I bought a 3D blastboat and used Boyd white enamel primer. It dried 3 days. Then I used Testors flat aircraft gray spraycan enamel and let it dry 3 days. Next I used Testors gray enamel brush on for details and let it dry 3 days. I used acrylic black wash and it dried1 day. Finally I used Testors dull coat spray lacquer. It dried 4 hours. I used frog tape to mask off and all the paint started to peel off. What did I do wrong? Thanks for your help.

What type of plastic was the 3D print made of? If it's from Shapeways and it's FUD (resin-laser cured) then you need to clean the model with alcohol and a gentle brushing before applying paint. What I believe happened here has happened to me before with FUD plastic when not properly/completely pre-cleaned: your paint dried onto a thin layer of residual uncured material that is not actually attached to the model. When you removed the tape it pulled the paint off as it dired more like a shell than a layer.

I clean my FUD models with a 40% Ethanol/60% Water mixture* and a "soft" toothbrush before painting, let the model completely dry (1-2 days to be safe) after cleaning and before painting.

*It's vodka, Skyy...cause I have a bottle and I wont drink that swill...

I like that tiny comment.

Probably easier to find than the above

Is it ok to use the paints that I have or is there a problem mixing enamel,lacquer,acrylic?

I personally have had nothing but trouble with non-acrylic paints, I'd recommend not trying to use enamels on these, but my reasons for that are more because they take forever to dry and smell bad, and I was never good at making them not look blotchy.

I think there's something going on with the 3D print materials. Cleaning it is a good idea, but if that doesn't work, I would reccommend trying using only acrylics and seeing if it works better. I'm not always sure of the chemistry behind 3D prints since they're all different, but I wouldn't rule out that the enamel paints just aren't getting along with them.

12 hours ago, 414taylor said:

Is it ok to use the paints that I have or is there a problem mixing enamel,lacquer,acrylic?

I've heard good things about Testors branded paints, I have only ever tried the white rattle-cans (priming Legion stormies/snowies/scouties). My personal preference, especially with 3D printed resin-laser/UV cured models is to use Tamiya branded paints (specifically XF-19 Sky Grey) for priming. Tamiya branded paints are acrylic and contain both isopropanol and glycol additives which create a better resin-paint bond than just standard solely water-based acrylics and, most importantly, it auto-levels while drying. Even if you're accidently overly generous with coverage it'll dry smoothly whether brush or airbrush applied. It works great in airbrushes with little to no dilution (with windex of course) depending on configuration (PSI, aperture size, nozzle shape, etc.).

As the Federation keeps nice, clean ships I did not wash or scuff up the Tamiya XF-19 Sky Grey basecoat on this NCC-72930 USS Shadowcaster. The light grey coloring is a single base coat done with an airbrush and, as you can see, it got great coverage with no loss of model-detail:

Thank you for the helpful input. When finished, I may send photos.

Is it necessary to use Alcohol? What about just regular soap and water? This is more from a availability pov.

10 hours ago, Ghosthacked said:

Is it necessary to use Alcohol? What about just regular soap and water? This is more from an availability pov.

I don't see why - chemically - one would be any less successful with dish soap and water than they would be with alcohol. Both remove non-polar organic compounds with a polar rinsate (all be it through different chemical mechanisms).

I've always just used alcohol. If you do use soap and water be sure to do a lot of extra rinsing. You would not want to replace resin residue with soap residue. To that end having soft water would be important (total hardness <1grain/gallon or <17.1mg/L) as moderately hard to hard water will detrimentally impact the performance and function of soaps.

Me bad smart next to big-smart man.

In other words my field of expertise is not in the sciences and I really appreciate that there are people that like ZealuxMyr that have the knowledge that has improved this world and continues to do so.

I use soap/water mix with any resin/3D printed model- let them soak in overnight and then scrub/rinse the model. Haven't had any issues with paint peeling/loss of paint so far. I use acrylic paints, mainly because like Kieranski said, I don't like the dry time or smell of enamel/oil-based paints.