im not sure if i should rivet or weld the floor on what you guys recon?? if i weld it should i get it done right the way round or just spot welded??

Is it a steel or ali floor?

If it's ali you gotta rivet (unless you have an ali chassis).

If it's steel then I would fully weld it. You probably know this already but don't actually do it all in one go. Stitch weld opposite ares etc. That way you may be able to minimise the heat input and therefore the distortion.

You will almost always get 'popping' when you step in the car. I've minimised it by running a couple of swages down the steel sheets before welding them in. Still hasn't fully worked though.

HTH,
James

[Edited on 1/11/04 by James]

it you weld a couple of extra bars across the car and mount your seats off them, the popping will stop.

be dead careful how you weld or your floor wont be flat!


atb

steve

quote:

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Originally posted by stephen_gusterson
it you weld a couple of extra bars across the car and mount your seats off them, the popping will stop.

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Its a steel chassis and ive allready put in an extra couple of steel sections to stop the pop! but i still might rivet it in cause me welding isnt that hot dont get me wrong im all right on bits but the thought os doing long runs is a bit daunting!!

As I said, you don't want to do long runs as it puts a lot more heat into the chassis and encourages warping.

Stitch weld it but fully join all the stitches together by working your way around.

Welding it on does have the advantage that if your chassis has 'bananared' a bit then it may well pull it flat again! (It certainly seemed to work on mine!)

HTH,

James

lol james, i know that feeling... didnt sort the twist though!

Hi,
I fully welded my floor by the following method:

1. Place sheet and cut to size. Cut 1/4" small all the way around to accommodate the seam weld and minimise subsequent grinding.

2. Tack weld on the underside in a few key places.

3. Turn the chassis right side up and stitch weld 1" in every 6" all the way around the insides of the floor. Try to stitch in a manner where consecutive welds are as far away from each other as possible.

4. Turn the chassis upside down and seam weld 100mm (4" at a time in a similar pattern. Try to use a "neat" weld with the weld favouring the chassis over the floor. I was able to run the weld down the edge of the floor and just nicely flow it all together pumping most heat into the chassis tubes to ensure penetration but without the need to almost any grinding afterwards. This is the reason for cutting the floor slightly on the small side.

Once the chassis has cooled to some extent turn it over and liberally paint etch primer or zinc primer into the seam from the inside of the car. Etch primer is best as it is quite thin and will flow into the seam but will adhere extremely well to the metal. Once this is FULLY dry use car body seam sealer to form a nice seal all around the inside of the floor.

Hope this helps,
Craig.

welding it is then! cheers for the tips craig that seams the best way forward never even thought of making it smaller so your not welding onto the outside edge!!

I made my floor a little smaller as mentioned by Joel above.

There is a disadvantage though (of course!). When you put you ali side panels on, will you want the rivets on the outside of the car or the underside? If you put them in the underside then there's a good chance you'll have to drill through the weld to make the rivet hole. And of course this is the hardest part to drill through because of the welding!

Cheers,

James

i too did mine smaller, but it was craig who mentioned it! i did the side panels smaller too and welded them.

Sorry Craig!

Joel,
You side panels are steel too?

You sure this car will be any lighter than the Sierra it came from?

James

Pah! That's nothing compared to our chassis that's been machined from a solid block of nutronium. Almost had a black hole form in the garage last night, it was a tense moment!

James,
You are right about the side panels attaching to the underside. That's how I did mine and you need to run the linishing wheel over the welds to make sure they are nice and flush before fitting the side panels. However, if you accurately make the floor 1/4" (even 3/16" ) inside of the chassis outer edge then you should be okay because the rivets will be (hopefully) 1/2" in from the edge and will miss the weld. I used PolyUrethane (Polyflex) adhesive sealant when I fitted the side panel and even dipped each rivet in a little blob of sealant to ensure a nice water tight seal around the bottom edge. I had also already painted both the chassis and the floor by the time I fitted the side panels.

Cheers,
Craig.

[Edited on 2/11/2004 by craig1410]
Quick addition - Make sure that your rivets have sufficient grip range to hold together your ally sides, floor and chassis. My chassis is 2mm ERW so I had 1.2mm + 1.6mm + 2mm = 4.8mm to go through which was towards the top end of the grip range for my rivets (Gesipa Polygrip).

[Edited on 2/11/2004 by craig1410]

Linishing wheel? A thick grinding disc did the job a treat for me!

You're righ though- the worse of the hardened area can be avoided- not sure my ali cutting will be accurate enough!

As for the rivets- good point. I'm slighly better off though as my floor is 0.8mm IIRC, chassis 1.6mm plus 1.2mm= 3.6mm
I've so far sealed all rivets ('P' clips etc.) with bath sealant stuff- never know, it might do some good!

Cheers,
James

[Edited on 2/11/04 by James]

'bananared' That ones going in the Oxford dictionary update next year. term used for car chassis resembling rocking horse runners. I tacked mine 2" every 6" approximately on the outside and then put some in between them on the inside. If you haven't already got one, get a flexible nylon backing pad (£6ish screwfix) for your angle grinder and buy some 60 or 80 grit fibre disks. They are kinder and cheaper (30p each) than grinding disks and last for ages. I keep one on a cheap grinder all the time, ideal for linishing and polishing.

James,
What I actually mean when I say "linishing wheel" is one of those grinder type flap wheels which you can get at Halfords. They are much easier to control than a solid grinding wheel and give a much better finish.
Cheers,
Craig.

I guessed that!

I used course grinder to take off the majority of material quickly followed by a flap wheel to polish out the grind scratches.

James

[Edited on 2/11/04 by James]