Acrylics - help

[Simond]

Looking through the threads on weathering & painting, and reading books on the subject, including Martyn's Welch's tome on railway paintwork, and books on military modelling, I'm still struggling to win with acrylics.

 

I've built and painted lots of models using enamels, occasionally over a cellulose base coat, and I've had some success painting scenic items with acrylics, but I cannot get to a satisfactory finish on "hard" surfaces using them.

 

The key reason I'd like to overcome this is that it's perfectly reasonable to spray paint indoors (it's winter!) with a water solvent, but sparing anything else needs warmer weather.

 

I'm using a range of different paints, mostly Windsor & Newton, I've tried mixing retarders, Matt & gloss media, water, meths, acetone, you name it, and brush or spray painting.

 

The airbrush gets clogged.

 

Brush painting seems to leave brush marks on anything wider than a sole bar. And the paints seem to sometimes not "wet" the surface well.

 

Others seem to get acceptable results. What am I doing wrong?

 

Ideas, comments, suggestion, etc, very welcome

Thanks

Simon

[Rumblestripe]

It sounds like you are using "artists" acrylics?

 

Try a modellers brand such as Vallejo or Games Workshop, in particular if you want to airbrush get the Vallejo "Model-Air" paints, which you can use straight from the dropper bottle.

 

Vallejo you might not find locally but there seems to be a local Games Workshop store in most large towns and cities and in out-of-town shopping centres. Vallejo is easily available via that there internet, Ebay and Amazon both have suppliers.

 

http://www.acrylicosvallejo.com/

 

http://www.games-workshop.com/en-GB/Painting-Modelling

[Simond]

Rumblestripe

 

Thanks for this, I am indeed using artists' acrylics. I rather foolishly thought "acrylics = acrylics"...

 

I do have some GW, son was into painting hobgoblins a few years back. I'll try them. Maybe next weekend.

 

Best

Simon

[keefr2]

How 'hard' is your tapwater - if that's what you're using to thin the acrylics? If you're in a hard water area then it's probably a good idea to try using distilled water instead, which should help reduce the clogging. I've used artist's acrylics many times to spray car models, succesfully using our very soft tap water & Winsor & Newton retarder - when thinned to the right consistency I find they spray just as well as 'proper' modelling acrylics on large areas. I now use the latter almost exclusively for painting my aircraft & military models, again thinned the same as artists acrylics. I can spray 1/72nd aircraft with freehand camouflage demarcations a pencil line thick. However - my airbrush still almost invariably clogs whenever I use acrylics! I think it's just something you learn to live with & the advantages of acrylics outweigh this problem. I just have a soft brush & jar of clean water next to me when spraying & get into a routine of cleaning the tip regularly during a spraying session. If you do this though, always remember to spray off the model first when restarting spraying after cleaning the tip - otherwise you get a nice splatter of dirty water on the model!

 

HTH

Keith

[Jeff Smith]

Whilst you won't be overcome by fumes from spraying acrylic paints indoors I would still think some form of extractor fan would still be sensible to have, or at least a mask as fine droplets of acrylic paint would not be good to breathe in. Personally I do not spray but have satisfactory results from brush painting hobby acrylics. Artist's acrylics I save for use on canvas...

[Simond]

thanks Keith

 

water here is very hard - another lesson learned!

 

I think the thing that annoys me most about spraying, is that when I thin the paint enough to spray well, I find it does not wet the model, but forms into droplets.  This despite having sprayed the model an hour earlier in rattle can primer, thus it is hopefully "grease free".  Of course, on more porous materials, this doesn't seem to matter, and I have had some success with card (see the Clyde Puffer in my Porth Dinllaen thread) balsa, foamboard and plaster/ground cover.

 

Thoughts about use of IPA to thin the paint?  I'll certainly try with DeIonised water.

 

Jeff, thanks for your thought about extraction.  You're probably right.

 

Though, by the time I've bought solvents, and set up a spray booth with extraction, I might as well go back out  into the garage, with my dust mask, and spray paints that work for me!

 

thanks again

Simon

[keefr2]

Thoughts about use of IPA to thin the paint?

