Casting alloys (7 Viewers)

[plasmapulse]

This might be for you oh Kilted one

I want to resume casting but I have two small men running/crawling around and my shop is alongside the kitchen area. Basically, I'd rather use a lead-free alloy. For health and my fear of leadrot.

Prices of metal are getting higher and higher (I have a model catalog with a price raise of about 33% on lead free pewter compared to last year) so I want to stock plenty of it but it has to be the right one that is suitable for dropcasting.

I read that lead free pewter doesn't cast as well as a alloy containing lead. (I thought it was the opposite) There are additives for it (bismuth I believe?) but I haven't used it before. I only used a commercial 80% lead - 20% tin mix.

Any advice is appreciated.

 

[Wolfgang]

I am facing thê same problem right now. Talking about health you should know that Wismuth/Bismuth (it's the same metal) is the least dangerous metal. In fact there are no "sideaffects" at all.
A good (propably the best) alloy for drop-casting ist a mix of 50% wismut and 50 % lead. It will cast at real low temperatures and the castings are excellent. Wismut has become enormously expensive over the last 3 years which makes this alloy almost unaffordable. The pricerange for one (1) kg is 49-65 € according to my research. The lead is the cheaper part here. Two ready mixed kg of this 50/50 alloy would cost me 99,-€. Given the average of 70 g of a casting (footsoldier) this will produce a mere 30 copies being worth 3,33 € in metal - now add all your other costs to that.
rgds
Wolfgang

 

[plasmapulse]

Yeah, with the current low dollar (I get all my troops from the US) it's almost better to buy them ready painted. For the best castings I would need a melting pot as I get a lot of miscasts probably due to low/high temperature. That's about 160 euros, which would require me to cast many troops to earn it back.

It's still a nice hobby though, homecasting. Thanks for the info.

 

[Gneisenau]

While not discouraging you from lead casting metals, I started casting when I was about 12. I've done this as a hobby almost non-stop. I had a lead level drawn during my annual physical last year and I was within 'normal' range. Since I'm 44 now and have not taken a whit of precaution for any of 30 years...I think I'm good. The problem with 'lead-rot' comes primarily from all-lead figures. Alloy figures (esp. those with antimony and bismuth) do not seem to suffer the same ailment. Solid casting (vs. hollow) also helps. I have figures I cast In The Beginning and recently I washed, primed, and painted a figure I cast over 25 years ago. It were just fine.
The price of metal has become an issue in the last couple years. I used to used "Model Metal" from Dunken Co. but the price has doubled in the last 3 or 4 years. That is the equivalent of Prince Augusts' best casting metal. It currently runs about 18 dollars/pound. However, on all but the absolutely smallest castings, I've taken to 'cutting' the mixture with linotype and also Dunken's Chess Metal. Linotype tends to require a high(er) melting point but mixed with some Model Metal and Chess, it's perfectly acceptable. It works esp. well in castings that I refer to as a "straight shot"...figures with no horizontal projections. I usually make a 3 pound mix, then pour small amounts on my concrete floor in the basement (or a piece of plywood) to make silver dollar sized "coins." I then add those at will to the pot later on. Any dross I've skimmed off, I pile in one corner of the casting table. With a clean ladle, I then remelt the dross. I can usually recoup at least 2 'coins' from this mixture before I'm left with dust in the ladle.

 

[trooper]

When melting down dross you will find it helps to shave some slivers from an ordinary candle into the mix, but do make sure you are in a well ventilated area as it causes a certain amount of smoke. It quickly seperates the metal from the waste which rises as a dust to the surface where it is easily scooped off. Make sure you retain the extruded dust in a sealed container as there is a degree of toxicity in it.

 

[kilted vampire]

Pewter, my friends. Also Del Prado figures! Some of them arrive at shops broken. Great source of metal. Holds and fills details. All the regular rules apply. One thing to remember, if you have been melting lead in your equipment when you change there will be traces of lead still in the metal.

Whom ever said that pewter does not work well does not know what they are talking about. Most of the figures that we buy are pewter/whitemetal. It works for me.

