Tig welder?

[pietpetoors]

I want to buy myself a TIG welder. But I see you get combination machines which offers MIG and TIG.

I see some of them says "not suitable for Aluminium TIG welding" , why would it not be suitable for Alu welding?
Like this one
https://www.takealot.com/matweld-welder ... ID66968725

I also see it says you can weld Alu with MIG, did not know you can weld Alu with MIG< I always thought you can only do it with TIG.

[Cres]

Aluminium uses ac witch a lot of tig machines can't do and s/s or mild steel is dc takes a lot of practice

[pietpetoors]

Thank you, so if I want to use it for Alu and mild steel it must be AC/DC

[pietpetoors]

Is there anybody who have one of these combination machines? MIG and TIG ?

Are they working OK or is it better to just stick with a TIG

I do not weld much, I need it mainly to weld body panels on vehicles and the odd Aluminium frame every now and then.

So if I stick to TIG something like this might be better?
https://arcwelders.co.za/matweld-tig200 ... ig-welder/

[Mud Dog]

For what my opinion may be worth, I would just stick to TIG. The whole wire feed thing can be a hassle IMO .... yes nice in many instances but with TIG one can feed as much as needed ... you can just flow existing metal together or add without having to constantly adjust or switch off wire feed rates. With TIG you can also change wire thickness at the drop of a hat if you need to.

Just my opinion and others might disagree with reasons that are valid for their specific use.

[pietpetoors]

Thank you.
How do one determine what thickness of filler wire you will need?

For example if I use it to weld mild steel body panels of 0.8 - 1mm what thickness of wire must I use compared to let's say 5mm mild steel?

Same with alu, let's say I need to weld between 2 and 5mm Alu ?

Can one just stick to one thickness of wire or do you need different thicknesses?

[Mud Dog]

The thicker the wire the more heat it draws so on thinner material it doesn't always make sense to reduce the wire size, however with thinner wire you can reduce the welding amps and reduce the heat that way and get a better penetration and flow. On thin material like body panels I would use a wire that,s about 1½ times the material thickness, so a 1.5mm filler rod is pretty much ok IMO.

When you're welding 5mm material it tends to swing the other way .... the material draws away a lot of heat, so a thinner rod like 2mm 2.5mm is better in my general experience. I'm not a qualified welder, so what I've learned as I went along might not be what's recommended in the trade. There must be guidelines available on line and I suggest you look at those first. Often there is also some info about this that comes with the machine.

[Stef]

I've always fancied MIG but with our alu canopy builds the TIG worked a charm and I've seen that same welder do stainless just as well

You could get those hose kits for the normal inverter welder, much cheaper but as mentioned you can't do Alu with it as it is only DC. A decent TIG with the AC/DC and all the settings would be the thicker end of R20k, so if you can lay your hands on a used one that would be 1st prize...and get a pro to set it up properly for you...it can be quite daunting in the beginning.

[maurits]

I would always use MAG for automotive and other thin body panel stuff, not TIG. TIG welding proces puts substancially more energy/heat into the base metal relative to the filler. This means more shrinking when cooling down. More tension after welding makes it harder to keep things straight (or properly curved).

Stock aluminum is fairly stiff due to fabrication. After welding you stand to lose all that. I would prefer blind riveting. To prevent corrosion use regular zinc plated carbon steel rivits. Don't use stainless steel rivits on aluminium.