Lead Molds

[Dan Dubeau]

Starting another thread on this topic because I didn't want to muddy the other two.

What is a better mold material for, say, casting lead hammer faces. Aluminum or steel. I have both and am about to make a mold. I'm leaning towards steel (o1, annealed). Also, do you need to soot the molds prior to casting, or does properly preheating provide enough "release". I know nothing of this subject, but remember reading years ago in a fishing magazine about using a candle to cover sinker and jig molds with soot prior to casting as a release agent. Not sure why I remembered that, but my memory works in strange ways....

[Spandau]

I've always liked the Frank Ford method using aluminum. It makes a smaller size head, but I'm sure it can be scaled up.

http://www.frets.com/HomeShopTech/Projects/LittleLeadMallet/littleleadmallet.html

[Yondering]

Either aluminum, steel, or brass all work fine. Obviously aluminum is somewhat less durable if abused, but I have several aluminum bullet molds that have cast many tens of thousands of bullets and are still going strong. If making a mold, I'd think first about aluminum just for ease of machining.

Even if you do go with steel there's really no need to make the mold out of tool steel. Pretty much any steel will do, as long as you consider the effects of warping; it just depends on the accuracy you require. Many of the best "steel" bullet molds are actually made of Mehanite because of it's stability. For hammer faces I really don't think it matters.

As for soot in the mold - it is more helpful for fillout. The idea of it being a release agent is common but really a misunderstanding of what it does. The soot is a thermal barrier to slow the cooling of the lead on contact with the mold surfaces, this allows better fill without wrinkles. If you want the best chance of a good clean cast the first time, preaheat a little bit and soot the mold.

Also, don't use a candle, match, or any material containing oil or wax for best results. Use a butane lighter or some other gas flame, a propane or acetylene torch both work well if you shut off the oxygen for a yellow flame.

[Yondering]

http://www.frets.com/HomeShopTech/Pr...eadmallet.html

Just a comment on the process here, related to soot. The picture under the caption "Got it this time:" is an example where the heat is about right, but soot in the mold should have given perfect fillout. The next picture below that is a result of having the mold way too hot.

Also remember to degrease the mold well after machining it; contaminants in the cavity are the primary causes of frustration with poor fill.

[RWO]

Aluminum works very well for lead casting. Bullet casters have used aluminum molds for many years. This site : https://leeprecision.com/bullet-casting/ has details. BTW you can get a double cavity blank mold with handles and sprue plate for less than $30.

RWO

[Dan Dubeau]

Thanks. I'll probably be using o1 for the simple reason I have lots of drops of suitable size. I figured Aluminum was used mostly from an easy to machine standpoint, but either would be fine. Good to know about the candle soot, thanks. Probably saved me some frustration. I can soot them up with acetylene, and preheat as well. A few degrees draft probably wouldn't hurt either.

[BobinOK]

The "Oops, not hot enough:" picture is exactly what my first try looked like when I didn't preheat the handle enough.

[Bob La Londe]

I make lead molds all the time out of 6061-T6. Steel might last longer, but realistically an aluminum mold will probably last a lifetime for most casual users if you don't destroy the hinges or handles by throwing it on the floor. Nobody even asks me about making lead casting molds out of steel. I do some steel work for high pressure stuff like press dies, but not for lead casting.

As to "sooting" the mold. Candle smoke is a common product for that. Some molds need it and others don't. A better application is a thin film of graphite spray. Drop-Out is made for the application, but I have found zero (0) difference in performance between Drop-Out and generic graphite lock lubricant you can buy in the spray can at your local box hardware store. Graphite does seem to work better than candle smoke in my opinion, but candle smoke is almost enshrined in some sort of ancient worship of alchemy with some casters. Others have an similar zealot's worship of the name brand graphite spray Drop-Out.

That being said I often find a light dusting of talcum powder does the trick for a problem mold.

In aluminum the lead does not wet out to it at any temperature I have cast with. Upto to over 800F degrees. Even after many castings when the aluminum starts to get quite hot. You do not need a mold release because of any bond in an aluminum mold as long as you have a little draft angle. Sprays and powders and voodoo magic are just about getting good fully filled castings. Even a couple square perpendicular faces are not a big deal if you can roll the casting out of the mold at a parallel angle with a handle of some kind. You just can't have all square faces. Even then you could design a push out mechanism to the mold if you wanted to.

