55 chevy pickup cracked body filler

[wilberweb]

Hi, guys hope this is the right forum for this question.
I have my 55 Chevy 3100 Ive been working on. I was just able to get back to work on my project. My question is I have some cracks on the top of my cab where I patched the roof panel. It was caused by me trying to bend the inside roof side trim lip where the rubber trim goes on the roof of the cab.I had all of the top of the cab finished. filler installed where it was a perfect match to the other side. and I went and messed with the trim on the ceiling trying to bend it out a little with a pry-bar, and that's when I noticed some cracks. What is the best way to fix cracks in filler after its blocked and smooth with a perfect profile. I have some pictures of the cab part I'm talking about.

Thanks
-Larry

[mygirlz55]

I am in no way an expert in bodywork. With that being said, I would take out the cracked filler and start over if the cracks are larger. I don't believe you will get the filler to bond well in the cracks and it may just crack again. I think the glazing putty is just for hairline scratches in the filler.
Hope this helps.
I 'm in the process of taking filler off my rear fenders that the previous owner thought he needed to emphasize the body lines of the truck

[OrrieG]

No good way to "fix" the cracks, R&R it. Even with glazing putty the cracks will eventually telegraph and open up affecting the paint.

[mr48chev]

Originally Posted by OrrieG

No good way to "fix" the cracks, R&R it. Even with glazing putty the cracks will eventually telegraph and open up affecting the paint.

Yep, take it all off and start over. That looks pretty thick and will probably continue to give problems later.

I've got some like that on the corners of my old cab that I chopped in the early 80's that has gotten moisture under it and cracked. I didn't have the patience to do it right then as I was in a big hurry to get it done.

[wilberweb]

Hi, guys thanks for the post.
I have started to remove all the filler and start over. I was thinking I should but wasn't entirely sure, but my gut told me I should take it all off. what I did find is that I used glazing compound to level out the low spots then filler over the glazing compound, and I think that's why it started to crack. I noticed that the glazing compound didn't set up, and was still soft. So apparently you cant put filler over glazing compound.
So luckily I caught it in time before I went further. I think if I would have left it I would have major problems when the paint went on.

Thanks for all the advice.
I can always turn to this forum for some great advice.

-Larry

[Chevette]

You may never stop the problem. Those roofs flex way too much. Even heat/cold cycles will flex them enough to crack many fillers. You may have better luck with "kitty hair" or the likes, but if your roof is in bad shape I would suggest getting a new skin. If you need proof, just push your finger down near the middle of the roof and you'll see just how easily they flex. Just sayin'.

[wilberweb]

Chevette,
I know they do flex a lot. When I installed the patch panel I got the panel to tight and it oil canned on me so I had to re-cut the panel, and stitch weld a little slower. Then I had to pound the underside with a claw hammer to get the metal to stretch back out. I sure wouldn't want it to crack. I'm sure some guys filled the cab section without replacing all of the top cab section.I wouldn't want to take the whole thing apart at this stage of the process.

-Larry

[mr48chev]

Can you shrink the metal enough so that you don't need but a light skim coat of filler? A few hours with a hammer and dolly and a little homework on shrinking metal might get it to where you can get with a lot thinner coat of mud on it. That was my problem on my cab where it has cracked through the filler. It was just too thick because I didn't take time to work the metal like I should have.

[dubie]

If you we're to use a fiberglass based body filler it would give that area some added strength,then you can follow up with some polyester based filler to smooth it all out. But first, you need to get that cracking filler removed
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[wilberweb]

mr48chev,dubie
I tried to shrink the metal as much as I could with that much panel it just oil canned on me, so what I did was let it go after it was all patched in, I stretched the metal where it oil canned with a hammer pounding it from the underside of the cab that did the trick. the reason it has too much filler is my fault I added way too much to the panel. It is relatively even I just thought I needed to float more filler then I needed. Over the weekend I took all the filler out down to the metal and just floated the seams. looks a lot better. I have some pictures of my progress so far.

[wilberweb]

Hear is what it looked like before all the work.

-Larry

[dubie]

Damn!!!! That is some ugly cancer !!! How big of a patch did you weld in? Just the size of what we see? Or did you make a bigger cut to take the strain off the corner?
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[wilberweb]

Small as I could both front and back.

-Larry