JB Weld re. Aluminum

3930dave · Jul 4, 2010

Hiya,

Not trying to insult real welders with a JB post here.....just wanted to get this question in front of people who have been playing with metal for "a while".

I need to fix a minor problem on the exterior of an aluminum head.

A wise wrench I trust recommended JB for this fix (makes sense to me), but also added that I should look for the JB version that is optimized for Aluminum.

Looking at the JB site, I can only see their generic version listed. The generic JB is listed as working on Aluminum, but I don't mind chasing down a better version.

Is my buddy remembering a variant of JB that doesn't exist anymore, or is it a industrial product that is not listed on their public site ?

Best Rgds, Dave.

whistlepig · Jul 4, 2010

Devcon is the best for metal repair.

Bedlam · Jul 4, 2010

ITW Devcon | Permatex | OEM Adhesives | Maintenance, Repair & Operations (MRO) Products

3930dave · Jul 4, 2010

Thnx for the note WP..... I've liked the Permatex products I've used the last # of years, looks like Devcon is the same corp.

The name rings a bell, but it was many years ago I would have used a Devcon product, so am not familiar with the current offerings.

Their site does list an Aluminum epoxy, I'll try to find it locally.

Best Rgds, D.

yomax4 · Jul 4, 2010

The best I have used and sold is called Lab-Metal. Also a product sold by Harris called Super-Weld. Lab-Metal is the only one ( as far as I know ) that contains Metal pigments. It sparks when you grind it. It still may be Epoxy Based like all the others. All you need to worry about is expansion and contraction because of the heat. If the repair is in a combustion area, Tig Weld it. Or better yet, Tig Weld it anyway.. Good Luck..

3930dave · Jul 4, 2010

Thnx for the options Yo.... the smallest Al. epoxy I've seen listed is 1lb, and that is a "bit" more than I need, so will check yours out too.

The issue on the head is with something like a frost plug (same idea, just smaller, about the diameter of my pinky finger). I have a slight seepage, from the water jacket.

A buddy (who has worked on a bazillion of these particular engines) has recommended super cleaning the exterior aluminum (he has the right tools) and filling this area level with a good Aluminum epoxy. Seems a reasonable approach for me to pull off, given an epoxy that is a thermal/chemical match for aluminum.

I want to try this epoxy approach, b4 trying to physically replace the plug.... don't have the resources to get into any serious welding/machining at this time.

This old engine has been good to me.... just hoping to keep the coolant where it can do its job..... :thumbsup:

E/S · Jul 5, 2010

Have you tried adding Alumaseal to the coolant system ?
I have had good results with it on aluminum.

E/S

s78wingrider · Jul 5, 2010

I always clean with denatured alcohol right before applying anything. Aaron

user.69169 · Jul 5, 2010

This JB Weld against Devcon thng stirred my curious up so I went looking at both websites.
Now Devcon does make a lot of different epoxys, I know their bronze one has made a good number of emergency bearings to get machines back running when the bearing was a month away, but when you get right head to head JB - Devcon, JB Werld comes up a winner.
JB has a higher temperature range, and is equal in strength to Devcon.

About the main drawback to JB weld is those dang little tubes don't seem to be big enough for the job at hand.
Then again once you open up a can of Devcon the second time to use it the dang stuff is a rock in the bottom of the can.