Plug Weld Help

[msommer001]

I am replacing several different pieces of sheet metal and I am using sheet metal screws to hold the pieces in place until I can get them welded. When welding on a vertical surface I am having some issues with getting a good puddle of weld. It is also difficult to hit both pieces of metal where they met since this area is really small due to the sheet metal screw.

I think I might abandon the sheet metal screws and just drill or punch the holes needs and then use clamps to keep the pieces in place and weld from there.

Any advise would be great.

 

[broncodriver99]

You could pre punch some holes as you put it together so you they are there when you start welding, just punch the outer panel. You can still use screws to put it together but then welding the screw holes isn't as critical of a job.

 

[nickgp]

Screw the panel in place about every 3 or 4 inches. Once the panel is in and fitted properly, remove every other screw. Using a 5/16 or 3/8 drill bit, drill almost all the way through the TOP panel. Now do your plug welds. Alternating on different spots as not to heat
the panel too much on one spot. Once you have done all that, rove the other screws and repeat.

 

[broncoitis]

Screw the panel in place about every 3 or 4 inches. Once the panel is in and fitted properly, remove every other screw. Using a 5/16 or 3/8 drill bit, drill almost all the way through the TOP panel. Now do your plug welds. Alternating on different spots as not to heat
the panel too much on one spot. Once you have done all that, rove the other screws and repeat.

That sounds like a good plan to me! ;D

 

[Scoop]

You could pre punch some holes as you put it together so you they are there when you start welding, just punch the outer panel. You can still use screws to put it together but then welding the screw holes isn't as critical of a job.

This is the method I use for plug welding a panel.

 

[sp71eb]

You should always have at least a 5/16 hole in the top panel that you are welding to make a proper strong spot weld. Make sure to have a good clean hole with all of the galvanized coating removed from the surface of the steel. Also don't be afraid to do some test welds on some scrap pieces of metal. Most people welding spot welds usually have the welder turned to low, don't be afraid to crank the voltage when welding some scrap and push it to the point of burning through and then dial it back. Also do some destructive test on your welds, it should tear a hole in one of the pieces of metal if you have a good weld. If I need to use a 1/4 sheetmetal screw to hold the panels together I will usually just weld the two adjacent welds and then remove the screw. A good rule is to put spot welds about 1.5 inches apart. It may sound like I am stressing this too much but it is very important to have all of your welds stick. It would suck really bad to get the truck all together and have some welds start to pop loose on you or cause a failure of the vehicle.

 

[TDS-03]

Get some larger self tapping screws/bolts. I did this when replacing floor pans and it worked nicely. Keeps the panel in place and you just weld the plugs one at a time as you remove. I think just standard sheet metal screws are too small.

 

[Wyflyer]

Screw the panel in place about every 3 or 4 inches. Once the panel is in and fitted properly, remove every other screw. Using a 5/16 or 3/8 drill bit, drill almost all the way through the TOP panel. Now do your plug welds. Alternating on different spots as not to heat
the panel too much on one spot. Once you have done all that, rove the other screws and repeat.

X3 on this. Plus the lower sheet must be clean of paint or rust

 

[englewoodcowboy]

For your weld on vertical panels you need to weld bottom to top in a "U" pattern. Do some testing on scrap. You want your welder hot enough that it just about starts to burn through so you are burning into your sub panel.

 

[DuctTape]

Screw the panel in place about every 3 or 4 inches. Once the panel is in and fitted properly, remove every other screw. Using a 5/16 or 3/8 drill bit, drill almost all the way through the TOP panel. Now do your plug welds. Alternating on different spots as not to heat
the panel too much on one spot. Once you have done all that, rove the other screws and repeat.

That's how I did it worked a treat.