So, 2 full days ago I sprayed this. I used some Tamiya tape to lay down to mark off some blotches to then cut out and place on. Ive never had to wait more than 2 days for the paint to cure....



Suggestions to fix it? Im guessing i should have waited longer for a cure? Using AKI acrylics for the 1st time. Guessing ill have to strip the whole thing? RATS!

The primer I used is something I've been using for a bit now. But never before w/ aki paint. It's rustoleum 2x ultra cover gray primer. Says works on plastic. In looking again at the directions it also mentions plastics made of polyethlene may hinder adhesion. Maybe the model is polyethylene?? It does not say if it works with acrylic or not or enamel or what??

Thanks

USS Quincy

Polyethylene is normally used in materials like plastic bags, and flexible plastic items similar to Tupperware. Most model kits are polystyrene, which I’m pretty sure this (Trumpeter or HB?) is made from, so I doubt that’s your problem. I can’t really tell, but It looks like your paint might be removed right to the bare plastic level, primer and all. If so, it’s likely your problem is Created by a mold release agent. To release kits from molds, a plastic release agent is introduced into the mold, which is frequently transferred to the kit parts. To insure good paint adhesion, even for primer, it’s necessary to clean the parts first in a mild solution of soap and warm water. I like to use lacquer based primers, applied sparingly with an airbrush, to eliminate this problem, but it’s always better to wash the parts first. On the other hand, if the paint is peeling away from the primer base, it’s likely a compatibility issue. I’m not familiar with “AKI” whatever that is— but if your referring to “acrylic” hobby paints, most should adhere well to an enamel primer, unless you’re using a strictly water based acrylic paint. There may be some incompatibility there, as a water based acrylic is more likely repelled by the enamel primer. Shouldn’t be a problem with Tamiya though, as it’s an acrylic lacquer, as long as it’s mixed with proprietary thinner.
VR, Russ

I developed the following drill for when I need to mask something, and I haven't had a problem since adopting it:
- prepare the model for painting
- put on gloves and wipe it down with alcohol; after this point never touch it with skin
- prime and let the primer cure for 24 hours
- paint and let the paint cure for 24 hours
- mask
- paint

I use mr surfacer primer and tamiya paint. My hunch is it's the clean and cure that makes a difference, but Russ has good advice about possible incompatibilities between types of primer and paint.

I've found that some masking tapes can be too tacky, so in order to reduce the tackiness I first stick the tape to a clean rag, T-short or even my jeans. It reduces the tackiness enough that I've never had a problem with paint pulling up, and I've never had any issues with it leaving lint behind.

Use lacquer primer. Acrylic primers just can't be depended on if you are going to mask.

What Russ and Gary said.

If the paint came off and the primer held it is a paint problem. If the paint and primer came off it is a primer problem. I do not use Humbrol for that reason. I painted a car model and after I was done and all had dried for a week I put some electrical tape on the body. When I removed it, it separated the paint layers. The top layer stuck to the tape leaving the primer and the first color coat.

You are using AK Interactive paint over an enamel primer. When you thinned your AK what did you thin it with?

One of the problems I have encountered with such paints as Vallejo, AK and the likes, in the eye dropper bottles,
is that they form a skin that sticks to the primer rather than bite into it and when masking, your likely to pull
it up most of the time.
When masking is involved, I much prefer to use paints like TAMIYA or AK acrylic lacquers which will bite into the
previous coat and I have never had tape pull up these paints.

Cheers,

I feel your pain. Had this happen to me a while back...



In my case it was the primer. I was trying a new acrylic primer and it did not hold. Since then I have only used automotive primer and have had no issues at all.

Ok, I understand the problem a bit more now— AKI= AK interactive (I just never heard it referred to like that). So you’re using a commercial spray primer (Rustoleum 2X) which can be either lacquer or enamel based, with a Acrylic based overcoat. And it sounds like it’s the paint pulling away from your primer. Although I’ve used 2X for woodworking and and metal products, and I know other modelers have used it as a primer, I wouldn’t use it as a primer for an Acrylic paint. Enamel spray plastic primers are designed to work primarily with enamel paints as an overcoat, and they typically have a leveling quality that smooths out the primer paint surface preparatory to a follow on coat of enamels. As such, they sometimes don’t have enough “bite” to hold an Acrylic paint. This is especially true if you applied it a little heavier in some spots. The “get around” for this is to slightly abrade the surface with fine sandpaper, or steel wool before applying the Acrylic paint. But the better solution is to use a “friendlier” Acrylic primer, such as a base coat of Tamiya, Mr. Hobby, or Stylnrez, etc. personally, I seldom use a commercial primer, preferring to use a lacquer based mix of an enamel hobby paint as a primer, which provides enough “bite” for any type of follow on coat. In some cases, I skip the primer coat altogether and use lacquer mixed with a base coat of Tamiya, Mr. Color, or Model Master paints. This insures delicate detail isn’t covered up with multiple coats of primer and paint.
VR, Russ