Welding early 80s french cars - tips please!

[dean0]

Hi,

I'm currently repairing various holes in the floor of my old Peugeot 205.

The welds I've done so far are quite inconsistent i.e. it seems to spatter/burn through or sit proud on the surface. I'm really after some tips - am I preparing right/using the right settings?

Details:
Clarke 150T welder - power setting 2, low. Wire speed 4
Gas: CO2 pub gas

Welding 0.8mm steel plate to 0.8/0.6mm steel.

Pics of the surface after preparation:

Underneath, it was really awkward to get in with a grinder so I did the best I could with sandpaper

The plate I cut to fit in place - leaving bout 0.5mm gap. Two holes to plug weld to the original seam underneath

Earthing position - attached well enough?

The results - from the top - looks OK but not a lot of penetration

The results from below - you can see the trouble with onconsistency I was getting - some places it has almost burnt through - others there's hardly a mark on the underside

Any tips welcome

Cheers!

Dean

 

[malcolm]

80's French cars are the way forward. We've got a 1.9GTi in the barn waiting for some love and attention. Doesn't get any though.

Thin metal is a pain. Looks like you've prepared the surface well which is really important.

Your power settings seem high. The calculator would have you believe the lowest possible setting would still be too high. What wire size are you using there? 0.6mm wire might be easier on that lowest setting.

Did you wire brush the weld before taking the photo? Any photos before the wire brushing. Was the weld black? Not enough gas wouldn't help the arcing.

CO2 doesn't help much either - it doesn't maintain a very stable arc at the best of times, and that gets more of an issue welding on low power settings. It's something that will make this sort of work difficult, but not impossible.

I'd go down to minimum power and 0.6mm wire and work out a technique from there on some scrap metal.

 

[dean0]

Yeah, thin metal and big engines make for a lot of fun. Got any plans for yours? Mine's mainly a trackday/winter hack. I've got a mk1 MX5 for use on the roads in summer but it gets put away for winter as I never want to have to weld it.

The weld on the right of the picture taken from the top is as I welded, there are a few scorch marks which I guess means my shielding gas isn't being as effective as I'd like. I was also using 0.6mm wire.

I was suprised by the power level suggested by the calculator. I tried the first settings a while ago and just got a slug sitting on top of the metal rather than a weld. I've bought a new earthing clamp since (thanks Weldequip) so I'll try it again on my next repair.

The real issue I'm having is establishing a stable arc. Quite often when I first squeeze the trigger there's a loud popping and it makes a real mess before settling down.


Dean

 

[malcolm]

Could be a bad earth (needs to be as clean as the weld prep) or wire speed too fast for the power setting.

The 205 isn't mine. I'm working on a '67 Renault 4 with the engine from a Renault 5 Gordini (not the turbo version). Well, was working on it - been on other things for the last few months.