# Drill Press Pulley Repair



## HMF (Feb 25, 2015)

*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]


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## rgray (Feb 26, 2015)

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


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## Billh50 (Feb 26, 2015)

very nice job


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## Getaway (Feb 26, 2015)

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


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## randyjaco (Feb 26, 2015)

Getaway said:


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


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## aametalmaster (Feb 28, 2015)

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


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## chips&more (Feb 28, 2015)

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.


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## Doubleeboy (Feb 28, 2015)

Very nice, thank you for sharing!


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## f350ca (Feb 28, 2015)

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


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## kvt (Feb 28, 2015)

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.


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## aametalmaster (Feb 28, 2015)

f350ca said:


> 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


I fixed an aluminum row boat that was flipped upside down. That was 4 years ago and it needs done again as the repair fell out. This time i am going to MIG weld it...Bob


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## Ulma Doctor (Feb 28, 2015)

nice work!!!


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## Warrenator (Mar 2, 2015)

Nice looking repair.  I'm sure it will last a long time.

I have my own tig setup so I have never taken anything in to a welding shop for repair, but it seems sometimes you could just pay the man with the gear to weld it.  I totally understand wanting to do it yourself, thats why I have the tig.  I wonder what they would charge for a quick weld on a clean, portable part like that.   Anyone?


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## aametalmaster (Mar 2, 2015)

Warrenator said:


> Nice looking repair.  I'm sure it will last a long time.
> 
> I have my own tig setup so I have never taken anything in to a welding shop for repair, but it seems sometimes you could just pay the man with the gear to weld it.  I totally understand wanting to do it yourself, thats why I have the tig.  I wonder what they would charge for a quick weld on a clean, portable part like that.   Anyone?


The problem with welding it is it may not be aluminum but some pot metal mess. And maybe the guy didn't have the chunk to put back in. But with a mig and if it was a nice weldable grade of aluminum that would be an easy fix even without the chunk. It would be done the same way welding it over a clean piece of steel and dressed up on a lathe. 20 bucks i would do it for just for reference...Bob


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