Finally got some work in on the Ranchero rear quarters. The ones that were as rotten as surstromming when I got it, and which I fixed like an asshole. Time to fix my fix - with The UnBondo!
Body solder or colloquially “lead” is any kind of metal used to fill holes, seams, surface imperfections, etc. etc. The main advantages over Bondo are strength, ability to seal a joint, hardness, reworkability, and adhesion (to a point). The downsides would include being much harder to apply, dangerous, potentially a lot heavier, time consuming, and finicky. Also, hard to master and archaic.
If that sounds like “something Ramblinrover will therefore be all over” YOU’RE FUCKING RIGHT IT IS.
I did a little a while back, but I had a lot of it to do. A lot.
Anyway, the start of the process is “tinning”, which is seen above. Tinning is the process by which the metal will be made to stick, and it’s arguably the most critical step. You have to clean the surface to shiny metal around where you’re working a good ways back from the work area, clean it to remove residue, and then daub on “tinning compound” with a brush while heating it with a torch.
Those of you who’ve done some plumbing solder may be familiar with acid brushes. Well, normal acid brushes, to apply acid flux to the surface and etch it, aren’t so great because mere fluxing of the surface isn’t good enough for the solder to stick like it should, and the solder is easier to work with if it’s on top of a layer of tin already on the surface. Enter tinning compound, which is acid, ammonium salts, and metal, which is applied at a hot enough temp for the metal particles to melt. That’s hot enough to burn up a lot of acid brushes. If you are a super-pro, like Gene Winfield, you can lay the compound on with a copper brillopad. I tried that, and it’s nice, but better for big flat areas than seams and requires some skill.
Anyway, post tinning, you have to wash it all down with baking soda, or burned flux and acid stay in cavities and can make for rot under the solder. Yech. Then, a little scuff with brillo if needed, and laying down solder. See first pic: it’s easiest if you suck like me and are working vertical to daub on and reheat to shape later. Shaping is done with maple paddles soaked in a special grease... or potentially just lard. Speaking of shaping:
I am aware this looks like ass. However, the important things have been done. The quarter to rocker seam is filled in, a low spot is filled, and I have struck the top seam (like striking brickwork) with one of the maple paddles which I notched for that purpose. There is now solder in the nooks and crannies of that contour line, and it’s built up some. When I take a reciprocating sander to the panel, I’ll be able to shape what’s there into more of what it should be. Furthermore, with the metal there, it will flex less and is sealed from the inner fender, so a thin skim coat of other filler will work right.
Here’s the other side. It looks better than the left, obviously. The panel below the line, though, looked like *crystallized* ass before Thursday, because it was handmade, got sprung in the process of installation, and was work hardened, as well as being “galvanneal” material, meaning a thin coat of zinc interfering with everything. I R Dum.
That tin is covering several holes and ripples and cauliflower-looking abominous fuckery that I got mostly straight but was the result of several angles of attack to remove a big oilcan... Anyway, it sucked. It’s right now, will file flat, and should be in the clear.
The only thing I didn’t wrap up for now was some work on the tailgate. It’s beyond an embarrassment, because the previous owner filled over serious rot and fixed it like a champ, and I had to rebuild it. It is rebuilt now, but all fucky. Another time...
Hey, did you know you can actually work metal that’s been soldered a little bit and it won’t crack off like Bondo? It’s true.