Firewall seam...how to fill?? with what??

[Topless69]

Guys I have read through the archives and didn't find an answer.I'm about to get started on smoothing the firewall. Now i'm going to do a 3/4 panel not a total coverage panel witch will leave from the wiper motor hole over open. This will leave the seam showing and will need to be filled with something.
QUESTION 1.) does this seam flex?
2.) If it flexes than bondo type filler will not work do to cracking..correct?
i was thinking about a lead based filler what did you guys do or what would you recomend. Thanks guys.

[GetMore]

Fill it with seam sealer?

[Topless69]

Jason is seam sealer like a calk or does it harden like bondo?

[GetMore]

It is non-hardening. Tougher than caulk, but still flexible.

[qwik1320]

I welded mine and ground down close, then used a little bondo to smooth out the imperfections. A few spots I didn't weld I used seam sealer, put a piece of tape on both sides of the seam to give a nice clean edge and then smoothed it in like caulk (wet finger with alcohol). After it dried I lightly sanded the tape edge to feather it in and painted. Looks good.

[class67]

I welded mine up!

[Topless69]

So there is a bit off flex going on. Have you guys who welded and then used bondo have any cracking issues down the road. Thanks for the info guys.

[tillman]

I used a product called All METAL. Got it from the local paint store.came in qt can.Worked Great.I read about it on the quick silver project.
https://static1.pt-content.com/images/pt/2009/04/29-1.jpg

[Topless69]

was that a auto paint store Tillman?

[Topless69]

Ignor the last question....I MUST have hit my head or somethink.:Alchy:

[67speedfreak]

I would weld the seam solid before adding filler.

Brian

[opnwide]

I tacked the seams together tight and used AllMetal followed by filler. The allmetal is tough to sand. If I was to do it again, I would've done more body work (too many high and low spots).