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Is JB weld strong enough for an aluminium RC car frame?

I'm building an aluminium frame for a radio controlled car. Will JB weld be strong enough to join the individual rods, and handle a few crashes and rolls? Also the general stresses from acceleration etc.
I've got some low temperature welding rods and a blowtorch but having huge problems with adhesion and flow to even get started with a join.

fiyero666 (author) 1 month ago

Thank you all for your help. I think it's clear that JB Weld is going to be ok for me to prototype with, but not to actually use. I think I'll have to see about getting some more suitable equipment in the future for the full racing version then. The low temperature rods are indeed tricky with only 2 hands. I may have to set up some sort of jig type device to hold things solid while I work.

Would a flux help with getting things flowing and knowing I'm at the right temperature?

I do actually have a rivet gun now so I will need to give it a go, although my project would work better with welds to make a more authentic model looks wise.

Triclaw1 month ago

it will hold up for normal use but racing and jumping no

rjkorn1 month ago

JB weld is a good epoxy but wont do it for you. I've tried many epoxies on rc models after crashes.

The best way I've found for repairs on flat pieces is to make a small patch plate and use some pop rivets.

for round tubes use another tube that fits inside or outside the orig tube and pin it with screws or rivets.

if your building new stuff with solid rods or round tubes just flatten the ends and drill for screws.

rjkorn rjkorn1 month ago

Forgot to say I had very good results on a .28 muffler with those low temp welding rods. Use a separate toothbrush sized wire brush with stainless bristles that never get s used for anything else.also a good turbo tip torch helps. mapp gas is great too but its a lot hotter and you might melt the aluminum if you're not careful

Also when adding the rod scratch the rod into the work. it helps get it to adhere.

Use a copper plate for a backer and you can flow the rod across the copper to fill holes.

I filled a 1/2 in hole in a muffler this way and after sanding it down on a belt sander it looked almost like one piece. there was a difference in color but after 2 runs you couldn't see that anymore. no one knew i fixed it and it outlasted the motor

Are you using a flux ?

rickharris1 month ago

Low temp aluminium soldering is very hard - You have to scrub through the oxide layer with a wire brush as you solder really hard to do unless you have 3 hands!

Use mechanical joints - If your using square section of any size try pop rivets. My full sized electric racing car was totally pop riveted together.

No JB weld isn't good enough. Aluminum is hard to weld. No low temp variant will work as the aluminum is great at conducting heat. If you don't have a TIG welder then you'll need to use brackets, nuts and bolts.

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