AK Real Colors Paint Adhesion issue (Acrylic Lacquer version)

[Paul2660]

I followed on the MR Paint post, but wanted to see if anyone was also having issues with adhesion with AK Real colors Acrylic Lacquer?.  I am using mostly their German WWII colors and have on a Trumpeter JU-87 B2 model.  I used some pre-cut masks  from LF models for the splinter pattern of 70-71 and had several spots were the paint lifted off when I pulled the masks off down to the bare plastic.  The masks from LF appear to be from Vinyl. 

My Prep before Paint.

Washed parts (dawn soap) before assembly

After assembly lightly sanded all main surface areas with 4x steel wool then 1000 grit sandpaper

Primed areas with Mr Surfacer 1000 grey

Then painted necessary base colors, on top RLM 71. After paint dried, I applied 2x cost of MR Paint semi gloss, after allowing it to dry 1 day, started masking. 

Everything worked OK, expect one large area that pulled off the wing in a couple of spots.  I can touch it up, but as it went all the way to the plastic, it will not look that good even after a light sanding. 

 

The masks have a good bit of tack and the paint issue was when I pulled one of the larger masks off. I was surprised to see after 2x costs of a semi gloss that the paint lifted off so easily.  The wing surface was also not totally smooth, but had just a bit of grit which I left thinking that this would help keep the mask from pulling off the paint. 

 

My questions, are has anyone else seen this with their paint? and besides the MR Surfacer primer, are there other brands of primer that I might consider?  Something that would in essence etch the plastic and make for a stronger bond? 

 

I would prefer not to use a rattle can, but for primer, I guess that is a thought, looking at auto primers maybe. 

 

Thanks

Paul

[D.B. Andrus]

Sorry to hear of your adhesion issues, very frustrating. 

I'd recommend sanding/prepping plastic with no finer than 600 grit, unless using a paint with an aggressive lacquer thinner base such as Mr Paint. The plastic may be too smooth using 1000 grit to give a less aggressive paint enough grip. Especially when using Mr. Surfacer with their leveling thinner.

 

My $0.02 worth.

 

HTH,

Damian

[Woody V]

That's odd. What did you use to thin the Mr. Surfacer? I use Testors lacquer primer (no longer available) and it's thinned in the bottle with acetone which is hotter than lacquer thinner and should (or at least it appears to) etch the styrene to create a molecular bond.

 

Other than that, my only other suggestion would be to put the paint down wet.

[Paul2660]

I am using the Mr color 400 leveling thinner for the Mr Surfacer about 50/50. For me Out of the bottle it’s way too viscous to spray.  I use either Mr Surfacer 1000 or 1500. Not sure if the difference.  I can try acetone to thin it but only as a last resort as acetone is very tricky to work with. 
 

Paul

[LSP_Kevin]

9 hours ago, Paul2660 said:

I am using the Mr color 400 leveling thinner for the Mr Surfacer about 50/50. For me Out of the bottle it’s way too viscous to spray.  I use either Mr Surfacer 1000 or 1500. Not sure if the difference.  I can try acetone to thin it but only as a last resort as acetone is very tricky to work with. 
 

Paul

 

Mr. Color Thinner (Leveling or not doesn't matter, and the number only refers to the size of the bottle) is the perfect diluent for Mr. Surfacer, so you're on the right track there. I would, however, probably thin it beyond 50/50 - especially if you're using 1000, rather than 1500. Those numbers refer to the viscosity of the product, and the lower the number, the more viscous it is, and hence the need to thin it more. If your goal is to thin Mr. Surfacer for airbrushing, then there's really no point using anything other than the thinnest variety, as the thicker varieties simply require more thinning to achieve the same airbrushable consistency.

 

Of course, none of that addresses your adhesion problems directly, which are a bit of a head-scratcher, and I wish I could help more with that.

 

Kev

[LSP_Kevin]

Funnily enough, I've just had some adhesion and peeling issues with Mr. Color! Thinned with Mr. Color Leveling Thinner, and the masking tape wasn't even over the blue (MC328), but the white! Where the edge of the tape touched the blue, it began to peel up when I removed the tape:

 

 

Not frustrating at all.

 

Kev

[Furie]

There have never been so many brands of paint on the market, in lacquers or acrylics, and yet there are still worries about paint sticking to plastic...
It's great to be in 2023 and still have a twinge of apprehension when it comes to removing adhesive masks, wondering if the paint will peel off...
I'm going to have to use MONTEX masks on MRP lacquer (And just before I paint with MRP-LPB FINE SURFACE PRIMER-BLACK), and I'm also going to have to go through paint-fastness tests before using them.

I'm gobsmacked

Edited May 29, 2023 by Furie

[Woody V]

8 hours ago, LSP_Kevin said:

I've just had some adhesion and peeling issues with Mr. Color! Thinned with Mr. Color Leveling Thinner, and the masking tape wasn't even over the blue (MC328), but the white! Where the edge of the tape touched the blue, it began to peel up when I removed the tape:

 

This happens when the paint forms a continuous film that goes from the model, up the edge of the tape and onto the top of the tape. Best way to avoid this is 1. use mist coats and 2. remove the tape as soon as possible.

[LSP_Kevin]

1 hour ago, Woody V said:

 

This happens when the paint forms a continuous film that goes from the model, up the edge of the tape and onto the top of the tape. Best way to avoid this is 1. use mist coats and 2. remove the tape as soon as possible.

 

Most of the sections that peeled off are actually on the old sections of the blue that didn't receive any overspray. And the tape came off the second I put the airbrush down. It was just so strange; I've never had anything like this happen before.

 

Kev

[Woody V]

2 hours ago, LSP_Kevin said:

It was just so strange

I concur.

[LSP_Kevin]

7 hours ago, Woody V said:

I concur.

 

I just realised that if you hadn't seen the update to my build thread, then it wasn't clear in my post above that I was merely trying to touch-up a ragged spot in the already painted blue section, and was not painting it in from scratch. Had it been a whole section of brand new paint that lifted, it would have made more sense, but not when most of the lifted paint is actually outside the area I was touching up!

 

Kev

[Woody V]

14 hours ago, LSP_Kevin said:

I just realised that if you hadn't seen the update to my build thread

 

Got a link? 

[LSP_Kevin]

1 hour ago, Woody V said:

 

Got a link? 

 

Here you go:

 

 

Hopefully you don't wince as hard as I have been!

 

Kev

 

[Woody V]

41 minutes ago, LSP_Kevin said:

Hopefully you don't wince as hard as I have been!

 

No wincing but I did get a chuckle from one of your first posts on that build:
"This looks to be another relatively straightforward build; or at least, I hope it will be"

[Neo]

If it went all the way back to plastic then its not the ak paint,it would be if the primer stayed in place. if those spots look like fingers. Could be finger grease, i never wash my models, but i do wipe them down with pharmacy rubbing alcohol 

 

The only time i had this kind of issue was when using alcladII black primer. 

 

On the note of other primer, ive started using badger stynylrez primer works really good for large surfaces but a real PITA if you ever want todo touch ups as you have to use a super large needles and 30psi, i.e goes everywhere 

Edited May 30, 2023 by Neo