Feedback needed please

[bainsk8]

Hi guy's I am new to welding. I have done much reading over the last few weeks and have taken on board a lot that has been said here. I am using Argon/co2 mix contract cylinder. 0.6mm wire.

I did have a practise run last week and it was very difficult to set the welder up and with a bit more reading I learnt that my liner needed replacing which I done today. I now have a steel liner installed and noticed a huge improvement and produced the sample piece below. I'm working with 1mm sheet metal and have labelled the welds in the photo's to what I thought was going on.

And the other side showing penetration.

Any feedback would be greatly appreciated.

 

[peteypt]

Hey!

The one you have labelled 'best' ain't bad, although for my liking I'd say it's sagging a little too much underneath (too much penetration) Infact a lot of the ones you've labelled 'too cold' have massive penetration!

Remember, wire speed, arc length, tip distance and travel speed all influence the weld. For 1mm sheet, maybe try lowest setting and hold gun in one place, tip about 3/8" from the metal with the gun nice and square and pull the trigger. Now adjust the wire speed to get a bacon sizzling in a pan kinda sound. Too high and you'll feel the gun start to push you and you'll get loads of splatter. Too low and you'll get an arc, the nothing until the wire touches again (or you'll get wire burnt in the contact tip ) You can hear and feel when it's more or less right.

Then keep your 3/8 and with the wire speed set to voltage start a run. Try pulling the gun, then try pushing the gun (you'll prob notice pushing gives a flatter bead with less penetration, pulling gives slightly narrower with more penetration) I tend to push on thin metal, but that's my preference. Your travel speed with influence the amount of metal you lay down, and ultimately the heat. There's an optimum, to fast, little penetration, to fast you'll lay a load of weld on top of the metal, but still get little penetration. Just play around until you get what you want / need.

Remember, as you start welding the metal heats up, to less 'preheat' time is needed, so speed up the travel to prevent overheating.

Welding 1mm sheet in 1 run ain't the easiest thing to do, but if you really want to do it in 1 run, I'd use the setting you call best and use a brass or copper heatsink behind to join / weld site. That'll cut back on the sagging, and take the heat out the metal to save some warpage.

You'll find it better on thin stuff like this to do a stitching kind of weld, like Malcom describes in the tutorials for thin stuff. I'd start by practicing doing a few 'spots' on the metal, watching the weld pool to see how it forms and melts the base metal, to get the feel for how long you have before you blow holes. To do a run, you just stack them together, slightly overlapping the previous weld 'spot'.

Note though that this technique is only really suitable for thin stuff due to potential cold laps.

What are you looking to weld? Guessing by the 1mm practice you're planning a car project? If so, you find the stitch method works best until you really get the hang of things as it keeps the weldpool small, meaning you don't blow holes in your motor

You'll also find when joining thin stuff that you want a good fit. You'll have plenty of power to fuse 1mm plate, so butt it right up and stitch it together. To much of a gap and you'll be holier than moses

Practise makes perfect, but you're doing pretty good. Certainly looks like you control the gun fairly well because there's some neat welds there, next to the holes :thumbs:

 

[cumbriasteve]

The one you think is the best is in my opinion a little flat and as peteypt mentions, has sagged through a bit, although it would be more than acceptable for a car repair and a damn sight better than many welds I have seen get through the MOT.

Top right and the top left 2 are the ones I think are about the best, nice welds and excellent penetration, if those are your 'learning' welds then you are doing great.

 

[bainsk8]

peteypt and cumbriasteve thank you both for leaving valuable constructive criticism. You are absolutely right I did have the voltage up more on the one I have marked that I think is best compared to the two on the right that I have marked too cold. Now I have a visual of what I should be achieving I will reset the gun for that bacon sizzle sound and lower the voltage.

I will post up my results of laying down some practise stitch welds, push pull and plug welds.

peteypt you are also right I have a 1969 Land Rover to repair, door pillars, both footwells and some other patches on the bulkhead.

Thanks again chaps there is a lot of info for me to work with.

 

[peteypt]

No worries, You'll have plenty of fun with the landy! I've just done a floor replacement in a friends 2001 disco. No idea how it got so rotten *wet dog blankets* *Cough*

 

[Chickenjohn]

You're making the usual mistake of beginner welders in thinking you have to run a continuous seam in 1mm for car repairs.

Not so, the weld bead has to be continuous, i.e. no gaps but how you get there can be stop start, highly recommended to read Malcolms "Thin Metal technique".

This is how pretty much everyone (myself included) does bodywork repairs on cars.

Thw other disadvantage of running a long seam in one go is the amount of heat you are putting into the panel may lead to excessibe distortion and blowing holes in the thin steel, the Thin metal technique minimises this:-

http://www.mig-welding.co.uk/thin-metal.htm

http://www.mig-welding.co.uk/flash/controller-stitch-weld.htm

 

[bainsk8]

Thank you Chickenjohn, I have taken a look at them and the links are of great help.

I will get some practising in at the weekend.