Painting photoetch

[fred tannenbaum]

Good afternoon all!

I have never worked with photoetch before and I was wondering if one has to do anything to the photoetch in order to get paint to stick to it, such as sanding or priming?

Thanks for any help!

Very sincerely,

Fred

[hakkikt]

I put larger parts in

I put larger parts in vinegar for an hour or 2 to etch the surface a little and give the paint something to bite, then clean the parts thoroughly. Does not work with small parts of course, so I just clean those with a Q-tip and alcohol before painting.

[JWLaRue]

Fred,

For the most part, I

Fred,

For the most part, I just sand with a very fine wet-or-dry sandpaper or use 0000 steel wool....just enough to rough up the surface.

-Jeff

[Guest]

I always use an etch

I always use an etch primer for metal parts.

This is available from any decent motor vehicle paint supplier. It's not terribly expensive, and half a litre will last you a long time.

Once coated with an etch primer, paint will never chip off.

Another tip I got from Dave Merriman, is to dip parts in ferric chloride, this puts millions of tiny microscopic pits into the surface, which gives lots of teeth for ordinary primer to cling to.

I find this technique useful for small parts, but prefer to use etch primer for larger parts.

If you spray the etch primer, use a good mask and/or spray outside. It's particularly nasty stuff, as it contains acid and thus is highly carcinogenic.

Andy

[tsenecal]

not sure how good it

not sure how good it is compared to others, but for those of us that hang out at hobby shops, tamiya makes a "Metal Primer", in their small spray cans. Item #87061

[gerwalk]

It's particularly nasty stuff, as

It's particularly nasty stuff, as it contains acid and thus is highly carcinogenic.

Andy

Cannot help correcting you (chemist here): The fact that it contains an "acid" it doesn't mean it is highly carcinogenic (won't put vinegar to my salad if so!) It may contain a carcinogenic substance that could be an acid too.

[gerwalk]

After doing a quick research

After doing a quick research I've found that many metal etchants contain chromic acid that as such contains Cr+6 a well known carcinogenic. BTW: I've also found others that don't contain that nasty substance.

[Guest]

Fair enough.

I'm not a chemist,

Fair enough.

I'm not a chemist, but I like to take the road of caution in cases like this. I was advised by a member of my local club to take extra special care when working with etch primers.

He'd personally witnessed many former work colleagues who worked with etch primer end up with lung cancer.

Andy

[JWLaRue]

Yup...which is why I use

Yup...which is why I use wet-or-dry sandpaper.....

-Jeff

[gerwalk]

It is wise to be

It is wise to be far away of anything containing CrVI (chromium six).
When using chemicals of any sort always read the MSDS.
Take care