Getting back into casting

[db22]

First post here . . . heard of this board at Graybeard Outdoors. Have started casting again after a 10-year layoff -- lucked into two big buckets of WWs for just ten bucks, and inherited some really nice old Lyman and Ideal molds, so had to give it another go.

Having trouble getting iron blocks to fill out with pure wheelweight metal, and also with Lyman #2 alloy. It's happening with both a .38 wadcutter, and with longer bullets, also .358 diameter (Lyman 358627 and 358318). When the blocks heat up and start dropping frosted bullets, one side of each bullet has good, sharp edges and the other is slightly rounded where it should be sharp. I carefully clean the molds with rubbing alcohol on a q-tip before starting.

I have a Lyman thermometer. Where should I stabilize temperature for pure WWs, and where for Lyman #2? I lost my old copy of the Lyman manual (found just enough of my old casting rig to get in trouble . . .)

Also -- when I make ingots of #2 alloy, they appear all frosted with a crystal-like surface. Is this just because the metal is too hot when poured, or have I contaminated it with something like zinc?

Thanks!! -- Dave

[Bass Ackward]

1. I have a Lyman thermometer. Where should I stabilize temperature for pure WWs, and where for Lyman #2? I lost my old copy of the Lyman manual (found just enough of my old casting rig to get in trouble . . .)

2. Also -- when I make ingots of #2 alloy, they appear all frosted with a crystal-like surface. Is this just because the metal is too hot when poured, or have I contaminated it with something like zinc?

Thanks!! -- Dave


Dave,

Glad to see you coming in from the cold. Welcome.

1. You don't say what method you are going to cast with. Just watch your thermometer and see what what temperature any mix melts at. If you are using a bottom pour, you will need to be about 200 degrees above that point. If you are ladling, you may only need 100 degrees over that point.

All of this depends on mold material and bullet diameter / weight / length as you may need a little more or a little less even depending on your cast rate.

2. The frosted is the surface tin cooking out of the mix. The crystallized surface is a more severe case of it. Frosted bullets are a nice concept if you don't have a thermometer. But when you no longer have that disadvantage, you are not limited. Turn down the temp for higher tin mixes.

The idea of the frosted bullet came about when guys started using WW and were used to the lower molding temperatures that higher tin mixes afforded. It was an idiot proof way to get them used to higher temps. WW is less than half a percent tin so losing that much on the surface affected nothing on the bullet looks or weight.

Higher tin mixes, particularly with larger diameter bullets, results in the problem you see.

[db22]

Yep, I sure did forget to mention my casting method. This time, I'm using a bottom-pour furnace, a Lee model that so far has been quite satisfactory. I used to use a ladle years ago, never used a bottom-pour before.

I was looking for some kind of guideline, and you have provided it -- 200 degrees above melting point for a bottom-pour rig.

Taking a vacation day today, and just got back from the range (man, it's nice to have the whole thing to myself!!) The Lyman 358627 is showing some real promise in my .357 Max NEF single-shot. The 358318 surprised me, by giving good results as well. I had feared that the one-in-17.5" twist of the NEF barrel might be too slow for a bullet that long, but sure enough, all the holes are round and print pretty close together on the target.

Thanks for the help!!

Dave