I need a mold repairman.............

[3006guns]

I have a Lyman single cavity mold for the 45 acp that I inherited from a very dear friend years ago. It's not fast, but it DOES cast a nice boolit. Problem: one cavity will not let the boolit drop. Okay, so after lapping the cavity (twice), smoking, etc. I finally discovered that the sprue plate is not sliding across both tops evenly, resulting in a microscopic "flashing" on one block so it requires a lot of tapping to release. Not good, and very slow production. A replacement sprue plate was tried, with exactly the same results.

I should have spotted this immediately before doing any lapping, as the rub marks are pretty self explanatory. It's okay though as the cavity is nice and clean now, without being enlarged. But I still have the problem of one block being about .001-.002" higher, causing the sticking.

Is there anyone out there that can remove the sprue plate stop pin, surface grind the tops even, reinstall the plate and pour a few test casts to see if there's any improvement?

[Winger Ed.]

That's a fairly precise machining project.

Any chance the Lyman folks could fix it for ya?

[GARD72977]

Draw file it and if it doesn't work scrap it.

[Conditor22]

I'd try resetting the alignment pins first

[Stephen Cohen]

If you felt confident you could drill an undersize hole in bottom of block to allows you to remove the stop pin with a punch, after that you could use a flat sheet of 1/4'' glass covered with fine wet and dry paper to remove the unwanted metal. I do think Winger Ed had best idea if cost was not an issue. Regards Stephen

[3006guns]

Thanks for the ideas guys. I'm a little reluctant to send it back to Lyman due to the poor customer service I've read about in the past, although maybe I'll contact them for giggles. Drilling/driving out the pin and polishing is a good idea too, as Lyman might charge as much as a new mold! I'll mull it over and determine what's best.

Again, many thanks!

[JMtoolman]

I have refurbished a number of molds by doing what was mentioned above. Remove the stop pin and lap the mold on a piece of glass with a wet or dry corundum paper taped to the glass. Lap in a circle motion or figure eight motion while holding the two blocks tight together. Stop lapping when you get an even finish, 360 to 400 grit finish is fine. Then lap the bottom of the sprue plate the same. Don't forget to break the sharp edges on both the outside of the mold and the sprue plate. Really clean them and re-assemble and start casting. The toolman.

[Bent Ramrod]

If you have something set up for collets, and one of the proper size, you can grasp the end of the stop pin, and with enough pulling, twisting, heating, oiling and cursing (not necessarily in the order given) the pin will come out. A good vise with soft jaws, squared-off for a good grip, will often do the trick as well. The regular jaws will work, but will mar the pin end.

Then it’s just a matter of a flat surface, fine sandpaper, and a careful eye and hand. Hold the offending block half vertical, and move it in a figure-8 pattern. When it’s mostly down to the level of the other block, hold them together and polish likewise for evenness. Do the same with the sprue plate while you are at it. When the bluing is converted to bright metal, all the way to the edges, the surface will be adequately flat.

Even if the stop pin is a little battered on the protruding end, it will still stop the plate when driven back in. You can, of course, remove any marring with a fine Swiss file.

[3006guns]

I'm going to at least make the effort to repair it myself, starting with removing that stop pin. I just tried it in my vise soft jaws, but no joy. I'll try it again with a little rosin on the pin......accompanied by the mentioned cursing, etc.

If THAT doesn't work, then I'll drill from the bottom of the block until I can get a punch down there and drive the pin out. If the pin gets too badly marred up, a replacement made from drill rod stock shouldn't be hard to make. Might as well drive the alignment pins out a bit too.

If I can get the pin out, I'll carefully draw file the higher block first (lot of metal to remove) then the two blocks together followed by final polishing. It's worth it to try and save the mold.....more sentimental value than anything else. At worst, I'll need to by a new mold. Two cavity this time!

[country gent]

Before doing any machining and metal removal. I would recommend looking the mould over good for burrs dings ad raised areas. Start with a cotton q tip running it over edges and surfaces look for pulled fibers, this indicates burrs and or sharp edges. Then with a decent magnifying glass look the edges surfaces over for burrs raised edges dings and such. Another is to use a 6" scales edge and check corners and surfaces for flat.
If nothing shows up in the above tests then it may be alignment issue Sometimes slightly adjusting the pins helps here. It may be on the older blocks that internal stresses have slightly warped the blocks over time. This can be harder to fix as the stress is still there.
Another thing area to look over is the alignment pins and holes as over time these can wear. Here sometimes a slight adjustment helps but if to much then holes may eed to be sleeved and pins recut.
Trouble shooting a misalignment issue is more checking inspecting than fixing usually. The fix once determined is not a lot of work.

If you have a drill press and some basic hand tools fixing a mould can be done. Removing the stop pin can be tricky. drilling a hole thru from underneath may work remember to drill it smaller than the pin so a shoulder remains when installing it again. A collet may pull it but Ive never had a lot of luck with them. If soft a he driled thru pin and tapped allows a bolt to be used tto pull it but then you need to replace it.

