alan2525

Painting Brass loco chassis and parts.

Some Non Ferrous Metals dont seem to take paint too well, particularly Aluminium and Brass. I'm going to use an acid etching primer but wondered if it was worth blasting the items to make a key for the paint. What grit would you use for brass. I'd want something non aggressive, just to give a satin sheen rather than a pitted surface!

Otherwise I'd just abrade the surface with wet and dry and make sure it's grease free prior to the primer which will probably suffice!

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GEEDUBBYA

Howdy Alan,

When i worked at the transformer factory (the ones on poles, not the robots), we "shot blasted" (sand blasted) all the conductors, we used aluminum oxide and we also used a silica bead media. The aluminum oxide is more coarse and leaves the metals abit pitted, however it is a consistant pitting all over.
On the other hand, the silica beads or "glass beads" as we called them left a better finish, one that could be polished easily.
Now we used both of these materials on copper and aluminum as well as brass but, I know from my experience with painting an aluminum boat or two, you can "wipe it down" with vinegar before painting. The vinegar removes the osidation and allows the paint to stick.
So, i guess what i am trying to suggest would be for you to use either the silica shot (glass beads) or you might try the vinegar on the brass, I havent tried it, but it might work.


have a good day,

Greg

alan2525

I know that Salt and Vinegar works well at removing the oxidisation from copper but haven't tried it on brass. Thanks for the advice.

Alan

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bogstandard

Good on fish and chips as well Alan.

I do a fair amount of brass painting, and all I do is flat the surface down with 400 W&D, chemi clean with cellulose thinners, then etch prime. Sticks like the proverbial to a blanket. The etch primer will automatically key into the surface.

John

GEEDUBBYA

Its Me again,

One more thing you might try that you will have handy around the house would be acetone, ask your wife if she will let you borrow her nail polish remover.
Another household item you will have that works on copper (not so sure about brass, but since brass is a copper alloy it might work) is lemon juice, I know it cleans both copper pennies and zinc pennies here in the states.

hope these idea help,

Greg

ps, you will either have the worst smelling undercarriage for your train or the best depending on which of the above you use lol.

radish1us

Do a Google for CITRIC ACID, it works a treat on brass, after silver soldering or whatever and you want to CLEAN it , use this stuff.

alan2525

I used celulose thinner on the brass after rubbing down with wet and dry, etch primed and painted with humbrol enamel. A month later took my fingernail to the paint and it comes off like a national lottery scratch card.



What am I doing wrong? Is it the brand of etch primer or am I just destined to get it painted at my local car body shop!

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radish1us

Have been in the same quandary myself, overcame it by using a very fine grade of sand, that is sold as a filler for between bricks, that have been laid for a footpath.
This sand is very fine and free running, it leaves an excellent key for the paint to adhere to, the surface of the brass was pitted, but with very fine pitting, two thin coats of enamel covered it nicely and left an excellent gloss to the enamel as well.
This sand could be used quite a few times, but it is not a hard sand like silica, that can be reused many times over. This path filler sand is only fine river sand, so it will turn to dust as you use it.

Have a look for some at your local hardware store and see what you think of it.

regards radish

crash93

this may help. I have found that the primer sold by games work shop works, I spoke to phoenix about there paint as I had bought some and had it on stock about two years and wonderd if it had a shelf life, he said id did and to test by test spraying a scap and leave to fully dry then do as Alan has done and use your nail and if it comes of it Pants ! I dont think he needed to tell me the last bit. I just binned it all and got some games workshop stuff for there Citerdel models


Phoenix Precision Paints

Attached Images

primer1.gif (36.2 KB, 6 views)

crash93

OOOOOOOPS sorry about the post above that is the wrong picture it should not have been ROUGHCOAT

Peter