Varnish issue

[Hailshamlad]

Having painted and applied decals to my kit, I proceeded to apply varnish to finish off.

This is a repeated process I have used on many many of my kit building.

I use Humbrol Acrylic and gloss paints, as normal. The varnish is a regular home ware gloss clear type.

Immediately the Acrylic bubbled and crazed, but only on some areas, it did not do the same on the gloss or affect the decals.

I have never had this happen and as I say, I have used the same paints and varnish process many times before without issue. I did leave at least two to three days before reaching this point.

My question for input, is there a specific varnish that should be used or are all equal?

Given that specific model paints are now so difficult to get in shops and model shops are disappearing fast.

 

 

[peebeep]

It's very difficult to specifically say what caused the problem, possibly the varnish you're using has a hot solvent base that reacted with the acrylic. 'Varnish' actually covers lots of different media, it could be acrylic, enamel, polyurethane, lacquer etc etc. It's very frustrating when tried and tested materials lead to a problem, it could be there was some specific circumstance that led to it.

[Kenneth ONeill]

This is why I normally use water-based acrylic varnishes (eg Humbrol, Games Workshop); they don't tend to react with pretty much anything!

[Hailshamlad]

I have to say that I was most surprised with this issue, as I have used the same varnish many times before.

But having said that, my previous varnish was water based and this one is most definitely not.

I did wonder if the advice is to go back to the previous varnish.

 

[Commander Vimes]

Sorry to dig up an old thread but I have just had the exact same problem. The model had been painted with Humbrol enamels then over coated with Johnsons Klear. After leaving it for a few days I have just varnished it with Humbrol acyclic matt varnish from a rattle can.

The paint job is now ruined as the paint in large areas has bubbled and crazed. This has never happened before and I have used this method for years with no problems and preferer to use acrylic varnish as it usually performs better than enamel.

[Commander Vimes]

I do know not to put acrylic over enamel which was why I Klear coated it to provide a barrier. I have just done a second model, this time with satin, and had exactly the same problem. As I said never had this problem before using this method, and now twice on the same day with two different cans and finishes of varnish I've had the same problem. I'm beginning to wonder if its a problem with the product. Repainting is going to be a difficult if not imposable as both models are basically finished with decals and the varnish coat was almost the last thing to be done bar fitting the odd detail. Most frustrating after weeks of work.

[Ratch]

As Peebeeb says above, the problem is probably linked to some kind of hot solvent in the aerosol. I had this problem years ago and quickly switched to airbrushing. I've not had a problem since.

[peebeep]

As Peebeep says above, the problem is probably linked to some kind of hot solvent in the aerosol.

 

 

Reactions with Klear are so uncommon I'd say it's 99.999% certain that solvent in the aerosol is causing the problem. If it's not evaporated before it hits the surface then the chances of a reaction are increased.

[Mark Fussey]

Can any party recommend an alternative acrylic based varnish to klear that can be sourced at the supermarket as I cannot locate this product I am aware the Mfr changed its name but again cannot find

Can an own label be used if so what would suggest or should I stick with Humbrol and similar Mfr's