I just picked up a mig welder (millermetric 135 with gas) thinking or hoping I could learn with trial and error. This information is something else, most things I never knew of or would of even thought of was just covered. What a great forum!!!!

 

I bought the Miller 135 about 2 years ago and I love it. If you do have to do any welding along way from your wall socket make sure you have a decent, heavy gauge extension cord to handle the load or your wleds won't be worth a #*%$.

Fantastic tips from all of you, thanks!
Bobby

 

gas welding aluminum with O-A is pretty easy if you use the right materials (and the right aluminum, some aluminum alloys are near "unweldable". What Jesse was doing was annealing (softening) the aluminum to make forming it easier. Most aluminum sheet is sold in a work hardened state so's not to get bent up real easy, and it gets continually harder the more you shape it until it eventually cracks if not annealed occasionally when it starts to stiffen.
The easy way to know when you have reached the proper annealing temp without melting holes in it (aluminum doesn't change color as it is heated, it just suddenly melts) is to turn off the oxygen to the torch so you have a big yellow bushy flame with a lot of sooty smoke. Run the flame over the metal leaving a layer of black soot on it. The soot is the heat indicator, it burns at the proper annealing temp. Now using a rosebud heating tip, adjust the flame to a neutral flame then begin heating the metal until the soot just burns off clean. It is not necessary to get the entire piece of metal hot at the same time, just be sure to burn the soot off the entire piece. A piece that has been heat annealed to it's softest state is called "dead soft". Do not try to work aluminum hot like you might do with steel. Hot aluminum is brittle and will just crack all up. A stainless steel wire brush (never use a common steel wire brush) is a good tool for cleaning aluminum just prior to welding it.

 

Dang, you guys are good. I bet I am not the only one that is saving your posts on my computer so I can find and read them when I have a question!

I have done some really nice flat welds now, but am having problems when I need to weld vertically. I have about decided to use the hoist and turn the cab onto its side to get a few of them. Any suggestions?

 

Now that makes since. I have often wondered about this part of it.

 

Start at the bottom and work upwards, point the torch in the direction you are moving.

 

Just a small tip for the guys running 130 amp ish size wire feeds. If you haven't used the adapter for the 10 lb spools you need to. Not only does your wire last a LOT longer but the feed pulls a lot more smoothly and you get much better welds. I was much happier when I switched.

bobby - I second your statement about useing heavy gauge extension cords, when you're welding you need the power at the tip not accross the cord.

 

Good advice. I just went to the 10 lb roll, and you can tell the difference. Plus I hate running out in the middle of a weld.

Right now, all I got is the Micky Mouse Power Cord that come with it, just like my old Lincolon Buzz Box, I am going to replace the Cord with a 50 foot one that is much heavier. Nothing worse then loosing amperage across some cheap cord. I can tell the difference when I use a light duty extention cord verses a heavey duty one.

 

Keep the extension cord as short as possible. Check the markings on the cord for the actual conductor wire size, the physical size of the cord can be just insulation. For a cord up to 10' long 12 ga is satisfactory. For cords >20' you want a 10 ga cord look for cords sold for window AC units. Try to avoid cords longer than 25' unless doing light ga work. If you have a unit with stepped output switch, and find you'd like power in between two settings, put a 25' 12ga extension cord on it.