Technical What to do - Thick Bondo

Flap wheel is a bit harsh and can put a lot of unwanted heat into a panel.

Best thing I've used so far for that and panel rust removal has been fiber abrasive discs:

Phil

 

Remove all of the old filler, the door may have already been patched before, and if the 1st patch seam is an inch higher then where you need to weld now, you would be pretty mad to discover you could have fixed the whole mess with your patch.

You can metal work the door skin pretty good at some places, but other places, you really can't get to the back side very well. You get it as close as you can stand to deal with it, file it pretty flat so it looks pretty good, then start spreading that skim coat.

I don't claim to be a body man, but I have done a lot of it. My problem with body work is I can only stand to do it for a short time. Its probably just my dumb ***, but once you start spreading filler and then sand, than add a little more filler and sand again, on an area as large as a door, its pretty hard to know how thick the filler really is. You can guess, but you really don't know unless you break through the filler and encounter metal. You can tell if you are really getting the filler thick, but for the most part, your not really sure.

When the paint goes on, smooth is the goal. How much filler is really there probably isn't as important as how smooth the panel is. Gene

 

I'm going to have to agree with remove all of the filler and then work the panel as close as you feel you can get it before you weld the replacement piece on. With the bottom of the door removed it is real easy to sit there on a comfy stool and work the metal with a hammer and dolly. Work it down to that "thin skim coat surface and then weld the piece on remembering from all of those welding sheet metal threads on here to just do short tacks and space them so the metal doesn't get too hot and don't carried away trying to run long beads.

As far as the thick plastic filler, that was standard used car stuff for years and may still be. Run it in the body shop, beat the big dents out so they are little dents and then lay on the pookie and use the cheese grater and air board to slick it off and shoot it and get it on the lot. Not a big deal and not the end of the world.

 

Me too, all the filler and paint comes off first. Then replace metal.

On removing that stuff: I'm working on my 56 Dodge pickup and finding unexpected rust, old body work and lots of paint layers. The fiber stripping disk work better than flap wheels or sanding disks on areas without lots of paint layers. I've settled on a multi-tiered approach. On areas with lots of paint, looks to be mostly old enamel, hit it with a heat gun then s****e with a razor blade. Works pretty well on larger areas. And, what really surprised me is the easy of getting the filler off. A little heat, OK a lot of heat, and a putty knife. Right down to the metal with no dust on me,the floor or in the air.

I follow the razor blade with 80 grit paper on a buffer, not grinder/sander. Less heat to clog the grit. Then the fiber disks in several sizes and shapes to get all the inside curves etc. The doors and jambs are particularly hard.

The real point of the ramble is heat and putty knife is the best way I've found to get the filler off with the least mess.

 

I dont find it generates much heat cutting the bondo. Thats why i said when you see metal back off. I guess to be clearer. When you see metal stop...it will cut through bondo in seconds. Ive never seen anything do better bit a lot of caution is definitely needed as well as a steady hand

 

Way way Back in the Day I new a Guy that had a 50 Ford 2 door coupe
that he wanted a Kustom car....................I guess you know where this Going.??
Well he put so much on this car (bondo) that it was called the Bondo Car!
When I had seen him I asked how the Car was & he told me he had
A little Problem with the Car! & I asked what was wrong with it
He said The car would not Run So I asked to pop Hood he Said No not
That it Runs BUT IT Wont MOVE .
From All the Weight from the Bondo it Wood Not Move, he had Fins that were
about 1 & 1/2 Ft. tall of the back & extended the Fenders Front & Rear.
I never Found out What happen to the Car Because I had to go in the
Service, I got my Draft Notice & went away.

Just My 3.5 cents

Live Learn & Die a Fool

 

I'm glad this car is getting fixed.
Some full on Bondo sculpture.

 

Grind the bondo back about 3 in above where you want to weld, put wet towel on the remaining bondo to keep it cool and weld it up and bondo it up and go.

 

Yup, heat gun and putty knife...and a comfortable working position..

 

I sent you a PM about some 41 coupe doors i have for sale

 

Helen never came back. She forgot her p***word.

 

If you guys watch "cold war motors", a while back they did a segment where they "repaired" a rusty door with bondo. Absolutely hilarious.

 

So far I have been lucky. Body was set on a new frame. I did some repair already under the gas cap area, but other than that she is pretty solid.

 

No, I am back. I just was on a work trip out of the country and was a little busy haha.

 

I wish I would have done that on the first door. I learned my lesson though, the other side will be coming apart in 2 different sections, so I have a better reference.

 

That's the rule of thumb I had heard too, but it just seems like SOOO much bondo.

 

I did this the other night. So far all the spots I have checked have just a thin ski layer of bondo. Even the other door only had a skim coat, I think I just picked the wrong door to start with haha!

 

This is the plan here in the near future. Just knock it all off and see what I am working with!

 

This is what I am afraid of. My skills in this arena are raw and I know it's going to take me awhile to do it. I just want to do the car justice and finish it well.

 

I feel your pain!

 

HAHA! Yes, it's my fault and my fault alone. Thanks for the tips though, the fishtail really made easy work of this.

 

This is exactly what I did, and it worked wonders.

 

Thanks for this, it was really helpful!

 

not sure were you got panels from , you may want to try these

 

Co**** wire brush on a angle grinder . Wear a mask ! Or heat and a s****er

 

Those are my choice as well. They remove a lot of material quickly, don't put an excessive amount of heat in the panel, and leave a decent tooth in the metal for new filler to bite into. I've gone over even blasted cars with these just to prep the metal

 

I had the same with my truck, being an old farm truck all its life , the roof and hood were trashed as the farmer used to climb onto the hood then the roof to sheet over the grain in the tall dump bed
The truck looked nice when i got it but i noticed the roof was dented on the underside so banged out the dent the bondo was 1" thick and some of the layers were still soft due to not having enough hardner mixed in
I had to start over knocking out all the dents and shrinking the metal back before applying just a thin skim

 

These are the exact ones that I bought! So far, I really like them.

 

If those doors are any indication of what the rest of the car is like, the doors are the least of your problems. I'd pull them off & find replacements... go after the rest of the body in the mean time.