well to be honest I mostly didn't want to dig out the proper soldering iron. It works with repeated applications, enough to soften Lock Tite anyway. Would have been faster to rummage through the junk box for the iron.

Also please don't ruin a good screwdriver by heating it.

This

Uses a clothes iron. Put it on 'high', set it across the base and give it 15-20 minutes. Make sure you're using a screwdriver tip that properly fits the screw slot...not a tapered profile.

Newer clothes iron have a feature that shuts them off if they're in the 'flat' position for a couple of minutes...make sure the one you use isn't that style. -Al

I have removed epoxy bedded barrels from stocks. I used a heat gun, as my gunsmith advised. I was told that you can break epoxy by placing the item in the freezer and taking it out and giving it a couple taps. Never tried that one though.

Heat always does the job with epoxies.

Freezing...not so much. -Al

This is the correct way to get it out without making a bad situation worse.

You can go up to 900 degrees at least without affecting the temper. You will ruin the bluing before then however. Use a propane torch and heat the screw until it "smokes", let it cool and take it out. You want high heat and fast as to not let it migrate through everything else and ruin the bluing.

I epoxy my bases on but put grease on the screws so I CAN get them out when I want.

Blueing can withstand approx 600F . Human touch senses too hot to hold at only 150F.

The steel and epoxies have different coefficients of thermal expansion; that's why freezing causes a glued-in barreled action to pop free after a couple of days in the freezer. Couldn't hurt to try it with the epoxied screw.

Give somebody some epoxy and they will bed anything.

Sometimes resulting in a sticky situation...

Epoxies are different, but not that much. They begin to break down at about 160-180F. That won't affect the steel at all.

Well, while we're on it....epoxy is wonderful for bedding bases, if you set it up right with straightedges and whatnot --- AND mold release compound.
But yeah, a big gun soldering iron with a good tip should work great. Been there, done that, "helped" things along with a blob of solder for conduction.

Intentional glue-ins are removed using heat. -Al

If no soldering iron available, you can do a redneck version.

Take a decent nail, flatten the tip into a shape that will fit in the screw slot. Hold nail with padded visegrips. Heat nail with propane torch so that it transfers heat to the screw. Let cool a bit and remove with good screwdriver.

If still stubborn, try again, only this time put a few drops of Kroil on the screw head as it cools. Let cool all the way down overnight--it will suck the oil down into the threads. Candle wax will often work that way as well.

Or, if you need to drill it out--I've had good results drilling a 1/16" bit into the center of the screw a little ways. Then switch to a 1/8" bit but run it in reverse to try to get the screw to back out.

I have had success with using a heat gun on epoxy AND red loctite. The heat gun will melt the adhesives without compromising the temper of the receiver. I just removed some red loctited screws on Friday using this method. By the way, use only purple or blue loctite on any small screws. Red is permanent and usually unnecessary on any gun screw.