Floor

[Jimmyd]

Given that I just happen to have a sheet of 2mm mild steel I was going to use it for my floor. Given the thickness and the fact it'll be fully welded would it be sensible to bolt seats to it? Using good sized washers or small plates to spread the load.


J

[frankie boy]

HI Jimmy
That’s how I did my car. I stitched wielded round the floor to stop it from distorting. Bolted the seat to that with large washers. No problem with SVA.

[Jimmyd]

Thanks Frankie. Just what I wanted to hear!!!


J

[adrianreeve]

Been wondering about this aswell. If you use ali for the floor, is it OK to just bolt seats to the ali if you use big washers? Seems to me that in the event of an accident, they would just tear?

What does everyone think?

Adrian

[Chris Gibbs]

My advice would be that if you're going to use ali I would weld in some 40 x 3mm steel trip to take the seat mountings, from the outside of the chassis to the transmission tunnel. There have been SVA failures when the tester believes that aluminium isn't sufficiently strong.

If you're using ali, bond the floor in place with polyurethane adhesive/sealant (Sikaflex or similar) as well as riveting, it all helps the chassis strength.

Cheers

Chris :)

[MikeB]

I have ali riveted and bonded floor and will be using the technique chris describes.

However do the bolt heads protude under the car? or is there a nother way?

[flyerncle]

A little heavier,What about 2 strips of 25x25 or 25x50 across between the chassis rails and bolt to that, surely they could not knock that back and it would be very strong.
Gives rigidity and a bit more side impact protection.

Thoughts on this one....


Cheers all

Flyer

[MCD]

A little heavier,What about 2 strips of 25x25 or 25x50 across between the chassis rails and bolt to that, surely they could not knock that back and it would be very strong.
Gives rigidity and a bit more side impact protection.

Thoughts on this one....


Cheers all

Flyer


thats what i intend doing next week when my subframes arrive for the bucket seats. 2 x 25x50mm rails between the outer chassis rail and the prop tunnel...all ali floor to save weight bonded and rivited

[UncleFista]

If I was building again, it'd be an ally floor for me.

The gap between chassis and steel floor is a lovely rust trap >:( even powdercoated. I reckon powdercoating the chassis, then fitting an ally floor would stop any rust.

On my car, rust has got hold right at the back of the floor, just in front of the axle. Rust is pushing the floor away from the chassis in between "stitched) welds. With it being welded it's not an easy job to remove, clean up and replace either ;(

[les g]

visitors to the 3ge stand at Exeter show might have also have spotted that they had put in some extra box sections for seat mounting :D
as for sealing the floor schultz is really good and what do people think of putting in a couple of strategicly placed drainholes
les g

[Cobra289]

I think I prefer steel floor and stitch welding using Zinc weld through primer to provide some protection, then just use Sikaflex to seal the seams.

I have just had an idea, what about spot welding the floor to the chassis rails. Has anyone done that before? That would be less distortion then stitch welding, but I guess could only be done on the outer rails and not the transmission tunnel ones.

Adrian

I agree with the Sikaflex to seal the seams, or some Epoxy putty.

A friend of me did make holes of 6 mm at the steel plate at the edges rails but also at the tunnel rails, he did fill weld the holes and he is pretty shore that it is better than stitched welds. No distortion of chassis, like some people think about.
The fill welds where made jumping from corner to corner to spread the heat, and the plate is about 6 mm from the edge so that the holes are close to the inside wall of the tube.

Regards,
Cobra289

[flyerncle]

Somebody correct me if wrong and please do,is there not an ever present possible problem with the Galvanic reaction between ally and steel to consider,

The old white powder problem (not drugs Gents ) seen in landrovers etc.

Just re-reading the post's and Adrian-H's idea of spot welding the steel sounds good too.
And yes you need a spot welder.
With regard to bonding I have seen a vehicle roof glued on and then picked up with a crane mounted magnet and shook about violently and it held,I myself have used similar stuff to replace panels but it is not cheap.
Your thoughts ?

[spud69]

On my floor i put a thin weld every 3" starting from the side rail and letting it run down and bond into the floor sheet, 16 gauge steel. After powder coating the finish has bonded the rest together very strongly. Its had my 16st clambering all over it recently and its stood up fine.

It may not have been the best way but it seems more than adequate.

[flyerncle]

Adrian
It is possible to spot weld one side ie: single sided weld and the only difference is that a large earth is used as opposed to the clamp method you referred to previously,Basically all you do is clamp a large copper earth tag to somewhere nice and clean and place the other electrode on where you want the weld and pull the trigger. The one we use at full duty cycle will blow holes in three body panel skins no problem and when you pull the trigger the cables lift a few inches. Well known for blanking SIM cards and screwing up mobiles.

Cheers ALL

[bobbyh]

what about a sheet of carbonfiber riveted in place?? this is what i was thinking about but i never thought about the rivets coroding and stuff.

would this be a good idea or am i been an idiot

[Cobra289]

what about a sheet of carbonfiber riveted in place?? this is what i was thinking about but i never thought about the rivets coroding and stuff.

would this be a good idea or am i been an idiot

Carbon fibers in contact with aluminum is a big problem. The aluminum will go into powder very fast. [Think and the rivets]
So use stainless steel rivets would be better. Check if they are water tight rivets, and don't forget that they are heavy to install. [you will need more force]

Regards,
Cobra289

[fabbyglass]

visitors to the 3ge stand at Exeter show might have also have spotted that they had put in some extra box sections for seat mounting :D
as for sealing the floor schultz is really good and what do people think of putting in a couple of strategicly placed drainholes
les g

You been "borrowing" manhole covers ...........:rolleyes:

[Peter-C]

I hope to plug weld the steel floor to the chassis. I will follow this up with spot welds on the inside of the chassis as per Spud69. Has anyone used this technique on their roadster. I've just had a practice at welding 16 gauge. Seems good. The problem is how do you seal the outside of the floor. Please see attachment.

Peter

[Cobra289]

This like perfect position.
Seal with the car industry kits, ask for the bond type that is used for car bonnets.
Other solution is to use Epoxy Kit.
For all the the aplications the key is cleanness, make de bond area as clean as possible.

Regards,
Cobra289

[Neil P]

Seam welded mine all round the underside to stop any water getting in. Painted the inside which has filled up the gap between the floor and rails. Nothing fancy but looks effective at the moment.

Neil