rusted driveshaft repair

[schematic]

There has been some discussion on how to do this. This is how I do it....

 

[emckelvy]

Looks like a good way to do it, the heat required for silver soldering shouldn't warp the driveshaft, as it does if you have a welder build up the seal area with stainless, for example. Then you have to have a machinist straighten the shaft, adding more expense.

I'd imagine silver-solder is plenty hard for a seal surface, should be quite durable.

What kind of torch are you using for your soldering, and how big of a lathe would be required to do this work?

Thanks..............ed

 

[schematic]

Acetylene torch. Doesn't take a big lathe. Mine is a 10" X 36" Emco. I prefer silver solder to brass as you say....it doesn't need as much heat.

 

[gm280]

I like the concept but actually wonder if the seal areas were ate up with actual good metal there, how long is silver sold going to last? Machine shops re-weld bearing journals all the time and re-machine them and it works very well. I would have re-welded those areas and use your lathe to turn them to specs again. I like what you've done, but fear those areas will wear rapidly... But hopefully I wrong... JMHO!

 

[schematic]

gm280
I haven't had one come back yet. These motors are 40 years old. The damage is caused by rust more than wear. If they last another 40, I'll be happy! LOL

 

[GA_Boater]

Silver solder doesn't rust, does it? Still it's one way to keep running when we can't find parts anymore.

 

[gm280]

gm280
I haven't had one come back yet. These motors are 40 years old. The damage is caused by rust more than wear. If they last another 40, I'll be happy! LOL

schematic, (and I like that name), don't get me wrong. If you're happy I'm happy. All I was doing is voicing my opinion. If you get years more service, I say go for it. I was only wondering that if these areas are being chewed up and was solid metal, how long would soft silver solder last. I know all about solders and silver solder is harder then standard 63/37 circuit board solder, but still not anywhere near as hard as steel. So I am not condemning you, just stating an opinion... By the way, you did some nice work on the lathe... :thumb:

 

[schematic]

I was only wondering that if these areas are being chewed up and was solid metal, how long would soft silver solder last.

It seems the metal used in these old shafts is low in nickel. I think they rust way more than they wear out. Silver solder is stronger than brass so It should last. Silver solder doesn't rust so it will likely outlast the usefulness of an old motor. I often thought about tigging some stainless on the erroded area, but thought it might be overkill. I'll try it on the next one that comes in. Its amazing how many of these old motors are still around!

 

[Mi duckdown]

I've done a few of old shafts. but I have Had access to lathes and silver soildier gururs. speedi sleaves

 

[schematic]

unfortunately, no speedy sleeve available for this size....

 

[emckelvy]

Question, what grade of silver solder are you using. I was doing a little studying on the subject and the different melting points are graded as "easy", "medium", "hard", etc. I reckon it would make a difference! I'm thinking you don't want to get the shaft too hot, as to avoid warping.

When I had my old machinist weld-repair shafts, he always had to straighten them afterward 'cause the welding would warp the shaft. They sure were nice when he was done, though! Sadly, he passed on a few years ago and I've found no one in the area with his expertise.

The lower-temp repair sure seems like a good way to do an economical fix and I'd expect the repair will last the life of the motor!

Thanks..........ed

 

[Mi duckdown]

To be honest I have no idea what grade silver solder. but it is hard. Never needed to straighten shaft. put it on vee blocks with dial indicator and they where fine.???

 

[schematic]

Ditto duckdown. The shaft doesn't need to get "red". No warping if you heat evenly. The solder I use comes in sticks.