Im using a steel floor on my car (please no cut it out and use an ali floor cmments)

and have just tacked it on so far, i was just wondering how much i need to weld it on? out and inside chassis rails? how much weld then how much gap etc?

What have others done?

Thanks

Mikkel

lol i'll probably get shot down for this one, someone will say its not good enough etc, however...

on my car, remember this is professionally built by SHP for racing, the chassis link bar brackets are stitch welded, i think its about a half inch weld, half inch gap, half inch weld etc. so maybe that gives you a bit of a guide? i'll measure the proper gaps later for you

I bonded and rivetted my steel floor no boing here

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Originally posted by big_wasa
I bonded and rivetted my steel floor no boing here

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mines a stuart taylor chassis and is stitch welded about inch welds with about 1 to 2 inch gaps iirc can get pics tomorrow if ya like let me know

chris

is that welded on both sides of the chassis rails? or just on one side?

It would be interesting to get a comment from an MOT inspector if there are any on here. I had it in mind that floor panels had to be fully welded all round when repaired so would have thought the same for original floor. How this is considered when the floor is bonded and riveted I am not sure!

I could be talking complete rubbish and the wrong idea, but will soon be doing the floor on my build and was also doing steel.

Adrian

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Originally posted by AdrianH
It would be interesting to get a comment from an MOT inspector if there are any on here. I had it in mind that floor panels had to be fully welded all round when repaired so would have thought the same for original floor. How this is considered when the floor is bonded and riveted I am not sure!

I could be talking complete rubbish and the wrong idea, but will soon be doing the floor on my build and was also doing steel.

Adrian

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i think seam welding for MOT only relates to 'repairs' bearing in mind a lot of cars are spot welded. i'm pretty sure a mot inspector told me that a few months back. he was also talking about cars with body kits where the whole sill is hidden, they could be rotten underneath and they're not allowed to check. all pretty grey really

i reckon stitch welding is the best as far as heat distortion is concerned. weld an inch on one, move to the other side of the car, do an inch there, etc.

Be warned if you do decide to fully weld take your time over it, I did this as my first attempt, tacked in place, then back filled, when I had finished and stood back to admire my handywork the floor was buckled

In the end I cut it out and replaced with ali bonded and rivited.

It was a complete PITA, especially as I worked from side to side to minimise heat distortion.

Regards Mark

[Edited on 25/12/08 by mark chandler]

As Mark says, mine too is fully welded, bit here, bit there, but it still warped. Welded all the way round the outside, with plug welds on tunnel/floor joins

Might work if you can restrict the heat to a very small area (by keeping the panel side of the weld cool - with a wet rag perhaps).

Still, at least the low points afford some sort of sensible drainage options - like drilling a hole in them

ATB

Simon

I drilled holes in floor 50mm apart and puddle welded them that way it will not bow. If you stay away from welding the corner of the box section it will not pull as the heat is not going up the side of the box, hope this makes sense. Also the floor does not have to be fully welded as its not part of the chassis

On my first chassis I stitched it as a friend who use to work for Louts back in the day said if you were unlucky enough to have a weld break the the max it could unzip was 2 gaps long.

Hope that made sense, Dan.

link

This is how I did the floor on my new project. Its made from a central heating radiator seam welded with no distortion and very strong

When I cut the radiator to size it was too heavy so I separated the front and back skin by drilling/grinding the spot welds.



[Edited on 26/12/08 by Bigheppy]

Puddle welding would be the "normal" ;-) way of doing it.

If you stitch-weld or puddle-weld, either way it seems like you're going to end up with large unpainted areas that will rust.

Has anyone tried brazing the floor on? In fact, why can't you solder it on, really. Seems like the lower heat might give a flatter floor.

Then there's true spot-welding...

[Edited on 12/27/08 by kb58]

I haven't decided how to attach my steel floor yet, however, I planned to use 'weld-through' primer to avoid the rust issue. Any thoughts?

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Originally posted by kb58
If you stitch-weld or puddle-weld, either way it seems like you're going to end up with large unpainted areas that will rust.

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I think that Epoxy resin alone will be rather brittle for the application.

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Originally posted by Echidna
I think that Epoxy resin alone will be rather brittle for the application.

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That's OK then!

I know zero where paint is concerned but would it work if you over thinned some paint
and ran it in the gaps between the stitches?
Wipe off surplus, let it dry, then paint as normal?

Paul G

I stitch-welded, but put seam sealer across - er - the seams. The aim being to stop the water getting into the joint.

This is just a thought from reading Bigheapy's post where he used the radiator. It made me think, that rather then putting the floor under the chassis, why not cut it to fit along the inner edge of the chassis rails. Then when it is welded to the inner edge there is no metal that can not be painted. It would mean continuous welds all the way around and on the roadster that is a few metres of it?


Can anyone see a down side?

Adrian

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Can anyone see a down side?

Adrian

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