I seem to have got myself into a unfortunate situation with my C-47. I airbrushed the top olive drab (Acrylic Model Master). Coverage was easy and looks good. I purchased some Pactra masking tape and after about 72 hours I began masking over the olive drab to airbrush the gray on the belly of the plane. Almost immediately, I noticed that the tape was pulling up the green paint. I stopped and repainted the olive drab and now am at a standstill, not sure what my next move should be.
I don’t know if it’s my tape or if I need to coat the olive drab with something in order to protect it. My hesitation stems from uncertainties regarding the use of acrylic and oil-based (enamels) paints over one another. If I am correct, it is ok to paint enamel over acrylic but not acrylic over enamel. My plan was to:
Spray Color A…mask…Spray Color B…mask…Spray Future…Decal…Spray Future…Spray flat clear coat enamel to undo the glossy finish of the Future.
Any suggestions on how I should proceed? You all have such good work on display here that most everyone has faced – and overcome – this problem.
The plane will have invasion stripes as well, so that just means more than two Future coats along the way, but I don’t know of any other way. Unless of course I have the wrong masking tape.
If I am correct, it is ok to paint enamel over acrylic but not acrylic over enamel.
I paint acrylics over enamels all the time. They seem to bond well to the enamel, which in turn bonds well to the plastic. I will paint acrylics directly onto styrene, but only if A) the surface has been cleaned thoroughly and/or B) I have no intention of masking it.
Bob,
Mate - I’m sorry to hear of your frustration - I’ve had that happen on a number of occasions - it always made my heart sink. But it hasn’t happened to me for years and years - here’s why.
Enamels and water based acrylics are both pretty compatible with each other - you can spray one over the other and shouldn’t have any problems at all. I do it all the time. it’s the laquer based acrylics that you shouldn’t spray over enamel or water based acrylics. The “hot” thinners in the laquer can eat enamel or acrylics.
Now - for your problem…did you prime the plastic before you hit it with OD?
Priming gives a slightly rougher surface (or “tooth”) for the paint to adhere to. Normally I lightly sand the plastic to give a rougher surface for the primer to adhere to…sensing a theme here? This is why virtually every primer ever made has a matt finish - a rougher surface than gloss.
Smooth, glossy surfaces really aren’t the ideal surface to squirt paint onto - there’s nothing for the paint to really grab onto.
To get around this problem, I more often than not prime my aircraft with (shock - horror) automotive laquer based acrylic primer…people say that it can kill your model, but I’ve never, ever had problems with doing that. It really grabs onto (or etches) the styrene and provides a foolproof primed surface for any other type of paint that follows. I also almost always paint my car models with enamel primer and then a laquer topcoat…
Having said THAT…and seeing as I’ve been building for more than 35 years, I’d try to get a little more experience before doing nasty, evil things like I do to models -
Your best options are:
Lightly sand your surface to be painted - with 800-1000 grit paper - and use it wet.
Prime…always prime…it’s far easier to identify surface defects in a primer coat than an unpainted surface - and correct them BEFORE you squirt the topcoat color.
Spray your topcoat with a paint compatible to the primer - sometimes the thinners in your topcoat can actually very slightly soften the primer a little, and the topcoat can actually “melt” itself into the primer coat, creating one single coat of paint - the thickness of this “melted” layer between the primer and topcoat is normally measured in microns - so don’t worry - just don’t “dump” the paint on - remember, less is more.
Always mask with a tape that’s as low-tack as you can get away with. Tamiya tape is the bees knees, Post-it-notes are fantastic, that blue painters masking tape can be really good, too, if rather expensive. I’ve also had great success with paper masks held off of the a/c surface with thin rolls of Blu-Tac…I can get an amazingly thin, scale-like feathered edge on cammo schemes.
For invasion stripes, it’s usually best to squirt the fuselage and wing areas with white and then mask them off BEFORE you apply the top color coats. It’s much easier to put color over white than white over color - opacity issues, you see. Takes more white to cover OD than OD to cover white.
Reference materials like How-To books are a GREAT place for tips and inspiration - try having a look at : http://kalmbachcatalog.stores.yahoo.net/scale-modeling-books-general.html - these are books that Kalmbach produces - aimed at the modeller and written by modellers - tons of hints and tips to help steer you in the right direction - which can help prevent these nasty nightmares like paint coming up with the masking tape.
I hope this might have been of some help - I’m not sure that it can save your current model, but it might help prevent this from happening the next time.
I appreciate all the information. Thank you! I haven’t worked on a model before this in many years, and to be honest, I cannot even remember if I used enamels or acrylics at that time. I certainly never used a primer (high school in the late 70s/early 80s at the time with little money – a can of spray paint was a luxury beyond description).
In any case, I will remember this for future builds. A lot has come back to me over the last couple of weeks, but I’ve also learned even more. Thanks again for the help–it is greatly appreicated!