Mold Repair

[seawolf]

I have a Lyman 358242 mold that I had bad thing happen to. I was casting and had a good session going until one of he screws came out of the handle that holds the mold half to the handle and that half dropped into the quench bucket. I think it has caused the mold half to distort and is casting out of round boolits. Is there anyone here willing to let me send them he mold and check it and make repairs on it? I will pay the shipping and repairs if you can help me out.
Thanks, Mark

[country gent]

There are several quick checks to do before condeming to be repaired. Set a straight edge ( 6" steel ruller works well, also can be set on a glass plate with a very light coat of oil to see the contact areas) at several places and both directions look for light under neath the straight edge. This will tell you if the blocks have warped from quench. Check some bullets from a previous run before the oops and compare measurements to after oops. Last is check the faces, vent lines, and alighnment pins and holes for dirt and or dings ( mould may have picked up dirt or crud from water or handling). Is this a single or mutiple cavity mould? I would really recomend doing these small things before working on the mould. Its ussually something fairly simple. Let me know what you find out

[williamwaco]

Also, put the blocks together and be sure they are aligned carefully. Then hold them up to a strong light and see if you can see any light through the crack. Especially looking down into the cavity from "above".

[bhn22]

Odds are that it was a bit out of round to begin with. Few production mould cavities are perfectly round from the factory. Post a pic of both mould faces and let's have a look at them.

[seawolf]

Received a PM from a member here he and I agree it would be more cost effective to replace the mold.
lessons learned:
1. don't buy from flee-bay unless it is a new mold
2. cast a small number of boolits then resize and check them out
3. be very thankful to he members here for the help and answers they give one and all for free.
Mark

[longbow]

How much out of round are we talking here?

I often cool my iron moulds in water or snow if I am casting fast and they get hot from the rapid cadence. I have never warped a mould this way.

A total sudden quench is a little more extreme I grant you but still I would be surprised if it warped.

Having said that, how many cavities is your mould? Mine are mostly two cavity and in fact all of my iron moulds are one or two cavity. A four cavity may have enough length to react differently.

Longbow

[Forrest r]

Molds are soft steel.

Get the mold hot, real hot and put it in a vise that has reasonably straight jaws and put some torque to it. Let it sit in the vise until it cools. I've bought several used molds over the years that needed a little tweaking.

[seawolf]

The mold is a 2 cavity. The quench only happened to one block and the mold was very hot, two or three seconds to get a firming of the lead sprue.When the weather cools down some I will mess with it some more. I took a lee 357 6 cavity and cast some more boolits and they size out fine. The two cavity mold boolits I have to put a cheater pipe on the press to push them through the lee sizing die. I am running them dry as I want to powder coat. I may try some alox on some to see if that helps then clean the lube off to PC. I also learned to cast only a few boolits with an unknown quality mold not 23 pounds as I did this time, casting was going so very good.
Thanks, Mark

[Seeker]

I'm no pro so take this as you like. If you are using a cheater bar to get them sized and are sizing them dry, then maybe your sizing die is leaded and that is what's causing the out of round.

[longbow]

I have trouble believing that the mould warped enough to make it that much oversize and if so then it will show up if you mic it ~ the boolits will be oval at the seam or they will flare top to bottom (spool or egg shaped if the block warped across the handle cutouts). It would take a lot of distortion to make it that hard to size them ~ like several thou.

From your comment "I also learned to cast only a few boolits with an unknown quality mold not 23 pounds as I did this time,..." I have to ask if you know what size they were casting before the quench event? Did you mic them or try sizing before the mould got quenched? Have you used this mould before and had no trouble sizing?

have you checked to make sure there is no lead splashes on the mould faces that will keep the blocks from closing all the way? That would certainly result in oversize boolits.

Just trying to understand.

Longbow

[seawolf]

This was a mold that was new to me and I went hog wild casting without making any checks on the boolits or sizing (leason learned) a wasted day on casting but no loss of lead.
I have cast more boolits with a different mold and used the same sizing die with no problem, I can push the boolits though very gently. So I don't think the sizing die is at fault.
I did not keep the boolits separate from before and after he quench and I have melted most of them back to make the 150 gr. boolits from the other mold. I ran about 50 with the other mold after I started to get a good cast then ran these through the sizing die to be sure they worked or if I was doing things wrong, got great looking boolits and have now cast 15 pounds about 700 by weight and will finish sizing them tomorrow on my day off.
I have not taken any more time on the old mold due to the heat in my shop but I will try to get it over to a friends shop where it is cooler. there is no finning on the boolit to indicate a failure to close completely.
Mark

[bhn22]

I had a warped Lyman mould once, and it finned at the parting line. I got even with it though. I know this sounds brutal, but I removed the sprue plate and hardware, then put screws in the threaded holes to seal them, then I floated the blocks in my lead pot which was set at 800*. After an hours heat soak, I removed the blocks, cleaned any specs of lead from the mating surfaces, then clamped it in a vise, protected by small oak blocks and let it sit overnight. It did scorch the oak blocks a bit, but it mated up perfectly, and never gave me any further issues at all. I still have it. It kind of sounds like you mould cavities may be out of round, have you considered lapping them? How far out of round are your bullets?

[texassako]

A slightly warped mold is a pretty easy fix. Drive the pins flush, lap mold blocks against each other until no light, drive pins back until no block wiggles and no light, cast a few to check out of round and cavity differences, use a couple of those first casts to lap back to round and same weight, and make sure blocks are completely closed(squeeze lap bullet a few times between blocks) before twisting that lap or suffer worse out of round bullets. I also have a couple of molds that cast accurate bullets that are out of round as cast and light shows between the blocks. Shoot them before messing with the mold is my motto.