dial matting

[george hoggardParticipant @georgehoggard40801]

Can anyone help me with the problem of dial matting? , a lost art at least I thought so until I saw a hand made bracket clock with superb matting! I was told it was done by a firm in the clock trade full stop.It looked as If It had been etched with acid and it was very crisp and regular I am going to try ferric chloride as used for etching circut boards .the other Idea is using a muliple punch but this causes the brass to sink . Any suggestions would be helpfull

All the best George

[george hoggardParticipant @georgehoggard40801]

[Richard ParsonsParticipant @richardparsons61721]

An old clock making friend used to do this. He used a set of wheels in a in a fork with a handle.

He made his by straight knurling a short length of silver steel using a fine knurl (actually I did it for him in the Myford). This cylinder was first drilled through the centre. He then cut thin slivers of the knurled steel which he faced up on his Boley and machined the edges so that had the same angle as the knurl. The disks were hardened and tempered. Four or five were fitted into a fork with a pin through the hole. The Handle was quite long and had a sort of curved end like the butt of a gun at the top end. To decide the diameter of the rollers I had to work out the distance apart of the lines of the knurl and their height I cut a full set of knurl cuts in the bar.

To use the thing, he secured what he was going to mat onto a thick-ish bit of ply wood which he secured to his heavy bench. He would then sit down put the wheels against the work piece and put the ‘stock to his shoulder, push down and rock to and fro guiding the rollers with his hands.

He brushed the work piece off now and again with a brass brush –from a shoe shop-.

Hope it helps

Rdgs

Dick

[NJHParticipant @njh]

Hi George

A good question! I have a clock dial to matt and I propose to use an engraving tool similar to:- this

I must say I have been putting it off for a while but I have tried it on a 2in square scrap piece of brass and it seems to give an acceptable finish. If you do proceed with the chemical method please post a picture or two. I would be a bit concerned that it might not be sufficiently "rough" and perhaps rather even. I don't think a little irregularity is out of place in a hand made clock.

The books I've read say that the punch method can distort the plate with all the consequent problems of flattening it again.

Any other advice gratefully received – don't want an expensive mistake!

Regards

Norman

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

One type of matting is done by coating the plate with resist , scratching through a random or systematic pattern , etching and then removing the resist . This can be a one stage process as just described or a two stage process where the plate is etched again without any resist present . The single stage process produces a web of quite sharp crossing lines , the two stage process softens these lines into a generally mottled finish .

Another type of matting is done by silver plating . By conrolling the current correctly the plating can be made to have a matt finsh .

In more general applications like instrument making matted surfaces are often done by satin chrome or satin nickel plating .

Specifically aluminium parts are matted by machine wire brushing with or without anodising .

Michael Williams

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Could use CAD produced pattern , printed transparency and photo resist to make etching process both easier and more versatile .

Or a CNC version of 'engine turning' .

If any of the patterns produced are too 'sharp' as first made they can be dulled back with (eg) wire wool .

Edited By MICHAEL WILLIAMS on 11/03/2012 23:41:18

[george hoggardParticipant @georgehoggard40801]

thank you for the information, I had a go with the ferric chlord and added some citric acid with it as I'd found out it would vastly improve it! Sadly it was no good.for my dial. I think my next . attempt will be on the lines of the roller as mentioned by Richard Parsons. I had tried that way before with no success but I think my wheels were to wide and needed to much effort on my part. _ Till the next time George.

[Ian S CParticipant @iansc]

How about a light sand blasting, Badger, the air brush makers also make a little sand blast unit. I would use a soft grit, and a stecil type mask, to protect anything you don't want frosted. Ian S C

[blowlampParticipant @blowlamp]

A needle scaler

Martin.

[johnp10Participant @johnp10]

Hello M r Hoggard.

If you will kindly contact me on johnp10@virginmedia.com I will send you details of a system of dial matting described by Alan Timmins which I tried and found it gave an excellent result.

Regards.

John Parslow.

[YouraTParticipant @yourat]

Hi.

Coming I realise *very* late to this thread, I'm reading Richard's description of the tool his friend made and I'm struggling with the phrase

>>
….machined the edges so that had the same angle as the knurl….
<<
as it's a straight knurl…

Richard – if you're reading this – would you possibly explain perhaps differently so I have a chance of understanding, or maybe sketch something….?

Here's hoping!

Thanks,

Youra.

[Bill Davies 2Participant @billdavies2]

Youra,

Looking at Richard's member postings, his last was on 27July 2012, so I don't think he will answer you. I think he means chamfer the edges to the same angle as the knurls (like pressure angle on gears). This would leave points which would I suppose give a matt effect when rolled repeatedly across the surface in all directions. It does seem like etching is an easier option.

Bill

[YouraTParticipant @yourat]

Bill,

I wasn't too hopeful of a reply, but thank you for your suggestion, which does make sense.

The problem I have with etching is the dimensions of the features – I think they would be too small if done chemically to look as they did on older clocks, but I'll try a few options and see.

Thanks again,

Youra.

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