Shaving the firewall with a plate

[BADNBLK]

I'm shaving my firewall in my 1991 Z28, and using the plate method to go over the hvac holes/mess on the passenger side vs welding in various small patches for each hole.

Question I have is Aside from welding the plate to the firewall, what should I be doing between the two? Plate is primed with ppg self etching... Should I use panel bond or something between the two?

I'm not a body man so any tips are appreciated

[raustinss]

yes i would think that lots of panel bond would be what you'd want to prevent rust starting between the two .....but also not a body man just a fab guy

[BADNBLK]

Panel bond is pretty intense stuff, and maybe a little more than I need? I know people have used panel bond to install plates/fenders and such before filler. I kinda even feel silly saying RTV type sealer around existing holes????

[raustinss]

no id use panel bond over any rtv or ??? you could bond the "middle" and then on the perimiter toss some small stitch welds and seal the rest of the seam to prevent gases from coming into the interior

[Yukon Cornelius]

I'm thinking of using these with some rtv to seal out fumes. I think the button head will look good.

http://rtlfasteners.com/RC/m.html

[minendrews68]

Just remember, rtv will not accept paint! If your going to paint any of the areas where the rtv is it won't work.

[Yukon Cornelius]

Just remember, rtv will not accept paint! If your going to paint any of the areas where the rtv is it won't work.

You're right. Maybe some seam sealer instead.

[BADNBLK]

I'm still welding this in. I'm just talking about the space between the two pieces of metal. Looks like most use nothing as the weld should seal it from the exterior. Sorry for not making that clear before.

[jlcustomz]

I've recently signed up on the SPI paints forum. Their epoxy is said to be one of the best & their costs for what is high end stuff aren't marked up from middlemen. Guys in their forum will use it on the backsides of areas for protection, right up to where they weld.

http://www.spiuserforum.com/forum

[LS1-IROC]

Cut the old sheetmetal out and butt weld it......Sorry, I know it's too late to offer up advice:-(

[raustinss]

Cut the old sheetmetal out and butt weld it......Sorry, I know it's too late to offer up advice:-(

X2 , I was under the impression that you didn't want to do any welding. Being as you are do this

[rreichert82]

If you are worried about rust forming between the two pieces cant you just use a weld through primer on any unfinished areas located between the two panels so you have a coating on everything prior to welding? Then I agree I that a seam sealer to keep things out of the passenger area then paint. Just my thoughts.

[BADNBLK]

Well I welded them in, and there is no turning back now. Again the back sides of the panels were primed with weld through self etching primer. I did throw a gasket maker type silicone sealer around the blower and hvac holes. The exterior is stitch welded up.

Appreciate the thoughts on it. I hope, and feel like there shouldn't be any issues between the panels in the future.