How to Use J-B Weld on a Motorcycle Gas Tank That Leaks

by Joel Parks
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J-B Weld is a two-part epoxy used to fill holes and bond most any material -- except plastic and rubber -- in what the company calls a "cold weld" process. This means that unlike a traditional weld where extreme heat is applied, J-B Weld achieves the same strength chemically, with no heat. Think of it as a special glue that begins to set when mixed together, and is "cured" in in 4 to 6 hours, or overnight. J-B Weld forms a metal surface that can withstand temperatures up to 500 degrees Fahrenheit, and the product is not affected by gasoline, which makes it a popular product for repairing metal fuel tank leaks.

Step 1

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Mark the area of the gas tank where the leak occurs, using a felt-tip pen or a piece of tape.

Step 2

Remove the fuel line from the carburetor by gently pulling up on it with your fingers. If a hose clamp is present, loosen the clamp first with a flat-blade screwdriver.

Step 3

Insert the open end of the line into a spare gas can.

Step 4

Open the fuel tap on the motorcycle gas tank by turning the lever to the "on" position, and let all the fuel drain into the can. The location of the fuel tap varies, but it will always be at the opposite end of the fuel line you have removed.

Step 5

Rough up, or scratch, the metal surface around the leak with fine sandpaper. This will allow the J-B Weld to form a better bond. The surface to be welded should be free of dirt, oil , rust and paint.

Step 6

Clean the surface to be welded with acetone or lacquer thinner on a shop rag.

Step 7

Squeeze equal amounts of J-B Weld hardener and resin onto a piece of tinfoil.

Step 8

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Mix the resin and hardener together using a putty knife or small wooden paddle.

Step 9

Spread a bead of the mixed J-B Weld over the crack or hole in the tank, using the putty knife or paddle to smooth the repaired area.

Step 10

Allow to dry overnight.

Step 11

Reconnect the fuel line to the carburetor and refill the tank with gas.

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