Thread: Firewalls - A contribution

A contribution:

When I finally got around to installing my sand blasted, overhauled, rust cut out in and new in both lower door pillars and the underside of the windscreen treated and refinished I found it would not fit! outrigger holes and chassis holes were all out. Outriggers 10mm. MMMMMMM! Trap for young players!

It did dawn on me that the original pressing stresses decided to go their different ways when the rust was removed during the sand blasting process, it "sprung". Then the top cut out and replaced, as well as the door pillar rust rectification.

Inserting all of the chassis bolts required lots of mixing and matching, in and outing, and judicious use of a crow bar and tension straps. However, the outrigger bolts at the base of ech door pillar were 10mm out and needed a tirfor to pull the door pillars in. This eventually caused one of the door pillars to "give" and dimple a bit.

LESSON!

Before undoing anything and removing from chassis a firewall needing work, weld on cross, and fore and aft bracing. Box the firewall in three dimensions. Any rust removal will cause the residual stresses to distort the firewall. Most likely the rust will cause it to "spring" once released.

Cheers

Rick F

When I went through this exercise I jigged the two support holes that bolt to the out riggers with a bit of RHS
There is a degree of give and flex in the gearbox tunnel area of firewall allowing support bolts to be podgered into place after repairs are done

Cheers Paul