So I replaced the fender to my 59 Tbird, The original seams were leaded in as this is a full uni-body construction, also I do not have a spot welder so I welded it in at the seams, plus there is some drilled out spot welds along the attachment of the inner fender that did not quite fill in all the way. Otherwise it is straight and square.

My question is I do not know how to use lead as a filler, and I have read very conflicting messages about metal filler like All Metal etc. some reads say this is the way to go others I have read is stay away from it! What is your thoughts, and if there is an alternative option that is equally as good for these seams please let me know, it is about 18 guage steel so that is the "step/seam". Also what is best to fill the old spot weld holes that are not completely filled? I was thinking something like 3m panel bond for the spot weld holes. I have to do a little smoothing regardless along this line due to the person that drilled out the replacement fender. All of this of course is going over epoxy primer.

And to clarify I will be using filler for some dings and dents, I am considering 3M Platinum plus or Rage Gold which will also be going over these seams if needed. I just don't know if or when metal filler is necessary and if the fillers out there other than skim coat style fillers are up to the task of something this deep without cracking or lifting.

I use the 3M platinum (not the plus) and have been happy with it.
Obviously we try to keep filler use to a minimum however today's fillers can easily handle what you have listed.

Thanks RT! Makes it easier. Hopefully the epoxy primer will create a little build as well.

Stay away from Fillers such as Allmetal, Metal2Metal, Labmetal.
They are Very Rigid and don't flex with the Panel casing cracking and lifting issues.
Dont get me wrong I have used lots of the stuff just not as a Body filler they Have a Purpose, Being a Body filler just isnt one of them.

I recently Picked up a Leading kit from Eastwood and a suggested video by Chevman.
"The Art & Scince of autobody soldering"
I haven't played with any of it yet but look forward to it. How hard could it be? LOL!

Is this a quarter panel on a 59 T-Bird you're replacing?
Auto mfgs used lead in 1959 because that's all they had.
Modern fillers work very well in most cases and are safer to use
than lead. If the seam you're filling is below the tailfin, something
like a short-strand fiberglass filler (Kittyhair) might work.
Lead is still better on sail panels, but it's hazardous and very
hard to work with.

I thought about the "kitty hair" filler, this is at the nose and down by the front door corner at the rocker, that part needs a little more filler had a hard time mating it. and there is a slight indentation, by using a straight edge its about 3/16" at the seam and less than an 1/8" outside of the seam. Considering there was close to an inch of filler in various areas of the previous fender I am pleased with the outcome, especially the fact that I am far more of a "bolt off/bolt on" type of person. Not sure if I would have bought this car had I known it was completely uni-body structure LOL. The rest has been a few smaller rust spots etc that was far easier to fill. I have some grinding of welds (yes the welding has been quite a learning curve as well) some odds and ends of body prep and will be putting on a couple of coats of epoxy to start the filler and smoothing of the body.

BTW I would like to stay with the same filler, is there such a thing as adding the kitty hair to filler or just pre mixed type?
Thanks for the replies!!

there is Long strand Fiberglass fillers and Short strand. I don't care for the long Hair stuff.
Messy hard to work with. I do like the short strand stuff from Evercoat though.
The Long hair stuff is for filling up huge holes or something that needs a lot of strength from the long fibers.

I like the Short stuff its very strong you can thin it down with Honey like regular plastic filler but its totally Water proof and its fairly easy to sand, working time is very short!!!!! you dont have much time to get it on a panel once activator is mixed in it.

The stuff I like
https://www.nationaltoolwarehouse.com/E ... 8GEALw_wcB

Duraglass and 3m Make similar products

Doright wrote:Stay away from Fillers such as Allmetal, Metal2Metal, Labmetal.
They are Very Rigid and don't flex with the Panel casing cracking and lifting issues.
Dont get me wrong I have used lots of the stuff just not as a Body filler they Have a Purpose, Being a Body filler just isnt one of them. ...

What about filling the area around the lead seam? My metal guy hung my quarters just like the factory would have, complete. The seam needs some filler, it's not filled completely with the lead. A local shop friend suggested using AllMetal in this area. Thoughts?

i've done several early birds what i did was to use a product call Fiber-all it like the kitty hair. i leave it down enough to apply a good skim coat over it to finish the seam out. I've never had a problem and some of the birds are 20+ years old. on most of the birds i would remove ALL the lead and do it this way. i just couldn't chance the fact that the lead would cause a defect and haveing to redo a body.
Jay D.