'Crazy Paving' paint

[PR19_Kit]

Soon after I'd finished my Canberra MR23 in 2009 signs of 'crazy paving cracks in the upper fuselage white paint started to appear, and less than a year on it had got so bad I decided not to show the model any more.

By now it's grown to ridiculous proportions, so much so that I can get my thumb nail down the crack that I've marked in the pic below! Both the white paint, my usual Halfords Appliance White, and the Klear coat have cracked. I've used the same technique countless numbers of times on my airliner models and I've never seen the problem before.

Has anyone else ever seen this and if so is there a way to avoid it please?

I'm  coming to the conclusion that the only way out of it is to do a very careful strip of the white bits and re-paint and decal the model. 

[JayBee]

.....and if you know of an easy way to strip the Halford's Appliance White, PLEASE let me know.

Jim

[Gondor]

Pollyfiller?

Gondor

[PR19_Kit]

.....and if you know of an easy way to strip the Halford's Appliance White, PLEASE let me know.

Jim

Yeah, I know the feeling Jim. I did it once on a DC10 and it took 240 grit wet and dry AND some paint stripper as well! 

Pollyfiller?

Gondor

Actually that's not a bad idea Alastair! It might be worth a skim layer of putty, re-sand and re-paint etc.

[kerick]

Are the cracks still getting bigger? If so then putty would be a waste of time.

Looks like a bad batch of paint to me. Better to get rid of it. I know, easy to say, hard to do.

[zenrat]

Looks like Acrylic clear over enamel paint to me.
The enamel continues to gas out for ages causing the clear to crack.
I have a few cars that's happening to.
I'd display it.  It gives it the gravitas of age...

If you put it in the stripping tank (brake fluid in this case) and then pull it out prematurely, wash it off and then hit it with satin clear you could get something like this.


Always make the most out of a build stuff up I say.
This one in particular had to be saved as it was one of my "ashtray" builds.

[PR19_Kit]

Looks like Acrylic clear over enamel paint to me.

I'm afraid not.

Both Halfords Appliance White and Klear are acrylics, and the same technique has worked perfectly on many of my airliners before.

[jcf]

The Halfords spray is an acrylic resin lacquer dissolved in hydrocarbon solvents, the Klear/Future is an
acrylic resin suspension in glycol/alcohol/water etc. The two are very different.

Acrylic refers to the chemistry of the resin used in the paint, it has nothing to do with how it is thinned.

[PR19_Kit]

The Halfords spray is an acrylic resin lacquer dissolved in hydrocarbon solvents, the Klear/Future is an
acrylic resin suspension in glycol/alcohol/water etc. The two are very different.

Acrylic refers to the chemistry of the resin used in the paint, it has nothing to do with how it is thinned.

Yeah, yeah.....

But the point is I've used the SAME paint/varnish mix COUNTLESS times before and since and it works perfectly, as it has for many other modellers.

So why did it go wrong this one single time?

[Go4fun]

The Halfords spray is an acrylic resin lacquer dissolved in hydrocarbon solvents, the Klear/Future is an
acrylic resin suspension in glycol/alcohol/water etc. The two are very different.

Acrylic refers to the chemistry of the resin used in the paint, it has nothing to do with how it is thinned.

Yeah, yeah.....

But the point is I've used the SAME paint/varnish mix COUNTLESS times before and since and it works perfectly, as it has for many other modellers.

So why did it go wrong this one single time?

It could be as simple as different humidity conditions.

[jcf]

As Go4 states it could be a matter of humidity; the Halfords wasn't as cured as it seemed; the
Klear cured too quickly, etc., etc.

Also were the Halfords and the Klear from batches of the same age as the times it worked well?

The formulas of a lot of paints, and 'floor finishes', have been tweaked in the last decade to
meet various requirements.

[PR19_Kit]

The humidity could have been the issue, although it doesn't vary all that much in these parts.

The Klear I use is all from the original formulation and I have four bottles of it in store as the newer version is rubbish for our purposes. I've built other models with the same rattle can of Halfords and the same Klear bottle and they're still OK.

It was so long ago I built it, March-April 2009, that I can't remember the weather then, but it may have been the humidity.

[major]

Humidity, different curing rates, contamination, expansion and contraction of the styrene, can all contribute!
Have had similar experiences when painting plastics and metal parts on various motorcycles. Using the same paints, on different parts, some would develop that 'crazy paving'. 
Only way to fix it, i'm sorry to say, is to strip it back.  

[Captain Canada]

That sucks ! No idea what causes it, but the aforementioned reasons sound about right. My only advice would be to try different primers or primer/ paint combos.

[zenrat]

As there appears to be a darker shade showing through the cracks it may be that the issue is not the white but what lies beneath?