Watch JB Weld Fix a Bad Cylinder Head

Be sure to pack some JB Weld next time you head off the beaten path.

Everybody’s off-roading tool kit includes the usual go-tos, but this Project Farm video contends that yours should also include JB Weld. Should your Jeep engine overheat and cut a groove in the cylinder head, Project Farm says you should be able to use JB Weld to repair the head. Words are cheap, of course. So the video above puts the heavy-duty epoxy to the test on a lawnmower cylinder head, and then on a leaky fuel tank.

To start, the video host cuts a deep groove in the two-stroke cylinder head, which would ordinarily prevent the motor from running. He fills in the massive crack with the epoxy, and lets it cure for 24 hours. After reassembling, the engine runs just fine, although he left on a little too much material and the piston nicks a bit. That could easily be fixed by removing the excess gook from the cylinder head. However, the video shows that you can work with JB Weld in a pinch, for a field-expedient engine repair.

CHECK OUT: What Forum Members Are Saying About This On-the-Fly Fix

The fuel tank also seals nicely with the product. If you get a small leak in your Jeep’s fuel tank, keep a drain pan on you to catch the excess. Then fix the tank with your JB. Of course, it requires curing to make the repair, so you need to factor that in.

We’ve also run across remarkable JB Weld repairs in the 24 Hours of LeMons. Just a few weeks ago, one racer explained that several years ago, a W-Body Pontiac Grand Prix had grooved its 3.8-liter V6’s cylinder head. Not only did that team repair the groove trackside with JB Weld, they also won their class and the Index of Effluency at that race. After that, they ran it without changing a thing for several more races.

What’s your best JB Weld or field-expedient engine repair?