Stripped handle screw hole, suggestions?

[Patrick L]

Taking advantage of the stay at home time to cast. Last night I went to put handles on a Lee 6 banger, and one of the screw holes is stripped. I'll figure out a solution, but if any of you have " been there done that" you could maybe share what you did?? Maybe save me a step or two 😉.

[CastingFool]

Haven't stripped a screw hole on a mold, but I have repaired stripped threads on other items by using helicoil inserts.

[Shawlerbrook]

Ditto on the helicoil.

[JonB_in_Glencoe]

I don't have any advice for repairing your Lee mold.
BUT, I have advice for anyone reading this, to avoid the problem.
I coat the threads with a copper based anti-seize compound.

I always store my molds without handles, so I have to install the handles (and remove them) for each casting session.
Threads seizing is a common problem with aluminum molds with steel screws...it's that dissimilar metal thingy along with the Heat-cool cycle. The aluminum will gall onto the steel screw threads, stripping the threads out the mold.

[jsizemore]

Like JonB I use anti-seize on all the screws on the whole mold. Doesn't matter if it's aluminum, iron or brass. I don't disassemble between casting sessions and even years later they come apart without issue. Cheap insurance. I also put a little under the sprue plate at the pivot bolt/screw.

[Springfield]

Heli-coils have not worked well for me, I prefer time-serts, as they are more solid. I also now use the copper based anti-seize, seems to have slowed down the stripped hole syndrome.

[Winger Ed.]

You might be able to tap it to another size that's a little bit larger.

[Patrick L]

Bingo Ed. I'm currently about halfway done making a slightly larger screw, just need to shape the smaller smooth nose where it goes thru the hole in the handles.

I'll try to post a pic later.

[Patrick L]

Springfield,

I agree. It just doesn't look like there's enough meat to get a heli coil in there, at least not with our a LOT of finagling. I think my idea will be better

[Patrick L]

So here's my fix



I took a 12-24 machine screw and chucked it in the drill press. I used a file to reduce the head diameter so it would fit into the hole in the bottom of the mold, the I masked off the threads to the height of the threads on the factory screw. I then filed the rest of the screw to the diameter of the smooth section that passes through handle. then just whacked off excess length. Viola!

Seems solid.

[Martin Luber]

I was going to say slip a sliver of aluminum foil in the hole then put in the screw but re tapping is a better option. Did you have to drill the handle jaws?

[Patrick L]

Martin,

Nope, I turned the front of the pin down to the same diameter as the factory screw!

[Thin Man]

When I find worn, stripped out buttplate screw holes in a stock I make a quick fix of the stock by dropping 2-3 toothpicks into the hole, then install the buttplate and screw. Carefully applied this may work for your mold but would suggested leaving the handles attached rather that on-off-on.