Problem with Tamiya Acrylics being to fragile

Tools, Techniques, and Reference Materials Painting and airbrushing
1

I recently switched to Ta,iya Acrylics from Model Master Enamel. Well I am working on two models currently, a Gundam Model and an Italeri Corsair. The acrylic paint on both is very very fragile. It is easily scrapped off with a fingernail. Well the gundam has no undercoat and the corsair has a model master enamel silver. I built a Tamiya Bulldog with Tamiya acrylics and it did not hace this problem. I am stumped. I have no idea what I am doing wrong. Any advice would be greatly appreciated.

2

Greetings,

I just switched to Tamiya and Gunze after getting fed up with MM. Both have been working very well for me. Before I gave up on MM I vowed never to use acrylics without a primer coat. Washing and priming make a significant improvement with adhesion.

Hope this helps,

Chuck B.

3

  1. make sure you wash your model before painting to get all the mold release and finger oils off…

  2. except for the silver undercoated model, use a primer… MM makes one as well as Tamiya, but good old Krylon works just as good… primer helps the acrylic stay where it should, on the model…

  3. what are you thinning with? sometimes that can make a difference…

  4. over the silver you just have to be very careful with masking, the silver doesnt give the paint much to bite into… you could try using some very fine grit sandpaper and rough the area you are going to paint over first… the microscopic roughness gives the acrylic something to stick to as well… Tamiya makes a finishing sandpaper that whould do just right to give it just enough for the paint adhesion without leaving gouges.

hope this helps… I know the frustration of seeing paint come off the model after all that work… primer was the main thing that stopped that happening for me…

4

I’ve built a bunch of gundams with my kids, they seem to use much smoother plastic. In some pieces I could definitely see why paint doesn’t stick as well. Enamel I suspect is hotter and eatting into the soft plastic better. I would try priming.

5

I have been using the Tamiya acrylic thinner. Their brand of thinner that is very expensive. I will try and perservere with the corsair and start over with the gundam and prime it first.

Thanks

6

how about trying gunze thinner? it probably eats intot he plastic a little more. tamiya thinner is alcohol so its less aggressive

7

As others pointed out, the keys to using acrylics succesfully are to make certain you remove any oil from the model surface (I use alcohol for that purpose) and / or priming the surface. Acrylics don’t bond to the plastic nearly as well as enamel or laquer paints do, and it doesn’t take much to cause them to lift. If there is any oil on the surface from the molding process or from handling (and there normally is some there) the water-based composition of acrylic paint cannot dissolve it like solvent-based enamels or laquers.