Pre-Thinning enamels in bulk: Having problems.

[Humbug]

Hi guys.

This is the first time I've joined a modeling forum and I am finding myself getting back into modeling after 8 years or so. I'm now upgraded from a single stage to a dual stage air brush so I can do detail work. I wish to use the air brush as my primary tool for painting. This is why I am trying to thin all of my paints in bulk. To be honest I hate doing the prep-work. It takes time away from the hobby in my opinion.

So specifically I am having problems with Humbrol brand paints. Some are which are more than 15 years old and others are brand new. My problems don't seem to be related to its age. I actually wrote an email to Humbrol asking for advice so I will just copy + paste to here. I think perhaps that they will not give me advice unless they can sell me a Humbrol product that would address my issue directly. I wouldn't imagine them wanting to advertise their competitors products. Anyway, here is my email:

Dear Humbrol.

I am trying to pre-thin my Humbrol paints for air brush use. I am currently am having problems with the pigment falling out of suspension very quickly and skinning. I.E. cured clumps or shards forming at the base. I currently have mixed all my colours with at least 2x~3x volume of Humbrol brand thinner. About half of my colours are brand new and some are very old, more than 10 years. My containers are sealed glass jars approx 80ml. about 80 percent fall out of suspension after a few hours and 10% settle after just a few minutes. I have found other brands like Tamiya take a very long time to settle and some don't at all. I have also found that nail polish with Tamiya lacquer thinner does not settle at all. I am having the exact same problems with my old Testors paints also. Even though they form hard clumps, they also take extremely long time to cure. My last model was coated with Tamiya white primer and Tamiya black enamel and was touch dry in an hour or so. The second coat was Humbrol gloss black (because I ran out of Tamiya) But it took a week to become touch dry and three weeks to cure or stop being tacky and smelly.

I have no idea between the chemistry differences between the brands but trying different brands of thinner hasn't helped. My guess is that there is a problem with the binder, emulsifier or anti skinning agents if there are any such additives. My question is: are there any additives that I can buy to amend the problems I am having? I wish to only paint via airbrush and I so I want to thin my paint in bulk. Any advice would be much appreciated.

Bust regards,

Brendan.

I hope some one in the modeling community will have some advice they can give me.

Thanks in advance.

Brendan

 

[tecdes]

If this was me I would sling all the old stuff away. Not worth all the problems of blocked airbrushes & spurting bits on the model.

The Humbrol pots are so cheap & on average you only need 4 or 5 for a model.

If you are getting separation of the pigments bits & skinning then they are for all intents & purposes finished.

I would not thin until I knew what I was airbrushing. Some times you may want a thinner paint for a particular item or a thicker one for others.

Laurie

 

[stona]

First I have to say that I've been using enamel paints by various manufacturers for more years than a gentleman would reveal and have never found the need to pre-thin the paints and store them thinned. I remember some old sage,many years ago,counselling me against storing thinned paints and I've always followed that advice.

Secondly there have been problems with the quality of Humbrol paints since production was moved to the Far East. I have bought a few tinlets which have been unuseable,others are very poor. Humbrol 11 used to be a good metallic silver,now it is just,well,grey. I don't hold out much hope for you receiving a reply from Humbrol.

I don't know what you model but as an aircraft modeller I have found alternatives to Humbrol for most purposes. I now use a lot of White Ensign's Colourcoat range.

Cheers

Steve

 

[rickoshea52]

Like Steve said, why would you want to pre-thin enamel paint in bulk? Enamel paint settles and separates anyway even before thinning is done. As a rule I only thin paint immediatley prior to use.

As also mentioned above, I would also ditch the old paint. I heard that Humbrol have brought paint manufacture back to the UK so hopefully the quality will improve and be more consistent.

 

[Ian M]

Thin them as and when you need them. As Steve wrote some times you will need the paint either thinner or thicker.

Also it happens sometimes that over thinned paint will split, revealing the pigments...can be handy at times, just not when you what to paint something.

Ian M