Dial Improvement

[David Mc]

I'm wanting to improve the dial of a ST OG. It's my clock, so I'm not going to endanger someone' else's clock. Here's a picture of the case and dial:Case & Dial. It is a painted metal dial.

1) The dial metal looks a bit like galvanized steel, but it is not magnetic - is it tin, perhaps?

Much of the white dial paint has flaked off, and someone at some point tried to touch it up. Looks like they used white house paint, with a 2 inch brush. The house paint can be chipped off, and leave the underlying paint that is still there in acceptable condition. I believe that I can color match and touch up the bare places in an acceptable manner.

2) How do I renew the black paint of the numbers? The Roman numerals on the dial look like they may have been outlined in something like India ink, and then filled in with black paint. Is this the approach I should take?

3) After I repair the dial, some of the old white paint will still be trying to flake off. Should I coat it with a spray coat of flat lacquer to try to hold it all together?

 

[David Mc]

I'm wanting to improve the dial of a ST OG. It's my clock, so I'm not going to endanger someone' else's clock. Here's a picture of the case and dial:Case & Dial. It is a painted metal dial.

1) The dial metal looks a bit like galvanized steel, but it is not magnetic - is it tin, perhaps?

Much of the white dial paint has flaked off, and someone at some point tried to touch it up. Looks like they used white house paint, with a 2 inch brush. The house paint can be chipped off, and leave the underlying paint that is still there in acceptable condition. I believe that I can color match and touch up the bare places in an acceptable manner.

2) How do I renew the black paint of the numbers? The Roman numerals on the dial look like they may have been outlined in something like India ink, and then filled in with black paint. Is this the approach I should take?

3) After I repair the dial, some of the old white paint will still be trying to flake off. Should I coat it with a spray coat of flat lacquer to try to hold it all together?

 

[eskmill]

I'm not in the business of restoring clock faces but I'll take a stab at some of your questions; last first.

3. Don't coat with lacquer to try and hold the flaking old coating. It will likely dissolve and smear the old paint which is likely a the old simple mixture of lead-white and linseed oil. Some skilled in restoring painted dials use a thin clear varnish to "seal" old flaking coatings but it must be done with care and crossed fingers.

2. Your observaion is on target. The old school "dial writers" outlined the numerals with black "india" ink, then filled the outlines with black. The techniques is still used by restorers.

1. Not tin. Zinc was the metal of choice for clock dials then and to some extent still. It is relatively inexpensive, resists corrosion and is easily treated with simple acidic solutions to prepare the metal for coating. Unfortunately, some common pigments appear to not adhere well to the zinc even when carefully prepared and primed. Exposure to light may have an influence on the detaching process. Many older Connecticut clocks have "flaky zinc" dials.

A carefully restored zinc face is an asset to the simple OG clock. The NAWCC Bulletin article describes a "diy" procedure for recreating painted dials. The convex area of the dial is probably a little challenging.

Flat silk screened replacements just don't do justice to an OG clock in my opinion.

Les

 

[TomT]

Hi David.

The dial is made from 0.020" zinc sheet. It was a common flashing material back when the clock was made.

If you examine the numerals closely on the dial you should be able to make out that they were originally outlined with a fine tip pen then filled in.

You can fine-tipped caligraphy pens at many large office supply stores and arts & craft stores. A caligraphy pen of the correct width along with some black india ink can be used to carefully touch-up the numerals. That's pretty much how they were done originally.

Matching the original white paint for touch-up is should be able to solve with a lot of trial and error.

As far as "sealing" the old paint to prevent flaking, there are several post on this board that offer suggestions. Since the zinc was not originally primed, I'm not sure any surface finish will actually prevent future flaking.

From what I could make out in your photo, the dial doesn't look like it's in that bad of condition so your restoration has a good chance of being successful.

Good luck with it....

Tom T (0157818)

 

[David Mc]

A appreciate the replys. I'll skip my lacquer idea.

1) Is there a type of varnish that will dry with a matte finish? I'd rather not make the dial shiny..

2) Since the dial is zinc, do I need to prime the bare spots with anything? Seems that I remember that paint won't stick to galvanized steel (galvanizing puts a zinc coat on, right?) unless an acid is used to etch the metal. Or is there some kind of paint that will stick satisfactorialy without priming or etching?

Thanks.

 

[David Holk]

Most varnishes are available in gloss, satin, and matt. Most paint store have agood assortment.

 

[TomT]

David,

As best I can tell, the zinc was not originally primed prior to painting. Attempting to etch the unpainted areas without affected the remaining paint is a pretty risky proposition.

In the interest of conserving as much of the original dial as possible, I would suggest re-inking the numerals, carefully removing any remaining loose flakes of the original white paint, then work on color-matching the original white with a good quality oil based paint.

It will take a number of paint applications to build up a thickness to match the surrounding original paint and you will likely have to very carefully "feather-in" the new paint with the old, but with patience and care you will be surprised at how much you can improve the looks and how much original work can be preserved.