Try Rotometal in SF.

 

[theBaron]

I use 2 basic alloys, depending on the material of the mold.

For metal molds, I use linotype metal, which is a lead-tin-antimony alloy (roughly 80-16-4, percentage-wise). It seems to melt at a higher temperature than an alloy with a higher lead percentage, and since I do drop-casting, that means that it stays hotter longer and fills the cavities in my brass or zinc alloy molds.

For rubber molds (mostly, Prins August, some also from RLJ Casting, and Castings, Inc), I use an alloy heavier in lead, over 90%, with some tin added. This seems to melt at a slightly lower temperature, which I expect will help extend the life of the molds, and it does seem to fill the details in the rubber molds well.

If I had a centrifuge, I expect that I would have to make adjustments, because of the different conditions (eg, centripetal force forces metal into the details, so the temperature might not be as much of a factor).

I do use tire weights, and have had no problems with them. But I do go through a smelting and cleaning process, I do not melt the weights and pour into my molds.

I melt the tire weights and skim the dross as much as possible. Then I use an aluminum muffin top pan to make casting pigs. The resulting pigs are about the size of a silver dollar (old-school silver dollar, Walking Liberty, or Eisenhauer, not the lame new coins), and are easy for me to manage, when I fire up the pot.

I have also melted down pewter items and made those into pigs, which I use to sweeten the pot, whether using the linotype or lead alloys. That is an imprecise process; I go by eye, watching how the metal pours, flows and how quickly or slowly it cools in the mold.

I have never had any problems with lead rot, with my metals. I think the main trick is to make sure your metal is as clean as possible, which to me has meant smelting to remove dross, then using the metal.

And I have not observed any health problems, from working with lead. I wash my hands, and I work in a well-ventilated area.

Prost!
Brad

 

[bromhead]

I use 2 basic alloys, depending on the material of the mold.

For metal molds, I use linotype metal, which is a lead-tin-antimony alloy (roughly 80-16-4, percentage-wise). It seems to melt at a higher temperature than an alloy with a higher lead percentage, and since I do drop-casting, that means that it stays hotter longer and fills the cavities in my brass or zinc alloy molds.

For rubber molds (mostly, Prins August, some also from RLJ Casting, and Castings, Inc), I use an alloy heavier in lead, over 90%, with some tin added. This seems to melt at a slightly lower temperature, which I expect will help extend the life of the molds, and it does seem to fill the details in the rubber molds well.

If I had a centrifuge, I expect that I would have to make adjustments, because of the different conditions (eg, centripetal force forces metal into the details, so the temperature might not be as much of a factor).

I do use tire weights, and have had no problems with them. But I do go through a smelting and cleaning process, I do not melt the weights and pour into my molds.

I melt the tire weights and skim the dross as much as possible. Then I use an aluminum muffin top pan to make casting pigs. The resulting pigs are about the size of a silver dollar (old-school silver dollar, Walking Liberty, or Eisenhauer, not the lame new coins), and are easy for me to manage, when I fire up the pot.

I have also melted down pewter items and made those into pigs, which I use to sweeten the pot, whether using the linotype or lead alloys. That is an imprecise process; I go by eye, watching how the metal pours, flows and how quickly or slowly it cools in the mold.

I have never had any problems with lead rot, with my metals. I think the main trick is to make sure your metal is as clean as possible, which to me has meant smelting to remove dross, then using the metal.

And I have not observed any health problems, from working with lead. I wash my hands, and I work in a well-ventilated area.

Prost!
Brad

Agreed I did most all these things in my own home cast and business,,I used solid tin pure solder available in rolls at a local hardware place,,other blends and alloys,fortunate I had -have enough metal to use until flash gordon returns from mongo. I would have a metal check in yearly blood tests,,tho I now find myself having slower thoughts every so often,,cant be age or ex wives.

 

[blaster]

Hi All,

The mixture of lead tin alloy gives the lowest melting point at about 60:40. More lead or tin only increases the melting point. The addition of small amounts of antimony or bismuth causes some minor expansion of the allow as the metal cools to give better definition within the moulds.

