O A welding.

[maddog]

After getting a pair of 80 cu OA tanks from my welding supplier for free (funny story) I made a cart and set to practicing my welding technique so that I have it down.

I just love O A welding. Its clean,quiet, gentle and unhurried. You can see exactly whats going on and you can stop and start whenever you like. I have a little Harris 5090 torch with a shutoff on the handle that lets you keep the valve settings. Its a beautiful little torch.

Ive been practising on 16ga sheet metal. The O A is for the small stuff. I was surprised that the time I invested in practising stick seems to have benefits for O A too and I got dialed in fairly quickly on all the basic welds. They say its all about puddle control and I guess once you get a feel for that its useful in all welding processes. The only weld that gave me trouble was the fillet which took more practice than all the other welds combined, but I finally got the hang of it after I took the time to put a pair of cheater lenses and a lighter glass in the goggles. It helps to be able to see - duh! It wasnt hard to get a bead in there but I found it very tricky to get the puddle to wet down to the root w/o blowing a hole in the vertical member. At first when I bent them over for testing I found the bead was just a bridge and not fused at the corner.

Now its on to out of position welds.

[cami]

It's a great process to learn. If you ever have to pick up a TIG torch you'll have very few troubles if you can already do OFW. I haven't welded with it in a personal or commercial setting in years and years but brazing or braze welding jobs pop up sometimes.

Can you take a course where you are? My learning experience with OFW was being given a torch, a few pointers, and getting to it...but my boss was paying for the time and the gas....Some formal instruction later on really opened my eyes.

OA isn't necessarily for the small stuff by the way....I have an Air Liquide #9 tip that can get a puddle the size of a quarter going. The filler rods disappear very quickly, and should the tip backfire you get one heck of a shower. The heat input to the work with OA is bad enough but this was insane...haven't used that tip since I was introduced to arc welding.

[maddog]

cami,

Thanks for the encouragement. I would love to take a course but there isnt much in my area. What I know about stick, I taught myself by practice and hanging out on the welding forums. I figure it will be the same for OA. My big ole IdealArc has TIG, I have all the stuff for it but figured I would wait till I got comfortable with OA. Other people have said the same as you that its good preparation for TIG.

[andy ebbers]

if you are able to master decent welds with the o/a torch and a filler rod, then you are well on the way to mastering any other method of welding! and, you will have a better appreciation for TIG welding technology. there is a reason why many welding courses start with gas welding! Andy

[KYBOY]

I learned OA welding using cloths hangers and #9 steel wire for filler..I have a friend who was a OA welder on Nuc. subs and he taught me a few tricks..He was certified to 95% penetration on Nuc. piping..Other than the heat I love OA welding..

[cami]

What on earth is 95% penetration?

I've never heard it expressed as a percentage. In my working life penetration issues have been expressed in terms of being too much(think globs hanging inside the pipe), or too little(a low spot/undercut). Either would result in failing a procedure test.

Any welding procedure test I've done wanted root reinforcement of about 1/32" and cap reinforcement not exceeding 1/8" if expressed as a percentage this would always be in excess of 100%.

You'd be suprised what welding codes (up here in Canada) allow for faults in pipe welds such as lack of fusion... but in a nuclear plant things are different. No faults are tolerated, period. Not one speck on your x-rays...no inclusions...no fusion issues...no undercut on the inside or outside of the pipe....nothing less than perfect....anyway...

Here's som OA content:

Funny thing though....in British Columbia we still have a PWP, or prequalified welding procedure(a common, industry-wide pressure vessel welding procedure) on the books that uses OA....but I don't know anybody who has it.