The Ford Barn - View Single Post - I found a crack in an odd place while pressure testing

glennpm · 08-20-2020, 10:15 AM

Yes good point on not using the J-B Weld Kwik version. It has poorer properties than the "regular"

From https://www.jbweld.com/product/j-b-weld-twin-tube

"J-B Weld™ is The Original Cold Weld two-part epoxy system that provides strong, lasting repairs to metal and multiple surfaces. Mixed at a ratio of 1:1, it forms a permanent bond and can be shaped, tapped, filed, sanded and drilled after curing. At room temperature, J-B Weld™ sets in 4-6 hours to a dark grey color. A full cure is reached in 15-24 hours. J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured."

For a vertical surface like yours, you will want to dam the J-B to keep it where you want. It helps to let it setup for a little while before putting the final coat on. For vacuum or injection in the crack, apply it right away.

I find that blue masking tape is good for the dam. You can also keep moving it up with a pop-sickle like stick for a few hours after you apply it. check it every fifteen minutes or so.

08-20-2020, 10:15 AM	#27
glennpm Senior Member Join Date: Sep 2014 Location: Wiscasset, Maine Posts: 1,982	Re: I found a crack in an odd place while pressure testing Yes good point on not using the J-B Weld Kwik version. It has poorer properties than the "regular" From https://www.jbweld.com/product/j-b-weld-twin-tube "J-B Weld™ is The Original Cold Weld two-part epoxy system that provides strong, lasting repairs to metal and multiple surfaces. Mixed at a ratio of 1:1, it forms a permanent bond and can be shaped, tapped, filed, sanded and drilled after curing. At room temperature, J-B Weld™ sets in 4-6 hours to a dark grey color. A full cure is reached in 15-24 hours. J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured." For a vertical surface like yours, you will want to dam the J-B to keep it where you want. It helps to let it setup for a little while before putting the final coat on. For vacuum or injection in the crack, apply it right away. I find that blue masking tape is good for the dam. You can also keep moving it up with a pop-sickle like stick for a few hours after you apply it. check it every fifteen minutes or so. Last edited by glennpm; 08-20-2020 at 01:38 PM. Reason: Tip