brazing ?

[croatankid]

I'm trying to braze a drain plug into my transmission pan. I brazed it once and it leaked. I found that the pan was cracked in the braze area. I ground the brazing off and brazed it again and it still has cracks. I wonder, I'm I getting it too hot? Is the plug, being thicker and the thin metal of the pan a problem? I went out a bought another pan today. The junk yard had no idea with the problem could be The reviews for this item talked about welding it in. Can anyone offer advice?

 

[Dirtman]

Well obviously welding is always going to be stronger than brazing so that would be my first choice if you can get access to a welder. Brazing stuff like that is kind of a dead and useless art anymore (no offense). If you're dead set on brazing are you using nickle silver rod? And are you allowing it to cool slowly enough?

 

[19Walt93]

I gas welded a drain plug into mine- using a coat hanger for a welding rod- and it worked fine, if you can braze it you can gas weld it, too.

 

[Dirtman]

Are you people time travelers?

 

[croatankid]

I think I must be. Aren't torgue converter vans brazed? Anyway, I don't have a welder. I can find a welder to do it I guess.

 

[JOLENE_THE_RANGER]

are you people time travelers?

hahahha

 

[Dirtman]

Aren't torgue converter vans brazed?

Kinda... Most converters just have fins that are press fit. Higher performance units have the fins furnace brazed to keep them from coming loose. the brazing is just "insurance" not the main joining method. They use furnace brazing because it is super duper cheap and requires almost no skill from the worker. The units are heated in a furnace to the proper temp to melt the filler and then roll down to a worker who basically just dabs a brazing rod on them without using a torch.

 

[adsm08]

Are you people time travelers?

Everyone is a time traveler, just most people only know how to go one way.

 

[Big'Un]

What are the trans pan and drain plug made of ? Are you using bare brazing rods or the pre-coated ones ? Using flux ?

 

[alwaysFlOoReD]

Parts need to be really clean and heated to the correct temp. for brazing to work well. It's been a long time but I have a couple projects on the back burner waiting for some brazing. Brazing is plenty strong, I have a nail puller that was brazed by my grandfather that is still working. I'm pretty sure old motorcycle frames were brazed together.

 

[Captain Ledd]

Is the pan steel or aluminum?

If it's aluminum then the whole thing might need to be heated and then cooled slowly. Just about anything cast gets cranky when brazed/welded.

If it's steel, I'm not sure what's going on, other than that there are a TON of residual stresses from stamping that are pulling it apart after what is basically localized heat treating. Also yes, you may be getting it too hot, and going past the upper critical temperature, where the carbon dissolves into martensite., and when it cools too rapidly in that state, it will definitely crack and be extremely brittle. Cooling slowly is the key. Though, similar things can (well, do) happen with welding too. This depends on a lot of what alloy of steel it is.

Given your pan is cracking and not the plug, the plugs weld-ability is fine.

Without being a super expert on welding/brazing, nor knowing exactly what the base materials are, I can only suggest slowly heating the whole piece, and slowly cooling it back down, I also think you may be getting it on the too-hot side of things.

Brazing is plenty relevant today, and a lot of materials are more easily brazed than welded as it doesn't melt the base material. The only difference between Brazing and welding is temperature.

Welding temperature is classified as any temperature high enough to melt the base metals together.

Brazing is done generally in the 1200°F-1600°F, so if you're getting the base metal hotter than a dull red, you're getting it too hot.

Soldering is a filler metal that is liquid below 850°F, basically low temp brazing.

 

[Dirtman]

Everyone is a time traveler, just most people only know how to go one way.

That's deep...

 

[croatankid]

OK, so I went to a junk yard and a body shop and no one offered any advice on what was wrong with my brazing. But while at the junk yard I found a a4ld off a four wheel drive vehicle. I bought the pan off it for $40.00. It protrudes a few inches lower and now I'll put the drain plug into it. I found a really nice welder who welded it for only $10.00 but I gave him $20.00 because he was worth it. So, to put a drain plug in I paid $40.00 for two drain plugs, $40.00 for another pan, $20.00 for welder, plus running around just to get a drain plug installed, that's $100.00. I'll also need a different filter with the deeper pan.

 

[alwaysFlOoReD]

Did you ask the welder about your braze job?

 

[black_demon69]

What he said



Also a couple of things that might help

1 there is a heat absorbing paste can't remember the name of it off hand but you can use it on the pan to help keep it from cracking.



2 you need a paste flux


3 when brazing 2 dissimilar metals like steel and brass you need a rod with a higher silver content I believe.


4 if you are getting material dull red it can get too hot very quickly



5 rod should follow the heat and flow into the joint any excess material from the rod does not make it any stronger and is just waste



https://www.lucasmilhaupt.com/NA/EN/Brazing-Academy/Brazing-Fundamentals.htm


https://www.google.com/url?q=http:/...XC4gQFggNMAE&usg=AOvVaw0YhfgyqwAG-8RSzw8lHTFH


Couple of links that might help you