Stripped sprue handle screw- Lee 6 cavity

[mjwcaster]

So while doing some long over due mold maintenance I found a stripped sprue plate screw.
I was already drilling and tapping for a set screw, should have done it years ago.

The best way to fix this is tap it for a larger bolt.
But I had no correct sized tap or bolt, or at least I didn’t want to look.

So I cheated and ‘patched’ the screw with some aluminum foil I had laying around on the bench.
Screw tightened up enough and then I tightened the set screw.

I wouldn’t expect this to last long, but with the set screw to hold it, it should be fine.

I also plan on keeping the screw/pivot lubed better, I am sure I have not been doing a good enough job.

On another mold, when I removed the bolt i found the threads were rusty.
I don’t thing the mold ever got wet, other than sitting on a damp sponge while casting.
I am guessing humidity in the garage just got to it.


And I need to install set screw wear point in the molds for the sprue plate to push against.
I am getting significant wear in the soft aluminum.

If I ever buy another Lee mold it is getting leemented right after testing to make sure it is round.


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[Dusty Bannister]

You might want to consider using the Helicoil thread repair kits where you drill out the threads, tap new threads and install the thread insert and you are ready to go with the same bolts or screws. It all comes in a kit so just determine the thread pitch and go for it. You might also consider just reversing the sprue plate on the mold. The hold down bolt and the sprue plate hinge are in the same location, just the opposite block. Just polish the top of the blocks and use the plate lube regularly and keep on casting. Dusty

[mjwcaster]

Thanks Dusty
I know there are options to fix it right, I have a tap set and have used help coils and other thread repair kits before.
And there is always the swap ends trick.

But I was just feeling lazy and tried a quick but hopefully good enough fix.

If it doesn’t work then I guess I will just have to fix it right.

Sometimes I strive for perfection, other times good enough is truly good enough.

A wise man once said- perfection is the enemy of good enough.


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[mjwcaster]

Also nice to still hear from you Dusty.
I found a thread from my first casting session in 2014 and you were offering useful advice back then.

You have offered me more than a few useful hints and tricks over the years.

Many thanks


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[kevin c]

...On another mold, when I removed the bolt i found the threads were rusty.
I don’t thing the mold ever got wet, other than sitting on a damp sponge while casting.
I am guessing humidity in the garage just got to it...

Worst rusting I ever got was in a mold I was speed casting with using a wet towel. No such problems before that, and none in subsequent sessions with alternative cooling methods.

Sorry for the drift.

[country gent]

I prefer the solid inserts when there's room for them over helicoil thread inserts. I have made insert from allen cap head screws that are very tuff. Drill and tap center of bolt and cut to length install

[MT Chambers]

The Lee is designed to strip at first tightening, that is why it has a left hand thread, and the softest alum. possible makes it easy.

[mjwcaster]

Worst rusting I ever got was in a mold I was speed casting with using a wet towel. No such problems before that, and none in subsequent sessions with alternative cooling methods.

Sorry for the drift.

Thread drift?
On this forum?
That’s a demerit.

I actually have used a sponge for cooling once or twice with this mold.

I wouldn’t think it would have affected it, with the mold at casting temp water would boil off quickly.

But that could be the reason for the rust.

Maybe the steam cleaned off any lubricant, leaving the metal exposed and more likely to rust.

Since these are aluminum molds I do not do anything to coat them after casting.
And it shows on the handles, not bad but a little rusty.
I plan on improving my care of my molds in the future, and not worrying about oil in the cavities so much.

And watching the sprue plates for warpage.
I have had issues before but never realized how lightly made they are.
I tried lightly bending the sprue plate back into shape by hand, just a little tweak.
Over bent it, way easier than I would have expected.




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[Petrol & Powder]

A helicoil insert would give you a repair AND a harder threaded surface when you were done, but a set screw would be difficult to work out.

I like the idea of a solid insert (like the Allen cap screw mentioned by country gent) but that's a lot of work for a Lee mold and you still have the set screw problem.

A larger hole and tapping for new threads seems like the quickest fix, followed by avoiding Lee molds in the first place . (sorry, couldn't resist).

[GregLaROCHE]

Does Locktite hold up to mold temperatures?

[country gent]

Actually if your going to add the set screw the solid insert is the only way when you drill thru the helicoil for the set screw it cuts the wire and the insert looses all its integrity and strength. A helocoil is just a string wound from diamond shaped wire on the right pitch. drill of cutting thru it cuts the wire and it will cause problems later.

[RED BEAR]

I just drill straight through the screw and mold use a smaller bolt and a spacer from hardware store for newer molds just screw works for old lee molds total spent about two dollars heli coil kit will work but cost more than mold.
This is a mold i cut down to make lighter bullet for my 32acp but it workes on any. I know its hard to see but drilled through original screw to keep the shoulder to hold spruce in place.

[Petrol & Powder]

Actually if your going to add the set screw the solid insert is the only way when you drill thru the helicoil for the set screw it cuts the wire and the insert looses all its integrity and strength. A helocoil is just a string wound from diamond shaped wire on the right pitch. drill of cutting thru it cuts the wire and it will cause problems later.

Yeah, I believe it would be difficult with a helicoil. My thought was the set screw could be shortened so that the end would press on the side of the helicoil and deform it enough to help lock the pivot screw in place. I agree that you couldn't drill through the side of the helicoil once it was in place.

[RogerDat]

I started drilling and tapping for a counter sunk flat head where the sprue plate handle hits the side of a 6 cavity Lee mold. Come standard on some other molds and seemed like a good idea. Not sure if I could ever wear down the aluminum far enough to really matter. I just didn't like putting that kind of disfiguring wear on the mold block when it was pretty easy to prevent.

I have found JB Weld will hold up to molten lead in a mold. Had an angle iron mold where the lead was flowing into the gap in a seam, filled it with JB Weld and it has held up fine so far. Not sure how it would do under a load such as a hinge screw would be but it hasn't fallen apart from the heat so it might be an option to fill threads then re-tap with same threads.

[country gent]

A lot of the epoxies have between a 500* and 600* break down temp. they do soften before this some. So on the mould blocks it might hold up, in contact with molten lead it will more than likely fail. I believe red lock tite has a break down temp in the 500* range also. not sure on the green or purple.

[GregLaROCHE]

Has anyone seen the video on repairing a crack in cast iron, by drilling and installing inserts with something like locktite and then drilling between them and installing more inserts?

[country gent]

The common procedure on old farm eauipment was to drill a small hole at each end of the crack. This helped stop the crack from traveling farther. Vee the crak out with a die grinder and small wheel in a undercut u shape. Then if it was over a pressured area braze or solder in the vee. If no pressure then it could be filled with epoxy. Oil journals and coolant journals usually got the solder/braze, returns got the epoxy. Ive seen a lot of wter jackets on the old internationals pathed with JB Weld lol.

[gwpercle]

" Sitting on a damp sponge ... " that's where the humidity came from , it doesn't take much for the rusting thing to do it's dirty work .
Gary