For smoothing matching edges a flat surface and lapping compound will do well once all burrs and dings are removed. A piece of glass fairly heavy piece of flat stock Or a surface plate and very fine sand paper. If using the flat stock very flat true plates can be made as follows. Cut 3 pieces. Stamp ID one edge of each plate 1 2 3. Deburr edges and lightly stone surfaces. Now lapp 1-2 with id marks aligned. then 1 -3 with marks aligned. next 3-1 with marks opposite then 1-2 with marks opposite. Work until all 3 plates are cleaned up rotating the id marks every time. You will end up with 3 truly flat plates allowing you to use 3 different grits with out cleaning. Staying with the coarser frits helps as it leaves a surface that will hold finer grits better. I made a set 1" thick X 6" wide X 6" long from aluminum plate. The soft aluminum holds compound good, they worked down to very flat and have held there well for years. Occasionally you may want to touch them up and canbe done the same way you made them

[blackthorn]

If you ruin the stop pin, consider using a roll-pin as a replacement.

[MT Gianni]

A good machine shop would charge as much as a new 4 cavity NOE or Accurate mold.

[3006guns]

Before doing any machining and metal removal. I would recommend looking the mould over good for burrs dings ad raised areas. Start with a cotton q tip running it over edges and surfaces look for pulled fibers, this indicates burrs and or sharp edges. Then with a decent magnifying glass look the edges surfaces over for burrs raised edges dings and such. Another is to use a 6" scales edge and check corners and surfaces for flat.
If nothing shows up in the above tests then it may be alignment issue Sometimes slightly adjusting the pins helps here. It may be on the older blocks that internal stresses have slightly warped the blocks over time. This can be harder to fix as the stress is still there.
Another thing area to look over is the alignment pins and holes as over time these can wear. Here sometimes a slight adjustment helps but if to much then holes may eed to be sleeved and pins recut.
Trouble shooting a misalignment issue is more checking inspecting than fixing usually. The fix once determined is not a lot of work.

If you have a drill press and some basic hand tools fixing a mould can be done. Removing the stop pin can be tricky. drilling a hole thru from underneath may work remember to drill it smaller than the pin so a shoulder remains when installing it again. A collet may pull it but Ive never had a lot of luck with them. If soft a he driled thru pin and tapped allows a bolt to be used tto pull it but then you need to replace it.

For smoothing matching edges a flat surface and lapping compound will do well once all burrs and dings are removed. A piece of glass fairly heavy piece of flat stock Or a surface plate and very fine sand paper. If using the flat stock very flat true plates can be made as follows. Cut 3 pieces. Stamp ID one edge of each plate 1 2 3. Deburr edges and lightly stone surfaces. Now lapp 1-2 with id marks aligned. then 1 -3 with marks aligned. next 3-1 with marks opposite then 1-2 with marks opposite. Work until all 3 plates are cleaned up rotating the id marks every time. You will end up with 3 truly flat plates allowing you to use 3 different grits with out cleaning. Staying with the coarser frits helps as it leaves a surface that will hold finer grits better. I made a set 1" thick X 6" wide X 6" long from aluminum plate. The soft aluminum holds compound good, they worked down to very flat and have held there well for years. Occasionally you may want to touch them up and canbe done the same way you made them

Ah.........the three plate method of working a surface to truth. I think it was Henry Maudslay in Merrie Olde England that perfected the technique back in the early 1800's or so. It still works too. When I first started playing with machine tools, I tried it and got the third plate down to within .001" over a 6" x 6" surface......but brother it took a long time! I decided that trusting the machine tool manufacturer's surface work was a lot easier.....

I'm going to put that particular mold on the back burner for a bit, as I just found a NEW Herter's mold of the same boolit. Of course, it has no set screw to hold the sprue screw, so some drilling and tapping is in order....probably a 10-32 with a bit of brass against the sprue screw. If that mold works, I'll go back to the Ideal and end up with two usable molds. Great way to spend a Saturday!

[3006guns]

An update guys...

I carefully drilled/tapped that Herter's mold to take a 10-32 set screw. THAT should keep the sprue screw in place! Modified some unknown handles by drilling the holes a bit larger to accept the (probably) metric handle screws. Degreased the mold and began casting. Within five casts I was getting very nice boolits that were the spitting image of the Ideal. I took a quick break and weighed one.....220.1 grains and each one measures .456 in diameter! Getting them down to .452 is reasonable and I can also use them in a .454 barreled revolver if I ever decide to.

The boolits usually fell from the mold with no effort, and if one did stick a slight tap with my mold knocker dropped it. I noticed that the Lyman design's lube groove is square in cross section, while the Herter's groove is slightly beveled. I'm sure that has something to do with ease of release.

Aside from the missing set screw, the Herter's has one other possible design flaw......the spue plate is thinner than a Lyman/Ideal. It presents no problems at all unless you start whollaping on it, in which case you need another hobby. Like destruction derbies maybe.

So, I'm finally good to go with a decent copy of the "service bullet" as Ideal used to call them. Again I have nothing against the Lee design, but to my eye the ogive looks like a volley ball stuck to the front of a cylinder. That's not fair either, as the Lee has served (and will serve) me well too.