My brother and I are making ourselves a couple of headers for VF40-46's and are curious what methods and materials folks have used (successfully) to braze or weld the aluminum flange to the aluminum pipe and for it to withstand heat and vibration.
 
Aluminum material is 6061 for both the flange and the header pipe.

Brazing seems like the easiest way to get the two pieces joined and have a complete joint.  4047 filler material seems like a good choice.

I am interested to learn what has worked for this application.

My brother and I are making ourselves a couple of headers for VF40-46's and are curious what methods and materials folks have used (successfully) to braze or weld the aluminum flange to the aluminum pipe and for it to withstand heat and vibration.
 
Aluminum material is 6061 for both the flange and the header pipe.

Brazing seems like the easiest way to get the two pieces joined and have a complete joint.  4047 filler material seems like a good choice.

I am interested to learn what has worked for this application.

    I haven't done it, but if I was going to, I would think that contacting Scott Dinger would be my first step. I don't know what he would charge but I know he has done a lot aluminum welding for modeling applications.

       I have "successfully" used the "magic" eutectic rods for welding aluminum, but, it is extremely difficult and the end result was a complete mess. It stuck two pieces of aluminum together, that's about all I can say for it.

      Brett

Lauri,

Is the flux you are using the Castolin 190-NHR  https://www.castolin.com/product/190-nhr-brazing-flux

There are a several options in the Castolin 190 range of products.  Can you specify which Castolin 190 material and what size you are using for your mufflers?
https://www.castolin.com/en-US/product/eutecrod-190

Castolin has some interesting flux core rods in the 190 series, 190cw / 192cw(higher silcon content).


I mentioned 4047 brazing material earlier.  4047 used with an appropriate flux looks like a possible good choice as well.  https://www.brazing.com/products/Welding_alloys/alloy4047.1.aspx

   Im glad this thread opened up the last few years I've messed with the idea of brazing & soldering Aluminum . I will need a lot of practice because most my stuff is a mess also. I'll probably come back with the setup I have tried.
    John L.

  Exactly, this is always the issue with any of the aluminum brazing/welding I have attempted - you are always a few seconds away from going over the top.

    Brett

Many years ago an old craftsman told me: "the right time is when the aluminum turns pale pink".  Once I think I had a hallucination, I saw the pink and the solder was perfect.  Unfortunately it was the only time, I have never succeeded before or after.

Massimo

https://www.alumiweld.com/

Works for what we need, just remember you have to heat the heavier material first. Of course you need a jig to keep everything aligned during the process. I am looking into having a run of these done over seas but need interest in quantity as minimums would be 50 to 100 pieces. If I was still traveling into the region I could find a small mom and pop that would do these but I no longer travel to south east Asia any longer for business.

Looks like you have 2 good options, Brent. That's nice.
Now, where can you get the thin walled tubing used in headers? I could use some.. L

  McMaster-Carr has tubing with a wall thickness of .028, sounds about right to me.

   Brett

Fill the tube tightly with fine silica sand and cap the ends. Make a jig out of hard wood to the radius you need. Heat gently and evenly as you bend around the jig. Old school method, but holds up.

Obviously not everyone has the same tooling, but that's the point I get to, and then tig weld it. To me, it's easier to control the bead welding. But, if you aren't set up... then brazing its wildly cheaper. Lol

Yep, that's how I understant it too. But in brazing the filler kind of follows the heat. It wicks through seams when you apply heat to the other side. I never do butt joints, that's why I ask. L

     There is such a thing as TIG brazing, just like brazing with a TIG torch instead of an oxy-acetylene torch use it as heat, use a dissimilar material with a lower melting point as a filler. I don't know how well it flows into joints, I have never attempted such a thing.

     I think your aluminum braze is a fine solution, and plenty good enough.

     Brett

I spent a few days googling and calling flux manufacturers.  Castolin, Messer, Vulcan, Continental, Superior, Forney,  ect.  Many of the fluxes out there are over $100 and some were $150 for 6-8oz.  Too expensive to consider, for me.  I found Tin Man Technologies in my searching and purchased the "Super Premium" aluminum flux from them.  It was reasonably priced and had good reviews for torch brazing.  TMT described its product as having been a preferred flux used by aerospace companies, ie. Boeing, Douglas, ect.   Neat company as well.  They did a replica of the Hughes H1 racer aircraft among many other cool projects.
https://www.tinmantech.com/products/welding/welding-flux/aluminum-welding-flux.php
 
I purchased 1LB of ER4047 .047" as well.  Under $20 on eBay.  As mentioned above, the Castolin rod that Lauri used is 4047, so this should hopefully suffice.

So, it will be fun experimenting with this stuff before I make attempts on the real projects.