Weld Thru Seam Sealer

[nicka]

Working on the upper cowl for a 71 Barracuda and was wondering what type of seam sealer others are using?  Planning to plug weld the cowl to the firewall.  I just viewed a video of 3M
Urethane seam sealer being used while spot welding the panel.

[Dmod1974]

Nothing will withstand MIG welding. Those products are specifically for use with spot welding. I tried despite the product literature recommendations and quickly found out they were right!

[torredcuda]

  Spot welding vs mig welding = not the same when it comes to seam sealer, mig welding will just spatter and melt it out. Best you can do is use weld thru primer and seam seal after welding and primer.