Humbrol Gloss+Purity Seal=cracked surface?

[Remington]

Dear LAFers,

a few months ago, I decided to include a layer of Purity Seal after gloss varnishing a miniature with Humbrol No. 35 as a first dulling-down layer. About 2 months ago that worked a treat. Lately I have been having a problem though with the surface of the miniature getting a certain cracked look to it... like the floor of a desert... and it happens rather quickly after being sprayed. I apply the Humbrol at least 24-36 hours before the Purity Seal comes into play and yet I still get that effect. I bought both Humbrol and Purity Seal again this week and I still get the same problem. Does anyone know where that is coming from? I can't think that it can be the weather conditions because I have a thermometer and hygrometer and I've had the same problem with 12 Celsius and 35% humidity as well as 19 Celsius and 50%.

It's as if the techniques I was using two months ago now all of sudden don't work any more. Any help is greatly appreciated.

[redzed]

old varnish.
chuck 'em out and start again.

[Remington]

Well, as I mentioned, I just re-bought both varnishes this week...

[redzed]

bought new, but were they new stock?
I avoid GW varnish like the plague.

[Remington]

Well, as new as they can be... I know the guys and asked them when they got them from England. And it was the GW Store here...

Could it be that the gloss varnish hasn't cured yet?

I seriously seriously hate varnish with a passion lately! Aaaargh!

[Orctrader]

Don't know the reason, though Zed is probably spot on.  You could buy something "new" today that was actually manufactured Heaven knows how long ago.

Hardly ever use spray varnish.  If I do I only use Testors.

If you want to "experiment" use the Humbrol on a figure then something other than the GW spray.  (Though with the time you've lost already, when not just use brush-on matt varnish over the Humbrol gloss?  That's what I do.)

[Remington]

Hey OT, thank you for the reply.

Well, you know I am also using the same Matt Varnish you are using, but in the case of the miniatures at hand, I wanted something flashier to the slightly grey-ish milky look of the D-R Soluble Matt Varnish, because the miniatures have dark skin. One miniature I managed to get right with the Purity Seal looks great in that more satin look, but I have no idea what I did differently, because a miniature varnished at the same time, was ruined.

I really need to call the GW store I bought the spray from on Monday. Maybe it is old after all.

I have to add, I am getting really frustrated here. Two weeks I am dealing with this. I am close to kicking everything in a corner....

I did it! I solved the problem... I, the idiot that I am, was too close to the miniature. I was using a different varnish some weeks ago that needed a shorter distance and forgot to change that. It's crazy that 5 cm can make such a difference!!!

[sgw74]

Your problem might be that Humbrol is an enamel paint and you are trying to gloss it with an acrylic varnish (I'm not sure if the GW spray varnish is acrylic, but it is a possibility).  As an ex-employee of a hobby store, I would see this from time to time and fell victim to it too (tamiya acrylic spray paint with a laquer varnish is a bad idea too, it creates a cracked pattern as well). 

Also speaking as an old hobby store employee, paints can sit on shelves for years before they are sold (especially odd colours like burgondy) and since humbrol has been around since the dawn of time...  there is a chance you got a bad batch.

[Remington]

Hey, sgw74. Thank you so much for the insights. What Kind of gloss would you recommend that is acrylic in nature? I have no idea though what the GW varnish ist. It doesn't say on the can. Their site seems to suggest it's either an acrylic or a polyurethane varnish.

 Interestingly enough though, yesterday I tried 'ardcote, the german equivalent of Klear and Vallejo gloss and they all had the same problem. That made me think that the culprit was the purity seal or the way I am handling it.

Also... Have you ever come across a situation where the distance produced such a problem?

PS: I will ask my dealer when he got his Humbrol. Maybe he'll know and be honest about it.

[Silent Invader]

Your problem might be that Humbrol is an enamel paint and you are trying to gloss it with an acrylic varnish (I'm not sure if the GW spray varnish is acrylic, but it is a possibility).  

This seems most likely to me, to.

The effect is called crazing and there's a bit about it here:

http://www.napaint.com/paint.finish.quality.htm

I use brush on gloss and matt by Revell.

Good luck! 

[Remington]

Very interesting, SI. Does the Revell Matt offer a similar Satin-ish feel like the Purity Seal? And surely, I can't be the only person using Purity Seal over Humbrol? I've read about people doing it so often... And how does the distance of spraying change the core problem of acrylic and enamel not mixing well together?

I am awfully sorry about all those questions... I just hope to understand this secret of the holy varnish.

[Silent Invader]

Am afraid I have no about Purity Seal as I've only ever used the Revell products.

The Revell matt does dry matt but if applied to excess it can develop a faintly milky finish.

I'm wondering if it is curing time rather than spray distance that is affecting your results.  The solvents etc in the enamel gloss coat will, if not fully evaporated, surely affect adhesion of the acrylic top coat? 

[Remington]

That definitely was my first suspicion, but 36 hours has always been enough before. I guess it will remain a mystery. I just hope that my solution by changing the distance will remain reliable.

[Plynkes]

In my experience, "Reliable" is a word that has no place in any discussion about spray varnishing. 

[Remington]

In my experience, "Reliable" is a word that has no place in any discussion about spray varnishing. 

Damn your true words! I think I'll start varnishing my miniatures with cement. I know you told me at the Tactica by the way, but what do you use again?