914 Floor pan replacement

[Ascaris]

I am restoring a 75 914 and am about to try to replace the rear floorpan and lower inner and outer firewalls (along with the battery tray, support, etc.) I am ok at metalworking (and used this as an excuse to buy a MIG welder - only had Acetylene before) but have never done this kind of work on a car before.

Any words of wisdom, things to avoid, etc. from those of you who have done this job?

Thanks!

[Bunky]

See the 914 Rotisserie questions below!

[Rich Hilgersom]

Or just go straight to the Pelican
Tech site:

http://209.6.145.21/techarticles/kyle_ehler_tech_series/914_floorpan.htm

[Paul M]

I replace pretty much what you have to do and while it was a good learning experience I can think of other things I would rather do with my time!!

Don't cut out any of the rusted areas until you have the replacement parts in hand. Sometimes you don't always get what you are expecting and it fabrication time!

If you are going to butt weld the pans be sure to practice. TIG is much better than mig, if you have access to it, because you cans see what you are doing better and a tig setup usually has more variable temp settings, also there's less cleanup (grinding).

With 20-22 gauge I needed to butt-weld (no overlap)at the lowest setting. I did it with my mig (couldn't afford tig) but it take a longer to do it. I have a lincoln 100. I used temp A and speed 3. Practice on some scrap until you get the speed right for your mig setup, it's tricky. You will make holes (burn throughs). If you burn a hole, I would tack the edges of the hole to fill it in, then grind it back down. On thicker welds, overlaps or spots, I used C temp (med-high) and 5-6 in the wire feed speed.

Metal prep the metal prior to welding. A phosphoric acid wash is good. Make sure all the rust is gone before welding the parts. Any rust there when you are welding just make holes and the welds will be weak due to contamination.

Hope this helps.