70's moto GP bike

Truckinduc wrote on 02/22/10 at 16:30:01:

Actually, yes I have, but it's been quite a while ago, back in school.  Out teacher said it was optional, since it's a hazardous substance, but it's good to know, and not many teach it anymore.  Plus the "lead" sticks they sell these days are pretty much lead free I believe, mostly tin and something I can't remember.  Anyway, The Eastwood Company has a lot of supplies for this stuff, I used to get their magazines all the time:
http://search.eastwood.com/search?w=lead&p=Q&ts=custom

The gist of it is: you have to prepare the surface, you can use a flux made for it, but our teacher just had us use acid-core solder, it'll stick to the metal (clean metal!) also.  Heat the surface until the solder will melt and stick to it, then smear it over the surface with steel wool until you've got your area covered.  Then heat your stick of lead until it's soft enough to smear some dabs onto your area, keeping the area warm enough for the lead to stick.  Careful not to overheat it, it'll run off, and potentially ruin your shoes, not to mention the feet inside them!  Then you'll need something to shape the lead; a wooden paddle coated with either parafin or beeswax will work, beeswax is best since it doesn't smoke, and smells good!  Just melt a little puddle of wax with your torch, and smear the paddle around in it.  This keeps the lead from sticking to the paddle.  Use the paddle to shape the lead to your liking, then let it cool off.  Use a body file (http://www.eastwood.com/file-holder-flexible-with-mill-cut-body-file.html) to fine tune it, and wet sand to finish.  A power grinder or sander is not recommended, since it throws lead dust into the air, not good!
I'm sure I've left stuff out, I haven't done it in over 15 years, but that's the basics.  It's actually pretty easy, and has the advantage of durability, and the shrinkage/expansion rate more closely matches that of the metal underneath.  Our teacher recommended it over plastic for things like door pillars, and anything with a sharp corner likely to get chipped out if using plastic filler.

My $.02!

Truckinduc wrote on 02/22/10 at 18:49:06:

You're welcome.  Hey, I actually gave advice!  Hope it works...

If the solder doesn't work for some reason, try the commercial stuff, although the solder should work.  We alternately used some kinda acid flux, and applied the lead stick directly to the metal after wiping the substrate with the flux.  Not sure exactly what it was, I think some kind of mild acid.  Looked like water and had a slightly sour odor to it.

If you have to weld the tank later, as long as it's not near enough the lead to heat it up much, it shouldn't hurt it.  If I remember right, there's some kinda clay-like substance you can put in a line around areas you're welding on thin sheet metal, that acts like a kind of heat sink, to keep the heat from spreading to surrounding areas quite as much.  A welding supply shop should know more about it.

Edit: Well whadayaknow?  Eastwood has it too! http://www.eastwood.com/coldshield-thermal-paste.html

Made a threaded female adapter at school.  Not as easy as it looks, internal threads can be a pregnant dog.



shaped the tank how I wanted it, and tacked it in.



I oversized the threads slightly to account for the shrinkage due to welding. It slill was a little tight afterward, but a little tap magic and its all good.

not that you havent seen this view before

prsavage wrote on 02/11/10 at 10:03:47:

I agree- boxing it in hides your skills- which are worth showing.
This is how choppers are built- by hand in your shop, not by writing a 30K check to some guys with a bunch of sponsers. Fine work!

rear tank mount done

steering damper is all mounted up. Gonna cut out a gusset for it tomorrow.