Aluminum Brazing

[atc250r]

Anyone seen this before? Watch the video on the right side. Good for engine blocks, boats, etc...

http://www.aluminumrepair.com/boat-repair.htm

[yorkiepap]

Hey atc250r,
Yes, I have used this type of rod for many repairs on the so-called "diecast", "potmetal", or "zinc-junk" as it named. It has a place in the shop. Anyone who does repairs on these "not-so-friendly" cast items that cannot be repaired by any other conventional welding process can make a decent $$$. These rods, under different names, ie.; HTS735, HTS2000, Aluminaweld, & others can be used with success.....by practice, of course. Your optimum results will be obtained by prepping the repair as you would any aluminum repair.....GOTTA BE CLEAN! I prep the same as 6061 alum....SS wire brush & acetone.

You must take into mind that these rods are not "welding" rods....they are "brazing rods". Welding is the melting & fusion of a filler metal to achieve bonding. These rods utilize the capillary action("tinning") as you would soft or silver-solder to achieve a solid joint. It does work & is quite strong if applied correctly. I use it for those repairs on the "diecast" items that many people do not want to discard....again....nice $$$. These rods can be used on regular aluminum, although you must keep in mind, the strength is not the same as aluminum welding. I personally would not use this rod for any repair that entailed any substantial force, pressure, or weight.

Here are some pics of a strength test with this rod I did on some 6061 alum. angle just to determine application parameters. It held up quite nicely, so it does have a use. I have a supply of the original HTS735 & I use both MAPP & O/A depending on size or repair. Hope this will clear up your understanding of this type of rod.

Denny

[aametalmaster]

I use Crown Alloys Royal Kirkrod. Similar to those others. And as Denny says they have a place in the shop. I too brazed some alum section together and i was impressed. But i wouldn't do anything that has to hold weight or run down the road like an alum trailer. But for junk potmetal they are fine...Bob

[yorkiepap]

Hey Bob,
Where do you get your Crown Alloys rod? I'd like to try some. Thanks...

Denny

[aametalmaster]

I get the Crown Alloys from my Miller dealer right up the street from me. I can ship what ever you want to try...Bob

[yorkiepap]

Hey Bob,
Thanks... I'll PM you....

Denny

[Portable Welder]

Yorkie Papp, This cant be right.

The guy down at the Flea Market selling the rods told me there just as strong as aluminum and that I can even use it to weld Ford Escort heads.

They welded his beer cans and I could barely tear them apart.

[Aerometalworker]

Yuck, flea market rod.......... One thing to keep in mind, is that even if you treat it as a brazing alloy, is that its not ductile at all, and can actually make the base metal brittle depending on the alloy. There are plenty of AL/Si brazing alloys out there that outperform this zinc based garbage. If I could have the hours back I have spent digging that garbage out of a previous repair to weld or braze it correctly.....

[seattle smitty]

Pap, is that an old SolidOx torch in your first photo, converted to use bottled oxygen? Did that myself; those SolidOx pellets never seemed to put out an even pressure for very long! That was my dad's purchase, out of a Sears, Roebuck discount shop for returned merchandise. It looked like a joke to me, but I used it a few times just to see if I could do anything at all with it. With the bottled oxygen it was considerably better. I carried it in my camper van, tapping into the van's propane supply for fuel. Never encountered the hoped-for occasion to make an heroic repair with it, unfortunately.

[engnerdan]

Yuck, flea market rod.......... One thing to keep in mind, is that even if you treat it as a brazing alloy, is that its not ductile at all, and can actually make the base metal brittle depending on the alloy. There are plenty of AL/Si brazing alloys out there that outperform this zinc based garbage. If I could have the hours back I have spent digging that garbage out of a previous repair to weld or braze it correctly.....

Aero,
What aluminum brazing materials would you recommend?

-Dan

[yorkiepap]

Hey guys,
I just want to provide a bit more clarity regarding these "junk" rods. Much of the "diecast" & "potmetal" items that have been made increasingly in the last 30yrs are heavily zinc laden. These rods are also heavily zinc laden & they do work for the "junk" repairs. For aluminum, nothing compares to a repair with aluminum rod & the correct application. I like to "braze" aluminum occasionally on very thin applications & I use TIG rod of 4043 or 5356 & I use alum. flux I get from TinmanTech. Common sense & the correct procedure should dictate the process of repair. If it is a non-load repair, or just a decorative item that just needs put back together, use the "junk" rod.....not gonna hurt anything. Many times, the "junk" rod works best because of the very low temp to get a good "brazed" repair. I am not promoting these rods for anything other than those "junk", heavy zinc laden pieces that even an aluminum rod will not fix.

To seattle smitty: I remember the old SolidOx setups they sold way back in the heyday of the "home-fixer-upper" repairs. These are MAPP & Oxy I use occasionally for really tiny repairs as I can maintain a really tiny "pin" flame. The only disadvantage is the oxy. bottles have a short lifespan.

To engnerdan: If you've never been to the TinmanTech site, go there & watch some super aluminum welding/brazing. Very informing.

http://www.tinmantech.com/

To Aerometalworker: Yes, you are quite correct. I find many weldors have never really engaged in doing aluminum welding or brazing from the "old world" masters who enjoyed O/A aluminum work. Personally, I love doing it & sometimes just sit & practice on all those cutoffs that are going into the "scrap" bucket.

Denny

[Aerometalworker]

Traditional brazing is done with 4047 filler, and brazing flux. The flux can be had from Kent White as its probably the easiest source. There are flux cored rods as well , but the fluxes contained in them are usually non-corrosive, and thus ineffective on the 5xxx series and some 6xxx series alloys. I should add that I do use flea-market rod, to repair pot metal.