Help! Varnish nightmares!

[VengeanceisMine]

Hi!,


I've just joined the site today but could really do with some advice. I've returned to the hobby after a nearly 20 year abscence. I have been remaking the kits of my youth (Airfix) and have been amazed at the range and quality of products on the market. I'm using an airbrush and have got the knack of using it with acrylic paints (Tamiya). My problem is that all my hard work and effort is being ruined by the varnishing stage! I've tried Humbrol spray acrylic gloss and Vallajeo Gloss and have had mixed results with both. Humbrol seems to give inconsistent results and the Vallajeo which I diluted with demin water left a horrible bluish sheen! ( I sprayed at 18 psi).


Any advice?


Second and just as frustrating is using acrylic metalcote with a superb finish, but when I varnish it just kills it and leaves streaks everywhere?


finally, can the oil in fingerprints be causing this?


Any advice would be really well received.

 

[dubster72]

If you're using the Humbrol from a rattle can, I'd suggest it's not been mixed sufficiently - standing them in a bowl of hot (not boiling) water prior to shaking helps.


Although I don't use Vallejo products (devils spawn!) I think using their thinner rather than water would provide a more consistent finish.


Don't use a gloss on metallic paint! It's really not necessary IMHO - the paint is sufficiently robust as is. The exception to that is Plastikote, but I'd steer clear of them anyway!


The best gloss coat I've used thus far is Humbrol Clear shot through my airbrush.


Hopefully this helps


Cheers


Patrick

 

[Deleted member 3568]

Steer well clear of humbrol matt varnish, if you do use it warm it up in a cup of warm water, and stir it all the time, or you will end up with white streaks all over the place. Oh and welcome to the friendliest forum on the net.

 

[Bari]

This is another option. http://www.scale-models.co.uk/threads/experiment-with-nissan-clearcoat-now-coated-and-polished.26782/#post-202855


I think that any clearcoat spray from your local car parts place would work (don't get the two part ones as the paint in the can goes solid after 12 hours). Of course try it on a test piece first. Or try Klear as it goes on very thin and you can build up the coats to get the shine you want as shown below.View attachment 115026

 

[tanktrack]

i use Vallejo matt varnish on all my models ie armour I use only their thinner and a few drops of flow assistor and have no problems ,as kpnuts states stay away from humbrol varnish I too have had problems with it and don't like it but this is my personal experience , if I was me I would get a few types and experiment to get 1 YOU like before touching a finished model .

 

[Airfix Modeller Freak]

A tip from me-NEVER USE ENAMEL PAINTS AND THEN USE AN ACRYLIC VARNISH AND VICE VERSA


It will ruin your model, so be careful when you start experimenting


John

 

[dubster72]

Just a point chaps - the OP is asking about gloss varnish, not matt! Also Humbrol Matt Coat is excellent!

 

[dubster72]

A tip from me-NEVER USE ENAMEL PAINTS AND THEN USE AN ACRYLIC VARNISH AND VICE VERSA
It will ruin your model, so be careful when you start experimenting


John

I must disagree most strongly there John! As an avowed enamel user, I've never, ever had a problem with using acrylic varnishes (gloss or matt) over my paint.

 

[Airfix Modeller Freak]

I must disagree most strongly there John! As an avowed enamel user, I've never, ever had a problem with using acrylic varnishes (gloss or matt) over my paint.

Oh dear. I have had this before....


I did a Dragon bf 110 in 1/32 and I sprayed enamel over acrylic, and it crackled, dried and gave a patchy finish. Definitely not great.


John

 

[rickoshea52]

I've had similar experiences to you with the two products you mention but also with Humbrol Clear. I am going back to Railmatch varnishes for my next build, never had a problem with their gloss enamel.

 

[Snowman]

I had issues with the Humbrol rattle can gloss acrylic over the same brand rattle gloss paint - started to pit all over when spraying my Ducati 900SS!:eek::mad:


For the Ducati NCR I used Alclad Aqua Gloss Clear.


For the rest of my work I've been using Vallejo gloss,matt & semi-gloss.

 

[dubster72]

Oh dear. I have had this before....
I did a Dragon bf 110 in 1/32 and I sprayed enamel over acrylic, and it crackled, dried and gave a patchy finish. Definitely not great.


John

So does one bad experience mean the practice is verboten? Surely not!

 

[dave]

I have never had a problem with acrylic varnishes on enamels and vice versa, particularly figures may have a mixture of the two paint types on them.


Humbrol Clear is brilliant for a gloss varnish, for Matt varnishes I tend to use Vallejo or Tamiya from a rattle can.

 

[VengeanceisMine]

Thank you one and all for all the advice. So if I am using a metalic acrylic paint but want to add panel lines, surely it needs a gloss varnish? But I am going to try other products on spare parts before I ruin another kit.

 

[Ian M]

I use the Vallejo products with no real issues. I do however use the correct thinners. Note that the gloss does have a blue/violet hue when you put it down, this is to aid seeing where you have been. It should clear as it dries.


I would also say that if in doubt test it out before covering you model with anything be it paint or varnish.


A common issue with varnishes ruining a paint job is simple. Paint dries, so you can touch it. Before you do anything at all over it it will need to cure. If you varnish over paint be it enamel over acrylic or the other way around, the base coat really needs to be fully cured before the next coat goes over. Failing to do this will lock any vapours in the first coat in and as they try to escape, they will bugger the varnish/clear coat.


There are exceptions to the rule but this is the rule I follow and have, as I said never had a problem.


Its a bit like woodwork. Varnish a bit of wood that is not 100% dry and the water vapour will cloud the bottom of the varnish as it tries to escape.


Ian M

 

[dougie]

Gloss is used on normal metallic paints like your car would have. Some metal look/finish paints ( different from normal metallic paints) don't get a gloss and if they do there is usually a specific one like the alclad aqua gloss or klear (can't remember it's exact name)

 

[Airfix Modeller Freak]

So does one bad experience mean the practice is verboten? Surely not!

I tend to shy away from bad experiences and their variables. I am happy to say it has never reoccurred since I started using lacquers and acrylics.


John