Add strength for little weight – seam welding

So, I remember from years ago, a friend of mine told me how he prepares RS2000 shells – after buying a second-hand one in good shape, it would be stripped back to the metal and seam welded rather than spot welded.

Mine isn’t seam welded where some of the strong panels join the spaceframe, but stitch welded (i.e. one cm of mig welding for every 5 or 6 cm of space). It’s quick, stronger than spot welding, but let’s face it – it’s an economy solution.

So, now I want you to queue the Ghostbusters theme in your head and hear me sing “welding makes me feel good”. As a result, I thought I’d quickly try a couple of quick seams in an easy to weld area to see if it’s worth the hassle. Quick answer is yes.

There are a couple of issues with the quick approach I’ve taken to see if it’s sensible.

  1. Firstly, grinding the existing the existing powder-coat back isn’t too tough a job (circular belt on the dremmel) but you need to go back quite a way, which I didn’t. The heat of the weld made the powder-coat peel back. I’m going to get a blow-torch and see if this will get more of the powder-coat off. This leads me to my next point:
  2. The powder-coat gives off fumes when burning away. I’ve had a sniff of this and it’s not pleasant. I will need to do the burning off with the garage door open, ideally with a breeze. Once I’ve burnt off the bits I want off, I’ll then weld it. One big burning. Maybe with a fan.
  3. There is a little inevitable powder-coat down between the gap of the panel and cross-member it’s stitch-welded to. This will cause a little pollution of the weld. I have a really nasty pointy grinding tool for the dremmel which gets most of the powder coat out. It’s evil, and I’d love to turn it on a dentist some time.

So, here’s the welds – they look good and really nicely round the corner off. The holes aren’t blow-throughs but screw-holes from whatever was mounted on there.

And here are some photos:


Here you can see the first weld, and the second shows stitch between the seams.

Feed the attention-whore