Stripped Lee Sprue Screw Can I Bolt It Instead?

[Driz]

I’ve got stripped screw with a set of 1980s Lee 38 /. 158 GN. In fine shape otherwise but the sprue screw curse is upon me. I’m a pretty good metal mangler myself but wonder one thing. Rather than messing around doing the set screw retap boogy why can’t I much more easily just through drill it for the next size bolt with a suitably long pivot section. Flip it over and inlet deep enough that the nut is flush and fix it that way.
I’m not trying to reinvent the wheel by any means but it seems to me simpler than fussing with taps on soft metal. If that’s a bad idea ( and it just may be because I see very no mention of doing it this way anywhere) someone tell me why.

[Dusty Bannister]

Two cavity or 6? If two cavity, right hand or left hand thread?

[Bazoo]

I done it. Used a 1/4 bolt. You will need to take the left side handle off the block and put a scallop for clearance but that’s not hard. I removed the pin by drilling a 1/16” hole from the top and drifting it out.

[Bazoo]

[Winger Ed.]

I've tapped a little bit of Alum.
I used plenty of oil, on the drill bit as well as the tap, and took out the tap and blew off the chips about every 1/4 to 1/3 of a turn.

Most of the problems I've seen with tapping a hole is when people think of the tap as a self tapping screw, just run it in,
and don't take it out to clean off the chips as it goes along.

[Dusty Bannister]

Bazoo, that might not work so well with the new style two cavity molds with that cut out on the bottom of the blocks.

[elmacgyver0]

You will probably think I'm crazy but denatured alcohol works great as a lubricant for drilling/tapping aluminum.

[Bazoo]

Bazoo, that might not work so well with the new style two cavity molds with that cut out on the bottom of the blocks.

No disagreement here. The OP said it was an 80s era mould though, so by my reckoning, my post is relevant.

[Driz]

This is the old style I picked up at the Munich Rod N Gun back in 1980 when I got out of the army. I don’t think I ever lubricated the poor thing and it sat for a couple decades in my cellar unused as US Customs gave us practice ammo so it went unused.
Me I like the simplicity of the through bolt idea. The nut on the bottom doesn’t look like a bother either. I like the “ keep it simple stupid “ concept . Is that bolt just sitting with the threads throughout the drilled hole or is it shanked throughout and the excess cut off?

[Dusty Bannister]

Yes, Bazoo is right, and the screw would have left hand threads so just replacing the screw could be a problem.

[Sasquatch-1]

I drilled the side and put a set screw in. I haven't had any problems since. I did put a small piece of foil thin metal to tighten the original hole.

[Bazoo]

I didn’t sleeve the hole or anything. It’s a “cap” bolt. That means there is a section of unthreaded shaft near the head. And that is an old style lock nut.

You can make a lock nut like that by carefully punching three deep marks on the face of a regular nut.

The new style lee mounds have left hand threads. These old style have standard right hand threads.

I don’t have a machine shop. I make furniture so I have woodworking tools. I did this with nothing more than a dremel and a drill press. I first removed the pin for the halve. Then I separated the handle joint to get rid of the left side handle. I put the sprue cutter in place and used that to center my drill it. Drilled it through. Then I estimated the relief needed for the handle and dremeled it in. Make sure you use a half circle cut and not a square notch or it’ll break at the corner of the notch eventually.

I drove the pin back in and very lightly used a punch to move some material at the outside edge of the hole to keep it the pin in place.

[metricmonkeywrench]

Just something to add, before I would go full pass-thru with a nut and bolt arrangement as a last resort I would at least attempt to drill thru and tap the aluminum block and use a bolt/screw less than the block height to see if that would work first. Single common size drill/tap packages are available at the usual hardware stores or online.

I use a hotplate to pre-heat my moulds and an obtrusive bolt would complcate getting full contact on the base.

[45DUDE]

Lots of things work. No need to spend a lot of time. A screw for an old Rochester qj carburetor is the same size <metric>and you can drill all the way through and install a nut. With the screw out drill A 1/8'' hole in the top side into the original screw hole and a self tapping screw will work fine. You need a wire stripper <every one has them>to cut the screw to correct length. Some mold handles aren't for strong enough for a larger screw. You don't have to drill all the way through unless your threads are really stripped. Takes about 15 minutes. Bazoo in post #4 looks good if your handles are strong enough. Lee handles are soft so drilling is easy.

[Bazoo]

I didn’t go the tap route because I didn’t have taps at the time. I used what I had for free.