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Now In: Shop SuppliesSEM Products → SEM CopperWeld Weld-Thru Primer - 40783
SEM CopperWeld Weld-Thru Primer - 40783

SEM CopperWeld Weld-Thru Primer - 40783

SEM CopperWeld Weld-Thru Primer - 40783

SKU:    SEM-40783
Price: $22.59

The SEM CopperWeld Weld-Thru Primer helps in reducing corrosion between welded substrates. Some features of the SEM primer are better conductivity, excellent adhesion to bare metals, superior corrosion protection, better spray ability, and coverage. The conductive properties reduce the heat zone that minimizes distortion and welding splatter. 

For best results, apply two medium wet coats with 3-5 minutes flash time between coats. For mixing, shake can vigorously for a minute after mixing ball rattles. This process enables color uniformity and prevents clogging. It is recommended that you use this primer when the temperature is approximately 70°F (21°C). Before the application of plastic filler, remove excess of the Weld-Thru Primer to prevent lifting.

How to prepare the surface before using the Primer?

  • Clean surface with SEM Solve
  • Sand with 80 grit paper until the surface reaches bare metal
  • Blow dust away and re-clean with SEM Solve

To Remove Clog:

  • Remove spray button with a twisting motion and clean with material that is compliant with VOC regulations
  • Do not use a pin or sharp objects to remove clog
  • After every use turn cap upside down and spray for a few seconds to clear spray tip

Technical Data Sheet


This item can only ship by ground within the Continental US.
Next Day or 2nd Day, AK & HI, & International delivery not available.


Customer Reviews
# of Ratings: 1
1. on 9/28/2013, said:
Great weld through primer. Copper is nicely conductive and will not clog your mig nozzle like the gray crap. Very much worth the little extra in price. Very nice product.
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