A LETTER HOME!
Hi gassers; I know I’ve been MIA, but not our of mind. I’ve been watching Youtube’s on auto body work. The big thing is— they all weld on “thin” metal, 18-20 gauge, about the same as a 55 gal barrel. This welding with a mig is totally different from welding plate or heavier metals. For you that understand this pass on the rest of this. I see a lot of newbies come on here with little experience welding, so I would like to give them an idea of what I have JUST learned after years of amateur welding .
First; Mig welding is NOT just pick it up-- point and shoot! Flux core is possible to use but, gas makes it simpler and better welds. Get .023 gauge wire. Take the time to set your gun up properly-- power or amps (what ever they call it) and wire feed. This will take time, but after you do it once, you will have the numbers you will need for future welding of this material. Start by putting both knobs on the lowest values-- try to weld ; it probably won’t weld. Turn the wire speed up to the 1/2 mark. If it won’t weld-- make the nice bacon frying-- turn the wire speed up to "full’ or “fast”. If it won’t weld turn the power to the next power setting and move the wire feed back to minimum. If it won’t weld–move the wire speed up to 1/2 max. If it won’t weld move the wire speed up to “full” feed etc. etc. etc. When you find a point where the “bacon” sound starts. Now adjust the wire feed up and down slowly until you get the smoothest sound. (The gas should be set at about 10 when the trigger is pulled. It can be adjusted for how much wind or air circulation you are working in.)
Clean all surfaces with a sander or grinder.
Your ready to weld. Thin metal is NOT welded by laying down a continuous weld. They use a series of “TACKS”. Tack the metals together using a tack about every 3 or so inches. Then go to a tack and start “welding” by putting a tack that is at the edge of the existing tack; let it cool for a couple seconds and then put a tack at the edge of the previous tack. After 2 or 3 of these tacks, move to one of the tacks holding the plates in position and do the same with 2or 3 tacks, then move again-- giving the welds plenty of time to cool. Some use an air hose to blow gently on the weld after the couple of tacks. Then continue adding a couple of tacks, making more of a continuous weld–whether you wait, move to another location or blow air over the weld, the weld has to cool to the touch before continuing.
To lay down a tack, set the weld wire about 3/8ths in off the metal-- pull the trigger-- count to “2” and as you are saying “2” lift off the trigger. Some as they are saying “2” will move the wire back towards the center of the tack you are stacking on. Check the back often to make sure you are getting penetration. Continue with this until you have a nice set of beads all all across the area you are welding.
Just an odd note; if you set you machine up properly and for some reason you are ‘blowing through’, don’t run to turn the heat DOWN-- try moving the power UP a mark. Having the power too LOW can cause you to hold the gun in one spot too long, building up too much heat. A Higher setting will shorten the time you have to hold the gun on the weld and gives LESS heat to the material.
The other thing I’ve leaned is GRINDING WELDS. You can’t just take a grinder to the weld to smooth it down. As you grind away the weld you are also grinding the material on each side of the weld. You don’t want that to happen. Many ways to avoid this that you can find on Youtube. A suggested one would be to use a grinding wheel in a vertical position so the edge of the wheel touches only the weld.
So see, there is quite of difference in welding thin metal. A couple of Youtube channels that I would suggest is Bad Chad and Fitzee’s (no “r” in this)
I hope something here will help some of the newbies get started welding thin metal. I have a stack of medal full of welds on my table from my practicing. It ain’t easy to learn and it is slower than laying down a bead unless you count the time you spend filling “blow holes” and hunting air leaks. I haven’t tried this on anything that has to be “air tight”, but I’m sure with proper penetration they will hold air.
I know one person on here that welds thin metal with stick welds. I would like to see a Youtube on that.
Hope to hear from some of you TomC
12 Likes