i have aquired some secondhand steel, some old school table frames, but there 1.25 in steel instead of 1 in,

will this make a great deal of difference?

If its 16swg then i will be stronger, 18swg same sort of strength but a little lighter maybe.

Either way should be fine unless you want to race it then you need book size.

There used to be a great write up on the links where someone did a thesis on the chassis and uprating it, maybe someone else knows where this info is now.

Regards Mark

Just beware of the quality of the material. It was probably the cheapest most basic material available in the design spec that still resembled metal.

Cheers

and dont forget that if it hasnt rusted, there is something there stopping it rusting, and its probably best to grind it off to prevent the weld being contaminated.

IME the tubing used for furniture is quite thin walled, so welding could be a PITA.

The other aspect is the cost, the correct tube comes in at around £125, probally less if you shop around. Its unlikely you will build something for less than £1,250 so this in reality could be viewed as a minor cost saving.

For peace of mind and ease of build I would purchase new metal.

I also had a supply of old school tables, in the end I used this material to build a rigid build table and ordered new for the car.

Regards Mark

I never had problems with new steel, but when I bought some surplus EW tubing, part of the seam wasn't welded at all.

Buyer beware, there may be a good reason it's surplus.

I didn't build my chassis so dunno cost of steel but from what I read, it is one of the cheapest parts of the car.

Do you trust you life to some manky tables designed to support a few kg?

If you are still insistent, then cut it to see what the cross section is like. And after dressing it up (filing and sanding down the end), you'll be able to measure thickness and see how well the weld is formed - post a piccy on here as I'm sure there are others more knowledgeable.

You could even try testing it - see if you can break the join by bending the section or trying to splay it apart with a wedge etc.

TBH it should be ok but then again what's the worst thing that can happen if your chassis snaps in half when you're tanking along at 90 mphh?