Prep before tig welding

[fredh]

I'm trying to learn to tig weld on my own. What are some of the ways to prep steel before welding. (Wire wheel,glass beed,lacquer thinner,sanding)I'm working with new mild steel A38. 3/16 thick at this time.
Thanks
Fred

 

[sqznby]

Grind the mill scale off with a flap wheel where you want to weld. You could wipe it down after with some thinner but, it's not necessary.

 

[Thumper68]

I usually hit it with the grinder to get rid of scale and a quick wipe with acetone.

 

[dogdog]

I usually just wire wheel and wipe with prep-all .... that is about it. It's not as corrosive to rubber as acetone / denature alcohol. and dries pretty quick, smells like the thinner, but no residue like the thinner. Thinner, Acetone, Denature alcohol also would work.... some people use those "non-chlorinated" brake cleaners.

Stainless, I do the same thing with a dedicated brush and back purge. with argon or solar flux.

Haven't done aluminum yet, cause I don't have access to them or a project that requires it. I heard you use dedicated stainless brush for it

a gallon goes a long long way....

https://www.ebay.com/i/331088742922?chn=ps&dispItem=1

 

[matt_i]

If its hot rolled, as was said, flap wheel.

If its cold rolled, degrease, but let it dry first.

I try to stay away from acetone.

 

[bobabuee]

you tube is good source for learning to tig weld ... there is a lot good people teaching like eastwood,chuckyE2009 , tigtime, to name few. key is cleaning parts, tungsten sharping, its lot to learn just starting myself to learn.

 

[VR6ix]

Flap wheel on an angle grinder works great to lightly cut through the mill scale. If you are delicate with a cutoff wheel or a grinding wheel you can do the same thing. Wire wheel wont do much to cut the mill scale. Get rid of the grinding dust before welding but no need for acetone or other chemicals.

Best way to learn is lots of practice time. This means torch time and not grinding time. TIG on mild steel can be fairly forgiving. I like to grab some 11ga off-cuts scrap from work and practice T-welds or lay them on top of each other and do lap joints. The shear edge is "clean" but the mill scale doesn't matter much for practice work. I nuked this piece by not allowing time between welds for it to cool but no prep-work at all - it's just practice. And it's damn ugly in the photo!!!

Good on-topic vid from Utube, Jody/WeldingTipsAndTricks:

 

[kazlx]

Glass bead can cause problems. Wire wheels don't really do anything. Like mentioned, if it's hot rolled, you can clean lightly with a flap wheel. Cold rolled, I usually just degrease. I use clean gloves that I just use for TIG and wipe the filler real quick as well. Make sure the gas is flowing before you start your arc.

 

[fredh]

Thanks for all the replys. Never new about gas flow before starting the weld.

 

[dr_clyde]

For hot rolled steel, I just quick grind off the mill scale with a hard disc or a sanding disc. Cold rolled I degrease with some acetone or lacquer thinner. I rarely do anything to aluminum or stainless, unless it's dirty or heavily oxidized.

I have never cleaned my filler, although I keep it clean and dry in rodguards.