# Alumiweld/Durafix



## fritz42_male (May 5, 2009)

Anybody got any experience of using these products? I want to fabricate some prop mechanics using aluminum and these seem like a good option.


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## corey872 (Jan 10, 2010)

I've used it on a couple projects. It works well if you follow the directions.

Brush all parts with a stainless steel brush immediately prior to 'welding'

Propane gas will work, I use MAPP gas for a bit of extra heat. If you have the option of fuel/air adjustment, try to run a neutral or ever so slightly fuel rich flame (keeps the Al from oxidizing while heating)

Scrape the rod against the aluminum briefly while heating to further disrupt the oxide.

Basically it's all about getting the oxide off the aluminum. I'd recommend watching some videos on youtube to get a 'feel' for the process. But in general, works as advertised! The one failure I had was in 'welding' some aluminum refrigeration tubing. Seems the joint had some porosity and leaked freon. But that was a pretty extreme case. For just welding up structural aluminum parts, I'd say it should work great.


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## hedg12 (Jul 6, 2008)

I used alumiweld to repair an RV awning frame last spring. It's held up great so far, even under some pretty strong wind. Corey's right about needing to clean the oxidation - it won't stick at all if there are impurities. I used white vinegar and a scotchbrite pad, then cleaned that with plain water & dried it thoroughly. I used an acetylene torch, but that's way overkill. Had to keep it turned way down & fairly far away from the work. Didn't try propane or MAPP.


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## fritz42_male (May 5, 2009)

Thanks for the feedback guys. I've ordered a pack to try.


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## corey872 (Jan 10, 2010)

Sounds like it worked for you, but the downside of the vinegar/rinse is twofold. Caustic (alkaline, pH>7, typically ~9.0 to 9.5) reacts best with the oxide layer and are typically used for cleaning. Weak acetic acid/vinegar (pH ~4.5) isn't terribly effective for that. Also, the post cleaning rinse with water is just putting an oxide layer back on the aluminum in much the same way you would see flash rust on a freshly cleaned piece of steel.

The scotchbrite pad may be a good substitute for the stainless steel brush, though. The main key is not to use a regular steel brush as it can leave particles of iron behind when then flash rust.

Also forgot to mention, the melting point of the aluminum and the melting point of the welding rods aren't too far apart. Also, aluminum doesn't really 'glow' or give any other indication it's about to melt. If you're welding thick parts, this may not be too much of an issue as they will pull heat out about as fast as you can put it in. But on smaller parts or <1/8" thick material, the heat input becomes a little more critical. So you want to use 'just' enough heat to get the rod to flow into the joint.


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## hedg12 (Jul 6, 2008)

Vinegar is what the guy at the Alumaweld booth at the NSRA Nats suggested to use when I bought it, & it appeared to work pretty well. The scotchbrite left a residue, which is why I wiped w/ water. Did it quickly & right before I heated the piece. It worked well for me.


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