I am about to fit the steel floor to the bottom of the chassis. I am planning to put primer (possible zinc 182) onto the bottom rails before welding the sheet on the outside and inside of the outer chassis rails?

Is this the way to go or unnecessary?

Any pointers gladly appreciated.

Cozza

i welded my floor on without priming the crack first, but that isnt saying much cos most of mine is a bodge...

cant see why it would be necessary provided it is all clean and primed at the end.

Use aerosol weld thru primer, its exactly what its designed for.

Its what I did - the primer scratches off quite easily so don't move the sheet around too much one you place it on your chassis.

Never driven mine mind you so i can't say how good it is, but i've stood on the floor many times. Be careful about it warping due to the heat of welding. I'd reconmend (which means i didn't do it but wish i did) a few tack welds around the floor, turn the chassis the right way up, put a heavy weight in the floor and then weld it - hopefully the weight will keep the floor down so you don't get the annoying "bong" when you stand on it.

Mark,
With all due respect, I tried the weld through primer but although it permitted a welding arc to be initiated due to the conductive paint, I found that the paint contaminated the weld badly and gave off fumes and particles of soot. I discontinued using it in the end.

What I have done with my floor is I have stitch welded it on the inside at a ratio of 1" for every 6". I then seam welded the outside of the floor fully in stages, alternating from side to side and front to back to avoid distortion. What I now intend to do is to paint the inside seam with zinc 182 or similar paint, perhaps thinned slightly to encourage it to be drawn into the seam by capillary action. Once this is fully hardened I intend to seal the seams on the inside with car body seam sealer. I will then check the outside of the floor to chassis seam and look for signs of the zinc paint coming through. I will give any holes a very quick blast with the mig to seal them up before painting the exterior seam with etch primer and top coat.

I hope this helps,
Craig.

i stitched mine at the corners and then opposites and diagonals until it was all done over a day. i should've tacked the inside more cos it still boings, so i'm gonna clamp it firmly down and weld the inside as soon as i can be arsed...

It'll still 'boing'!

Tried really had with mine to stop that and no luck. I've even run a pair of swage lines down the length of each piece of floor and that hasn't completely got rid of it.
The only good thing is that if you 'boing' the floor down it tends to stay there so won't do it again!

Cheers,
James

...boing... Sheesh!

Mine boings - at leat it used to, but it's settled down to being permanently boinged downwards. I've also glued rubber mat onto it, so hopefully that will discourage it.

In the light of experience, I wish I'd glued and rivetted 3mm ali sheet instead...

David

quote:

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Originally posted by David Jenkins
In the light of experience, I wish I'd glued and rivetted 3mm ali sheet instead...

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quote:

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Originally posted by blueshift

Wouldn't that bugger the torsional stiffness though?

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second the 'watch for distortion' thing.

I fully welded the floor and it did distort a bit. Just hope I dont run over any discerning locost builders!

Stopped the 'bong' by welding an extra rhs support across, which will be covered by carpet and whatever anyway.

atb

steve

Just go over the joint with seam sealing mastic after welding, job done.Gives a neater appearance too.
Bob

The seam on the underside of my floor was very tidy indeed, even if I do say so myself.

This is mainly because I was welding 2mm ERW tubing onto 16swg sheeting and as I had cut the sheet so that the edge ran down the middle of the ERW I was able to direct most of the heat into the ERW and just melt the edge of the sheet nicely. This gives a very nice smooth weld and really doesn't need much linishing or finishing. It also stands a good chance of being water tight and seems very strong.

The "boing" thing is a very slight problem for me at present but I have run a couple of 3/4" square ERW under the front and back of my seat which should help.

Cheers,
Craig.