Lathe chuck rustoration

[Henrik]

I have acquired 5 lathe chucks in various states of disrepair over the last couple of years, all from eBay (obviously - that's where all our rusty objects come from, I bet).

Anyway, as I now actually have a semi functioning lathe, I want to start using the chucks, but they are all dirty and disgusting. Condition-wise, they look like this or worse:

I have never disassembled a chuck before, but it was dead simple in the end (couple of screws at the back), and separating the chuck body to get at the internals.

Once the first chuck was apart, it was degreased with wd40 and brake cleaner and the bits chucked in the electrolysis tank (I *LOVE* this method - it's awesome) and left for a week.

After cleaning, I was left with:

I chucked the bits in the oven to dry off to avoid surface rust (hence the glass dish), and was of course severely told off by the Mrs. At least the bits came out OK

Back in the shed for a light coating of gear oil (no idea if this is correct or not, but it works in a gearbox so I guess it should work in a chuck too):

and fully assembled

I had no idea what the chuck was originally, but it turned out to be a Pratt:

Now that it's been cleaned and oiled, it's nice and smooth to use. Don't know yet if the jaws will require grinding, but will find out once I have everything set up.

 

[Henrik]

The second chuck looks disgusting inside, but it's getting the same treatment currently:

 

[penfold]

I've got a couple of chucks waiting for round tuit resupply and then they'll get the same treatment.

 

[rikrobson]

After the electrolysis, to avoid surface rust, I rinse in Phosphoric acid and then let the items dry.

 

[Pete.]

I bet that Pratt steel body chuck wasn't cheap to buy new.

 

[Henrik]

After the electrolysis, to avoid surface rust, I rinse in Phosphoric acid and then let the items dry.

Very good idea - I'm going to order some.

 

[DAPPH]

I like Pratt chucks , they seem very robust & reliable .
When my chuck is on the lathe I push a bit of sponge foam in from the jaw end to level with the back of the jaws ......to keep crud out the spindle & to prevent any muck travelling through the spindle onto the alloy gears .

When I want to take it off & use a weighted push rod to push the foam back out of the front , this usually takes out a lot of crud . I then use a bottle brush that just passes through the spindle to give the spindle and the inside of the chuck jaws a good brushing followed by a spray of WD40 and adull push through from left side to the tailstock this notrmaly removes almost all bit of turning crud.
I then close the jaws and remove the chuck then insert a purpose made foam rubber disk 1/2" thick in the thread hole as this helps keep crud out the threads when it's sat under the bench .

 

[Henrik]

Second chuck's insides came up nice after cleaning:

What a difference a week in soapy water makes:

All the bits (except scroll):

Also a Pratt:

Complete! Unfortunately the jaws still look a bit discoloured, but never mind, at least it's nicer this way than when I started.

 

[Henrik]

Next victim isn't as nice (it's got no brand name on it, so I'm assuming cheap no-name chuck). It is however reasonably light for a 6", which I don't know if it's good or bad, but at least it is easier to handle than a solid lump.

 

[T0rnado69]

very interesting thread henrik.
they have come up really clean.

i have 3 or 4 chucks i got off ebay a while back from an engineering company that was slowly selling stuff off

wanted one to put on the adaptor plate that fit on my rotary table.

once i get my new tank sorted and the few large bits i need to clean, il start doing the chucks too.

 

[Pete.]

I'd at least stone the rear register face of that 4 jaw Henrik it looks pretty badly dinged-up I doubt it would sit well on a backplate. They have come up nice and clean though nice job.

 

[Henrik]

I'd at least stone the rear register face of that 4 jaw Henrik it looks pretty badly dinged-up I doubt it would sit well on a backplate. They have come up nice and clean though nice job.

Good point about the back register, it looks pretty beat up now that you point it out...

I'm hoping to adapt this for my rotary table, but the table is the same size as the chuck, so mounting will be interesting.

 

[Henrik]

wanted one to put on the adaptor plate that fit on my rotary table.

What kind of adaptor is this? I need to fabricate one... I'm thinking something along the lines of locating in the centre and then using some kind of drivel to locate, err, axially.

Fixing the adaptor on the table might be a problem, though..