How much heat can J-B Weld withstand?

Original J-B Weld can withstand a constant temperature of 260ºC. The maximum temperature threshold is approximately 316ºC for a short term (10 minutes).

Refer to individual product packages for more temperature information.

Will J-B Weld hold up to extremely cold temperatures?

Original J-B Weld has proven to maintain its characteristics to temperatures as low as -55º C.

Will J-B Weld work on an automotive exhaust?

Because of the extreme temperatures of exhaust systems, we do not recommend J-B Weld for use on exhaust manifolds and catalytic converters. Nor do we recommend the product for repairs within the combustion chamber. However, in areas where the continuous temperature is less than 232ºC, we do recommend our HighHeat epoxy putty stick.

How can I remove J-B Weld after it is fully cured?

When fully cured, J-B Weld can only be removed by grinding or filing it off, or by directly heating the product above the 600º maximum temperature threshold.

Is J-B Weld toxic?

No. When fully cured, J-B Weld is non-toxic. However, we do not recommend consuming the product.

Will J-B Weld conduct electricity?

No. J-B Weld is not considered to be a conductor. It is an insulator.

Is there anything that J-B Weld WON’T bond to?

While JB Weld will bond to all most anything, there are a few things it is not suited for. This includes:

  • Any flexible rubber surface
  • Leather
  • Vinyl
  • Canvas
  • Polypropylene plastic
  • Polyethylene plastic

Can I thin J-B Weld to make it easier to pour?

Yes. Add up to one teaspoon of acetone or lacquer thinner per two ounces (one full package) of mixed product.

Is J-B Weld microwave safe?

Yes, JB Weld is Microwave safe.

How long will the tubes of JB Weld last once open?

The tubes of JB Weld will last upto 25 years once open, though we are sure you will have use them much, much faster than this.