OP
OK, I had to get diverlink.com's ip address from someone else. Got the page.
V-weight
- Thread starter jonnythan
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FredT
Guest
Lead does not melt clean unles it is new virgin lead. Radiation medical isotope shipping shielding is about the only way to get this in scrap form. Almost all other scrap lead has impurities and dirt on or in it, and wheel weights have a fair amount of iron in the clips as well. Iron floats on lead and can be removed with a magnet. The rest of the debris is gathered together by the flux for easy removal as a cake skimmed off the surface of the melt. It also helps to put the lighter alloying elements back into solution.
The basic alloy components besides lead, and their result.
Tin: This lowers melt point and decreases surface tension for a better mold fill. A target of .5% to 1.5% in the mix is good for maximizing the surface tension effects, beyond that you are simply spending money for tin, and lightening the alloy. Tends to float on the lead if not fluxed in.
Antimony: Hardens the lead, and makes it so it will take some heat treatment. Common in wheel weights, monotype and linotype, and hard lead shot.
Arsenic: INCREASES surface tension. Used to make shot round, nasty to breathe in vapor form. Will be found in all lshot products to one degree or another. NOT added to an alloy mix on purpose.
Cadmium and a few others are added to battery lead plates to make the batteries more durable. It helps support the lead sulphate generated as the battery discharges. Avoid melting things like that.
NEVER add zinc to lead alloy you intend to cast! What it does is turn the molten mix into a cottage cheese consistancy unless it is severely overheated.
OP
I was going to melt down a couple of old scuba weights. Will I still have this problem?
I have poured a lot of weights in various form and have never used flux... and some of the lead pieces I've thrown into the pot were covered with crud like grease and adhesive... plus the little steel clips from wheel weights.
I just skim the floating crud off before pouring.
That said... I think I will try Fred's suggestion to chuck some beeswax in next time.
OP
How do you skim the crud? And where do I get a little beeswax?
I use my crud scraper. I suppose you could use a spoon. As for beeswax... I dunno... I was always told to mind my own beeswax but since I couldn't find mine I couldn't mind mine.
Maybe Fred will help us out.
FredT
Guest
My most common flux is bacon grease, and I make sure it lights as quickly as possible. Once the fire goes out the cake is ready to remove, and most lead oxide will be reduced to metal.
Beeswax is a craft supply and is often available at art stores that sell candle making supplies, and commercial fluxes are available at Midway and other online shooting supplys.
I use a stainless steel deep frying dipper as a skimmer. The removed debris is cast into a concrete disposable buoy weight to increase it's density.
FT
kalvyn
Guest
OP
So the backplate came in today, and after a bit of playing with the harness and ogling over how well it fits, I went down to Home Depot and picked up some plumber's putty, and a couple of 5x7 aluminum sheets. Wal Mart sells little blocks of beeswax in crafts - it's used to moisten thread to prevent tangling.
So I cut the aluminum into 2" strips and put them through the cam band slots. I created dams over the strips and a dam at each end of the plate.
Pictures of this, and the pot with the weights, are at http://jonnythan.com/scuba/
FredT, you said that I should be sure the plate is perfectly clean or else the lead might blow up in my face. There's some putty residue near the putty that I haven't been able to get up. Will this cause a problem?
I'll put some masking tape over the holes, then I'll be good to go.
UP, I got the idea for the aluminum strips and putty dam from the picture I saw of your channel weight. Do you just pour the lead directly into the middle, and let the ends fill up? How do you pour?
You guys are extremely helpful... I've never done anything like this before. Thanks
So I cut the aluminum into 2" strips and put them through the cam band slots. I created dams over the strips and a dam at each end of the plate.
Pictures of this, and the pot with the weights, are at http://jonnythan.com/scuba/
FredT, you said that I should be sure the plate is perfectly clean or else the lead might blow up in my face. There's some putty residue near the putty that I haven't been able to get up. Will this cause a problem?
I'll put some masking tape over the holes, then I'll be good to go.
UP, I got the idea for the aluminum strips and putty dam from the picture I saw of your channel weight. Do you just pour the lead directly into the middle, and let the ends fill up? How do you pour?
You guys are extremely helpful... I've never done anything like this before. Thanks
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