Welding - any tips

Hi guys,

I'll be hopefully starting some welding practice this weekend as I'm hoping to clean the bay quite a lot. Any tips - I've read up quite a lot but was planning on just having a crack on some test pieces first then getting stuck in lol, never really hurt before

Apparently 80% of MIG welding is getting the welder set up correctly for the thickness of the steel. I had a go ad welding a new arch onto a mk1 cab, and just kept putting holes through the thin steel panels, because the MIG voltage was set too high. Better to start with a lower voltage and work your way up. As far as wire speed goes, that depends on your speed, so probably a bit trial and error to be fair. I reckon if you get some 1/2mm sheet mild steel and just have a go at welding bits together, you'll find it's not all that difficult.

^^^ yep all in the setup get yourself a scrap piece of similar thickness to what you are going to work on. Get a good flow of gas. Use the correct wire thickness for the job for bodywork 0.6mm is best.
Next to set up the welder you want to pull a constant bead across your test piece using a low current and an average to low speed.

If the weld is sitting on the surface your current is too low.

If you are blowing holes through the piece your current is too high.

If the welding wire is spitting and bouncing of the wire speed is too fast.

If the wire is melting back to the welding tip then the wire spped is too slow.

When pulling a constant bead and everything is nicely set up you should hear a lovely hummm/buzzz.

If you are a novice it is best to start of with stitch welding where you literally make lots of tiny spot welds all stitched together in a row. These are easier to grind back too if you are looking at smoothing the bay. For grinding back the welds use abrasive flap discs on a grinder not grinding discs. It goes faster and leaves you with an easier surfae to prep.

There's a really good book sold by old pond publishing I think.... I'll look it up when I'm at my parents...

I really need to learn how to weld. It's the only skill I don't have and it's holding me back!! Oh and a full machine shop and ramp would be nice too

I read somewhere that if you MIG stainless, you have to rust treat it afterwards. Is this true?

I was lucky enough to have a friend TIG weld my downpipe sections together and it's super neat, never seen such tight welds. Is that only possible with TIG?

What is TIG out of interest? LOL!

great thread.
I too would love to learn how to weld.
what kit have you bought then Saysomestuff ?

Mig = Metal inert gas and uses the filler metal as the electrode.

Tig = Tungsten inert gas and uses a tungten tip as the electrode. you then create a weld pool and use a seperate filler rod. It's the only way to weld aluminium. Think of it as finely controlled gas welding.

Mag = Metal active gas like mig but you use a different gas which actively prevents oxidisation.

Millspeed is a good one to speak to as his doctorate was on spotweld heat treatments. I've forgotten everything I learnt at uni pretty much, although I was a member of the institute of welding.

Certain stainless steels develop martensitic regions when welding and can corrode. Can't remember the grades that suffer badly from it though.

dirtytorque wrote:great thread.
I too would love to learn how to weld.
what kit have you bought then Saysomestuff ?

I was bidding on a fairly decent welder but i missed out - might end up renting one tbh, I can't see a persistent need for one.

Great info though - it's one of those things that seems really scary but actually (hopefully!) ends up being common sense.

Cole, you can get reasonably cheap ones on eBay. Just get one and do what you need to do and then re-sell it if needs be!

Just been doing a little research.
From what I can gather TIG is a slightly more involved slower process but gives a finer finish.You can also lower amperage for fine control for finer metals.
Also apparently tig welds are stronger,so for structural stuff TIG is the way to go..
It is differcult to master tho..

MIG is quicker easier to learn but cruder.


However...
I found this quote.

IMO if you are questioning whether you need a TIG or MIG, then you aren't doing enough welding to make the TIG cost effective. The opinion does not apply if you have more money than you know what to do with.

In other words if you have to ask....

Pls note this is the result of about 20 mins research.

dirtytorque wrote:Also apparently tig welds are stronger,so for structural stuff TIG is the way to go..

For deep welds you can put down a single tig weld at the root of the groove you've made, then follow it up with several overlaid overlapping mig welds.

I've seen gun repairs where the action has been tightened by laying several thin tig welds across the hinge surfaces.

Toad wrote:

dirtytorque wrote:Also apparently tig welds are stronger,so for structural stuff TIG is the way to go..

For deep welds you can put down a single tig weld at the root of the groove you've made, then follow it up with several overlaid overlapping mig welds.

I've seen gun repairs where the action has been tightened by laying several thin tig welds across the hinge surfaces.

If you had to buy one which would you go for?

For occasional general non-pro use I get the impression that MIG is the way to go?!?!???Albeit a bit of a compromise.?!?

dirtytorque wrote:If you had to buy one which would you go for?

For occasional general non-pro use I get the impression that MIG is the way to go?!?!???Albeit a bit of a compromise.?!?

I'm just watching a couple of second hand ones on eBay....not that I can afford it at the mo

mrbeige wrote:

dirtytorque wrote:If you had to buy one which would you go for?

For occasional general non-pro use I get the impression that MIG is the way to go?!?!???Albeit a bit of a compromise.?!?

I'm just watching a couple of second hand ones on eBay....not that I can afford it at the mo

Glad I'm not the only person that tortures themself this way.

dirtytorque wrote:

Toad wrote:

dirtytorque wrote:Also apparently tig welds are stronger,so for structural stuff TIG is the way to go..

For deep welds you can put down a single tig weld at the root of the groove you've made, then follow it up with several overlaid overlapping mig welds.

I've seen gun repairs where the action has been tightened by laying several thin tig welds across the hinge surfaces.

If you had to buy one which would you go for?

For occasional general non-pro use I get the impression that MIG is the way to go?!?!???Albeit a bit of a compromise.?!?

I was going to buy a really good second hand MIG a while back and still would like one. MIG is definitely the better choice for our sort of use. Take the reel of wire off and store it in the dry when you're not using it so it doesn't corrode.

You should be able to do everything from light panel work to heavy structural stuff by laying several beads of weld down. We currentyl have 2 arc sets at home, a general 13amp set and a 15 amp oil cooled Oxford unit for heavy duty stuff.

I have a mig in the garage but it ain't strictly mine more the father-in-laws and the brother-in-laws. Needs wire, gas, and a new nib or end. Haven't had any cash to sort it out and get some practice but will when I finish the build.