Remember, the clock dial is around 150 years old. Attempting to make it look prestine will lead to an "over-restored" look which tends to lose the character of the piece. A careful touch-up that retains the character-of-age will usually provide you with a more satisfying final restoration.

I think your main challenge will be color-matching.

Good luck with it.

Regards,

Tom T (0157818)

 

[David Mc]

ALthough I appreciate the comment that it is better not to have the dial too pristine in appearance after my repairs, I think the likelhood is that with my skill level, the appearance of the dial will tend to go in the other direction..

I was able to match the paint fairly well. I used plastic model paint. Mostly white, with a dab of black, yellow, and brown. As correctly stated, the old paint is quite thick. So to get my paint match correct, I have lots of opportunities to try, as many coats will be needed.

I did very carefully paint the zinc surface that I intended to paint with vinegar, hoping that it might etch the metal surface enough to hold the paint well. The vinegar did not seem to damage the old paint.

I did notice that the old paint was quite soluble in methyl alcohol. Does this indicate that the old paint was the linseed oil/white lead mix?

 

[TomT]

I've never performed any lead testing of the paint although I know there are kits readily available. Since leaded paint was pretty common when the clock was built, it's reasonable to assume that the paint is leaded.

Be sure to post some before and after photos for the rest of us. Phil can help you post them is needed.

Regards,

Tom T (0157818)

 

[John C. Losch]

Many years ago I used to hang out in the Burt Dial Co. shop. Ed Burt was an early member and founder of NAWCC. A couple of points I think I learned there: DO NOT USE INDIA INK! It will run into the pigment of the surface paint, tends to feather, and cannot be removed. I think Burts used pigment in linseed oil, but I don't know the proportions.

The paint used on zink dials was oil paint using zink oxide for pigment. The coefficient of expansion was closer to that of the dial plate, and that made the paint adhere better. I suspect the base coat on those dials would have used slow-drying linseed oil for the vehicle. Even the finish paint was dull or "flat", probably implying a high ratio of pigment to oil.

I have seen formulae for these kinds of paint in some old books of formulas from the mid and late ninteenth century. Perhaps an internet search will turn up some of this information.

All the answers you need are out there if you can look in the right place, or ask the right person. Today, professional dial painters have all of this knowledge, but asking them for it is like calling the doctor to see what you can do to avoid paying him for his services. Jcl

John C. Losch
Holliston, Mass.

 

[David Mc]

OK, as Tom T asked, here’s a picture of the dial before repairs Old Dial and after repairs Repaired Dial . I’m reasonably pleased with how it turned out, but I do have some concerns, primarily having to do with how long the dial will look acceptable.

By the time I finished scraping off the loosest flakes of old paint, essentially all the old paint outside the chapter ring was gone, and many of the minute markings were also gone. Most of the Roman numerals were still there.

The biggest problems were: matching the paint, finding the center of the dial, and accurately repairing the minute marks (many of which were missing, or obscured by my repairs) and repairing the numbers. The paint matching became easier when I realized that the old paint did not have an even color; it is somewhat mottled. So, after I got the repair paint to approximately the right color, feathered the edges in and slightly sanded, I used artists oils very sparingly to tint different areas of the dial, to make the new paint as mottled as the old paint. I then sprayed with a matte finish clear coat, to provide a uniform base for further work.

I found the center of the dial, and marked in with a compass and technical pen the rings that make up the minute marks, and went over faded minute marks and replaced the missing minute marks. I then colored in the Roman Numerals with a technical pen. I then sprayed a final coat of the matte finish clear coat over all to provide protection.

My concerns have to do with the many different coatings involved in my repair:
1) The original paint and black markings
2) Model paint
3) Artist’s oil paints
4) Technical pen ink
5) A matte finish spray coating from Rust Oleum

Right now, all these coatings are co-existing in harmony, but I wonder what the long term repair will look like?

Thanks for the help and encouragement from all who responded.

David

 

[TomT]

Bravo David!!!!

You are to be congratulated: First for taking it on and second for seeing it through to a good result.

As for long term durability? Doubt if anyone can say. More importantly, you gained a lot of experience in the craft and the next one you do will likely be easier.

As for finding the center of the dial, I've used an old LP turntable with a wire pointer to get the chapter rings centered. You can then build a simple wooden fixture to hold your pens vertically as you rotate the turntable and dial. It give a nice even line.

Glad to see you went for the fix yourself.

Regards,

Tom T (0157818)

 

[MikeFields]

Hello, I'm a beginner and am interested in restoring the dial on my E. N. Welch OG 8-day. I'm studying this thread and another one called "Worst dial restoration EVER!" but when I try to click on any of the photo links above I get a 'typo in hyperlink' error. Does anyone know if photo links expire on these threads after some time, or if the online repository of them moved? I just ordered a set of technical pens and oil colors and artists' 120lb paper. I'm going to start by making a color wheel as in the June 1997 NAWCC Bulletin article. Tom T I love the turntable idea. Thanks so much!

 

[shutterbug]

When photo's are uploaded to this board, they are kept indefinitely. But when people use another storage facility, they often disappear with time. That's the issue here.