Welding Tips and Tricks

I had to mcgyver an oil drain flange for my new turbo. To make it clear I cut off the male AN end off the flange and carved up a 45deg hose end for the pipe and used an npt to an adapter for the tip. Everything looked fine, leak tested and reefed in it, was good. Then a friend told me that AN spec calls for the hose ends to be 7075. I called the manufacturers and the hose end was a Russell who confirmed the pipe is fine. But the adapter is Earl's and they said all their anodized fittings are 2024...

So I ended up cutting it off and welding the tip I cutoff earlier on to the pipe.

But because it's such a huge pain to remove this thing (I had already installed it), that to make myself feel better I put the tip in a vice and whacked it with a hammer a few times. Other than putting dents in it, nothing gave.

This made me wonder what exactly does it mean for the material to be unweldable? Ok it's not an engine mount but it's not decorative either, I applied some solid violence and there was no sign of cracking, let alone failure.

BigD wrote:I had to mcgyver an oil drain flange for my new turbo. To make it clear I cut off the male AN end off the flange and carved up a 45deg hose end for the pipe and used an npt to an adapter for the tip. Everything looked fine, leak tested and reefed in it, was good. Then a friend told me that AN spec calls for the hose ends to be 7075. I called the manufacturers and the hose end was a Russell who confirmed the pipe is fine. But the adapter is Earl's and they said all their anodized fittings are 2024...

So I ended up cutting it off and welding the tip I cutoff earlier on to the pipe.

But because it's such a huge pain to remove this thing (I had already installed it), that to make myself feel better I put the tip in a vice and whacked it with a hammer a few times. Other than putting dents in it, nothing gave.

This made me wonder what exactly does it mean for the material to be unweldable? Ok it's not an engine mount but it's not decorative either, I applied some solid violence and there was no sign of cracking, let alone failure.

Unweldable metal will weld but it usually cracks in the HAZ.

exnailpounder wrote:Unweldable metal will weld but it usually cracks in the HAZ.

Is this something that happens gradually, like the piece may exhibit acceptable strength initially but break later on? Or if it cracks it will crack right away, like welding cast iron?

BigD wrote:

exnailpounder wrote:Unweldable metal will weld but it usually cracks in the HAZ.

Is this something that happens gradually, like the piece may exhibit acceptable strength initially but break later on? Or if it cracks it will crack right away, like welding cast iron?

It depends. Some aluminum will crack right after you weld it. I don't have any experience welding unweldable metals because I find out what alloy I am working with before determining whether to weld it or fasten it. Just be aware that some alloys are classified as non-weldable for good reasons. Thats about all the help I can offer.

big D
http://www.thefabricator.com/article/al ... num-alloys
craig

motox wrote:big D
http://www.thefabricator.com/article/al ... num-alloys
craig

That has always been my go-to article for unweldable aluminum alloys...Great minds think alike...Thanks Craig!

I often wondered what alloy AN fittings were made from as it would be fair to say that a bunch of the racecars I was around had welded fittings in some application and I can't ever recall any breaking or cracking. When you went to the " priceless unobtanium treasures " box there were always some special fittings that had been made and saved.

We'd always use 5356 as filler and just clean off the anodizing. Cracking or porosity was never an issue. Usually the hex on the welded piece is ( should be ..) held with a wrench against the tightening torque, if access permits.

I've welded up bowden cable holes to be re-machined in 7075 T 6 stepper motor pulleys with 5356, no cracking or porosity.
But the weld area would have stayed in O condition and there was no load on the weld area.

Which highlights how dangerous it it to have unidentified material in a shop where machined parts are used in welded applications.

Even 2024 T 3 can be welded using a strip of the same as filler, I was a witness to the lengthening of a flange on a .040" panel to be riveted................not at all impressed !

It's pretty common practice to weld fittings on aluminum oil pans and valve covers for oil recovery for the dry sump. Never had one break or crack smashed the hell out of couple on oil pan when motor came loose flipping.

Thanks kiwi, practical experience is always valuable.

dirtmidget33 wrote:It's pretty common practice to weld fittings on aluminum oil pans and valve covers for oil recovery for the dry sump. Never had one break or crack smashed the hell out of couple on oil pan when motor came loose flipping.

The weld-on bungs are designed for it, so they would be made out of 6061. But it makes sense for the nuts and other threaded fittings to be made out of stronger aluminum. I checked with Aeroquip, they also said on their hose ends, the nuts and cutters are 2024 but the pipes connecting the two are 6061.

The few times I've tried, it cracked instantly. Once the weld area was diluted enough with filler, it held and even hitting it with a hammer did nothing. I haven't tried it but I wondered afterwards if Al-Bronze might not work for the application.

-Sandow