Worn ink disk

Hi
I have a Model no.3 (9” x 6”) bench-top press which has a worn ink disk: the disk is slightly ‘dished’, with a flat spot in the shape of a ring around the centre of the disk. One suggestion I’ve been given to rectify this to have a disk cut from steel which I could then fix over the top of the existing disk. This would of course have to be absolutely flat and stable, and my engineering knowledge doesn’t stretch to knowing how I should specify this to a steel engineer (the type of steel / thickness / manufacturing tolerances) or if this is even practicable.
I’ve read a previous post on here relating to re-machining flat a C&P disk, but I don’t have the ability to do this myself, and I’m nervous of letting an engineer loose on my (irreplaceable) ink disk, hence the idea of an ‘add-on’. (I apologise to any offended purists out there!). Does anyone know of a print engineer in UK who could handle this work?
Alternatively – I’m going for broke here! – does anyone have a spare replacement ink disk for this press? It prints really nicely, except that the inking issue slightly limits the work I can do. Any advice will be gratefully received, so thank you in advance.
Geoff (UK)

PS: I’m new to this site, so excuse me if this has been covered elsewhere (although I did trawl the discussion posts).

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Your proposed solution is doable, but it raises several challenges. The first would be the issue of attaching the steel disk to the cast iron ink disk.
A better way would be to have a machine shop turn the disk in a lathe to bring it true. Then it would be a bit low and a washer of appropriate height will be needed at the collar to bring it back up to correct height.
Get some ink on your shirt.

Another solution you could easily implement is to find a flat surface larger than the ink disc or about the same size, and surface-grind it against that flat using the abrasives and techniques used to make telescope mirrors — put some coarse carborundum, maybe 80 grit, on the “tool” with a bit of water and push and pull the disc face down on it in a “W” pattern, rotating the disc and your position with each “W” stroke. This was commonly done on a 55-gallon drum, head end, walking around the drum. After getting a flat surface with #80 grit you change to finer and repeat until you reach about 400 grit, by which time you have a lovely smooth flat disc. By finding a “tool” that can be also pushed, like the disc, and making a holder for tool and disc interchangeably, you can periodically flip them and avoid making a concave depression in either. The technique was used for many years to make both telescope mirrors and optical flats precise to 1/4 wavelength of light. Carborundum grit in a variety of “meshes” should be available from an auto parts or repair supplier, as the same grit is used for grinding and lapping car engine intake and exhaust valves.

Bob

As You have already implied, that Engineering (turning) is not within Your sphere of learning (Yet ?) And You do not have too much faith in Our precision engineers, just for starters Measure OR have measured the overall *Wall Thickness* of the disc, from the face of the Disc, (to View) to the Obverse (back), >excluding< the Ribs and the Ratchet teeth, talk to any reasonably proficient Precision Engineer, WITH The overall diameter of the disc, and the mean average of the *wall thickness* and request an opinion as to the feasability of *Turning* the disc back to true.!!
The reason being that generally Table top M/c,s with cast Iron/Steel disc,s are normally well over engineered, for thickness, by implication (normally) able to withstand more than one True Up via turning, ??

*****
With a Table Top that size,? there is not exactly Tons of pressure on the Disc, (even with reduced *wall thickness*)
more like a few ounces, and the *wall thickness* from the centre spindle, Boss,! to the extent of the Ring that carries the Ratchet teeth, has to be able to withstand a few Thou” machined off.

*****
Still concerned about possible weakening, by machining >Off< etc, perhaps, Marry/Combine, Inky,s & A.L.P.s, as above, source a Stainless Steel, auxiliary Disc, the exact size of the original, (with chamfered edge to accommodate the approach of the rollers !) and BOND the S/Steel to the original with Chemical Metal, Two fold exercise, ???
A. Adhesion, and the Chemical Metal, B. will act as, Make Ready in the traditional sense, under the auxiliary Disc..

According to the Curing Time for chemical metal-Bonding, access to a Nipping Press would be beneficial,!!! but not essential.

Inky, nice to see, the resurrection of the, signing off and closing. ??

I will stick with my first suggestion as best solution. There is another you may wish to consider.
Here on this side we have body shops who do repair to auto bodies and fenders. Thirty years ago in New Zealand I found that they called these tradesmen panel beaters. I thought that an interesting name.
These folks use an epoxy putty/filler to fill some dents and dings. Three brands here are J-Weld, Redhand and Bondo.
With a very clean disk probably cleaned with nonresidue alcohol, spread the filler compound on the disk. From several places around the disk and across diameters, spread the filler evenly with a straightedge to get it as smooth as possible. Finish up with fine sandpaper or emery cloth held to a sanding block. This process is doable at home. Ink onthe epoxy filler material should clean up with mineral spirits. Nothing stronger.
I have not used this process on an ink disk.
Get some ink on your shirt.

I have a similar problem with a Squintani Model No 2 a low middle or high rim. I keep meaning to pop into Harry Rochat in Barnet when I’m passing, they make the Albion presses.
They have all the equipment and made a repair on the No 2 before. If you are in London they are a short walk from High Barnet tube station. I am away at the moment but can call in and ask them when I get back.
Paul

image: Squintani No 2.jpg

Squintani No 2.jpg

Thanks everyone for your suggestions - very helpful and I am pondering which way to go!
From the picture, Platenprinter’s problem on his Squintani Model no.2 looks like it might be exactly the ‘opposite’ to mine- the edges of the disk look lower than the centre? But I guess the result will be the same - uneven inking.
Contacting Harry Rochat is a good suggestion - perhaps we should batch our problem disks for a discount deal! I’m also going to take the disk to a local ‘precision steel engineer’ for their view, and will let you know what they say.
Thanks again,
Geoff