Brazing Aluminum

[Booth]

Has anyone ever tried brazing two pieces of aluminum together??

A friend of mine droped off a tank for me to use as a livewell and it did not hold water very well. I do have a spool gun for my wire feed but I wanted to try this low temp aluminum brazing rod (700f melting point no flux). The trick so far has been to get the parent metal uber clean and bring it up to temp before the filler rod is introduced. This is a first for me and I wondered if anyone else has tried this before and has any tips?

Thanks,

Paul

[CAMAN]

If the existing weld or aluminum is cracked or pin-holed in any way you will want to grind away any of the exposed areas to virgin material. Otherwise the filler rod will not stick and you will be fighting with it.

Get yourself a brand new quality stainless steel wire brush and some acetone. Wipe the area with an acetone soaked rag then brush the area very good. Wipe down with acetone again to remove anything that may have broken loose and brush lightly again. Apply liberal heat with a rosebud torch, Do NOT remove the heat until you are 100% sure it is hot enough to accept the brazing rod otherwise you will have to let everything cool and clean the area again. If you have to do the joint along the length of the tank start in one corner and slowly work to the other side never removing the heat from the material but following it at an appropriate distance with the filler rod so it is being melted by the heat in the aluminum and not the torch.

[Gordie]

Ditto on what CAMAN said as they say Cleanliness is next to Godliness!!!!

Only weld or braze a little at a time as not to warp the seam you may want to braze in a couple of different spots so one spot can cool while you are welding on the other.

It is difficult to braze aluminum but it can be done Good luck

[Eric Wettschreck]

How thick is the metal on the tank? I ask as TIG welding this may be the route to take. I've never had much luck brazing aluminum. Not saying it can't be done, I just suck at it.

When I have to work with aluminum I always try to TIG weld it if I can.

As stated, clean the bejessus out of it. Use stainless steel wire brush and not a carbon steel brush. You need to clean the oxides off the surface of the aluminum and carbon steel will embed more oxides into the aluminum. When you think you have it clean, you only have it half clean so clean it more.