New weldor, intro and q's (long)

[jeffm]

For the last few decades of my life, welding has seemed to be a skill only in the grasp of those with long of beard and/or depth of wallet. However, after a xmas gift 'welding kit' from the folks and a pile of money on my own part I'm finally going to start welding. Just thought I'd say 'hi' and let everyone know what I'm up to to see if I'm going the right way.

My goal is to teach myself to be a decent gas weldor, maybe graduating to another process later. I suppose I could take a class. However I'm busy helping with a movie production, keeping a house in line, aviation, computer science and about 900 things so free time is never schedule-able.

I read 'Welder's Handbook' by Finch and have started reading a great Hayne's manual. This led me to start with gas, as they seemed to say to learn with that then you'll be able to easily pick up other processes. My stick roomate hates me for not getting a box or mig, but that's how it is. I've leased 1 ea 150 cu ox/c2h2 bottles from local CK. Found some rods, goggles, metal, grinder, vicegrips, etc etc and have enough things to basically weld. My feeling tho is I'll be buying welding stuff until I tip over :)

My home doesn't have a great shop or garage which pretty much limits me to working on weekends, when I have time to drag the mess into the sideyard, work, then put it all away. Nonetheless, I've played a few times. Sunday I did my first weld of two pieces of sheet, and built my first tool! (mech. finger, from Finch's book)

Hopefully I'll be good enough to build my own gas cart soon. That will be fun, and the two-wheeler I'm using now is a hazard!

Well, that's me, now for the questions!
First, when I'm cutting sheet or even thick angle the steel seems to melt back onto itself after I pass, and I have to go back and blow it out again. I admit I might be using the wrong tip, it's whatever one came with the kit. I'm using 20 psi o2
Firebrick: I won't even mention my current welding surface, it's that bad. But the only thing close to firebrick I can find is some of the stuff fireplaces are made of. Will that work? I've called masonry people, welding people, noone knows what firebrick is.
Tank size: I did two 150's, but many times I see a bigger Ox then fuel tank on gas carts. I guess that's a good setup for cutting. For welding I'd figure fuel would be bigger then ox, since acetelyne doesn't compress well, but that's me. What size to you use?
This is for arc, etc but are self dimming helmets worth anything? Finch kind of talked them down, but many people use them.
Finally, are those "retractable hose spools" worth anything in oxyacy kits? They look cool but frighten me for some reason, if that bearing seal decided to leak....

I'm sure I'll come up with more questions later! Thanks a lot for any help!

[Arbo]

The only one I'm going to answer right now is the cutting question. I used to have the same problem. My settings are 7PSI on gas and 40 PSI on O2. I keep the tip slightly angled in the direction of the cut. This tends to keep the heat going in that direction, and you will have less problems with your cut running back together. Practice.......and good luck. Keep it up, and you'll have alot of fun.

[Rocky D]

Originally posted by jeffm
First, when I'm cutting sheet or even thick angle the steel seems to melt back onto itself after I pass, and I have to go back and blow it out again. I admit I might be using the wrong tip, it's whatever one came with the kit. I'm using 20 psi o2
Firebrick: I won't even mention my current welding surface, it's that bad. But the only thing close to firebrick I can find is some of the stuff fireplaces are made of. Will that work? I've called masonry people, welding people, noone knows what firebrick is.
Tank size: I did two 150's, but many times I see a bigger Ox then fuel tank on gas carts. I guess that's a good setup for cutting. For welding I'd figure fuel would be bigger then ox, since acetelyne doesn't compress well, but that's me. What size to you use?
This is for arc, etc but are self dimming helmets worth anything? Finch kind of talked them down, but many people use them.
Finally, are those "retractable hose spools" worth anything in oxyacy kits? They look cool but frighten me for some reason, if that bearing seal decided to leak....

I'm sure I'll come up with more questions later! Thanks a lot for any help!

You don't mention what material thickness you're cutting....1/8" steel, use a 000 tip, oxy @ 20 and Acet @ 4...sometimes it helps to lean the tip back, instead of perpendicular.

Firebrick, is used for lining heat treat ovens, I only use it to silver braze on. You don't really need it.

Oxy tanks are bigger on carts usually because you use more of it.

Auto-dim helmets are OK, but have another one for a back up. I have one and use it most of the time. My other helmet has a #8 shade lens in it for heliarc welding.

Retractable hose reels....I think I'm with you on that one. We have one here, but I don't use it.

IMHO for what it's worth...have fun and be safe...

[Roger]

The dealer that sold you your gas should have gas welding booklet for free or small fee.

If your cut is welding shut with slag you have too big of tip or cutting too slow. Cutting torch should be traveling down cut line so fast it's just short of loosing cut. Gas cutting gets difficult on thinner than 1/8" so you angle torch into direction of travel so it is sort of cutting thicker metal cross section real fast.

[Steve W]

jeffm, welcome aboard. I get lots of great advice and help on this site form the experts and everybody else. I also check out these sites for knowledge and help.
http://groups.google.com/groups Just type in the search for what you are looking for

http://www.ytmag.com/cgi-bin/boards.cgi

I started out in 93 with a Miller thunder bolt and chop saw and 4" grinder. In 99 got my Miller mig and gas bottle and 41/2" grinder. Last Nov. moved up to act/oxy torch setup and thaught I had all I would be able to afford to get. Then I was surprised x-mas morning. My wife and kids bought me a Hypertherm 380 plasma cutter. Most expensive present I've ever gotten. Of course the next day I had to go to Lowes and buy a new air compressor. I absolutely love the plasma cutter.

[morpheus]

another possible problem with your torch cutting is that you don't have the torch tip close enough to the work piece. I've fought the same problem you describe off/on for a while and could never figure out what I was doing right the times that I cut cleanly. But just this weekend I noticed that I was holding the tip of the cutting torch a bit too far away. After realizing this and paying more attention to my technique I must say I'm getting much nicer cuts with my torch.

- jack

[Hobart Expert Rock]

JEFFM..........ALSO WELCOME ABOARD..........I THINK IT IS JUST TECHNIQUE BUT COULD BE WRONG AND HAVE BEEN BEFORE... TRY SOME DIFFERENT TECHNIQUES, HIGHER GAS, DIFFERENT TIPS, DIFFERENT METAL ETC......... SOMETIMES YOU GOT TO BE A METALURALGIST.........FILE,MAGNET, GRINDER, ETC..... HAVE SOME FUN WITH IT NOW BUT ALWAYS TRY AND BE SAFE THOSE PESKY SPARKS CAUSE FIRES AND BURNS..........DONE THE ONE FOOT HOP MANY A TIME............................GRIN..........ROCK
SSCOTT@MILLERWELDS.COM

[jeffm]

Hey everyone, thanks for all the replies. I'll try upping that ox psi and I'm still getting the 'tilt' right. And I did find firebrick (no more exploding patio masonry! yes!).

Is welding in the cold a dumb idea? Everything I read says 'the hotter the better' but I really want some practice so I can make some things when the weather gets better. It'll be around 10F tommarow.

I suppose cold didn't stop them from making the Alaska Pipeline however.