DIY Re-lacquering brass lenses

I really hoped that I'd never have to explain all this again, but................
I trained as a clockmaker in the 1960's. I worked in a small clock factory in the Clerkenwell Road, this was the clock / watch making centre of London at that time. The factory produced 50 English Fusee Dial clocks and a number (depending on orders) of Time Recorders (clocking in clocks) a month. The brass parts of the fusee clocks (not the friction areas) were laquered in the traditional manner, that is hot laquered with a shellac based laquer. The colours of these lacquers were varied by including different ingredients that could change the laquer colour from gold to green tones (God knows why anybody would want green, but there you are). We heated the brass parts up, one at a time, on an old clock dial placed over a gas ring and when we judged the parts to be hot enough we brushed the laquer on to the brass using a brush that was sold to us as a "camel hair brush" (a little ol' health and safty tip, the brass will be hot, very hot). I have a lens made by the London Lens Company (if you look that up and get a result let me know). The hot gold laquer applied to this lens somtime between 1865 and 1880 is virtually perfect. I once repaired a clock from Eastleigh Locomotive works that had been in the works for 50 years (we were good in those days, and we made things) and the laquer was perfect.
You are not going to get the results that they got in the past with cellulose laquers made for the auto trade, but they are very handy and I've used them on lens boards, but I'm old and don't care if the laquered finish dosn't last for 50 years. Last comment, there is NO gold in gold laquer. If any of you are masochistic enough to want to make yourself some "hot" laquers I might be able to find the odd (bloody odd) formula.
If I've been a boring sod, or p......d on anybodys bonfire, I'm sorry!
Best wishes,
Pete

Hi Pete,

Thanks for explaining it again. First time I see it. I am highly interested in your bloody odd formula! Is that with Dragon's Blood? I commit myself to try it and publish the results in this forum (if I ever find the ingredients, of course).

Rgds,


Wagner

Wagner,
Give me a bit of time for research, I'll get back to you. The books are "somwhere".
Pete.

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Originally Posted by Pete Watkins

If I've been a boring sod, or p......d on anybodys bonfire, I'm sorry!

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You post was brimful of punctum. Not only do I have fond memories of creating supreme bafflement by going into a camera shop here and, in my halting Swedish, asking for a "Camel Hair Brush". The fact that I had dutifully looked up the Swedish for "camel" ("Kamel" :-) did not help at all.

And then there is the fact that my grandfather briefly worked at the Eastleigh Locomotive works - before moving to the much more sexy job of making Supermarine Seafires nearby.

And then there are my two big hundred-year old brassies. A pre-Dagor Dagor and a Suter aplanat, both of which look like they were engraved and lacquered yesterday, although the matt finish and colouration tell you they can't have been. In proper storage, classical lacquers do seem to last forever. It would be nice to know how they were done.

FWIW, I also have a hundred-year-old Zeiss "comet spotter" telescope. Here the lacquer is intact, but the underlying brass has turned a wonderful greenish-black. Although used for outdoor observing, the scope has been looked after well since purchased new by my wife's grandfather, so it's worth noting that a good manufacturer and classic lacquer is no guarantee of a long-lived shiney gold finish.

This section is from the "Handicraft For Boys" book, by A. Frederick Collins. Amazon: Handicraft for boys./p>

Lacquering Brass and Copper

To lacquer a brass or a copper article dip it in a weak solution of sulphuric acid and water and then wash it in clean water. Next put the article on a piece of sheet iron and heat it over a gas jet or in an oven.

It must not be heated enough to color it but just so that when you place your moistened finger to it it will sizzle; now put on the lacquer and this can be done by brushing the article over with a camel's hair brush or by dipping the article into the lacquer.

How to Make the Lacquer
Put 1 ounce of tumeric powder, 2 drams of annatto and 2 drams of saffron into 1 pint of alcohol.

Let it stand for a week or 10 days and shake it often; pour the clear liquid into a bottle and put in 3 ounces of yellow shellac; let it stand for a couple of weeks more; shake it often and pour off carefully. Then you can put it on. Lacquers can be bought ready made from Hanson and Van Winkle, Dealers in Electroplating Supplies, Newark, N. J.

Perhaps this would do?

Thanks for your kind words Struan. GPS the formula looks very usable. I only made some of this stuff once (about 25 years ago) because it was always available over the counter. I've found one formula from 1884........here we go, Take 2 ounces of the best pale shellac and add this to one quart of spirits of wine (Methelated Spirtis). Mix without heat by continuous agitation for five or six hours (I think that i shook it up now and then but over a period of a few days). If it's not clear it can be filtered. Do not leave it in a bright light. Here's a quote from the book "It may be coloured for yellow tints with tumeric, cape aloes, saffron or gamboge, and for red tints with annato or dragon's blood". Good luck in your quest for dragons blood, none of our local supermarkets stock it :-) We didn't acid dip parts to be laquered, they were all grained using emery paper in a lathe or using linishing machines. Pendulum bobs were polished on a polishing lathe.
Best wishes,
Pete

Reason for the heat is so that it 'flows out' when brushing, right??

So, if you are spraying, the retarder will do the same, right??

Sorry ic-racer, you need the heat to set the shellac. The laquer is brushed or sprayed on the hot (140 f) metal and it becomes hard on cooling. If the work is too cool the laquer will have poor adhesion. This comes from Cannings' Handbook on Bronzing, Metal Colouring and Laquering published in 1960. I've never heard of a retarder being used with hot laquer, it's a very old process.
Pete.

Thanks Pete and GPS,

I will try out your formulas and post the results here as promised. Give me a couple of weeks.

Rgds

Wagner

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Originally Posted by Pete Watkins

Sorry ic-racer, you need the heat to set the shellac. The laquer is brushed or sprayed on the hot (140 f) metal and it becomes hard on cooling. If the work is too cool the laquer will have poor adhesion. This comes from Cannings' Handbook on Bronzing, Metal Colouring and Laquering published in 1960. I've never heard of a retarder being used with hot laquer, it's a very old process.
Pete.

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Ok, for shellac based lacquer that makes sense. I was thinking of nitrocellulose based, but that's probably not what was used by lensmakers back then.