tapping for handle pins

[kbstenberg]

I got a used Lee 6 cav. recently that I have been fine tuning. The last tuneup is that I have to do is re-tap the handle screws. The screws work there way out as a casting session progresses.
I have never tapped steel or aluminum. So I am asking for help before I start.
I have the options of putting a set screw in each handle pin. Or buying a tap and hopping it tightens up the screws
Kevin

[smokeywolf]

Kevin, a tap will clean up buggered threads. It won't tighten or secure screws that back out. I would try some Loctite Threadlocker Red 271. It will allow disassembly with a combination of heat and tools. I don't think the heat of the mold blocks alone will cause your screws to back out.

[imashooter2]

Cut the counterbores a little deeper and use lock washers under the screw heads.

[captaint]

+1 what is2 said. That'd be the deal. enjoy Mike

[Ben]

Give your mold this treatment and your problems are OVER ! !

http://smg.photobucket.com/albums/v494/haysb/Lee%206%20cav%20mods/?albumview=slideshow

[375RUGER]

Use a thin star lock washer and you wouldn't have to counterbore.
You could also pour a little lead on the screw heads while the mold is hot. Then if you need to remove the handles it will melt right off when wanted.

[imashooter2]

In my experience, the counterbores are just barely deep enough for the screw heads. Even a star washer will place the screw head proud of the mold base and give you a "bump" over most mold guides (should you use same).

[375RUGER]

my lee 6er came with the heads proud of the base anyway, so I just thought maybe they all did.
I guess it would matter if using a guide.

[kbstenberg]

I will try the small star washer to see how it works. Kind of Leary because the screw is already loose in the threads. But we will see.
I suppose Ben's setscrew will be my next step.
Thanks all. Kevin

[Jeff H]

Give your mold this treatment and your problems are OVER ! !

http://smg.photobucket.com/albums/v494/haysb/Lee%206%20cav%20mods/?albumview=slideshow

+1

I have had to do that on enough LEE moulds that I did it before I started casting twith my last two LEE moulds. I have had to do it to the alignment pins on two 6-cavity LEE moulds as well.

I am not a machinist but my Dad is a seasoned T&D Maker and shared some aluminum tapping tips with me that have worked well for me on LEE moulds:
When you D/T aluminum, try loading the flutes of the drill and tap with vegetable shortening (the white, creamy stuff, not oil) and it will capture the chips to keep them out of the way and leaves a great finish on the holes. Very handy for small/precise holes and threads. Another "tap tip" is to not run a starter tap all the way through a through hole, or, if in a blind hole, use a plug tap in place of a bottoming tap (a broken starter tap can be used to make either) to provide a little extra grip on the screw threads. He also advised experimenting with a tap drill slightly smaller than recommended on the charts for aluminum as well.

[44man]

I do not own a six cavity mold so I don't know the screws. The two cavity molds use a self tapping metal screw.
Tapping a hole for a screw that comes loose is no help but changing the screw after drilling deeper and tapping can. Then add a setscrew at the side of the screw to hold it. I cut a tiny hunk of brass rod to insert in the hole first so the setscrew does not bugger the threads. A chunk of copper wire also does good. Don't force a steel setscrew into the threads.
Another way is to file a flat on the sprue screw for the setscrew.
On handle pins I drill and tap for a setscrew but there must be a little space between the pin and screw so you should shorten the pin. Never tighten on the pin, you can warp the mold.
I don't like the staked in pins on the Lee.