Re: Engraving

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "exeric1" <exeric1@y...>
wrote:

> This may be a bit off subject but hopefully someone will know. I'm
> planning on using my CNC to engrave brass and also wood. The brass
> won't be engraver's brass - that is it won't be film coated - but
> will be straight unfinished brass. I plan on paint filling the
> engraving by hand. Will paint stick to unprimered clean brass? I
> can't seem to find anything about that. It just seems to me that

its

> too difficult to align tiny bits of paint over primer without

either

> having parts of the primer show or having the paint appear
> differently where paint covers bare metal and where it covers

primer.

>
> The same question applies to hand color engraving on wood. I think
> it might be easier here because one could just seal the whole

piece

> of wood after engraving and then color it. How is this stuff
> normally done? It doesn't seem like it should be such a big deal

There are commerical sticks of colored paint that are made to rub
into engraving. You can get them from Artisan Engraving Supply at
http://www.artisan-es.com/
(download their catalog). As long as the intended purpose is
interior use they should work fine. For exterior, the epoxy approch
is better but a lot more messy. The challenge with brass is the
finish after engraving. If you want a polished surface you will
have to spend a lot of time with finer grades of abrasives and then
polish to get the high gloss gold look. Brass "ages" and gets dull
over time so a final clear coat is in order. There are specific
spray applications for brass and copper.

As for wood. The best way is to apply the surface finish and a
sealer prior to cutting or a clear sealer if no surface finish is
desired. Cut your pattern and finsh as desired in the cuts. You
can use an artist brush to hand paint recessed areas then carefully
apply a surface finish but it takes longer and you have to be more
careful in the application.