I got a new Welding setup... (Page 2 of 2)

I'm right off 75 near the Maumee river. not the best neighborhood in the world but im sure you've driven through much worse. I think maybe i should set something up as I've been hankering to build myself a custom workbench using some square tube and a cheap/mis-cut kitchen counter top from one of those home improvement warehouses. Be a good project to test the units with, for sure.

You'll have to bring me Lafayette Coney Island. Yum!

(now to go looking for materials)

I just don't want to learn bad habits.  I figure a real welding class will (help) keep that from happening.

I camped out youtube videos and talked to my dad a lot on welding and practice and techniques. when he finally came up before the gingerman october race, he brought some scrap, and set up a few exercises for me. While he did give me a few pointers about my biggest achillies' heel (welding thick material to thin a la spreader plates to unibody) he actually was pretty impressed/excited by what i was able to do as an amateur given his pointers and my limited experience. Either this machine was making me look better or i studied the right youtube videos!

So Jeff; you get your MM140 yet?   I wanna goto the auto show this weekend maybe i should take that as an excuse to stop by...

FWIW, the Tractor Supply store that's only 10 minutes from my house now sells welding tanks.  After running out of gas on a saturday (again), I found this out.  Took my old tank to the store, traded for a shiny full tank for less than local weld store charged for refilling my tank.

For what it's worth, most Home Depot's have a stock of welding gas bottles and refills. That's where I got my 75/25 mix bottle for the same reason, Jeff -- just too damned inconvenient to go to the welding supply store during daylight hours.

Not sure you guys still want to know this but when welding thick to thin point the heat (actually the torch or mig wire) at the thick stuff and do quick little flicks towards the thin stuff (heat slightly towards the thin maybe 20% of the time.)  That gives good penetration in the thick stuff and helps from blasting through the thin.

You learn a color for too hot looking through your welding helmet after a while.  You either let off, up wire speed, or move faster if you can and obviously turn the heat down if its too high.  If you dont let off at this color it will drip and depending on where it falls you get a molten metal fireworks.  Dont weld above your body is a pretty general rule if you like your bits.

Setting the wire speed correctly to the heat is the thing to concentrate on.  You should hear a consistent sizzle when welding.  If the sizzle sound "bounces" feed rate is low.  If you feel it pushing you away feed is too high.  If you are snotting up the weld the heat is too low or wire speed is too high.  Once you get the feed and heat right its all in the shape of the bead.  You dont want it digging in and eroding (usually moving too fast or heat is too high) the stuff you are welding.  You dont want it bubbled up and not penetrated either (usually heat too low and moving too fast.)  Practice is your friend.  Just listen for the nice sizzle and it will help you progress faster than trying to learn to weld with the wrong heat/feed speed.

Also, make sure the wire feed is consistent.  If the cable for the mig gun is kinda knotted/bound up the wire speed can bounce.  Large radiuses in the cable help.  Also, the feed roller tension might be low if its not kinked and feed speed is bouncing.

Gas flow is fairly important.  Too low and the weld looks like lava rock/ black sugar.  Too much gas shield and it cools the weld puddle or can blow it around if its really high.  Obviously too much is better than too little.

Make sure the mig tip is good and the wire is pretty tight to the hole in the tip.

Good luck.

That was helpful, jrbe, thanks!

There is a very similar thread over on the ChumpCar forum and something came up that should be posted here as well.  A cage builder posted this link http://www.brewracingframes.com/id75.htm about the dangers of using Brake Cleaner to clean steel before welding.  Everybody needs to read this and be sure to be safe around chemicals.  He recommends using only acetone to clean the steel before welding.

That was terrifying!!  What a rough story to read.   Almost any one of us could make a mistake like that.

Maybe I'll move to cleaning brake parts with simple green.

Holy shit, I had no idea brake cleaner (my favorite chemical, but I've never welded) broke down into phosgene. I know enough about phosgene based on the little bit I know about refrigeration to stay the hell away from it - so I'll definitely keep that in mind once I start learning to weld!