Reel Repair by Alan Tani

Joe, The regular (long cure) JB weld can handle up to 500f. I've also seen a youtube video that showed it's magnetic and conductive, but I haven't tested that yet.

The quick cure JB is crap and I wouldn't trust it for anything. Not for high heat applications either.

*edit* I just checked some cured high strength JB Weld and it does attract a magnet. The MSD says 5-10% iron. I also tested with a multimeter and it's not conductive.

I have read about making conductive rubber,I forget all the details,but it triggered me thinking about red high temp rtv,if you could infuse it with
Graphite to be conductive & how conductive must the material be to powdercoat?

Ideally, it should  have the same conductivity as the surrounding metal that you are coating, so that the coat will have uniform thickness.  I doubt the powder would stick to rubber well, plus there's there problem of the rubber flexing. The cured coating would have to have a comp compatible amount of flexibility.

And conductivity is just one problem, you have to deal with without outgassing and expansion/shrinking as well.


Interesting that JB Weld has steel powder in it.  I wonder what the value is.  Maybe it helps hold it together when you machine it. You can't drill and tap normal paste epoxy.

-J

Quote from: jurelometer on November 26, 2025, 05:57:18 PM

Quote from: oc1 on November 26, 2025, 05:01:26 AMI've always wondered how adding graphite powder to epoxy resin can increase tensile strength and rigidity.  Since there are no reinforcing fibers it seems like the graphite/epoxy mix can only be as strong as the epoxy holding the graphite particles together.  But, boat builders swear by it.

This is a different case. I don't think the purpose of these type of resin additives is to strengthen the resin in a standalone situation. 

Plywood boat builders use it like an armor coating applied after the layer(s) of composite material has dried.

What if you applied your JB weld or whatever you use, and bake it in advance to deal with outgassing etc and then do your powder coating after it cools?

Quote from: oc1 on November 28, 2025, 06:13:18 PM

Quote from: jurelometer on November 26, 2025, 05:57:18 PM

Quote from: oc1 on November 26, 2025, 05:01:26 AMI've always wondered how adding graphite powder to epoxy resin can increase tensile strength and rigidity.  Since there are no reinforcing fibers it seems like the graphite/epoxy mix can only be as strong as the epoxy holding the graphite particles together.  But, boat builders swear by it.

This is a different case. I don't think the purpose of these type of resin additives is to strengthen the resin in a standalone situation. 

Plywood boat builders use it like an armor coating applied after the layer(s) of composite material has dried.

According to West Systems, aluminum powder is used to make a bit harder coat, which also helps to make it more water resistant.  It is also good to remember that harder doesn't mean stronger, it usually means more scratch resistant, but also more brittle. 

Graphite powder is used to decrease friction on surfaces like rudders, but I could see it also being used along the bottom if you drag your skiff up a beach. The graphite in the epoxy is sacrificial, as the exposed graphite is relatively soft and will get worn away. Looking at what the boatbuilders have to say, it looks like the epoxy/graphite blend is not as tough as the standalone epoxy, and occasional sanding can be used to expose fresh graphite.

https://www.westsystem.com/products/420-aluminum-powder/

Quote from: JasonGotaProblem on November 28, 2025, 06:17:37 PMWhat if you applied your JB weld or whatever you use, and bake it in advance to deal with outgassing etc and then do your powder coating after it cools?

Maybe.  Or maybe not.  The more you bake it, the more it degrades- which could increase outgassing.  It is rated  up to 500F, so maybe it won't degrade too fast.  We don't know what it is outgassing.  It might be worth a shot.

The stuff that is made for compatibility with powder coating  (Lab-Metal) has a lot of very nasty VOC solvent in it which is going to exit the paste (and enter through your skin) quite quickly.  A different (and presumably better- or they wouldn't be doing it) way to reach the required viscosity during application.

Also, there are lots of interesting surface finishes, not just wrinkle. Veins, rivers, or stuff that looks like a brick, an old bronze statue, or wrought iron.  The most aggressive finishes will hide just about anything- for example this gold vein.  It might be an interesting finish on the right piece. I would like to do a big International with this finish - it would definitely confuse the Penn fanboys



I used a much milder matte that is supposed to look a bit like a used steel tool surface on this 722. It still hid a couple smaller finish imperfections.



These might be an option to hide any imperfections on a part that needed a lot of patching.

It might be worth applying an epoxy powder primer as a first coat as well.  Primer helps the paint stick better to the substrate, and provides a uniform base coloration, so you are less likely to see a color change around the patches.  I have been playing with epoxy primers for about a year now, so I don't know how much they help with durability, but they do go down pretty easy, and are recommended for high corrosion environments.

