Question on making a mold for pouring lead into

[schemer]

I want to make a mold for pouring lead into but now that I have looked at buying lead, I realize I need to ask a few questions as all lead is not created equal. If I want to be able to bend the lead easily but also to hold onto what I bend it around, is soft virgin type lead the best? Or do I need some tin involved. It seems that all the people selling melted down wheel weights have the hard type mixtures. I am wanting to make wheel weights for motorcycles. They typically have a slot and slide down over the spoke and are tapped onto the spoke nipple. Tape on weights are usually too wide to fit properly although they work ok on the rear wheels as they are wider, but if you need a substantial amount of weight it looks goofy as they usually come in 1/4 or 1/2 ounce sizes. They off road type, or dual sport bike sometimes have a rim lock that adds 3-5 oz and takes a bit of weight to balance. I also may need some pointers on making the mold. ;D
Thanks in advance,
Dave

 

[Zigeuner]

Pure lead is very difficult to find. Most of it is alloyed with antimony to harden it. Unless you get it direct from a metal supplier, it's likely to be an alloy.

My new 2011 Harley-Davidson Dyna Street Bob has flat wheel weights that are held on with double-sided tape. I guess it must work.

 

[schemer]

Zig,
Thanks for the reply. I realize the stick on weights work, but if the rim is not wide enough where you stick them, which is the case on many front wheels on dual sport bikes, the fitment is ugly and unprofessional. Of course if I make my own even with 2 sided sticky tape I can modify thickness and shape and solve that problem. the My plan is to make the spoke type weights that I used to buy, and save some money as they can add up when using a lot of weight in the case of balancing a wheel with an internal rim lock. I found and purchased some soft lead that can be scratched with a finger nail and will go from there. I figure I can more easily add stuff to make it a harder mix, then take it away to make it a softer mix.
Dave

 

[Zigeuner]

author=schemer link=topic=2161.msg13976#msg13976 date=1305298775
Zig,
Thanks for the reply. I realize the stick on weights work, but if the rim is not wide enough where you stick them, which is the case on many front wheels on dual sport bikes, the fitment is ugly and unprofessional. Of course if I make my own even with 2 sided sticky tape I can modify thickness and shape and solve that problem. the My plan is to make the spoke type weights that I used to buy, and save some money as they can add up when using a lot of weight in the case of balancing a wheel with an internal rim lock. I found and purchased some soft lead that can be scratched with a finger nail and will go from there. I figure I can more easily add stuff to make it a harder mix, then take it away to make it a softer mix.
Dave

I'd be concerned that it wont stay on if it's too soft. There's not much room on the Harley wheel but they got the weights on there. The Harley dealer sells them. Hopefully you won't need too much weight.

Here's a picture.

 

[schemer]

Here is a pic of what I want to make a mold to pour lead into, and make my own various sized weights for motorcycle spokes. I work on tires and wheels so it is not just for my own personal use. These can add up if I buy them and pay shipping and then the customer needs 3 or 4 ounces of weight. It cuts into my profit on a tire/tube change and balance if I eat the $$ for the weight, and they give me dirty looks when I tell them those weights are not cheap and try to charge extra. ;D These look better and take up less space in a sense too.

Thanks,
Dave

 

[Highpower]

LEE PRECISION makes blank bullet mold blocks that you could drill/machine to your specs.
They are aluminum blocks that will machine easily but you will also have to deal with how you want to handle the center hole, and splitting the side of your weights if you want to be able to crimp them over your spokes. You will also need a pair of handles for the mold as well - also sold by LEE.

Or you might want to look at some fishing sinker molds that you might possibly adapt for your purpose.

Mixing wheel weight alloy with some 50/50 bar solder would probably give you something usable as an alloy for your wheel weights. Not too hard - not too soft.
Just my 2¢

 

[schemer]

That is an idea worth looking into. If I can machine the part that makes the slot would be ideal as I don't want to rework each one after I eject it from the mold. I will think on it and may look further into it.
Thanks,
Dave

 

[schemer]

krv3000,
I already thought of that but figured it is easier to add tin and/or antimony to it, to make it harder, then to try to remove it if it is too hard. I may be wrong about that but once I get going I am sure to find out. ;D I did read about fluxing etc and also to be careful not to remove the tin that floats on top (its a different color) when skimming. I guess you stir it back in. But I have to start somewhere and I think I will be able to have a formula that works if I have a plan and mix it myself.
Thanks,
Dave

 

[schemer]

author=desmocrat link=topic=2161.msg15738#msg15738 date=1307065363
Try Smooth-On (rubber mold supply), and look for the rubber that can withstand lead/tin/pewter. The alternative that I am intrigued by is the shot that you put into the tire and it self-balances the wheel. Do a search for Dynabeads on the www. Yes, the stick on weights have to be removed or taped over with duct tape before use on the track...PITA.

I looked at the Smooth-On site but didn't find the rubber that could withstand pouring lead into. The Dynabeads look interesting but I deal with more dirt bike stuff and with rim locks the lead weights would be cheaper to use. Interesting stuff though,
Thanks,
schemer

 

[pdentrem]

Have you tried Rio Grande?

http://www.riogrande.com/

It is more for the jewelery trade but the supplies are the same. Also you can used glass bead reinforced autobody filler. I used it to make a mold of a lead soldier and cast hundreds if not thousands of soldiers from the one mold. Just do not let it get hot. You could use more than one mold and thus rotate the molds to keep them cool.

Also you should get a copy of a phase diagram of the alloy that you intend to use. It would be a great help to understand the soild to transition zone to liquid zone. The phase diagram will show tempuratures vs alloy precentage. A small change in Tin or Antimony in a Lead alloy makes for changes in temp and flow characteristics. Here is a link that will help explain about phase diagrams.

http://www.chemguide.co.uk/physical/phaseeqia/snpb.html

Another area that can help you is the hunting and shooting books. Lead shot and bullets have been around for a long time. Lyman produced books on casting and hardness of alloys. May help to answer questions and give you more ideas as well.

I could go on but without pointed questions, I would just be rambling. http://www.hi-rel.com/