Morning Simon,

 

I use IPA to thin Tamiya 'acrylics', but if you try these, you'll tell instantly from the smell, that they are yet a different type of acrylic! They will thin with water but are solvent based rather than water based & work much better thinned with their own brand thinner or IPA - they also smell as badly as enamels! I find water based acrylics all have their own reaction to different thinners, sometimes even between colours in the same range of paints - trial & error there I'm afraid. I do have a spraybooth, but find it awkward to get close enough to the model in it to do intricate work, so tend to spray on the bench wearing a disposible surgical face mask (I bought a large box off e-bay) - I've convinced myself that if they're good enough for the airborne contaminants surgeons may have to face they should be OK for 'non toxic' atomised acrylic paint...!

 

As to the beading, I find that usually happens when I've actually overthinned the paint despite it seeming to be optimum for spraying, but it can also be that I've got the air pressure turned up too high or even another case of peculiar characteristics of some colours. In a specific case, early WW2 RAF colours of dark green, dark earth & sky. In the Xtracrylics range, the former two invariably spray really well, whilst the sky almost always causes pooling & beading! I have no idea why, but I also have a friend who has exactly the same thing happen to him - in this case we use a different brand of paint! Just part of the black art of spraying acrylics I suppose! I've been using them for decades now, but they still fight me far more than enamels, but when they do work well I really prefer using them as they do give a superb fiinish & dry so much more quickly too.

 

Keith

[Simond]

Thanks again

 

More trials

 

More errors!!!

 

Best

Simon

[Jeff Smith]

Best not to use the IPA in the brown bottle.......

[Gene]

I really find the Vallejo Model-Air acrylics are very easy to use and give a great finish....I spray them at about 12-14 psi. They can be thinned if needed( very very very rarely) with regular ammonia-based glass/window cleaner. I also always prime my models with Testors Dullcote out of a rattlecan, it gives the model some tooth for the acrylic paint to grab onto.

[70021 Morning Star]

Simon,

I'm a professional artist - mostly aviation or maritime subjects in oil on canvas, but do occasionally use Artists Acrylic paints.

 

Artists acrylics are designed 'to show brushstrokes', as though the artist was using oil paint.

 

If you dilute Artists acrylic with water, it will go matt.

 

Artists acrylics won't usually work in an airbrush, as the pigments aren't ground fine enough, and will block the airbrush.

 

So they're not suitable for painting model trains. But, perhaps you could buy a stretched canvas, and have a try at being a David Shepherd, doing a nice artistic painting portraying a 9F steam locomotive?

 

All the best,

Rick

[Jeff Smith]

I'm not a professional artist but as noted in an earlier post do dabble with artists acrylics on canvas. I always use them straight from the tube as most are not intense enough to be diluted without going transparent - whilst multi layered transparent painting is a technique in its own right its not the way I paint. I gave up oils years ago as they take much too long to dry (six months or more....) undiluted.

 

The only acrylics I use for modelling are the dedicated model paints and the craft paints - and all brushed.....

[Simond]

Rick,

 

Thanks for this insight. I'll restrict my use of artists acrylics to ground cover & so on, where I have had some success, and stop trying to make them do what they ain't meant to do.

 

The chances of me doing a David Shepherd are marginally higher than me doing a Jimi Hendrix..., but it's a nice thought!

 

Jeff,

 

I really like the way I can dilute enamels and they go transparent, makes washing weathering onto models much easier. If I could reliably do this with acrylics....

 

I think I'll bite the bullet and buy some dedicated model acrylics.

 

Thanks again

Simon

[Jeff Smith]

Simon,

 

I was referring to artists acrylics being diluted for use on canvas - I don't do this except sometimes for the under-painting, ie roughing in some colours and shades prior to the final details and colours.

 

Model acrylics dilute nicely for weathering just like enamels but are considerably more environmentally friendly.  I use Testors Acryl thinners for most 'model' acrylics but just water for the craft type of paints for wood structures.  Styrene needs proper model acrylics designed for use on plastics and even then can be a bit transparent requiring several coats, but usually dries quickly so if painting a coach for example by the time you've done four sides the first one is dry enough for another coat.

[Rob Pulham]

Hi Simon,

 

Another recommendation for Vallejo acrylics here. For the colours that I use that are not available in the model air range I thin with tamiya thinner (because I have a large bottle in stock) but they do their own range of thinners. I thin them down to the consistency of milk and rarely have problems.