How to Glue Steel With J-B Weld

With a tensile strength of 3,960 psi, J-B Weld is a structural adhesive, meaning that it makes permanent repairs that are as strong as the material it bonds. Its ingredients include epoxy adhesive mixed with fine particles of iron and steel. J-B Weld consists of two parts; either part washes off your hands and tools easily. When cured, J-B Weld withstands temperatures of over 500 degrees Fahrenheit (300 degrees Celsius), making it a suitable material for repairing engines and other moving steel parts that generate heat. It isn't suitable, though, for super-hot applications, such as automobile exhausts.

Step 1

Clean the surfaces you intend to bond thoroughly to remove grease and fine dust. The most effective way to do this is to wash the surfaces with a strong solvent, such as acetone or lacquer thinner.

Step 2

Roughen the surfaces with sandpaper or by scoring them with a sharp knife. This increases the bond strength of the adhesive.

Step 3

Deposit equal amounts of J-B Weld epoxy and hardener on a disposable sheet of cardboard. Mix them together with a thin plastic spatula or the tip of a utility knife blade. Stir thoroughly until the mixture is a uniform gray color.

Step 4

Apply the epoxy to one of the surfaces being bonded and join the pieces. If you're patching a crack, fill the crack with the adhesive.

Step 5

Clamp the pieces you are joining with clamps and leave them undisturbed for four to six hours. Similarly, if you filled a crack, leave it undisturbed for the same amount of time.

Step 6

Allow the adhesive to cure for 24 hours before subjecting the repair to strain.

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