slow drying time - Humbrol enamel

[Mark Pearse]

Hi everyone

 

I did a first top coat in a mixture of Humbrol gloss enamel colours (3 tins, 2 of one colour, one of another), didn't add any thinners or anything else; it was done over a thin coat of Zinser oil based undercoat that had been well sanded & was well dry.

 

The Humbrol took ages to dry - almost a week so far, it's still not dry enough to sand but it is close. It was very nice paint to use & the finish is good, despite the gradual accretion of dust over the week....

 

My 'workshop' is a cool garage, not really damp & not really cold, maybe 17 degrees C & things don't go mouldy there.

 

 

Anyone comments? My thoughts are that I just need to do the next coats in a warmer location, but I am surprised that it took so long. 

 

thanks in advance, MP

[mtaylor]

Mark, 

 

The temperature may very well be a factor.   Can you put in the house or somewhere warmer?

[Jack12477]

My son is a professional painter (fine art and houses) and says paint generally will not dry/cure properly at or below 40 F but your 17 C is about 63 F so almost room temperature (68 F ) - maybe the humidity is too high.

[druxey]

Generally, Humbrol should be dry in hours, not weeks! It may be a combination of both factors mentioned, both temperature and humidity. 

[Mark Pearse]

thanks, I'll give the model an upgrade to residential class & see how we go....

[komdgurhan]

1. Stir the media well before use.

2. Thin with cellulosic thinner.

3. Apply multiple thin coats till achieving the desired result ( with airbrush if available )and give some flush off time between coats.

4. Let it dry at least 48 hours in a dustless and warm condition.

5. Try not to use gloss paints ..... make it shiny with gloss clear coats at the end .

Edited March 23, 2016 by komdgurhan

[kurtvd19]

The guys in my local IPMS club who use enamels wait 2 - 3 weeks before doing the sanding / polishing of their paint jobs.  Dry to the touch does not mean fully cured.  Another reason I use acrylics.

Kurt

[Telp]

Although many people use enamel paints due to their consistency you can get as good a finish using acrylics and if you can spray the acrylics then more the better. I have painted aircraft (not models) in acrylics and the finish when built up gently can be superb. When painting anything always put some of the paint you are going to use on a spare piece so that you can monitor the drying ect outside of the main work. Although you say tthe finish was applied to a fully dried surface you have to remember that deep within the paint it may still not be fully cured, many paints can still react with an undercoat and if that undercoat is not fully dry any rubbing down can force it to re react itself.

 

Even a simple thing like stirring can be a big issue, never stir paint round and round, always stir it round and upwards to bring the pigments all together and always turn your paint tins over at least once a week to prevent them forming too much oil as this never gets stirred in correctly when people give the paint a quick stir. One other thing, if you store paints in rooms with low temperatures you will after a while kill the pigments, I always keep mine in a little box in a room somewhere. Hope it all sorts, if not, try rubbing the finish with a gentle green dish scour pad, that will help it dry some and get some air into it although you may need to overcoat with a thin finish.