The backing bar is used commonly by welders to cool the welded metals and they are generally made up of a copper or aluminum metal and clamped to the base of the weld piece whether it is just a piece of thin sheet metal or a body panel you can use it either way.
Best way to weld sheet metal.
To weld sheet metal with solid wires use electrode positive ep or reverse polarity.
Tack weld in place.
Ditch a 1 8 inch tungsten electrode for something much smaller like 1 16 inch tungsten.
The best way to weld galvanized steel regardless of welding process is to remove the zinc coating from the joint.
Take some time to make your patch a perfect fit.
When welding a long bead on sheet metal you ll put excessive heat into the panel and run the risk of the puddle falling through the panel.
Forget the larger 1 8 inch tungsten electrode and use a smaller one.
Everyone who works with metal from metal workers and mechanics to jewelers and hobbyists knows gluing metal needs good preparation.
Learn how to mig weld automotive sheet metal in about 5 minutes or less.
The best two electrodes for welding auto body sheet metal is either ceriated tungsten or thoriated tungsten.
Tack weld different areas of the joint about an inch apart.
Making a patch panel.
Tack welds are simply small welds that barely penetrate the metal and aren t pushed or pulled to form a bead.
The best way to weld sheet metal panels together is by butt welding which is joining them side by side see picture below.
The best way to estimate the heat input needed for welding is by applying the 1 for 1 rule this means that 1 amp should be used per 1 thousandth 0 001 inch of thickness.
1 for 1 rule.
Tack welding is the best way to hold the metal in place before you fully weld it to the original metal.
This will hold it in place and allow you to weld.
For most everyday situations and simple diy projects a liquid adhesive or glue for metal is the best solution.
Sheet metal warps easily and also can burn through easily.
Butt welded panels withstand stress better than any other type of weld joint.
A better technique is to move around the weld seam doing short quick stitch welds that you eventually connect all together.
I keep it short and to the point in this welding instructional video and show how ve.
This adds two operations.
Removing the coating and re spraying or painting the weld seam after welding to regain corrosion resistance.
How to weld auto body sheet metal with a tig welder.
Ideally there should be a 1 32 gap between the patch and the.
Metal glue is a great way to join metal to metal or metal to other materials.
But when it comes to stainless steel or other nickel based metals less heat is needed.