[Terry M. Hunt]

Trunk floor and two sections of floor pan(footwells) on my 66 GTO convertible had to be replaced. Welding was done with lap joints not butt welds and turned out fine. Some kind of seam sealer was smeared along the seams on the top and bottom of the replacement panels. I’m not overly concerned about the top side, but the bottom just looks crummy. I want to improve this by scraping out this blob of sealer and replacing it with something that can be finished smoother. I imagine I can’t make the seams completely disappear, but I need something that can finish the seams as smoothly as possible. I don’t see body filler surviving in this environment. I researched panel adhesive, but apparently this stuff would not live in close proximity to a heat source like the exhaust. Maybe some sort of two part epoxy is what is needed, but I need brand names, part number, user experiences, etc.

[Dave R]

I weld them solid, grind and paint as I don’t trust anything else in sensitive areas. I’d be concerned about structural integrity, especially with a convertible. Top lap can be filled with seam sealer.

[Terry M. Hunt]

Both the top seam and bottom seam have been welded solid so I don’t think structural integrity is an issue. The. Issue is the ugly bottom seam that has just been slathered with some kind of seam sealer which makes the repair stick out like a sore thumb. I realize that I may need to grind on the welds some more, (being careful not to leave them too thin or weak) but eventually I’m going to need some product to smooth out this area of weld bead where the two panels are overlapped. My question is “What should this product be?”

[Dave R]

Sorry I misunderstood. Yes, get the goop off and grind what you can. With the lap welded solid top and bottom, thinning isn’t as much of a problem if you stay on the weld when grinding. For minor filling in under car areas, I use Fiberglas filler. Mixes like bondo but is waterproof and then sand and paint over. I’ve never had a problem with rust using that underneath a car or around wheel arches. I don’t recall the brand name but it has small fibres in it.

[tooski]

I used Devcon metal weld to repair a gas tank. It spread like body filler and seemed to me to set up much harder. I didn't attempt to do any finishing. There is also JB metal weld, but I have only seen it in the small tube syringes.

[bdk1976]

After cleaning/grinding down to clean metal, I'd probably go with Metal 2 Metal (or similar) filler in your situation and bury it in epoxy primer before topcoating with whatever you choose.

[6d7gto]

JB Weld Marine Weld. Good to 350 degrees Only trouble is, it seems to only come in small tubes as far as I know. Great stuff and can even double as seam sealer...yet it can be sanded to make that seam seem to seemingly disappear!

[MUSLCAH]

Been using this stuff for years....excellent product.

And I guess Bitchin Rides was spying in my shop....cuz I saw a can of it in their shop ..( On the TV Show )

[MUSLCAH]

Upol....Fibral ...it’s a fiberglass reinforced filler...tough as nails

[tjs72lemans]

I've used regular JB Weld on three projects. One was lap welded while the other two were butt welded. The butt weld ones are not noticeable at all one I sanded and primed/painted. On an inside quarter that was lap welded I used the fiber reinforced filler and sanded and also now not noticeable.

[Terry M. Hunt]

Many thanks for all your suggestions

[VCho455]

With proper surface preparation fiberglass filler will do the job. It should be the easiest to apply and finish. Plus it will work well with an epoxy primer over it.

See the PDF in the link.

https://www.southernpolyurethanes.com/epoxy-primer


Unless your exhaust is close enough to burn the paint I don't believe that the heat from it would affect any of the products mentioned above including the panel adhesive.