Fillet weld

[rorie]

I read a lot on here about a 135amp mig only managing to weld about 4mm steel. Am i correct in assuming this is just for butt welds? If i want a fillet weld, surly the steel thickness doesnt really matter?

 

[BrokenBiker]

the general rule of thumb is that you use 1 amp for every 1 thou of work material. so 135 thou is 3.429mm. which means on full whack you could get a puddle of that depth, so you could weld material that thick in one pass and get full penetration, in theory, your choice of shielding gas will alter this slightly, also the temperature of the material will affect it too.

it is my understanding that you do not get as deep penetration on fillet welds because of the angle of the work and so on. you would need to perform multiple runs in order to get a good strong weld on say 10mm plates with a 135 amp welder

 

[Lawnmowerboy]

You will find you need a lot more heat in a corner fillet. Even with a weld prep you will feel like you need a lot more power. Made some security boxes from 4mm last week and had the 260a tradesmig on power setting 8. It's really not nice welding thick stuff with a titchy welder knowing you need lots more power!

 

[BrokenBiker]

try welding 5mm fillets with a 100amp, takes half a reel of wire!

only for show though, nothing structural so im not worried about it breaking.

 

[backpurge]

As said above, fillets generally need more power