So I am trying to get my car back together, 69 Malibu. I have been working on the frame, firewall forward, and all that entails, engine, etc. POR'ed the frame, new suspension, bushings, steering components. Just got underneath the car and started scraping and cleaning. Someone before me, replaced the floor pan, 2 piece, seam in the middle. Welded them in from the inside. The seams under the car were filled with silicone caulk and painted over. I scraped and dug all this crap out, cleaned everything, and now my question; For multiple reasons, I am not going to re-do the floor pans now. Can I use fiberglass under the car over these seams to seal them? And will it hold? I will not be selling the car, way more invested than it is actually worth, too much personal value, etc. I was thinking of laying fiberglass over all of these seams, and putting some sort of undercoating over that. Will it work? I know going into this it isn't the "right" way to do it.
Thanks,
Jeff

Seam sealer will work, and will probably be easier to apply.

Towards the last of this thread, the guy used por-15, anyway take a look at it, http://www.hotrodders.com/forum/save-your-rusty-floor-board-108056.html?highlight=fiberglass+floor+pans.

Rob

Andy,
Once again, thanks for the help. My concern is that the seam sealer will only fill the seam, not cover up the cruddy look. I am not trying to make a silk purse out of a sow's ear, but everything else is done right. Engine bay, new engine, etc. Then to look under the car, the newer floor pan will be painted nice, except for these crappy seams under the firewall where the welded the new pieces in. I know nothing about sheet metal work, but my 12 year old and myself could have done a better job. Just looking for a way to not see that when I look at it.

Rob,
Just read through the thread you suggested and I think I will try it. Do you think the fiberglass and POR will hold up under the car to cracks? I read where multiple layers works best so that's what I'll do.

If you want it to look good, take it to bare metal, 36 grit should get it, if it isn't all bare metal after your done grinding or sanding, clean it with acryliclean, then just brush on some epoxy, then duraglass body filler, then coat it again with epoxy, then something like chassis black.

You can put the duraglass on a quarter of an inch thick if you want to, as long as it has epoxy on both sides moisture can't get to it.

Rob

Jeff, this was also in that same thread.


Front drivers floorboard on '77 up 123 Chassis Mercedes Benz are fiberglassed over, they are the only section of floorboard that does not get soft over time.

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As long as its sealed from the top so moisture can't get to it, so brush the epoxy on the top side then seam sealer on top.

Duraglass will take a lot because of the fiberglass in it, and don't worry about getting a little thick with it, I've seen lots of cars with 3/4'' thick in it and still solid, I don't think its a good idea to lay it in really thick, but if put in right it will hang.

So I guess fiberglass or por-15 would work, but mix it and put it on exactly like the directions say.

Andy,
Once again, thanks for the help. My concern is that the seam sealer will only fill the seam, not cover up the cruddy look. I am not trying to make a silk purse out of a sow's ear, but everything else is done right. Engine bay, new engine, etc. Then to look under the car, the newer floor pan will be painted nice, except for these crappy seams under the firewall where the welded the new pieces in. I know nothing about sheet metal work, but my 12 year old and myself could have done a better job. Just looking for a way to not see that when I look at it.

Oh, I gotcha, I was thinking it was down the center of the trans hump. Try All-Metal or fiberglass reinforced filler.