Aluminum brazing

G

Gordon

100 W
Joined
Jan 4, 2009
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173
Has anyone here had any experience with brazing aluminum ? Here are a couple products.
I am skeptical of any "as see on TV" products but wonder if it could be any good.http://www.durafix.com/
Here's one from a reputable company. http://www.aluminumrepair.com/aluminum_repair.asp

I've got an aluminum rear rack that I'd like to beef up a little for my batt box and i pilfered some alum rod that was laying around at work. I thought if these rods were any good I might get creative. Who knows? maybe I could build a whole new bike frame from a bunch of old lawn chairs and tent poles
 
Gordon said:
maybe I could build a whole new bike frame from a bunch of old lawn chairs and tent poles
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This is going to end in tears.
*subscribes*
:lol:

For reinforcing racks etc it'd be fine, you've got nothing to lose. I wouldn't trust making a custom frame though!
 
To be honest. If I was going to build a custom Ebike frame, I'd get ahold of some decent steel, some good brazing rod, and go from there. One could do a much better job, as it's easier to work with for the hobbiest. Also, the weight differance on an E-bike frame is neglibile to Aluminum when you get up into the 80-90lbs range.
 
Gordon said:
Has anyone here had any experience with brazing aluminum ? Here are a couple products.
I am skeptical of any "as see on TV" products but wonder if it could be any good.http://www.durafix.com/
Here's one from a reputable company. http://www.aluminumrepair.com/aluminum_repair.asp

I've got an aluminum rear rack that I'd like to beef up a little for my batt box and i pilfered some alum rod that was laying around at work. I thought if these rods were any good I might get creative. Who knows? maybe I could build a whole new bike frame from a bunch of old lawn chairs and tent poles
Click to expand...

I fixed the brake handle of my motorbike with it. it works. its cheap if you get it from harbor freight. I paid $12 for 12 sticks

the problem is the heat to do it anneals the aluminum, and makes it soft.
 
I've used http://www.aluminumrepair.com/aluminum_repair.asp
with great success and by carefully heating the aluminum I didn't change its temper. It takes a lot of practice not to overheat the material and keep it at just over 700 F its not easy and I have overheated material and got a good braze joint but ruined the material. Very tricky to get right. I would be very careful about building a bike with the stuff. Its so easy to ruin the material and not know it until its to late.

Mark
 
Gordon said:
Has anyone here had any experience with brazing aluminum ? Here are a couple products.
I am skeptical of any "as see on TV" products but wonder if it could be any good.http://www.durafix.com/
Here's one from a reputable company. http://www.aluminumrepair.com/aluminum_repair.asp

I've got an aluminum rear rack that I'd like to beef up a little for my batt box and i pilfered some alum rod that was laying around at work. I thought if these rods were any good I might get creative. Who knows? maybe I could build a whole new bike frame from a bunch of old lawn chairs and tent poles
Click to expand...

I have a hard time with that one "brazing aluminum" It takes alot of heat to braze things and aluminum loves to just melt quickly into piles of... I have welded it before and it was very tricky as when it is hot enough to weld it turns watery like and runs all over. If you weld fast enough at just the right time it can work great. Might I suggest you just save up for a stronger rack.
 
I will admit, for those savvy at brazing, HTS-2000 is probably one of the best. Better than Durafix. I've toyed with both.

Here's a bike I repaired the chainstay with HTS-2000.

It's still going.

DSC01038.jpg


DSC01090.jpg


And no, I'm not converting this one to an Ebike. :mrgreen:
 
Thanks for the advise. Of course I was joking about frame building.

I think I'll give it a try on the rack. I'd like a stronger support to the seat tube than the thin stainless adjustable ones that came with the rack. I can picture them buckling in a hard stop. I also plan a pair of rods connecting to the seat stay. The challenge seems to be to heat the alum just enough to get the rod to flow.
 
The real key to using Aluminum brazing rod, is to keep the flame moving. I found it was best to use a nice spread MAPP flame. Not a small fine point flame. You don't want to concentrate the heat in one point. You want slowly heat up the whole area around where your working. Once it's hot enough, you'll know this by repeatedly testing a spot with the rod. Be very careful not to hit the rod with the flame. Always allow the metal to melt the rod for a strong joint. Once a little melts, tin it immediately into the area to be worked. Then, heat it again, and add more rod to fill the crack/joint to be repaired. Only apply just enough heat to kep it hot enough to melt the rod, but don't keep adding heat, or once the temp gets over 1000F, you can damage the temper as you approach melting point. The rod melts around 730F (or so, I can't remember exactly), so keeping it just barely above that is all you need.

It took me several tries on some scrap to get it down, but once you get the idea of how it works, it really is some decent stuff.
 
boostjuice said:
HTS-2000 repair capabiltiy and strength testing http://www.youtube.com/watch?v=N-cv3R4fWZc
Click to expand...

Impressive
 
boostjuice said:
HTS-2000 repair capabiltiy and strength testing http://www.youtube.com/watch?v=N-cv3R4fWZc
Click to expand...
Wow, I saw the video, very cool!

I'll use this to repair my 4011 as well as reinforce the spoke flanges all the way around on both 408 & 4011.

This product will also allow me to fab my DIY aluminum frame knock-off of the Revive . . . with a simple propane torch ! 8)

COOL ! ! 1

Thanks for the info, boostjuice ! Just in time...

J
 
That is just the most amazing video! I have got to get some of that. We did brazing in bodywork class, it's a lost art that is making a comeback thanks to products like this.
 
etard said:
That is just the most amazing video! I have got to get some of that. We did brazing in bodywork class, it's a lost art that is making a comeback thanks to products like this.
Click to expand...

I use the stuff in real world applications and can say the brazing material is excellent but be careful its easy to think you have a good joint when its not. The video makes it look easier than it really is. Done right and I have done some of the same test that are in the video the brazed joint is stronger than the parent material when brazing 6061-T6.

Mark
 
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