Which Weld Type ?

[DamirGTI 325]

Ok. been waiting for my mate the body man yesterday to inspect this rust business and give me a bit of advice however he didn't show up , so i still need some info regarding floor panel welding :

 

1. Which weld type should i make all around the floor panel edges - butt weld or lap weld ?

2. How to protect/treat these highlighted areas (floor stiffener and main chassis rail) before i proceed with plug welding floor panel on top of them ? (will reproduce OE pattern for welding floor panel over chassis rail and stiffener with the same amount of spot/plug welds and in the same places .. further on i'll make an overlap joint of the floor panel on the side across the flat steel bar welded next to the inner sill)

3. Is it necessary that i try to make/cut entire floor panel from sheet steel in one piece or can i make/cut it from two pieces ?

4. Anything else i should know before and after this floor welding job ?

 

 

Thanks !

Damir

Edited November 15, 2008 by DamirGTI

[mickie 3]

lap weld would be easier. welding it from the top and from the under side..

 

treat the rust with something to remove it, then paint it after. wax oil bits..

if you're wanting to use sheet steel, i'd try do it in one peace, cant you buy floor pans for this car ?

 

seam seal the new floor pan when you're done

Edited November 15, 2008 by mickie

[Cameron 16]

Could well be better ways, but I would:

 

1) Lap weld for sure, unless you're reeeeeeeeeeeally accurate with your cutting. Will be much less likely to blow holes.

2) As for treating those areas, you could use a paint removing pad in your grinder to bring it back to fresh metal without losing too much metal thickness. Use some metal treatment and then give them a coat of weld through primer if you're spot welding, if you're plug welding then remove the primer where the welds will be.

3) It'll be easier to weld in if you make it in one piece, saves having to have a seam down the middle somewhere. Depends how difficult it is to make the panel in one go I guess.

4) Just make sure you don't have any contaminants (paint / sealant etc) where you are welding, bring 5mm either side of the weld area back to bare metal before you start otherwise it will look like a dog's dinner.

 

Hope that helps.

[SeanO'Connor 0]

Could well be better ways, but I would:

 

1) Lap weld for sure, unless you're reeeeeeeeeeeally accurate with your cutting. Will be much less likely to blow holes.

2) As for treating those areas, you could use a paint removing pad in your grinder to bring it back to fresh metal without losing too much metal thickness. Use some metal treatment and then give them a coat of weld through primer if you're spot welding, if you're plug welding then remove the primer where the welds will be.

3) It'll be easier to weld in if you make it in one piece, saves having to have a seam down the middle somewhere. Depends how difficult it is to make the panel in one go I guess.

4) Just make sure you don't have any contaminants (paint / sealant etc) where you are welding, bring 5mm either side of the weld area back to bare metal before you start otherwise it will look like a dog's dinner.

 

Hope that helps.

I put a full floor including inner outer sills and load bed into a Mini pick up, I used mig and lap welded then filled the sills with expanding foam. Painted it all in Hammerite rust prevent paint stuff, then loads of underseal bitchimin type paint, then it was painted in the paint shop, don't think it will ever go rusty again.

[Jrod 7]

From what I've read foam encourages more rust by trapping moisture.

[SeanO'Connor 0]

From what I've read foam encourages more rust by trapping moisture.

Possibly, if there is moisture in there in the first place, however I welded new sills in a dry garage, so it's doubtfull that any would be trapped.

[Jrod 7]

But water is going to get in there eventually and when it does the foam holds it.

[dirtdog 4]

why expanding foam? Will comeone please think about the weight!!!

 

While your there why don't you just flat bottom the car?

[Paintguy 0]

Possibly, if there is moisture in there in the first place, however I welded new sills in a dry garage, so it's doubtfull that any would be trapped.

That may have worked on a mini, but the sills on a 205 are designed to let water from other areas drain through them.