Petejoe - that's what I figured. Thanks. I'll hold out till I get my tig. I dont have any pressing aluminum work right now anyhow. "As for the Grinding, I weld patch panels in with about 1/16" gap all around and adjust my welder, and Travel speed to make the bead as flat as possible. The gap helps a lot towards getting full penetration without excessive heat, but a less experienced operator may have trouble with blowouts unless they put Copper behind the gap." If you are welding steel, I heard you can also put aluminum behind the gap to evade blowouts. For those that don't have any copper hanging around. I havent tried it though...
i want to add something that many rookie welders do when they get their first 110 mig machine and try to weld, particularly sheetmetal. COLD WELDS! they set the machine on the lowest setting and blob on some barely melted filler that has NO penetration, thinking they are doing the right thing, they read in all the magazines and the hamb not to overheat sheetmetal, but they under do it. you don't want to blow through, but you gotta get some penetration and fusion! i have found that it is still easier to mig weld sheetmetal with too much current than not enough, i had an old millermatic 30 welder, it did not go very low at all, current wise, i had to get used to making quick tacks and get out!
penetration:: Yes that's an area that needs to be discussed. When welding. seeing discolored sheetmetal as viewed from the back side is not enough heat and penetration. If you are getting perfect penetration the seam in the back looks exactly like the front and looks like it was welded from that side. When welding thick material, it's important to actually watch the base metal melt and become molten. Viewing your welding rod and/or wire turn molten is not sufficient. Which I had some pics of good penetration to show.
No doubt! Another thing to look for is the sound when you are welding, when you get your settings right it should sound sort of like a tuned tattoo gun when you are laying a bead...! Not all sputtery.
Well truth, stick is like tossing water in a frying pan full of hot bacon grease. Definately the cro-magnon, and arguably, most difficult art of welding.
Ok i am going to throw my 2 pennys in here. each form of welding has its place. Mig tig and good old arc weldeing. for really fine work the tig is the best, mig i find for general welding and simple fabercation. but if you are going heavy apps like something that you want to be sure it will not come apart or thick steel then arc is the only way to go... i know its no real direct answer. now el cab quit reading books and go build something...
Yes my leige, I received my dropped axle last night, my springs are coming, I have a frame (needs boxing). I may have a roller frame with the drivetrain in place before spring if I play my cards right.
Good deal. I am looking at a 29 ford express cab p/u right now. I might be diggin up some goodies myself. and starting over
"they read in all the magazines and the hamb not to overheat sheetmetal," The ideal setting has to take Travel speed into account. The quicker you can get across the Joint, the less heat actually spreads into the surrounding metal. Using lower amperage with a MIG to try and keep the Heat down in the surrounding metal does not work. Since getting a MIG to operate at lower amperages means also lowering the wire speed, it takes you longer to lay down a given length of Bead. That means the hottest part of the Bead, the Puddle, is traveling across the joint at a slower rate and the surrounding metal absorbs more heat.
Have any of yall used any of those heat dissipating pastes they make for welinding sheet metal, etc? I have never tried any - is it worth it? Any that you'd recommend?
welding, not welinding.... oops. El Caballo, I hear you on stick welding. It's messy, but its good for heavy duty stuff. Yep, all the processes have their place. I want to mess around with leading sometime...
Fuck a tig. I am so tired of this crap of "tigs b da chit". Get your mig and build shit. All my work is done with a mig and I will never get a tig. Bottom line is that your melting two pieces of metal together. Thats all..............
i have posted this before, but if you want a whole message board full of welding tech go to WELDING MESSAGE BOARD later jim
Both TIG and MIG have their place and if you can afford it I would buy both but for versatility for the money I would recommend a Henrob oxy/acetylene torch, it welds steel, aluminum, cast iron, stainless, cuts steel over an inch thick and a complete set up is about $600 including regulators and renting bottles. The torch also goes by the names Dillon, and Cobra. I use one quite frequently and would choose it over the TIG and MIG for doing sheet metal fab where I have access to both sides of the panel. I have read a lot on this thread about minimizing warpage by using a less heat but metal becomes molten at the same temperature no matter what process your using so why not use a gas weld that is about twice as soft an easy to finish as a TIG weld and About ten times better than a MIG which finishes like shit because the weld cools so rapidly and it deposits fill whether you need it or not. If your interested in a Henrob you can check them out at http://www.cut-like-plasma.com/
[ QUOTE ] but once you get over 1/8" material you are pushing the welder to its limits. [/ QUOTE ] I'll agree with that. I have a SIP 130 amp mig, and it's fine up to 1/8" plate, but above that I can't guarantee a good weld. Sometimes it comes out rock solid, but others, whether it is my lack of skill, practise, expertise, whatever, the weld is just not trustable, especially if it is in a place I can't grind out and re-weld. I prefer using my 160 amp stick welder on 1/8" or larger chassis work. My MIG only cost me, new, £150, or about $230, and the stick welder was only about $120, but they do their job well enough. Cheers, Paul B
one important thing to consider with any type of weld is of course joint preparation and the strength that that joint will require. This means the design of the joint and also any weld preps, i.e bevels root gaps etc! This must be considered with any type of weld system you are using
[ QUOTE ] I have read a lot on this thread about minimizing warpage by using a less het but metal becomes molten at the same temperature no matter what process your using so why not use a gas weld... [/ QUOTE ] The problem with oxy-acetylene processes is that they produce more radiant heat which can be a big problem for those folks who don't have a higher skill level. For the guy who is a newcomer to the hobby or hasn't mastered the learning curve MIG is the easiest route to go.
"For the guy who is a newcomer to the hobby or hasn't mastered the learning curve MIG is the easiest route to go." I agree 100%. I have seen plenty of beginning TIG welders do it too. They don't yet have the skills required for travel speed and adding filler and they will end up with a 1/2" of glowing red metal on each side of the Bead because they are moving way too slow. Thats why I have stressed travel speed. When I weld a joint with a TIG or MIG, the heat affected zone is less than an 1/8". I am welding at a much higher heat setting than most of our apprentices do, but since I have been doing it for 15 years, I am able to translate that higher heat into faster travel speed. TIG or MIG, doesn't make a difference. If you are skilled enough to translate higher heat into faster travel speed, you will put less heat into the surrounding metal, while still getting penetration.
The Jalopy Journal
