Drill Press Pulley Repair

Aluminum Pulley Repair
published with permission of Mike Slater

Hi all,
I was faced with the challenge of repairing a chipped aluminum pulley - thought folks here might be interested in this approach.
A little background:
I recently aquired a multi-speed pulley assembly for a Southbend drill press I'm getting ready to restore.
Unfortunately the large pulley on the 4-step pulley had a large chunk missing.
Replacing this pulley was going to be difficult - so repair was the best option.

Since I don't have a TIG or MIG setup, I did some research and decided to try some of the low temp aluminum rods. (I chose Durafix - there are others)
These are an aluminum alloy that melts somewhere in the 750 deg range. It really goes on more like solder but is very strong.
I practiced on a spare broken pulley before trying this on the important piece. (PRACTICE FIRST!!!)
The results are better than expected.
A steel piece was placed on the back side of the pulley as a form - the Durafix will not stick to steel.
I used a regular torch running MAP gas. Everything has to get to temp before the rod can be applied - then you basically "tin" the cracked area.
Once tinned you can keep adding rod to fill the area.
Let it cool naturally then use a belt sander to get to the rough shape.
I finished this on a lathe. After this is polished it will be practically invisible.
ATTACHMENTS


Better to overfill - its a pain to add more material after the initial "fix"


On my practice parts I used a propane torch but had a devil of a time keeping every thing hot.

On subsequent practice parts I developed the technique shown in the photos.
CLEAN the part well - oil even from your hands screws things up
1/8" steel backing - anything thinner warps as heat is applied.
Steel is supported on the ends only to keep heat transfer at a minimum.
With these 2 techniques and the MAP gas I was able to get and keep everything hot.
This pulley was pretty large - probably 6.5" at the large end and a fair amount of metal in the middle for bearings. Plus the break covered a large area.


[Re: Writeup on pulley repair
Mike slater Feb 23 at 10:13 PM
Hi Nels,
No problem - happy to share.
Mike
May I post it on H-M to share with our SBDP owners?
Nels]

Wow nice....Looking good.!!!

very nice job

Thanks for sharing that repair. I have a pulley that needs that same repair. Its for my little Burk no. 4 mill. Great job.

Nelson that's the same stuff i used on that pulley i fixed for you years ago. And you are right its better to add too much because it is hard to go back over it again for a dab...Bob

That looks great! And a lot better than the time I tried that low temp aluminum solder stuff. About 20 years ago at a local Flea Market was a guy selling the stuff. He had a booth all set up with different examples of repair pieces. From aluminum cans to holes punched in a motor cycle motor casing. Well, I bought some of the stuff, took it home and it did not work like the FM Demo. Haven’t tried it since. Have got a TIG now, but maybe should revisit the idea after seeing your great job…Dave.

Very nice, thank you for sharing!

I have to repair the bottom seam on an aluminum pontoon boat. Using this or a similar product has crossed my mind. Does it wick like lead solder? I need to do this repair from underneath.
The one company's add showed them repairing a boat but it was flipped upside down.

Greg

That looks great, how did it machine? Every year here at the Rodeo and Fair a guy is selling the stuff and I always take a look at it, but have never tried any of it. I was always afraid it would break out to easy.