Learn how to weld threads

I went to see a mate of mine last weekend, we did some grinding on his 740T5 project to clean up some rusty spots here and there, we found a small hole in the bottom of the chassis rail and he went to borrow a friends welder and came back with a proper, professional MIG. The welds went on soooo much better than with my hobby MIG (Clarke 150te). We did some practice welds to set it up how we wanted it and I couldn't believe how much easier it was to get a decent, solid bead. The wire feed was super smooth (unlike my Clarke that kind of pulses the wire out) and there was loads of shield gas coming out)

I guess its no surprise when you look at the price difference between the two machines.

Though I did have a problem when welding upside down (first time I've tried it) When the wire hit the metal and melted, it just kind of fell off in a ball and most often, went down into the shroud. Is that normal? Is there any way round this apart from turning the car over?

There are a couple of awkward patches to do in the floors in the area of the forward jacking points and outriggers. Is it best to weld these from inside the car?


PS, good idea on the How to weld thread.

No wire feed probs like that on my 151TE, its smooth enough for rock 'n roll. Might be a minor prob like rusty wire? Clogged liner, manky swan neck etc. Mine was giving a bit much of the brown dust recently, chucked in new liners, swan neck etc and all is good and beads neater too. No doubt it's never gonna be as good as posh kit, but it's good enough for for DIY tomfoolery.

My spare welder (sip migmate something or other) did this, so I replaced the liner with one from machine mart - works a treat now - smooth as you like. The liner was about seven pounds I think, and although is for a different welder, is easy to adapt.

I have pics somewhere of how I did it - I guess this thread would be a good place to add them ?

I've got plenty more to do on that Zodiac so keep an eye on that thread. I'll be working upside down, outside, limited access, Clarke 150 MIG on a 50m extension lead and disposable CO2 bottles so you can see how it's done

Good pics there. The Clarke's a bit less hassle to change the liner - but loosen the cover forward of the wire feed roller (4 screws) don't attempt to remove it - there's nuts on 2 of the bolts ... these let you know they exist by the little "plink" sound from the 'hidden' compartment. For which you have to remove handle, remove cover screws and rotate back the whole cover.
Swan neck replacement's well worth doing, and it has a small liner of it's own. I bought a kit from Wilstar, which has the lot in plus shrouds and nozzles.

I think this would make a great Wiki entry SOC .. good idea... I need to fix the wiki, having broken it somehow! ...

Thanks for all the knowledge share folks.

Be sure to release the tensioner each time you put the welder away. I never used to and ended up with a non-springy spring and eventually twisted the whole mounting to hell.

I have a SIP MIGmate with a new liner. From before it's much improved! If you can, go for a steel liner which has less resistance, and that can unleash a new breath of life into a tired welder.

One thing. Do you guys overlap, or weld in like for like with the panel meeting up spot on, hence appearing as if it was never welded before?

A bit of both, it depends on the circumstances. Butt welding (no overlap) is a right pain but necessary at times, overlap is easier but messier (and creates a double skin perfect for the rot to set back into if you arnt careful) Quite a lot of the repair work I see involves tearing off a rusted out patch and doing it again properly.