Weld or Braze return bung?

[slipnfall]

Hi folks, My oil pan is cracked, so I figured it's time to get my oil return bung on while I'm replacing it. I'm using a weld-in 10AN male bung from summit(p/n EAR-967110ERL). It's steel w/zinc coating. I'm wondering if it would be easier to just braze the bung on? The pan is a stainless steel, correct?

Think my propane torch would get hot enough to braze it on? Obviously some flux would be used(I think they use a borax flux for brazing?) I'm guessing brazing would allow the metal to flow around the area much better than a weld would.

Any suggestions? I'm very good with electronics soldering, but have never done anything this large of scale: my friend made the brazing suggestions(he said the oil pan metal is a little too thin for him to attempt, since he's a novice).

Thanks for the help.Jamie

[UK-SRi]

Brazing should work, degrease well before you start, use some rockwool under the work to help stop things burning. Also you need to rig up something to stop the bung dropping out when its hot.

Borax is the flux, needs about 700 centigrade. Some of the heat guns will braze if you restrict the flow of air going in a little, I have done that to a door skin before now.

Mike

[slipnfall]

Really, just a heatgun? Everyone I'v spoken to today has told me that a propane torch will not get nearly hot enough. I was considering an oxy-ascetaline torch or something similar(like MAPP gas/oxy combo). But I figured for the price of those setups, I can just have someone else do it for me. I was quote $20 today to have it done, which I don't think is too bad.

Thanks for the advice anyways, I appreciate it. This will be something I'll look into again when I get to the intercooler piping stage.

'Slip

[fiznat]

I would weld it. The oil pan metal is pretty thin compared to the thick steel bung, I bet it would be a pain to get the bung to start to melt without burning holes or deforming that thin pan. Brazing is cool for a lot of stuff but when you have two parts that are of very different thickness, and an oil pan that needs to remain in a particular shape, I think the torch puts out just a little bit too much heat over too wide of an area.

[slipnfall]

From my understanding, welding requires a much higher heat than brazing, although I'm sure the durration of this heat is important also.

Brazing is using a third sacraficial metal, with a lower melting point than the material, to join two pieces. Welding actually melts the pieces to some degree, and I'm guessing uses the 'filler' to aid in bonding and heat transfer.

I found a great deal of information on brazing at:http://www.inductionatmospheres.com/brazing.html

Just a quick quote:

Brazed joints have great tensile strength – they are often stronger than the two metals being bonded together. Brazed joints repel gas and liquid, withstand vibration and shock and are unaffected by normal changes in temperature. Because the metals to be joined are not themselves melted, they are not warped or otherwise distorted and retain their original metallurgical characteristics...Both brazing and welding work well for joining metals with similar melting points, but it is generally easier to join dissimilar metals with brazing. Simply choose a filler metal a lower melting point that either of the metals to be joined.

[UK-SRi]

Hi,

I had a black and decker heatgun that was supposed to limit at 600Centigrade. Brazing needs 650-730 Centigrade for a brass/bronze brazing rod.I had to ever so slightly restrict the air flow in to get the braze to melt on the door skin, but it did do the job.

Mike