Aluminum brazing rod?

zuren · Mar 4, 2020

Has anyone ever used aluminum brazing rod in a project other than patching holes? I'm considering a storage box build and would like to make it out of aluminum. My thought is to build a frame out of aluminum tubing or angle, then skin it with aluminum sheet. I'm still thinking about how to make the lid and thickness of aluminum. This video is what has me thinking about brazing:

https://www.youtube.com/watch?v=jtvOkI_pvMI

The overall structure will need to be stout enough to be stepped and potentially sat upon. I've never played with the brazing rods so I'm not certain how solid of a bond they create. I would also braze the seams to keep it as water-tight as I can.

Thanks!

CedarRiverScooter · Mar 4, 2020

I did not have success using that process. When I did get it to stick, it didn't have much strength. & that is when the whole thing didn't melt from too much heat.

If you don't want to get it welded, rivets are pretty easy to use & are durable. Just have to use lap joints.

JediFish · Mar 4, 2020

I seen a YouTube video of a guy trying to make a toy box with aluminum framing and brazing and he surmised it was a failure. Rivers or welds would be a safer way to go

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maintenanceguy · Mar 4, 2020

I've used the Hobart aluminum brazing rod to fill holes that were worn in corners of an aluminum boat hull. It worked very well.

I've done a lot of brazing of cast iron with brass rod and a lot of brazing of copper tubing with 5% and 15% silver solder. The aluminum brazing rod was harder to use but it did work.

I did a test piece brazing two pieces of 1-1/2" flat stock together. I then used a chisel to separate the two pieces to see how strong the weld was. The base metal broke before the braze broke.

I don't believe it would have worked very well if I was trying to build up a filet as if it was welding. Brass rod can be built up but this stuff was too liquid when it melted. Other types of brazing rods have a eutectic temperature where it's somewhere between a solid and a liquid and you can sort of push it around like a sticky, unstable putty. Aluminum brazing rod was more like solder - liquid or solid. I had a difficult time getting it to fill in holes because it was just flowing through the hole - but I eventually got it to work.

Clean base metal was critical or the melted rod would just bead up on the surface and not stick.

PGRChaplain · Mar 5, 2020

For strength you need to Mig or TIG weld it.

MrGiggles · Mar 9, 2020

Like others, I have messed with it and not had a whole lot of luck. More of a pain than it is worth.

If you can find a local welder and make arrangements to bring your stuff in when he's already set up for aluminum, it can be surprisingly cheap to have it done by a pro, and you'll never have to worry about the welds.

nccatfisher · Mar 9, 2020

Most welders that do it regularly have a dedicated machine for aluminum and don't have to "set up". I have two set up at all times. One with a spool gun and one TIG.