Dura Fix aluminum rods?

[hoz]

has anyone used this stuff? Does it work? I have plans to make a custom aluminum carrying yoke for my canoes and thought this would be a good way to weld the pieces together.

http://durafix.com/

[Dave Fleming]

Hmmm, sounds too good to be true, sooooo??

Welds ***stronger that Al.****?

I don't think so.

Rule of thumb with MIG welding is 80% strength of parent material in Al..
I'm guessing that TIG would be a bit stronger.

YES, one can use gas welding on some Al. alloys.
In fact one of my mentors was a Specialty Welder at Mare Island Naval Shipyard for over 25 years. He worked with the Engineering Dept. developing Gas Welding techinques for Al.

But the proper way is with shielding gas around the weld spot. We used a 50/50 blend of Argon and Helium. Got to keep Oxygen away from the weld. When welding 5000 and 6000 series in fishing vessel and yacht construction.

[sdowney717]

This type of rod does work. You use no flux just heat it up and RUB the stick on the hot aluminum to be welded. You have to rub it to break up the oxides and get a bond. I would get the metal as clean as possible first.
I went to the local welder supply and bought Aladin sticks. You could probably do the same. I repaired some aluminum gear cases.

[stef]

I have not used the product myself. A quick review of the data sheet for Dura Fix and Aladdin 3in1 show similar melting points and application ranges. It can also be used to repair "white metal" castings, or generic zinc diecast products.

Based on the specific gravity number 6.7 and intended application, one would not conclude that this is a aluminium rich product (Al s.g. = 2.7, Zn s.g.= 7.6). It is interesting to note that and alloy of ~95% Zn and ~5% Al has a melting point around 716F and a specific gravity of 6.8, hmm. I won't bore you with a more detailed metallurgical explanation. I would have to do some more research (find a larger phase diagram) to better define the above ball park numbers.

I was not able to find a MSDS for either product so the ultimate compositions are unknown. I would be very suprised if there was not some form of flux incorporated into the product to aid in "wetting" or "oxide softening" in my opinionated opinion.

This product appears to be a zinc dicast welding product adapted to an aluminium soldering application.

Like anything else involving welding/brazing/soldering, joint design, practice and temperature control will be the key to making it work. Temperature is a bit more critical with these types of alloy systems since it is very easy to over heat with the equipment being used or the geometry of the part which would create thicker oxide layers which the rubbing action may not be effective on.

Will it work? I would sit on a fence for this one since there will be as many anecdotal stories on both sides much like, the best boat, paint, wood, etc etc. Yes, depending on the application, surface preparation, actual alloys involved, joint design etc etc, and no for the same reasons.

Next steps. I would talk to the tech guys, not the sales types, and get the required joint geometries. I would review the yoke design to see if the geometries work. Then I would test my skills.

I hope I have added to your insight on the product.

Stef

ps. after reviewing my post I think I need to get a life or at least go sailing. :confused:

[Jon Etheredge]

I have not used the Durafix product so I can't answer your question.

But if you want to weld aluminum with an oxy/acetylene torch you might check out the stuff from this guy:

Aluminum welding and brazing supplies (http://www.tinmantech.com/html/aluminum_gas_welding__brazing_.html)

I have heard very good things about the lenses that he sells. Reports are that the lenses make it much easier to see the temp changes in the base metal. In my experience it is <u>really</u> hard to see the temp changes when gas welding aluminum with a standard welding lens.

[sdowney717]

I have welded aluminum with oxy-acetylene. you got to be real careful, the base metal can get hot enough to soften and let go and it seems to do this in a broad area at once.