Alumifix Flux-cored Rods

[John Turney]

I saw this on Facebook, and although it sounds wonderful for joining aluminium, I'm wondering if it's too good to be true. Anyone tried it?

https://dealygiftshop.com/products/...cA5Dv8oSI7OfIHrwFFPEx-ARnepiEXUX-LaXXjK-mupUE

 

[TR3driver]

I tried a similar product years ago, to repair a TR3A thermostat housing. Watched a fellow at the state fair solder blobs to beer cans, then use the blob to tear the can apart, "proving" the weld was stronger than the base metal.

But my propane torch just wasn't enough to get the housing hot enough to flow the solder. I guess there was a reason he was using beer cans (which are extremely thin)!

And by the time I got an OA torch, I'd lost the rods and used the special SS wire brush for other things (which supposedly ruined it for this purpose).

At that time, a used housing turned out cheaper than the kit anyway

 

[Bayless]

I remember the guy at the state fair.

 

[martx-5]

I used a similar product to repair the aluminum capping on my TR3, which is thin like the beer can Randall mentions. There were a few other heavier items that I used it on that were maybe 1/4" thick. On the heavier stuff I used a MAP gas cylinder. The stuff works well if you clean it properly with the stainless brush. I pretty sure it's a zinc alloy.

Edit: Below is the stuff I used...AlumiWeld...In the FAQ, they give the physical characteristics and mention that it is a zinc alloy. I still have 3 or 4 rods.

https://www.alumiweld.com/

 

[dklawson]

I have used a similar product with success on diecast aluminum. It was from National Welders and has/uses no flux. You get the broken part up to temperature with a propane or mapp torch, move the flame out of the way, and rub the aluminum rod on the broken area to be fixed. If the temperature is high enough (about 700 oF) the rub-on rod scratches through the oxide coating on the broken parts and tins the surface. Over the years I have used it (the same package of material I bought over 35 years ago) to repair several broken aluminum parts. Harbor Freight sells their version of the stuff now.
https://www.harborfreight.com/8-piece-low-temperature-aluminum-welding-rods-44810.html

Another apparent version of the same....
https://selectrode.com/2111-a-rub-on-solder-for-aluminum-without-flux/

The rub-on aluminum solder I used is harder than regular aluminum but not stronger. The tensile strength value for the second of the two solders linked above is 35,000 PSI. Tempered 7075 aluminum is about 70,000 PSI while 6061 is in the low 40,000 range. For the applications I worked on the strength was never an issue as the parts were typically ornamental. Remember that this rub-on solder doesn't really melt the base metal, it's more like it tins the surface so if you need strength, TIG welding will generally be better.