Hi I am spraying a loco & finishing it with a matt laquer, & I have a problem. Any over spray is drying white & makes the loco look as if it has been through a snow storm. What am I doing wrong? Can any body help please? Roger.
On 13/03/2006 18:56, Barbara Mitchell said (or was it Roger??),
It sounds as if one of two things may be happening.
1 - you haven't stirred the varnish enough. Matt varnish is just gloss varnish with a matting agent added, so needs to be well stirred - 30s to a minute with a bit of bent wire in a minidrill should do it, (or 20 minutes with a cocktail stick :-) ) 2 - the atmosphere you are spraying in is damp and/or cold. This can cause blooming, which might be what you are seeing, although that tends to show as a milky white coating. This effect can depend on the type of paint you use......and talking of which, which varnish are you using?
I did think you might have water in your airline, but if that was the case you would see it on the target area, not as overspray.
"Barbara Mitchell" wrote
Hi Roger,
I've not used Phoenix but have used Railmatch aerosols and I reckon to shake them for a minimum of 20 minutes. This has the advantage of not only ensuring the paint or varnish is thoroughly mixed, but the heat from one's hand warms the paint too.
I also always spray in a warm environment.
John.
Warming aerosol cans to about 40 degC helps no end - finer spray at higher pressure. Stand them in hot water (50 degC max) for five minutes or so, shaking briefly every couple of minutes. Always spray in a warm environment. Make sure the light is good enough, and from the right direction so you can see the moment the paint layer flows over (the 'orange peel' just disappears.
Any varnish can be matted by the addition of magnesium carbonate powder. I got my last lot from Boots.
Consider using artists matt picture varnish - very thin layer. Only problem is that the best of them require airbrushing with warm air.
>On 13/03/2006 19:38, Barbara Mitchell said,
I've never got on with their aerosols, although I swear by their paint through an airbrush. This time of year is out for spraying normally, although I will occasionally heat up the back bedroom (aka broom cupboard) and use that as a spray booth. I wear an appropriate face mask, and once the models are taken out into a warm, dust-free environment, the room gets bl**dy cold once I open the window!
It might be worth making a spray booth so that you can safely spray indoors, which avoids any problems of cold and damp. At least, it does if you have central heating, which I don't! There was an article on making one in Scalefour News last year, and basically it is a large plastic box (I've bought a 60 litre storage box from Staples), with a couple of fans and cooker hood filters. I just happened to have bought some of the bits to make one last weekend!
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