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braising aluminium general questions.

Posted: Wed Nov 18, 2015 9:32 pm
by funfool
I am building a set of mirrors, using 1/8" aluminium, I need to attach a aluminium block to the back of the mirror.
This will have the drilled 3/8" thread, for the rod to mount to the bars.
I can just drill holes through the 1/8 plate and counter sync the flat head the screws.

Problem is, I will mill 1/16 out of the back of the mirror, 1/16 out of the frame, sandwich the glass.
So the screws will now only be going through 1/16 into the mounting block.
I would also like to use some aluminium rod with flux included, pick it up at harbor freight, but already have.
You just use a propane torch to get the needed 750 degrees to braise aluminium.

Has anyone used this method before? can it hold the block? my mirrors have some weight to them, 1/4" thick plus glass.
What about polish? I will fly cut the mirrors and engrave the backs of them, will this aluminium rod look like a turd?
How about on a headlight and braising mounting tabs and brackets for a headlight bucket,, will it hold up in strength to that?

I have a small mill and a lathe, cutting torches and many machinist tools, will be a few months before can buy a welder, want to get started now. Do I need to wait?

Re: braising aluminium general questions.

Posted: Thu Nov 19, 2015 7:09 am
by gearhead1951
There is no problem with the strength , but some of these rods can be a significantly different shade of "silver" than the alloy that you are brazing to when polished ! You can counter that somewhat by carefull assembly and using minimal rod for the job !

Re: braising aluminium general questions.

Posted: Fri Nov 20, 2015 4:57 pm
by funfool
Thank you for the reply, and a vote for strength.
I also asked in a welding forum to see what they thought. They had this link
http://weldingweb.com/showthread.php?46 ... ng-Options

Just in case anyone else would be interested in it.
I am going to try it and see for myself how long it will last.

Re: braising aluminium general questions.

Posted: Sat Nov 21, 2015 6:35 am
by gearhead1951
another variable is the torch used , I know a retired USN hull tech who uses a " Henrob" torch !

It is a version of the oxy/acetylene torch that creates more localized heat and is favourably comparable to "tig" !

Google it ! The rights to this equipment has changed hands (and name) a few times but it is still on the market and even the oldest ones (if you make a good flea market grab ) is supported by the latest mfg !

Re: braising aluminium general questions.

Posted: Sat Nov 21, 2015 10:24 am
by Customize IT
I have brazed everything but aluminum?

Very interested on how it works!

Think I would find a tig welder AC and just do it that way if at all possible?

Re: braising aluminium general questions.

Posted: Wed Nov 25, 2015 2:42 am
by railroad bob
A long, long time ago, I welded (brazed) aluminum, using a torch and electrode that was heated and dipped into a can of flux.
It worked well, I don't remember how the color looked, but seems like it was kinda lumpy looking. Might have been my technique, since I had no experience.

For an application that will be very visible, constantly, I agree with Nathan about using TIG. If you aren't familiar with TIG on aluminum, it is pretty easy once you have everything set up. Since you use minimal electrode, the parts are primarily just fused together.