I have used POR on many projects, but never with a top coat. One buddy used POR on his windshield frame without a top coat and had to remove it and do over with epoxy primer. An old buddy in the body shop business over forty years recommended I use the PPG DP90 primer and that is what I used. It has been there for 10 years with no problem and no rust showing.

What I believe to be most important is that your top seals so that water does not accumulate under the molding and into the windshield frame and t-top bar. If you discover a fool proof way to do this, please share. I filled my channel with clear silicone caulk before closing it up. If others have used POR with a top coat successfully, I defer to their recommendation, if that is what you would like. I have no experience doing this.

 

[QUOTE=Red 69;1580158859 I filled my channel with clear silicone caulk before closing it up. If others have used POR with a top coat successfully, I defer to their recommendation, if that is what you would like. I have no experience doing this.[/QUOTE]

I heard that Home Depot type silicon has acids that eat metal

Steve L

 

Ok so you say the POR needs a top coat (is that because of the UV thing with POR)? And I should just fill the whole top channel with a silicon caulk?

Is there any way to tell if there are acids in it? Like and MSDS or something?

Will

 

No, I didn't say POR needs a top coat. I said I have never put a top coat over my application of POR. As long as the POR is in a place where it doesn't get in direct sunlight you shouldn't have a problem. My frame and suspension related parts have been on over five years and still appears close to as just applied. Other parts like my windshield frame were painted with PPG DP90 exclusively and without any problems. The entire fiberglass underside of my car's body and wheel well openings were painted with PPG and remain easy to clean.

The windshield frame is essentially covered in moldings and not in direct sunlight. BTW....since I don't top coat my PPG epoxy primer, I add 1/3 more hardner to give it a semi gloss finish. Without this, it has a rough texture to grip a top coat best. Another advantage is it brushes on well, has good flow characteristics and is compatible with most materials on your surface, unlike POR. PPG DP comes in about eight different colors.

As far as filling the channel goes, I am always looking for a better way. I don't like to downgrade a method or technique without offering a better suggestion. I can't comment on the silicone eating metal, as I don't know the manufacture details. I know without a doubt that PPG DP90 is compatible with seam sealer and it will not eat metal and can go over paint of any description and can be painted. This might be another option to fill your channel, but is slower to cure.

I have to question the comment on silicon sealer eating metal, as it is commonly used around aluminum frame windows on homes. It would be easy enough to stop at a body shop supply shop and ask what they recommend or call the silicone sealer manufacturer for specifics on their product. If it goes over epoxy primer, it isn't in direct contact with the metal, correct?

You do want to block any openings to the A-pillar in the windshield frame. Water access here will promote corrosion all the way down to your kick panel and #2 body mount. In a perfect world they would be water tight and not leak, but most leaked from the factory. This is why there are so many rotted A-pillars and #2 body mounts. This can spread back to the rocker channels.

Don't take anyone's word for anything without checking things out. Do your homework and be confident what you choose will be in your best interest. All brand products are not exactly the same, so best to check them out.

 

Go here for my WS Removed thread....

http://forums.corvetteforum.com/c3-t...post1580509094

Will

 

Alrighty...The birdcage is done and treated. I POR15'ed it, then topcoated it with flat black spray paint. Then I used the eastwood internal frame coat to coat the inside of it. Then I sealed it with caulk.

I installed the upper WS trim clips. Here's my question- Can I reinstall those two lower WS corner pieces that like locate/support the WS, and can I install the wiper rest/stop bracket and then install the WS?

Essentially, what can/cant I install before the WS is put in?

Will