Rgds Victor

 

[Captkronos]

Hello everyone, if not already mentioned, a great source I've found for an assortment of casting metals is RotoMetals. This is MUCH cheaper than resorting to solder wire. Check it out:

http://www.rotometals.com/Low-Melting-Alloys-s/21.htm

 

[blaster]

Hi,

thanks for this website. My understanding of tinlead alloy at approx 40:60 is is that it gives a single eutetic point. Some of the low-melt alloys here generally appear to rely on substituting bismuth for lead, leading to some wide variations in melting and strength:
http://www.frymetals.com/products/tinleadsolder.html

Another concern is the use of cadmium in some of these alloys. In our partly amateur hobby (especially in home casting), I would prefer to stick to the usual tinlead alloy until I know more.

Rgds Victor

 

[Captkronos]

I'm not sure what type of molds you use in your castings. I use RTV silicons, so melting point of the metals is a concern for me. Lead melts at over 600F, finding a good RTV silicon to handle that temp is tricky. I use Mold Max 60 from Smooth On which CAN handle lead, although it is only designed to handle metals up to about 575 or so. The Bismuth based stuff at rotometals has worked very well for me so far, and I often cut it with lead just to make it even cheaper. The Bismuth based ingots I believe have a melting point as low as 158-190, or you can go for one with a melting point around 212. Even when mixing with lead, I haven't seen any mold damage yet with the silicon I use. They even have one they characterize as "toy soldier metal". I gave it a shot at $12 a pound. I was buying solder at double that price.

 

[blaster]

Tinlead alloy melts at 183oC so its not a problem with using RTV. I take your point that bismuth can substitute for lead substantially to bring the cost down. I am just not that familiar with too much Bismuth in my toy soldiers.

Again, I stress that for home casting, one should avoid the alloy containing cadmium.

But thanks for this info. I share with you a similar lead substitution alloy product (Viromet) from this website.
http://www.asahisolder.com/Product_Range/Catalog Specs_V349_Bar.pdf

When I inquired about the price, it was about 5x the cost of the usual tinlead alloy.


Rgds Victor

 

[Captkronos]

Sorry, I don't know if I said that backwards or not, I use lead to cut my cost on Bismuth, which is much more expensive. I cut my pours with about half lead and half the casting alloy from that site. Works okay so far. Also, as an aside, the silicon muffin pans work great for pouring your leftover ingots, much easier to pop out than with metal pans.

 

[blaster]

I think that we all get our alloy from where we can get it cheapest, rgdless of the actual content.

Thinking about my own post, I won't be substituting my method for the time being with that Viromet product due to the very high cost and also I don't know its content, perhaps another metal and won't know whether its potentially toxic or not.

 

[Captkronos]

How right you are about that. Many times I've thrown whatever scraps I could find just to get a pour. When I first started it was fishing sinkers with a bit of pricey solder wire tossed in the pot.

 

[Igor]

I'm using different alloys for different parts.
For casting rifle i use an alloy of tin and lead
equally with the addition of 3% antimony and 1% bismuth.
For the body using an alloy of 30% tin, 3% antimony, lead the rest
For heavy items i use alloy 80% lead 7-10% antimony tin rest

Ready-made alloys are difficult to find. I buy different alloys containing tin-lead-antimony-bismuth and mix in different proportions

 

[Mitch]

fascinating thread and, very helpful as I want to cast some of my own figures lots of great info to help
Cheers
Mitch

 

[kilted vampire]

Try looking at rotometals.com. They have lots of great metals at fair prices. Personally I would use pewter. Though expensive it is safer,melts at a lower temperature, and fills details much better than any lead alloy.

 

[theBaron]

I was fortunate enough to meet a dealer at a flea market, who salvaged print shops. The ladies love the old drawers/trays from printer's cabinets, for displaying little knick-knacks, but along with those trays, he collected a lot of finished linotype (ie, cast type), and bars of the metal itself. He hooked me up with enough metal for me to cast for another 10 years without having to replenish.

Prost!
Brad