High Casting Temperature

[Shiloh]

I recently got a used Lyman 35891 .38/.357 Wadcutter mold with handles for $30. It cleaned up nice from some light rust, burred alignment holes, and plugged vent lines. It looks like it sat for years.

I get good boollits from it but my casting temp to get them is around 900 degrees, amost as hot as my Lee 4/20 pot can get. From what I understand is that there is the possibility of tin cooking out. Is this possible to do??

Some of the folks here get perfect flawless boolits from there molds at temps as low as 725 or 750. These are WW with about 4' of lead free solder added to the melt.

I flux as the top of the melt turns a brownish gold color as I though this might be tin from the alloy.

The boolits don't come out shiny, but not frosty either. They look similar to the color of the silver model paint that we used as kids to paint model airplanes, kind of a silver gray.

Let me know your thought on this folks!! Thanks a lot!! :)

Shiloh :castmine:

[chunkum]

Shiloh,
A good bullet design! Your query is one that I think lots of casters have pondered upon and for which, few really know the explanation. I've experienced the same variability in temperature requirement for good fill out that you describe. My observations are that 1) this is NEVER the case with linotype. It's ALWAYS a wheel weight alloy involved. 2) Smaller volume bullets (both in weight and diameter), in general , fill out better for me at more "reasonable" temperatures (750 or thereabouts), than larger diameter, larger caliber bullets do, and the larger the volume (in general) the hotter the alloy and the mould have to be for good fill out. (with WW alloy). 3) Most of the time but not always, the addition of tin (up to 3% or 4 %) to a troublesome WW alloy improves fill out, though the higher (850 - 900 degree) heat requirement for both alloy and mould is seldom alleviated. 3) I haven't used the older more traditional pure lead and tin alloys (1 : 20 and its variants) much but, in my limited experience with them, they don't exhibit this same "heat addiction" that you're pondering about. 4) Lots of experienced casters, particularly on this forum, apparently do not share my (and your) experience and go happily along with perfectly filled out non frosted bullets from pure WW alloy without even the benefit of additional tin. One wonders?

Then there is the seemingly increasing disparity between the traditional "standard" WW hardness and the BHNs I regularly find with my alloys from locally obtained WWs (Mississippi), the old standard purportedly having been around 10 and my WW Ingots (and bullets cast from them) ALWAYS testing at least at 12 and more frequently at 14 or 15. I correlate these with a Saeco and a Lee and, though my competence, veracity and general moral character have been called into question on this issue, my certainty on this remain unshaken. I've been forced to go to a half and half - Lead and WW alloy to get the hardness results once obtained with just WWs. Go figure....

After considering these things, I think several things are likely: 1) current commercial WWs are likely being manufactured from older recycled WWs (and maybe other things) and the metals (and the percentage of these) of which they are composed have become more variable in the process. 2) this is an ongoing process, and 3) the "heat addiction" of current WW alloys is, most likelly due to alloy contamination with metals other than Lead, Antimony, Tin, and Arsenic, the exact nature of which, I know not. But I do know how to make them fill out and that is to add heat (and usually some tin - up to a point) as needed.

If you want pretty non frosted bullets for purposes of pictures to be posted on forums as "examples" of your skill and proficiency, use lintype. They will always look good and gather rave reviews from the envious viewers who will "oooooh" and "awwwww" over them with envy and confusion over their own inability to get the same results. For shooting, the WW alloys (with their heat addiction fulfiled) will furnish a filled out frosty crop of fine shooting missiles. It's just the current state of things. At least those are my thoughts on it.
Best Regards,
Chunkum

[VTDW]

"the old standard purportedly having been around 10 and my WW Ingots (and bullets cast from them) ALWAYS testing at least at 12 and more frequently at 14 or 15."

My experience exactly! Aged WW seem to always check at around 14.5 Bnh for me.

[GSM]

Shiloh:

If it's a 4 banger with the large blocks, your temperature experience is about the same as mine was. I have a couple of "more mature" Ideal moulds in the wadcutter style and couldn't get a complete bullet until I raised the temp to 800-825 using 80% WW & 20% lino.

At first I thought I had not cleaned the blocks well and it was casting nasties. After the second cleaning (boiling & wipe down with brake cleaner) they were still dropping nasties and almost got launched accross the garage. The light bulb went off, boosted the pot temp and they started dropping beautiful slugs.

Most of my other moulds work well around 700, so it threw me for a loop to have to raise the temp that high. Just the nature of the blocks.

[HORNET]

Shiloh,
I wouldn't worry too much about it, it's not that unusual to run into the occasional set of really annoying blocks that require lots of extra heat to get good fill. I've got a single cavity 410459 that's almost impossible to get a good fill on despite all the tricks including making a new sprue plate of 1/8" aluminum with a humongous opening.
You might try smoking the cavities like you would on aluminum blocks, sometimes that helps. Some blocks are just heat sinks for no apparent reason.

