Sealing a stock firewall

[Milwaukee Midget]

I'm looking for advice on sealing a stock firewall.  The class is GT, the car is steel.

I'm staring at numerous holes and thinking it would make more sense to simply overlay new steel over the existing wall, or preferably aluminum (easier to fab in my under-equipped garage), rather than try to patch each hole.  I don't trust rubber plugs, and I like the idea of a smooth, clean looking, airtight firewall.

My welding skills aren't pretty, and am curious if such and overlay would be acceptable to the rules if it were attached with sheet metal screws, bolts or rivets.

If I can go this route, any advice on a sealant between the sandwiched pieces?

Thanks, all!

Chris   

[Peter Jack]

Don't use sheet metal screws. They should never be used anywhere on a race car. They never stay in place and always migrate toward the tires.

Bolts and washers might work well for smaller holes. Socket heads would look clean on the firewall.

Pete

[Cajun Kid]

I would use .090 Alum and attach with  1/4 20 Button Head Stainless fastners with washer and lock nuts on the inside.

No need for a sealer in between if you use .090 Alum sheet over stock firewall.

[LVMAXX]