JB weld trick

F

frederick

Well-known member
my cub's steering column was grooved from years of rubbing against an implement plus had gouges here and there, but it and several other rust pitted or damaged parts are planned for powdercoat.
JB1.jpg
I learned that JB weld will hold up under the heat of the process, plus it has a metallic component that bondo does not offer. unfortunately it slumps big time.
a simple solution in this instance was to trowel in the liquid putty and spiral wrap painters tape around the shaft, forcing the excess material out and confining the putty to the damaged areas. JB2.jpg
when set it only took a couple of swipes with a file and finish sandpaper.

Frederick
 
Very nice, I've rebuilt all my steering wheels that way using a little coat at a time. Like epoxy glue after it drys it sands very well.
Your tractor's looking great Fredrick. :wink:
 
Good idea, let us know if the JB takes the powder well, or not. There is a filler available, from Eastwood, for use when powder coating but I haven't tried it.
 
Make sure your powder coater knows you used JB Weld for a filler. There isn't much difference between the curing temperatures for most powders and the melting temperature of JB Weld.
 
The powders I use call for initial temp of 425deg. until flow out, then 20min. cure at 375deg. I have cured them at a straight 375deg. and the results appear the same, might not be as tough, though.
 
First off, one powder isn't the same as every other powder. There may be more types of powder out there than there are of wet paint. There are some low temperature cure powders but they typically have a longer cure time and may not be as durable so your coater probably isn't using them anyway.

Although it varies from one type to another, curing temperatures around 400 degrees are fairly typical. Note that those are cure temperatures for the substrate, not the surface of the coating. How does the coater make sure each chunk of iron reaches 400 degrees? He sets the oven 50 or more degrees above. The oven is heated by hot air blown in one or two places (think convection oven). There will be hot and cold spots inside the oven. How does the coater make sure the cold spots are warm enough to cure? He adds another 25 degrees to the setting. Cure time is shorter at higher temperatures. Want to cut 5 minutes off the cure time so you can get another batch in the oven? Easy, crank the oven up another 20 degrees. By now, your 500 degree JB Weld is a puddle on the oven floor. The coaters upper limit on temperature will be whatever avoids burning the coating (which he probably learned the hard way).

That is why I said to make sure your powder coater knows you used JB Weld for a filler.

Check http://www.tiger-coatings.us/index.php?id=1341 and click on the data sheet "2100 Series 49" about a third of the way down the column on the right. Look at the cure parameter charts on page 2. They are fairly typical.
 
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