can anyone give me advice on colour filling engraved brass?

[David Smith]

Hello Geoff,

We never lacquer brass plates as we’ve never found anything that works. Most tend to start coming off and discolouring and then you have an even bigger job to refurbish the plate than if you had left it unlacquered. We advise customers to just give the plate a polish over with a metal polish as and when needed.
For painting we use cellulose cleaned with thinners.

David

[Rodney Gold]

Use car duco rather than enamel.
As has been said , coating it is problematic as no coating lasts eternally.
However , if you look at your yellow pages under metal finishing , you WILL find that there are plenty water based dip type coatings that are extensively used in the bag fitting/buckle etc industry. You can try one of these. The other option is to passivate the plate , which gives a wonderful crushed finish not that easy to do , but essentially it involves dipping in a chromic acid solution – also avaialble from plating supply houses or metal finishers.
The biggest problem with polishing brass is the white residue left in the engraved sections after using brasso or the like – the solution to this is to polish and then spray the plate with pledge furniture polish or something like that and wipe it down, This removes the white residue and gives a further layer of protection.
In terms of engraving , the best brass to use is engravers brass which albeit i harder than normal brass , engraves beutifully without lubricants and no burring at VERY high speeds , although it is more expensive than normal 1/2 hard brass , the fact that it engraves and polishes better is well worth it , IE the amount of finishing is majorly less. It also doesnt tarnish green and doesnt pit like ordinary brass over time. Make sure the brass you get is totally scratch free and has a protective coating.
I posted a while ago about ETCHING brass , search for that as well.

[Geoff Smith]

Thanks for the info guys. I’ll take the plunge and hope it all turns out well. Being new at this it’s all a hit and miss for me and I value your input.
Thanks!
Geoff

[Fizgig]

Hi Geoff,
Clear coatings and exterior exposure. The two dont mix. There are some companies that tell you they do ( but its all in the marketing)

In Australia’s climate clear coatings dont last …..

2 types of coatings are generally sold, Solvent and water based.

Generally the coatings sold as UV clears in solvent paints have what are called UV inhibitors in them. These work for a short while and eventually break down, think of it as using Glad wrap as a T shirt in the sun..very little UV protection…you will get sun burnt and the Glad wrap will break down.
Solvent based clears have “long oil”s in them, slower drying more flexible than quick dry clears . The longest oil solvent clears also tend to be softer than shorter oil clears, I.e. Marine varnishes, manufacturers recommend up to 4 seperate coats of these products ( essentially to build up the microscopic UV inhibitor layers with each coating, less coats means less inhibitor to protect the substrate)

( quick dry solvent/ oil clears have, what are termed short or medium oil bases, these are in turn a much more brittle coating, very fast dry , but as a result very poor in their exterior longevity, examples of those type of coatings are, implement enamels , fast dry paints, pressure pack ( spray can) coatings
You see for a coating to be UV protective it actually needs to block the sunlight (UV rays), the more opaque it is…the better it blocks the UV, clear coatings have little or nothing in the way of fillers or binders that allow this process to occur, the ones marketed for UV exposure have UV inhibitors a sort of absorbent powder put in the clear resins when it is manufactured..they have limited life. Longer oil products teamed up with quality fillers and pigments give longer exterior life I.e Hi gloss exterior house paints or signwriters enamels.

Water based coatings are different in that they utilize polymer systems that are much more flexible and elastic. the general problem there is they are soft coatings and tend to build up dirt more readily and are a bugger to remove ( almost impossible ) for future repair etc work, not so suitable for items requiring abrasion resistance.

2 other groups of coating on offer are 2 pack poly urethane’s ,cross linked chemically, generally with a iscocyanite part 2 mix, this makes the coating rock hard, chemical, abrasion andweather resistant, ( with added UV inhibitors) like auto clears . these tend to have a longer exterior durability, purely because of the quality of material that goes into them, however still a short term fix for exterior metals

and powder coating, with UV clear ..once again ditto the above with auto finishes.

Auto UV clear finishes are designed to go over other Auto finishes, that do much of the absorption of the UV rays.

So….if someone has a wonder clear for long term exterior UV protection..
don’t believe them…

regards

Peter