Thought I had a very solid floor and trunk pans until I sandblasted them today. About 1/2 a dozen pin hole appeared. :( Nothing major but holes about 1/16". And I thought I was ready to paint the underside. I need your help here! :confused: I don't think this warrants a total pan replacement. Here is my plan and please comment. Clean all the areas on both sides, use POR's epoxy putty, then cover with POR15 on the inside of pans. This is not a big deal for the floor pans because I was going to paint the inside floor boards anyway. My concern is the splatter paint in the trunk. Will that adhere to the POR15? Once this is corrected I still plan on painting the underside with zinc primer and urethane paint. Any suggestions will be appreciated.

You should weld up the holes. Only 1/2 dozen should be a piece of cake.

tim68rsss, painted the trunk floor with the POR-15.Let it sit for a day or so, then covered that with the POR primer. Covered that with the spatter paint and then several coats of clear. The primer from POR is the same color aqua as that in the spatter paint. Turns out very nice. If you are near the Mechanicsville area I would be happy to let you look at the trunk. graemlins/thumbsup.gif

I don't have answers for you but I have some questions. Did you encounter any problems during the process? Did you do interior and underneath? What about all the sand leftover in crevices? I've heard some say it's not good to sandblast (heat buildup/warped metal?), but maybe the floors are thicker, no warpage? Getting ready to do mine and blasting seems to be the easiest, but I keep hearing otherwise. Any tips? I know it's a lot of questions, but ANY help would be appreciated.

what we did with my floor and parts of the trunk where holes were small was put duct tape on the underside of it and mix some fiberglass, it worked great and held the shape pretty well too.

Rickfifty, Alot of sand every where! Blew as much out as possible before putting back into the garage. My car is mounted to a rotisserie and I plan on using forced air and a big shopvac to get the rest out. Probably no way to get it all. I hired someone to do this blasting. He had a gas powered compressor and took only 1.5 hours. It would have taken me a whole day using my blaster. No warping that I can tell just pin hole showing up that I didn't expect! If you have a way to clean up after the blasting this is the best route.

Unreal I know you said I should weld up these holes but would POR's epoxy putty with POR15 work as good. I don't have that type of welder and no way of transporting. I plan on coating all the inside floor and trunk pans with POR15 after the repairs. I plan on using the POR's primer before topcoating as 67camss/rs suggested.

I am not a POR fan, so I see no need in using it. It does have it's place on RUSTY metal, you don't have rusty metal, you have nice, clean, sand blasted metal.

I feel the first thing you need to do is determine just how thin this metal is. If you have some pin holes, it is likely the metal is thin in the surrounding area and that the pin holes are just where it was the worse. Push on it with a screw driver to see if it is solid. If it were solid with only the pin holes, OR the thin area is in such a place where structural integrity isn't compromised, I would urethane seam seal it after etch primer.

There is no reason to go off with POR and all that if the floor is solid. If it is thinned and there is a structural integrity issue, that is completly different. Now, again, you have to determine how bad it is, does it need to be replaced or would a coat of Everglass or Kitty hair do the job? Or even a coat of resin and some mat maybe? Those are questions only you can answer after close inspection.

Tim,
I would go for the welder. When people get in and out of your car the floor pan flexes a tad and I don't think the POR would hold up to it. I don't know for sure on this since I haven't used the POR for patching. You can get a little 110V MIG welder for around $500 or maybe you can borrow or rent one for a day. They come in real handy. Hold a piece of copper or aluminum on the backside of the pin hole and weld it from the other side. A little clean up grinding and your done.
Roger

Roger, the problem is, if the floors structual integrity is questionable, welding holes is NOT going to do a single thing. You would need to put new metal or something. If the metal is pitted thru, it is likely ready to break thru RIGHT next to that hole, so what good does it do to weld the hole?

I had the same problem with a 69 driver I'm doing. I had a few pin holes in the floor pans and I Duct taped the underneath and use the POR Patch on the top. I used a plastic squeegy to smooth it out. I let it dry for a few weeks and sanded the underside down ( the POR patch doesn't sand very well)primed it, painted it and it looks great and it's very strong and flexible. I took a real bad piece of floor I removed from another car to test this procedure. The holes were alot larger and the metal was thinner. I twisted it and banged it with a hammer and it really held up great. I'm not a big fan of the paint, but I think this product is good for this purpose. I left the test piece outside (it's still there after the entire winter) and every thing is rusted except where the POR patch was applied. If you want a quick fix I think this would be better than kitty hair or fiberglass. Both those products allow moisture to get between the metal and the product and rust forms. The POR patch will adhere very well to the blasted metal.

Kurt did you use the POR patch or the epoxy putty? :confused: Seems the epoxy would be stronger. After tomorrow I will have both products. Cleaned all the areas on the inside tonight and will apply one of the products tomorrow. Not sure which now. graemlins/clonk.gif I plan on painting the inside floor and trunk pans with POR15 and on the underside zinc primer with urethane paint. Should last a long time especially no more damage than it has after 35 years. I'll let everyone know how it turned out. graemlins/thumbsup.gif Thanks everyone! graemlins/beers.gif

I used the POR patch. I have also used the epoxy, but In order to get it real smooth you have to wet it a little which you know what happens when water mixes with bare metal. If the holes are really big I might use the epoxy (works great on plastic). If your talking very small, holes pin holes,another idea would be to use the panel adhesive, the stuff they use to glue on 1/4 panels and door skins. I have used it for both applications and it works great. It seems to me it would work, the only thing is I don't know how flexible it is.

I had a few small pinholes in the floor of my 4x4. Our paint foreman (35 plus years of industrial paint work, and body shop on the side) said for something that small, to buff BOTH sides with a grinding wheel to get ALL the rust out. Then he told me to take JB weld and spread over the holes like you would Bondo. After that I covered it with a 2 part epoxy. 7 plus years now and have never had another problem. He did caution to do this only if the holes were smaller than about 3/16th of an inch.
Anyone else ever done this? Like I said, I have had no problems after 7 years.
Is this a good way to do this? I have a few in the trunk of my 67 and was planning on doing it the same way, but wanted to ask here, for ya'lls opinion.
Thanks,
Virgil

I've used the por-patch before. It's awesome. You can smooth it right out with a wet finger and when it dries it is hard as a rock. I really doubt you ever have a problem with them areas again. I did both sides of my floors and trunk with por-15. On the bottoms I then used the por primer and then base coat/clear coat. It turned out great. John