Aluminum Brazing with HTS-735-II rods?

[Karl in NY]

Sold by http://www.alumiweld.com as well as Harbor Freight, etc., etc.

The Youtube videos of this stuff are impressive, for hole patching, thread repair, even new fabrication using angle and bar, and plate stock.

For alloy boat projects, is there any reason to avoid this product, assuming someone doesn't want the expense and
learning-curve of a TIG setup?

Like to braze a new aluminum cleat to the gunnel, for example, or to fab an anchor locker?

[gandrfab]

I have seen it or something like it at a welding show.
I would only use it in a bind, but I weld and have the equipment.

I don't think it would be a good idea for something that would take the stress load a cleat should handle.

[Karl in NY]

Many of the available videos show that the weld is actually stronger than the parent metal...when struck with a hammer, the base metal fails before the braze bead does.

Unlike TIG, the base metal is not melted and fused, however. But the stuff seems to have enormous surface tension allowing major openings to be bridged. The thread-restoration videos were particularly impressive, as was the ability to close a big hole in the base of an aluminum beer can...obviously not something that needs to be done, but just a demonstration...no future in brazing leaking beer cans.

I'm wondering if there are issues with galvanic corrosion in a salt-water environment. The melting temp. of these sticks is around 700*, allowing propane, MAPP gas, and even soldering irons (on smaller repairs) to work. One video of a repair to an aluminum cylinder head showed pre-heating in a home oven to about 500*, apparently due to the mass of the object being brazed.

The melted rod material apparently adheres only to non-ferrous metals, including aluminum, brass, copper, bronze, and "pot metals" which I think are aluminum/zinc mixtures. No adhesion at all to steel, which was used to advantage in one video that showed the construction of a threaded aluminum stud using a steel nut as the mold.

[aluminumweldcom]

An Update regarding where HTS-735-11 can be purchased. The sources mentioned carry different rods, NOT HTS-735-11. Also HTS-735-11 is NOT sold on Amazon or ebay, not sure what they are selling. HTS-735-11 is only available from Aluminum-weld.com. Buyer beware of copy cat products and fakes. Read the specifications. One source states LOW TEMPERATURE 647C. That equals 1197 F. about the same temperature aluminum melts.
HTS-735-11 melts at 735 F. New DIY videos on youtube search HTS-735-11 on youtube. I hope this helps.

[gandrfab]

Welcome to the forum.

[aluminumweldcom]

Thanks, Glad to be able to contribute.