Thanks.. I appreciate it.Outlaw said:Chad, personally, I think anything you have to offer will be a benefit. Your quality of work and knowledge is invaluable. I really like the idea of being able to weld sheet metal without a backing plate. Not an option for me with Mig. I can do it, but end up with those burn thrus you have to fuss with until they are closed and god only knows what the back of those welds looks like? I have to get more confidence in fitting my patch panels. The big window conversion came out awesome and anywhere I had more that .023, the Mig does pretty well closing the gap as long as I can get a heat sync behind it. I would really like more on the Tig welding too.
metalman;n81871 said:I use thin copper to back up butt seams where ever possible. Not as a heat sink or for a burn through, the benefit is that it back gases the weld and keeps it from oxidizing. Some people call it sugaring. I use TIG with the copper back up and the back side looks almost as good as the side I weld from.
http://www.lincolnelectric.com/en-us/support/welding-how-to/Pages/good-mig-welds-detail.aspxOutlaw;n81176 said:By using a copper heat sink behind the weld, I avoid the burn thru with the hotter settings. This is with my MIG. Have not made the leap to TIG yet.
I never looked at using a heat sink as cooling the weld, but rather preventing burn thru.
Chris_Hamilton;n81876 said:I thought "sugaring" only happened with stainless. Mild steel doesn't need back gassing. Backup plates are a crutch, really like Chad says it makes a weld harder to planish and it actually causes more warpage. If you are having issues when butt welding work on getting a tighter panel fit. Good tight fits generally solve burn through issues. If you are burning through on a plug weld you are doing something wrong. Usually too high a heat setting.
chevman;n81879 said:
funny how this works, I picked up on tig welding steel really quick, but I have been a slow learner when it comes to aluminum.jlcustomz said:Well, finally got my miller syncro 200 home from the day job's shop & plugged in to my new 60 amp line I just ran so I can get to work. I mentioned before I got pretty decent at aluminum pretty quick as well as stainless , but not that good with 20 ga steel. So I started practicing a little. Seem to have a harder time seeing the fit line & puddle with steel. Think it's an eyesight issue. More lighting close by helped a good bit . second small sample was at least 50% better than first. Will try cheater glasses next , some smaller wire, & maybe some different lighting, should be good enough soon. Guess I could draw 2 white chauk lines, but that sounds like a crutch. Might also try a few mig sample runs for a few areas hard to work with a tig on the vehicle.
BUT, even though my first tig sample in over a year is ugly by professional standards, many amateur mig users probably wish they could get that amount of penetration without burning through & sand down to almost undetectable. That's the beauty of a good tig machine.
Do want one suggestion here. May be doing several welded areas off & on between the day job schedule before setting up to spray epoxy. Need something for temporary rust protection. Maybe just spray a little rattle can self etching primer & sand & wirebrush it off later?
PS, Outlaw, may want to try adjusting your mig angle or holdout a little further away with the mig as another fine tuning method. May also try a rotary wire brush in a drill just before & during welding. Steel does not get the sugar thing on the backside of welds, but it does oxidize a little, especially after heat.