Seam sealer? What to use for vent ports in e-body cowl?

Posted By: Mopar72Man

Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 03:16 AM

I am doing some firewall/cowl patch work and need to clean up some metal here, rust bullet it and apply some seam sealer.

What is the preferred sealer to use and is there something available locally? I'd like to try to pick up something this weekend

Posted By: poorboy

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 05:40 AM

I've had pretty good luck with the NAPA brand automotive seam sealer in a caulk tube from NAPA. 3M also makes a decent product available in a caulk tube, but I like the NAPA stuff better. I don't have a part number on hand right now.

Its kind of pricy, and is only good for about a day, once the tube is opened, but I use it on all the weld seams when I put replacement floor pans in cars & trucks. Some have been in service over 10 years and is still sealing the seams & pin holes. Gene

Posted By: ahy

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 06:07 AM

Poly-urethane caulk from the home improvement store works well as seam sealer. I lay it down then use a stiff brush, with a little thinner if needed, to smooth it out.

Posted By: Adam71Charger

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 06:23 PM

Quote:

Poly-urethane caulk from the home improvement store works well as seam sealer. I lay it down then use a stiff brush, with a little thinner if needed, to smooth it out.

I went this route too. I used a roof flashing sealant formulated to be permanently flexible and can bond to multiple substrates. I used it on every floor seam of my car and some sealing areas under the quarter windows. I was skeptical at first but this stuff bonds very well and is very flexible and durable. Glad I used it. Cant remember if I painted it or not. Takes awhile to cure, about 7 days. I used it with a caulking gun, didnt thin it at all.

http://www.homedepot.com/p/Loctite-PL-S3...75273/203163733

Posted By: DaytonaTurbo

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 06:55 PM

I've used PL Premium before. It's a urethane adhesive. I work at a large truck/trailer shop and for trailer repairs we use sikaflex, which is another urethane based sealer/adhesive.

Posted By: TJP

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 09:06 PM

I recommend staying with sealers intended for auto body applications. 10 to 20 years down the road they will still be in place doing their intended job. I have seen more than one instance of substitute sealers failing after 5-10 years.

Posted By: DaytonaTurbo

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/04/15 10:04 PM

Quote:

I have seen more than one instance of substitute sealers failing after 5-10 years.

Like the factory mopar crap that crumbles to pieces on our old cars?

Posted By: TJP

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/05/15 02:53 AM

Quote:

Quote:

I have seen more than one instance of substitute sealers failing after 5-10 years.

Like the factory mopar crap that crumbles to pieces on our old cars?

back in the day the engineering and thought was 10 years was adequate. Fast forward 40 or so years and the 60 to 70's technology did its job that it was intended to do. We now have new technology available and skimping on body sealant is not something I would advise

Posted By: ahy

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/05/15 03:37 AM

Quote:

I recommend staying with sealers intended for auto body applications. 10 to 20 years down the road they will still be in place doing their intended job. I have seen more than one instance of substitute sealers failing after 5-10 years.

FWIW I used to use 3M body seam sealer in the quart cans. The formula changed some years ago and it started shrinking and cracking after a few weeks or months. Also once tried "bondo" brand seam sealer in the caulking tube. It would shrink and crack in a few hours.

The polyurethane type sealers seem to hold up very well... both the dedicated auto brands from Eastwood or a body supply hose or the home improvement store stuff.

Posted By: Adam71Charger

Re: Seam sealer? What to use for vent ports in e-body cowl? - 04/05/15 10:38 PM

Quote:

Quote:

I recommend staying with sealers intended for auto body applications. 10 to 20 years down the road they will still be in place doing their intended job. I have seen more than one instance of substitute sealers failing after 5-10 years.

FWIW I used to use 3M body seam sealer in the quart cans. The formula changed some years ago and it started shrinking and cracking after a few weeks or months. Also once tried "bondo" brand seam sealer in the caulking tube. It would shrink and crack in a few hours.

The polyurethane type sealers seem to hold up very well... both the dedicated auto brands from Eastwood or a body supply hose or the home improvement store stuff.

read a lot about people having trouble with the 3m, but they do have tons of different seam sealers now they probably have some great stuff.

When I spoke to the LORD FUSOR tech guy, the way he described the product was the way it behaves during and after curing, and the bonding quality to certain substrates. Thats how I found what I wanted, I needed something that could hold up against drastic temperature changes, was waterproof, bonded well to bare metal and epoxy, and remained flexible during expansion and contraction. PL30 had the characteristics I wanted and so I gave it a shot (at $5 a tube) and it worked great. Stuck like cement but remained slexible like gumby. Have had no issues at all with it.