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epoxy reccomendation.

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I used belzona 1111 super metal epoxy that I had at work to attach a bracket that I machined for brushless motor for my brothers 1/8th scale rc car (its a monster it smokes outlaw nitro cars). I used a boring bar and got a 0.001 fit then had to mill a slot in the part so its a c shape with about 300* of contact to clear the motor leads (a clamp type bracket wasn't possible so we won't talk about that). Anyways it eventually broke the epoxy. This bracket doesn't take the torque the front of the motor has a stock bracket for. This one just keeps thr motor from yawing and ruining his pinion gear.

Also i need to epoxy an aluminum spacer to a mountain bike cartridge I have. Its not a spring seat ot anything just has an oring which will create a seal between the fork tube and the cartridge to create a chamber which I will be able to apply pressure to the cartridge bladder it kinda sorta resembles those bladder kyb cartridges.

The cartridge tube is so thin there's no chance of welding, cutting a snapring groove or threading.

So again I must rely on epoxy.

So any recomendations on best avaliable epoxy?

Edited by englertracing

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marine tex epoxy from a boat dealer is the strongest stuff i ever found..i have used it to repair engine cases after a chain came off and broke a hole in the clutch arm pivot and it lasted longer than the bike...not sure on your application but it is good stuff..

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i've had good luck with west systems marine epoxy. it's a two part gel epoxy that we used to use on everything from repairing blown edges on snowboards to sealing bartops and boat transoms, leaky petcocks, you name it. flexible in all conditions, tough as hell, and stick to anything. for small jobs you can get a 5 pack of little repair packs for about $30.

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The Belzona you mentioned is pretty much the best there is. Is heat causing the failure? Look in to a higher temperature rating.

Edited by 1987CR250R

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Plus 1 on West Systems, plus they provide technical support, data sheets, and instructions for different types of repairs. Do a Google.

There is a big difference in strength between expoxies like West Systems and the common resins like Bondo or those used to build fiberglass stuff like boats and Corvettes.

You need to look at the heat rating specs as there are some 500F epoxies.

Edited by chuck4788

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The Belzona you mentioned is pretty much the best there is. Is heat causing the failure? Look in to a higher temperature rating.

I feel like it was too brittle like concrete.

And may not have appreciated the anodized surface.

The heat at max was 150f.

I was kinda dissapointed by the belzona I knew before I used it it was the best.

It's possible I messed up the mixing procedure.

My little brother fixed the motor clamp with regular old jb weld.

Will the marine stuff hande oil???.

3m tech support reccomends dp190

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Think you hit the nail on the head with mention of the anodized sufrace. Rough that shit up and try some panel bonding adhesive. It is used for weld replacement in the automotive industry and withstands flex seen in sheet metal applications. If it still fails increase your surface area.

Edited by 1987CR250R

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+1^^^^

 

you need to rough or remove the anodizing. most epoxies won't bond well to it.

 

i'd probably acid etch it. bead blasting would also work.

Edited by schrode

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yep, surface needs to be clean dry oil free and a little rough, epoxy forms a mechanical bond and will not stick to real smooth surfaces, which is why you can peel it off of a plastic scraper ect..  I have used west system and for wood anyways is always stronger then the material I bond with it.  I have used JB weld with good  results to fix holes in crank cases.  It was not under any mechanical load, but did get heat and vibration with no ill effects.

 

And yes surface area is your friend.

 

Bondo stuff and polyester based stuff is not good at making mechanical bonds.  It dose chemically bond to itself real well however.     Solid FRP part ( polyester is fine) bonding that FRP part to another surface ( epoxy is better.)

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