I just received my Goodmark floor pans from Ground Up. They have a black coating on them. Is this weld through primer, or do I have to grind it off before welding? Also, how do I prep the surface for painting with POR-15?

TIA, Kevin

You will have to take off the primer where you are welding,red scotchpad should prep the rest o.k.. Should put on a weld through primer after removing the black(stuff). Mike

Never hurts to remove the black coating before welding, If possible use 3M weld through primer as the other brands seem to want to sputter a lot, don't know why, just experience. As to the Por 15, I went with spray on truck bed liner top and bottom. Por 15 is actually more for rusted metal and bonds and chemically alters the rust. If you have some, then touch it up with the por 15 then coat the whole floor pan and trunk pan with the truck bed liner top and bottom, never rust again, thats for sure. could probably use the trunk for a fish pond if ya wanted....

oh yeah, another good one, after you have done the insides of the quarters, doors, fenders, etc. and have completely finished painting, use the anti corrosion wax (stuff that VW and other manufacturers base thier anti corrosion warrantee on) in all the lower cracks and crevices. this stuff will not allow moisture to stand in the usual rust out spots on a chevelle.
ya see, I plan on driving mine in the rain! I don't want to rust or bubble ever again.

I'm going over mine with silver Por 15 paint from the inside and whatever I use on the exterior of the body underneath. They tend to rust from the inside and Por does a good job of preventing rust from occuring. There are a lot misperceptions about Por only being a coating for rusted surfaces. It works just as good on new surfaces with the proper pre-treatment of the metal. I have pictures of a battery tray that was treated with Por over five years ago. It's been exposed to battery acid and anti-freeze from the radiator overflow tube and the finish is just as tough as the day I installed it. There is absolutely no sign of corrosion.

Thats Electric Deposit Coating. You can weld through it. It is a great weld thru coating and i usually don't remove it.You also do not want to paint clean metal with POR 15 unless it is POR Chassis coat which is a top coat.Regular POR 15 does not stick well to clean, smooth or painted/primed metal.I can show you pics of were it peeled off in sheets on my new floor pans after about a year.

I really like the idea of the paint on bedliner stuff on the floor pans. I put POR-15 on my floor pans, but did not prep correctly (if at all) and I am getting peeling in a few spots. I am using POR-15 on everything I can (mostly chassis and suspension parts) but I think that bedliner stuff would be great for the floors. graemlins/thumbsup.gif Good idea. graemlins/waving.gif POR-15 is great stuff but it must be applied correctly. Last night I wire brushed a 3' section of my rusty chassis just to remove loose surface rust, blew off the dust with compressed air and applied POR-15 and it looks awesome. That will not peel off because that is what POR-15 was designed for. ;)

Randy and Marshall are both right on the mark in my opinion graemlins/thumbsup.gif

I did what Randy is doing...

http://users.erols.com/ruther/69conv/bodywork/porslvr_drv.jpg

Absolutely. Do not weld through Por 15. In areas where I have to do any welding, I use 3M's weld through primer on the faying surfaces. Everything else gets coated with Por after I've finished welding.

Lookin' good Jerry! graemlins/thumbsup.gif

For the people talking about bedliner - would there be any need to use the sound deadner mats under the carpet or would the bedliner do it? I am considering using bedliner myself, but am wondering if coating top and bottom wouldn't be better than the factory stuff.

One more time on the prep of new metal on the POR15. I sandblasted my frame ,used metal ready and all their prep stuff but i didnt clean the 'dust' of from the prep stuff; now the por is kinda pealing around some of the bolt holes :( .

Just like regular paint,prep prep prep.