Aluminum is fine.

This is less than 1% of the lead molds I've made. http://tacklemaker.info/index.php?ac...sa=view;pic=47 Just a few I made for myself. Most of course have long since been shipped off to customers. The two on the right came from Pamela at Hilts/Dolphin. She makes diecast aluminum molds in steel molds. I make custom machined molds out of aluminum and when required (like press dies) steel.

EVERY CUSTOM MOLD GETS TESTED BEFORE IT LEAVES MY SHOP. This means I have to try all the various things... like candle smoke, graphite, spray, talcum powder, or whatever so I know how hard or easy to mold is to pour. If I get a customer with a religious devotion to candle smoke and I know talcum powder will work better I may even include a small bag of the stuff with the mold.

One advantage to aluminum is that it transfers and sheds heat an order of magnitude faster than steel. Steel could heat up to near your working temperature and stay there to the point where if you were making a lot of castings you might actually start to see a slow down in freeze off times. If you are only making a few castings it might not matter, but I think if you were using it all day it could be an issue.

One advantage to steel is it does not grow as much with temperature. I think only around .001 per 100F degrees.

Don't go think steel and water is a good idea. BECAUSE molten lead and water is a very bad idea. A droplet of water falling into a lead pot will expand exponentially and may send lead splatter around the immediate area.

[Yondering]

http://tacklemaker.info/index.php?ac...sa=view;pic=47

Neat stuff, I enjoyed looking through those pictures.

[Bob La Londe]

Neat stuff, I enjoyed looking through those pictures.

Thank you. Unfortunately since I do mostly custom I can't show some of my best work. I have a policy of not showing a customers custom work without their permission.

[Dan Dubeau]

All done. Just waiting for my phone to upload to Imgur. I basically winged it off of some "important" dimensions from my Armstrong tips, but left it a bit deeper in case I wanted thicker faces. ~3* draft in the outer pipe, and ~3* in the opposite direction on the inner. 5/16"-18 threaded hole. The fit between the two is a nice tight slide fit with sharp corners left on It's all scrapbinium. The outer sleeve is some random thick wall pipe, and the bottom I'm pretty sure is 17-4 stainless. Initially thought it was O1 when I grabbed it, but as soon as I started turning it I was pretty sure it was 17-4. I love that stuff.

Don't know when I'll get a chance to try it out as I'm pretty busy this weekend, but I'll post up when I do. In theory the sleeve should pull straight up, allowing me to unscrew the bottom from the newly cast face. In theory.....

I was going to make a top piece too, but figure if the face turned out too gnarly I can use the bottom as an arbor to hold it so I ca turn the face flat for use. At the end of the day its a hammer face and I'm gonna whack stuff with it. See busted up green one for details.....

Bob, you were typing while I was turning and I read your post while waiting for the pictures to load. Great info, thanks. I appreciate all the advice from everybody.

Ok here are the pictures.

[Bob La Londe]

You can get lead alloy in different hardness also.

[Dan Dubeau]

Nice work Bob. Just checked out your link to your molds. I always wanted to make my own jig mold but kinda got out of fishing for a lot of years until recently (last 4-5). I might give it a shot. I do love making my own lures, spoons, and flies though. Been doing that since I was about 10 when I inherited my great grandfathers fly vise (homemade) and all the rest of his materials. Nothing more satisfying than fooling a fish into eating something you made.

Getting ready for the hard water season up here, and was making plans with a buddy today to head north after Christmas. Can't wait.

[Bob La Londe]

Go for it. Its a lot of work, a fun challenge sometimes, and I get paid for it. LOL. Jig molds. Soft plastics molds. Resin crank and topwater Molds. (You do have to use a mold release agent with resins)

And then there is the odd ball stuff people ask me about.

With your mold draft angle may not be as important as worse comes to worse you can press the casting out of the mold. Like you said, its a hammer face. A press rod mark won't hurt it any more than the first thing you hit with it.

[HWooldridge]

You can get lead alloy in different hardness also.

And the melt temps differ between alloys. I cast a lot of bullets and linotype melts at a substantially lower temp than pure lead. Depending on the mold, you can often get a good pace going and rip right along.