-J 

Let me play catch up .  From J B weld site .
https://www.jbweld.com/product/j-b-weld-professional-size

   A better read on J B .  https://artizono.com/is-jb-weld-magnetic-understanding-its-properties-conductivity-and-uses/

Can it be powder coated .  https://www.powdercoatingforum.net/forum/powder-coating/292-j-b-weld-anyone

  I do have a rotor cut that is cured for 3 years , so that one is next .  I will try sanding it a little more to get the pin hole out .

I do have some aluminum plates that lived in saltwater to experiment with  .

      Primers is something I will try , at first I was a little concerned about getting to thick with 4 layers of powder , primer ,base coat candy coat and clear coat .
     But this can help in certain situation to cut down the gap in cases .

 https://www.eastwood.com/garage/6-reasons-you-may-need-to-use-primer-when-powder-coating/?wickedsource=google&wickedid=CjwKCAiA86_JBhAIEiwA4i9Ju2hWYf7vmyFe806MYDJyzg6aKKJ8IRAK0tfcBAn9_AfciWAASeBJmBoC4x4QAvD_BwE&wickedid=606086287133&wcid=17570997070&wv=4&wickedsource=google&wickedid=CjwKCAiA86_JBhAIEiwA4i9Ju2hWYf7vmyFe806MYDJyzg6aKKJ8IRAK0tfcBAn9_AfciWAASeBJmBoC4x4QAvD_BwE&creativeid=606086287133&wcid=17570997070&wv=4&gad_source=1&gad_campaignid=17570997070&gbraid=0AAAAAD_t6zGgUHJTy26NTgs5o9oeE4ljn&gclid=CjwKCAiA86_JBhAIEiwA4i9Ju2hWYf7vmyFe806MYDJyzg6aKKJ8IRAK0tfcBAn9_AfciWAASeBJmBoC4x4QAvD_BwE

https://www.columbiacoatings.com/understanding-powder-coating-primers-and-their-applications/?srsltid=AfmBOopyg-4CMP3oXzDsJTFZKCv6FcjJydwoYrGeOwGEL_PYq8rtRcXL

This might sound disgusting, I found that JB Weld can be smoothed if you wait 20-30 minutes when the outside skin starts to set, then you can smooth it out and reform it to better fit the repair.

The disgusting part is, it requires spit. Spit on a finger and use that finger to firmly work and smooth out the JB-Weld. It will remove any high spots and pin holes and negate the need for much touch-up work later.

Quote from: jtwill98 on Today at 04:32:07 PMThis might sound disgusting, I found that JB Weld can be smoothed if you wait 20-30 minutes when the outside skin starts to set, then you can smooth it out and reform it to better fit the repair.

The disgusting part is, it requires spit. Spit on a finger and use that finger to firmly work and smooth out the JB-Weld. It will remove any high spots and pin holes and negate the need for much touch-up work later.

Yes that does work . I usually wait about 90 minutes , then start working it . Spit , thumb and razor blade .

Quote from: jtwill98 on Today at 04:32:07 PMThis might sound disgusting, I found that JB Weld can be smoothed if you wait 20-30 minutes when the outside skin starts to set, then you can smooth it out and reform it to better fit the repair.

The disgusting part is, it requires spit. Spit on a finger and use that finger to firmly work and smooth out the JB-Weld. It will remove any high spots and pin holes and negate the need for much touch-up work later.

Heck, that's been standard procedure when using the JB Weld rotted wood restoration kit ever since it was first introduced. They also suggest spray misting water over the surface prior to smoothing with a plastic putty knife. I figured out that little trick years ago when using Elmer's wood restorer prior to JB's takeover/release.

Quote from: Midway Tommy on Today at 05:44:46 PM

Quote from: jtwill98 on Today at 04:32:07 PMThis might sound disgusting, I found that JB Weld can be smoothed if you wait 20-30 minutes when the outside skin starts to set, then you can smooth it out and reform it to better fit the repair.

The disgusting part is, it requires spit. Spit on a finger and use that finger to firmly work and smooth out the JB-Weld. It will remove any high spots and pin holes and negate the need for much touch-up work later.

Heck, that's been standard procedure when using the JB Weld rotted wood restoration kit ever since it was first introduced. They also suggest spray misting water over the surface prior to smoothing with a plastic putty knife. I figured out that little trick years ago when using Elmer's wood restorer prior to JB's takeover/release.

Or the Minwax filler , that was auto body filler !