painting etched brass

[Tony Fairbrother]

I am trying to brush paint a couple of etched brass kits to fit my Kato chassis's.Local model shop sold me a pot of Humbrol No.1 Grey as a primer suitable for brass and for acrylic top coats.
I  brush painted the primer and it covered the brass beautifully , but ,a week later,  any acrylic top coat I try to brush on doesnt want to go on ,streaks, looks awful , any ideas

thanks for any advice  , Tony

[engerth399]

Hi
I would recommend an etch primer as the starting point on brass.  Halfords do a good aerosol one.  Alternatively brush on types exist and I am surprised your shop didn't recommend one.  I prefer an aerosol as you get a finer coat and are less likely to lose detail.  Then Halfords grey primer before starting your colour coats.  Don't be disappointed if the first coat doesn't cover adequately, two coats and possibly three are likely.  EXCEPT if your top coat is a red, I don't know why but reds seem to cover very poorly.  So then after the etch primer use Halfords Red primer and then the red top coat should cover easily.  Then gloss varnish before the transfers and final protective coats of varnish.

Peter

Despite the references I have no financial interest in Halfords!!!!

[engerth399]

Hi
It occurred to me that my reply was not as complete as it should be.  I did not mention preparation and cleaning before painting.  After construction is complete key the brass using a fibre glass pencil or brush, then clean the whole model thoroughly, I use Vim or Ajax scouring powder and an old tooth brush.  Rinse off very thoroughly and leave to dry at least overnight ( if the domestic authorities will allow, the airing cupboard is an ideal place).

Peter

[Tony Fairbrother]

thanks Peter , a trip to Halfords is due

[Tony Fairbrother]

Also , a fibreglass pencil is winging its way to me from Amazon

[JulienW]

I wonder if the problem is that the Humbrol paint is an enamel (oil based) one and the acrylic is water based...

I tend to use Citadel Miniatures (Games Workshop) spray paint, either 'skull white' or 'chaos black' as the primer coat on pretty much everything (brass, white metal, plastic - they do a grey too, and probably something approaching red oxide). The advantage of these over car body paints and primers is that these are designed to fill any imperfections in the metal surfaces, but these are often the same size as the fine details on our models.

Once primed then I use pretty much anything (enamel or acrylic) over the top without problems, though I do find that the Tamiya acrylic paints can be a bit streaky at times.

[Tony Fairbrother]

thanks for the reply Julian.  The model shop said the primer was suitable for etched brass (and it did cover well). I asked if it would be OK for acrylic top coats and they said yes. I will try spray primer but 'er indoors wont let me do it in my current workshop (conservatory)! My garage may be too cold for spray painting at the moment but I will see. In the meantime ,when my fibreglass pen arrives I will see how much paint I can remove before starting again.  Regards ,Tony

[Jeff Schumaker]

I wonder if the problem is that the Humbrol paint is an enamel (oil based) one and the acrylic is water based...

Painting acrylic over enamel should not be a problem. Painting enamel over acrylic, not so good.

Jeff S.

[engerth399]

Can't say I've had problems with enamel, even much thinned to go through the airbrush, over acrylic. I normally allow a lot of time to dry and harden.

Peter

[JulienW]

thanks for the reply Julian.  The model shop said the primer was suitable for etched brass (and it did cover well). I asked if it would be OK for acrylic top coats and they said yes. I will try spray primer but 'er indoors wont let me do it in my current workshop (conservatory)! My garage may be too cold for spray painting at the moment but I will see. In the meantime ,when my fibreglass pen arrives I will see how much paint I can remove before starting again.  Regards ,Tony

In my own experience the main thing with spraying in low-temperature environments is having the tin of paint and the thing being painted too cold.  A wet day is also no good.

I tend to spray things in our outside loo (we have an indoors one too! ::) ) but get the spray booth (old cardboard box to catch the overspray) and spray stands (plastic pots that once contained pasta sauce) ready whilst the model(s) and paint are indoors in the kitchen, shake the spray paint for the required 2 minutes in the kitchen (where I'm warmer too!) then quickly step out to the spray booth and give things a good coat of paint. The plastic pots allow me to turn the models around to spray all sides, and I also sit the models on card off-cuts that are sized to fit into plastic boxes (like the ones the 009 Sales stand have sold from time to time), so as soon as I've finished spraying the cards with the models on can be picked up, put into a box, the lid put on and then they can be brought back indoors (and put on the radiator in my workshop) to dry / cure without too much of the smell bothering the domestic authorities.

As others have posted paint can be a funny thing, and what works for one may not work for another.

I've had problems with the otherwise very good Tamiya acrylic paints not being easy to brush-paint and producing streaky results, but that seems to be regardless of what I'm painting them on (unprimed surface, primer, or any other type of paint  - acrylic or enamel) and usually a couple of thin coats does the job better than trying to ladle a thick one on. I've also had paints do odd things when thinned, so try to use proper 'enamel thinners' rather than white spirit (and Tamiya thinners in their paints) to avoid problems.

[jimowers]

I wondered, Julien, why my spray attempts were so successful. It is not an outside loo in my case but rather a balcony 150 feet above the sea with a good sea breeze going to take away any fumes.

[Andrew Emery]

You'll find Tamiya acrylics, thinned just slightly with Tamiya Thinners and sprayed through an airbrush, to be the most wonderful finish imaginable. Their Semi-Gloss Black for instance, seems to blend effortlessly with many factory-finish blacks, avoiding the need to strip entire models.

Andrew