Jacobs #3 Chuck/Rust inside

6

65arboc

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Hi all,

I bought a used mill a few months ago and in a box of accessories that came with it I found a #3 Jacobs chuck on a MT3 taper. The thing is stuck and won't turn. I tapped it with a hammer and a lot of rust dust is falling out:angry:. Knowing it hasn't been used in a long time, is there any way to loosen up this chuck and get the rust dust out of it? Also can a person disassemble a Jacobs chuck without special tools? If this isn't the correct sub forum, please move it.

Thank you,

Jim
 
I had this with a smaller chuck once. I did the following:
1. Electrolysis with using an old PC Power supply and a rebar sacrificial anode.
2. "baked" it dry in makeshift incandescent light bulb "oven".
3. Lubed it with grease.
4. Put it to work.

I never did open it up, my theory was to try that AFTER de-rusting it. I am not in the Evaporust camp. Lots of smart people use those kind of products, but I am not among them. Electrolysis has never done me wrong.
 
65arboc said:
Hi all,

I bought a used mill a few months ago and in a box of accessories that came with it I found a #3 Jacobs chuck on a MT3 taper. The thing is stuck and won't turn. I tapped it with a hammer and a lot of rust dust is falling out:angry:. Knowing it hasn't been used in a long time, is there any way to loosen up this chuck and get the rust dust out of it? Also can a person disassemble a Jacobs chuck without special tools? If this isn't the correct sub forum, please move it.

Thank you,

Jim
Click to expand...

http://www.jacobschuck.com/keyed-drill-chuck-repair-guide

Would that taper by any chance be threaded for a 3/8-16 drawbar rather than with a tang? If so would you be interested in selling it?

- - - Updated - - -

Shopsweeper said:
I had this with a smaller chuck once. I did the following:
1. Electrolysis with using an old PC Power supply and a rebar sacrificial anode.
2. "baked" it dry in makeshift incandescent light bulb "oven".
3. Lubed it with grease.
4. Put it to work.

I never did open it up, my theory was to try that AFTER de-rusting it. I am not in the Evaporust camp. Lots of smart people use those kind of products, but I am not among them. Electrolysis has never done me wrong.
Click to expand...

I'd be reluctant to use any kind of chemical or electrolytic rust removal on an assembled device with seized moving parts until all attempts at disassembly had failed.
 
John Hasler said:
http://www.jacobschuck.com/keyed-drill-chuck-repair-guide

Would that taper by any chance be threaded for a 3/8-16 drawbar rather than with a tang? If so would you be interested in selling it?


Jim
- - - Updated - - -



I'd be reluctant to use any kind of chemical or electrolytic rust removal on an assembled device with seized moving parts until all attempts at disassembly had failed.
Click to expand...
Sorry John it has a tang and thanks for that link. I don't have a press so how would I get that sleeve off?
 
I've got a bunch apart using pvc pipe of the right diameter and a small bench vise. That was kind of hairy for the 1/2 Jacobs but it went fine. The 3/8 one was a piece of cake. A bit fidly to get back together but not hard if you take your time
 
Soak it with PB blaster,Krole, or 50/50 ATF flude and accidtone.
 
Got it apart. I soaked that thing in PB Blaster, actually immersed it, all day yesterday. It was still a bear to get the ring off as I beat on it for about a half hour before it began to move:phew:. There is no rust on the jaws or the threaded split ring but the housing had plenty of surface rust on the inside where the jaws slide. I got most of it cleaned up last night except the bores where the jaws slide. I'm going to use a dowel rod slotted for a piece of emery to smooth out the bores. BTW I think this is one of the good ole boys as the jaws and the housing are marked 1-2-3 so I can't get them in the wrong hole, for sure made in the USA by a craftsman. Should be good as new when I get done. The info I got here on this forum really helped with this project. You guys are GREAT!

Jim in Pa
 
Glad you got it.:applause: Get that thing cleaned up and lubed and you will have a nice chuck.:thumbsup:
 
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