Stick weld sheet to plate? Need Help

admin

I'm trying to weld sheet metal to 1/4" plate and no matter what I do the sheet metal burns up and does not stick.
Reply:CBRXX,What I sometimes do is punch or drill holes in the sheet metal. Then place the sheet over the thicker steel, and concentrate filling in the center of the hole with weld until it is completely filled in. You want to make sure there are no gaps between the sheet and the thicker stuff or it might blow the sheet steel away. You will have to adjust the amperage accordingly. What method are you using to weld, and dose whatever you are welding require a continous bead?................hope this helps,Pat
Reply:I'm trying to do T-joints, the sheet metal connects to the steel plate at 90* angle. If I concentrate the weld on the plate it looks good but its just flux that sticks to the sheet, and it breaks off. As soon as I focus the arc on the sheet it blows right through.
Reply:As George Jetsons' dog, Astro would say:  "Rot's-a-Ruck" !I've tried that too, with similar results.The next time I try that dance-step,  I'm going to try 6013on straight polarity...(stick - , work +).....and move pretty fast.Remember...the weld only has to be as strong as thesheet metal,  not the plate.I'll be the LAST one to let you down !
Reply:T joynt sheet to plate is pushing the difficulty scale with MIG, and on stick you're really pushing beyond that.The best way would be to use a copper backer bar behind the SM and a lot of prayer as you ease the weld onto the SM.For stick definitely a 6013 rod 3/32 and practice first.If you have DC, carbon arc Everdur (phosphor bronz) would be a lot easier, and probably better way to go.Appreciation Gains You Recognition-
Reply:Why not just bolt it on or use rivets?
Reply:Make sure your fit-up is good and tight.  Also turn the amps down.  I've done a lot of this with 6013 rods. so keep working at it.  Tig welding would be the way to go here.  Good luck
Reply:Look at the picture, its a 60' awning with the metal frames 2' apart. The frames are held in with self tapping screws, now I have to weld them. The frames will be covered with plywood then with metal, plus it will have to stand up to wind and snow loads. I don't think the screws are strong enough. Attached Images
Reply:I know it can be done because someone did the right side of the building, and they did it good.
Reply:Yes, it can be done, but it isn't easy.You'd have a far stronger joynt if you weld 1/8x2 strap stock to the heavy steel, and then attach the thin purlins to the strap stock with glue and screws, and the job would be alot easier to accomplish.You also need to consider the plywood becomes a major structural component when it is attached to both the purlin and the beam.Appreciation Gains You Recognition-
Reply:cbrxx,To me, that is a project that is ideally suited to an adhesive.  With the screws and an adhesive you will end up with stresses distributed over a much larger area than you could ever achieve with welding.Good Luck!Bill C "The more I learn about welding the more I find there is to learn..."
Reply:You will need to concentrate the full puddle onto the thicker material and then ever so easily wash up onto sheet metal. It is easier said then done. I was a sheet metal worker for years in maintenance at Briggs & Stratton I left before all jobs went south or ch ch ch china.J P Streets Welding LLC