[leftiye]

It would be very interesting to (maybe even have that alloy analyzed) to match the hardness by diluting Linotype, and maybe add some tin to get it up to 2% and see what temp that wanted to cast well at. Might be it would prove the contamination theory? Makes one tempted to only use Lino/ pure PB alloys don't it?

Heat sink molds might work out better if sat on a hot plate or in a mold heater while casting to get the mold hotter.

[Shiloh]

Thanks for the answers folks.

I'm going to try adding linotype to the alloy. I don't like the idea of lino in handgun boolits at velocities lower than about 900 fps or a little higher. I prefer to save my precious lino for sweetening the alloy of rifle boolits.

I just want to be sure I'm not going to hurt anything with the high temps. I do however, find myself to be a little anal about dropping well formed boolits. Weights are more consistent from slug to slug, as well as boolit balance.

I suppose if I need to use a higher temp than so be it.

Shiloh :castmine:

[chunkum]

It would be very interesting to (maybe even have that alloy analyzed) to match the hardness by diluting Linotype, and maybe add some tin to get it up to 2% and see what temp that wanted to cast well at. Might be it would prove the contamination theory? Makes one tempted to only use Lino/ pure PB alloys don't it?

Heat sink molds might work out better if sat on a hot plate or in a mold heater while casting to get the mold hotter.

This just might clear the air somewhat. I've been trying to accumulate as much plumbers lead as I can for just the reasons given in this post.
c.

[44man]

I have to ask if you are using a good thermometer or if you are going by the dial? I suspect something is wrong with your alloy, my Lee pot holds pretty close to the settings.
Need more info--is it a single cavity? Are you bottom pouring or using a ladle? Is the spout clean or full of crud? What does the lead stream look like? If you use a ladle, do you pour from above the mold or do you put the ladle tight to the mold. How long do you hold the ladle on the blocks before tipping off? Do you have a steady casting rhythm or do you stop to smoke and drink coffee?
There are just too many things that require much more heat then normal and most of the time it is how you are casting.
I can't just answer your question and I don't think anyone else can with the lack of info you gave.

[Shiloh]

I have to ask if you are using a good thermometer or if you are going by the dial? Lyman Thermometer.

Need more info--is it a single cavity? Double.

Are you bottom pouring or using a ladle? Bottom pouring. about 1/2" drop

What does the lead stream look like? Solid. If I go an inch or more drop, it'll bead in the stream.

Do you have a steady casting rhythm or do you stop to smoke and drink coffee?
I try and keep a rhythm. Especially when I start getting good bullets.

I get great boolits. It just takes a high temp to do it. I flux and scape the bottom and sides so all the crud floats to the top. I've used Marvelux, 50/50 lube, and beeswax. Haven't tried sawdust or kitty litter.

The melt is clean of debris. About 4-5 feet of 95% tin 5% antimony solder added to the melt

Shiloh :castmine:

[44man]

Everything sounds good to me. It just might be what the mold needs. It sounds like none of your other molds need that heat.
I remember having to do all kinds of stuff to molds when I lived in Ohio to prevent rust. Had a few rust anyway and it was a job keeping ahead of it. It seems to me I would have about the same problems in that some molds acted different. (Been a long time.)
I don't have the problems here and all I need is to keep some mold prep on them. My basement is dry and nothing gets rusty. I have to wonder if something happens to the metal after it rusts! Does it seal the pores?
Maybe someone else can come up with an answer.
It sounds like you cast very good.

[Bass Ackward]

It's all about getting the mix to stay fluid long enough to fill correctly. The worse conditions are, the more heat or tin you will need for what ever the reason from contaminated metal to the wrong block material for the mass of the bullet.

I say that virtually every time that I have a heat issue with a mold, it can be cured by increased or I should say corrected venting. The only other reason that I have experienced, is if the flow rate is too slow, but this normally occurs with much larger bullets. You still need a smooth stream from the pot and it should remain smooth for a couple of inches. When I get the flow interruption I either need to adjust the flow rate or clean the spout which can be a PIA from a safety standpoint.

I'd say, the tin isn't helping you any in this case and isn't needed if you have to run that hot, so why use it? Just use the WW which will be fairly immune to heat and crank on it until you get what you want.

[Shiloh]

I rotate the metal rod that plugs the spout many time before casting. I also scrape very well in this area while fluxing to bring any debris to the top. I can't see it mind you, but I think that I do a good job of cleaning in this area.

I do get a leak from time to time where small drops fall and splatter. My cure for that is to turn and re-seat the plug. I am almost done with this batch of wheel weights. I separate by smelt when at all possible.

My next attempt will be with salvaged range lead poured into "muffin" ingots.

How long a stream should one get from a Lee 4/20 pot without beading in the stream?? Also, My 20lb pot holds just over 15 lbs of ingots filled to the top.

My other Lyman molds give good results at around 825. I don't cool the iron Lyman molds like I do the aluminum Lee molds. I touch the Lee molds to a wet towel about every third pour. My Lee molds are 6 gang TL molds for handgun boolits

Shiloh :castmine: