COWW composition, straight from the horses mouth

[PuppetZ]

Hi castboolits. I work for a car dealer up north and was researching something about one of our suppliers today. A guy told me they no longer sold lead WW so I went to reasearch it and ended up on the website of a Quebec based wheel balancing weight manufacturer, Plombco. Of special interest to me was the fact that they had a MSDS sheet for their product. Usually these include what the composition of the product is. Here is the link for their lead WW : http://www.plombco.com/files/media/MSDS%20Lead%20Wheel%20Balancing%20Weights%20.pdf

You will probably remark that they list iron as a major componenent of the WW's. Come to think of it, the clip is actually made of iron and is a component of the product they make, hence why it's between 2 and 20% by mass of the actual finished product. I dont know if these are based of tests they run but I'd guess that these are some average numbers. The lead alloy components should therefore be : Pb +- 95%, Sb +-4%, As +-0.30% (I know, that doesn't add up to 100%...). So here it is, this is what this particular manufacturer claim their COWW are made of.

YMMV.

Frank

[Larry Gibson]

That's with new COWWs and is pretty indicative of most. However the reclaimed/remanufactured COWWs probably have a bit less antimony and tin due to oxidation in the remanufacture process or so i was told by a company rep many years ago. That's why I recommend the addition of 2% tin to COWWs. The tin combines with the antimony and makes it go better in solution with the lead. The sum of the total is a much better alloy. The price of tin does seem high but it only takes 1 lb of tin to make 50 lbs of COWW alloy a much better alloy. It is in the same BHN range as Lyman #2 alloy but is more malleable. I prefer COWWs + 2% tin to Lyman's #2 alloy.

Larry Gibson

[pennysride]

When recovering the lead from wheel weights do you you flux it?, and with what? I've got a guy that is bringing me about 50 lbs of weights to mix with some nearly pure lead I already have. Where do you get your tin? Sorry, 61 years old and don't know stuff.

[dbosman]

Definately! Flux. Wheel weights are usually dirty.

You can add tin by using a tin alloy from RotoMetals (a sponsor, at the top of the page) by adding pewter, or bar solder.

There are alloy calculators here
http://castboolits.gunloads.com/showthread.php?105952-Lead-alloy-calculators&highlight=alloy+calculator

[PuppetZ]

That's with new COWWs and is pretty indicative of most. However the reclaimed/remanufactured COWWs probably have a bit less antimony and tin due to oxidation in the remanufacture process or so i was told by a company rep many years ago.

Well of course your mileage will vary. That's good for this manufacturer product only but I'm guessing they'll all come close to that. You'll remark that Tin is not listed as a component of the alloy, so there is little to none. I found it interesting to see the specs from a manufacturer datasheet and passed it along. Since what I use in my alloy is 95% from this particular manufacturer, it's a good starting point for my chemistry I guess.

[PuppetZ]

When recovering the lead from wheel weights do you you flux it?, and with what? I've got a guy that is bringing me about 50 lbs of weights to mix with some nearly pure lead I already have. Where do you get your tin? Sorry, 61 years old and don't know stuff.

Flux with DRY sawdust. You mix it good with the lead and skim the trash that floats to the top. I'd suggest giving a torough read to this book. It thaught me a lot on the craft. http://www.lasc.us/Fryxell_Book_textonly2.pdf

[Defcon-One]

Pennysride:

Don't forget to sort them and weed out any Zinc ones. Usually marked Zn and much harder. I flux with pine sawdust. Smells nice and works even better.

OP:

I do not think that US wheel weights have any more than 3% Antimony, maybe less! And they do have .25% Tin.

[Larry Gibson]

Sort out the zinc and SOWWs as mentioned. I smelt with a dutch ove on a single propane burner. I flux with beeswax (other waxes work also such as parifin contrary to some) or a commercial flux. I throw a wooden match or two onto the melted wax, the matches light greatly reducing the smoke and the burning wood helps flux also. I stir with a large serving spoon until the alloy is fluxed and just dirt and the clip ons are floating on the surface. I scrape/scoop the dirt and clip ons off, then flux the alloy again to remove a lot mor dirt and debri. I then pour into ingot moulds. I don't add the tin until I can weight the ingots to determine what the 2% for them is. I sometimes remelt the ingots and add the tin but most often just add 2% tin as the ingots are put in the Lyman Mag20 furnace.

I got by last tin from Bill Ferguson out of the Phoenix, AZ area. The Antimonyman is also a good source for pure tin as is rotoMetals. I don't hesitate to pick up bars of 50/50 ot 60/40 solder at garage sales also. Haven't used Pewter yet.

Larry Gibson

[Larry Gibson]

Well of course your mileage will vary. That's good for this manufacturer product only but I'm guessing they'll all come close to that. You'll remark that Tin is not listed as a component of the alloy, so there is little to none. I found it interesting to see the specs from a manufacturer datasheet and passed it along. Since what I use in my alloy is 95% from this particular manufacturer, it's a good starting point for my chemistry I guess.

Good thread. The %s are close to what we have down south just that remanufactured WWs dilute the % of antimony and tin. I usually figure about 3 - 3.5% antimony and less than .25% tin which is why I always recommend adding 2% tin. Again, good info.

Larry Gibson

[destrux]

Interesting that their stick-ons have the same composition as the clip-ons (minus the steel clip).