Cowl / feder seam sealer

I've read the various posts and need some advice. It seems the good sealers are the 2 part 3M types, but these need a special gun and I can't spend the money for that right now. The urethane "Home Center" flashing in a caulk tube looks like the best alternative, can this be applied over any base coat (por-15, rustoleum, etc.). or does somebody else offer a better auto urethane "caulk tube" for this application?
Some of the 3M versions cannot be applied over a lacquer base. Thanks.

Mitch

 

Use the black polyurethane roof and flashing sealer....it will stick to anything. Just make sure the surface is clean and free of any loose material. Use rubber/nitrile disposable gloves to apply the sealer since it is a pain to remove from skin. Can be removed w/mineral spiritis but much easier to just remove disposable nitrile gloves.

 

Can the urethane be applied on the rustoleum, regular primer, or Eastwood rust encap. for instance? Not sure which I'll be using yet.
Thanks.

Mitch

 

you can get brushable seam sealer from any autobody/paint supply store.

 

Urethane will work over sealers, primers....etc.

 

Re: Cowl / fender seam sealer

Thanks. The sealer there now is sitting there, and blocks of it can be flicked off with a finger. It's dried out and has absolutely no adhesion.

Mitch

 

that old original sealer is a oil/tar based material and over time the oils in it dry out somewhat and it starts cracking and pulling off rather easily as you have found. The stuff George mentions sounds great....it'll probably stick to just about anything (as long as it's not oily/dirty) and stay put. A big plus is it's black just like the old seamsealer stuff they used on the firewall areas.

 

The stuff George mentions sounds good to me as I have tried several types including 3M in a can and tube and the stuff is gray or tan and it cracks really fast. I cannot believe 3M makes such crap.

 

Hey George, how long does this stuff take to dry???
I applied some this afternoon, it went on well, but it hasn't begun to harden yet.
The instructions say to wait a week before painting over it!...in your experience, do I have to wait that long?
Thanks!

 

I just got done using this stuff.....yesterday...installing the trunk and floor pan plugs......my experience....here in FL...hitting 90 almost everyday....takes about 1-2 days for it to cure.

 

Thanks George! Guess I'll plan to wait at least a few days before I paint over it.
Appreciate the quick reply!:TU:

 

George. can the stuff you use be brushed on to duplicate the factory brushmarks on the cowl?

 

Dave, I applied it with a caulking gun, then went over it with a brush. It brushed out pretty well, but it's a bit 'sticky' going on, and did not flow out much...so brush marks stand out, IMO, too much. It cleans up nicely with lacquer thinner, so it's possible it could be thinned so it will flow out more.
After one day, it's still tacky, but firm. I'll paint over it next weekend.
George, have you successfully painted over this stuff?

 

It can be brushed but it is very viscous.....you would probably need to use a brush with the bristles cut about 1/2" to 1" from the handle....to make the bristles firm to make a good "brush" impression/marks on the polyurethane.

I have painted over this many times and never had a problem. I use it on the cowl, trunk pan and pass. floors when restoring a car...works great with minimal effort. I usually apply it with a caulking gun and then use my finger to smooth the seam (hands in nitrile gloves...easier to clean up)

When using it on the trunk pan where I make my lap joints....I use a body filler squeegee(4" wide) to make a nice wide smooth finish.

 

Good info. Hope I will get to this point soon.

 

I've got the sealer, brushes, all the areas scrapped and cleaned with lacquer thinner. Not really much rust, I plan on spraying the black rustoleum over the whole cowl once cured.

Mitch