White acrylic paint

port perran · January 10, 2020, 05:19:35 PM

So......I'm sure someone will know the answer to this.

Why does white acrylic paint take about three times longer to dry than other colours?

Has anyone else noticed this?

Just something that's been bugging me as I'm an impatient sort who has painted a lot of plasticard white lately.

dannyboy · January 10, 2020, 05:31:16 PM

I cheat and buy white Plasticard.

Seriously, I can not say I have noticed Martin - the last thing I painted with white acrylic was err.............white card. Which begs the question, why paint white card? (I can not remember why I thought it necessary at the time).

zwilnik · January 10, 2020, 06:37:37 PM

Are you painting over primer? That might help. Also it may depend on just how thick you're painting it on. If you're spraying it evenly and light with an airbrush over primer, it should dry pretty quickly.

Train Waiting · January 10, 2020, 06:55:37 PM

Very interesting. Paint characteristics varying with colour.

I struggle with acrylics unless for scenic work and the like. With enamels, I'm finding I now get on better in general with Revell than I do with Humbrol. Unless Martin had posted this, I would have been too embarrassed to admit that I find success varies according to colour. Maybe this is related to the surfaces I'm painting or the batch the tin came from.

What I do know is that I'm very happy using Humbrol 84 and Revell 37. And wary of Humbrol 25 and Revell 57. All these are new tins purchased from the same shop.

As an experiment, I dug deep in the garage where the paints I used in my 'P4' days had been abandoned. Some are dead but others are still useable and are very good indeed - 1990s Humbrol! Back then I had no problems painting wagons and almost always used Humbrol.

Finally, I have noticed that different colours from the same manufacturer can have a distinctly different smell. At least to me.

I do so hope an expert will come along and explain all this.

Best wishes.

John

port perran · January 10, 2020, 07:23:17 PM

Quote from: zwilnik on January 10, 2020, 06:37:37 PM
Are you painting over primer? That might help. Also it may depend on just how thick you're painting it on. If you're spraying it evenly and light with an airbrush over primer, it should dry pretty quickly.

It's just brush painted. Sometimes over primer, sometimes straight onto the plastic. It makes no difference. White takes considerably longer to dry.
It's not an important issue at all just an observation really.

John - I haven't had a good sniff at the different colours. Interesting stuff.
And yes, acrylics aren't ideal on plastics but I have found, and that's why I'm using a lot of white, that white gives a distinctly (to me) "whitewashed" effect, which is what I set out to achieve, when painted on with two coats.
All good fun.
Martin

Newportnobby · January 10, 2020, 08:04:13 PM

Slightly off topic but this brings to mind my history in rotogravure, flexographic and offset gravure printing where we used mainly Fishburns, Coates and Croda inks. These tended to have different drying characteristics and many's the time a job was only 4 colours but was sent through 6 printing stations purely to add the extra drying needed before the substrate was coiled.

weave · January 10, 2020, 08:56:46 PM

Hi Martin,

Sorry I don't know the answer but just wanted to share your pain. I hate white. Everything should be painted black. It dries in about a minute and looks great.

When it comes to ships I wish Sealink had gone for a Pirates of the Caribbean 'Black Pearl' livery

.

Even other colours aren't too bad. Spraying or painting white, all I can say is

.

Luckily my Spanish walls and buildings aren't predominantly white too.......

.

I've calmed down now

.

Good point. Thanks for sharing.

Cheers weave

swisstrains · January 10, 2020, 08:58:00 PM

Curiosity got the better of me so I had to try it.

Vallejo Flat White v Vallejo Flat Red on Plasticard. Both equally touch dry in less than 10 minutes.
Tamiya Flat White v Tamiya Flat Orange on Plasticard. Both equally touch dry in just over 10 minutes.

stevewalker · January 10, 2020, 10:41:43 PM

Quote from: Newportnobby on January 10, 2020, 08:04:13 PM
Slightly off topic but this brings to mind my history in rotogravure, flexographic and offset gravure printing where we used mainly Fishburns, Coates and Croda inks. These tended to have different drying characteristics and many's the time a job was only 4 colours but was sent through 6 printing stations purely to add the extra drying needed before the substrate was coiled.

From 1998 to 2001 I worked for Operational UK and we were designing, installing, maintaining and calibrating VOC reduction equipment for Flexographic and Rotogravure units. I spent much of my life during that time away from home, visiting sites all over the country - mainly Lawson Mardon Packaging and Flexibles and Colodense, but various others too. Amazing to see. I remember going to LMPF Workington to diagnose and rectify a fault and needed the machine stopped while I calibrated a replacement sensor. They were printing Italian Kit-Kat wrappers, complete with a release layer and Coldseal on the last two stations, on a web 1.2m wide at 150m a minute (IIRC) and they weren't properly stopping for another 3-1/2 days! I managed to fit the sensor while they were running and calibrate it during a 10 minute stop for a blade change (at about 4:30am).

emjaybee · January 10, 2020, 11:11:39 PM

I'll apologise for being a little off topic, but it has some relevance.

Henry Ford offered his Model T Ford's in "any colour you like, as long as it's black".

The reason for the colour choice was simple.

Black was the only paint colour that dried fast enough to keep up with the pace of the production line.

weave · January 10, 2020, 11:56:48 PM

This will teach me to check my spelling before Googling potential answers after a few drinks, although you never know, might come in useful

.....

https://www.wikihow.com/Dry-Pants-Fast

Cheers weave

Bealman · January 11, 2020, 12:32:18 AM

TrevL · January 11, 2020, 06:03:05 AM

Quote from: weave on January 10, 2020, 11:56:48 PM
This will teach me to check my spelling before Googling potential answers after a few drinks, although you never know, might come in useful .....

https://www.wikihow.com/Dry-Pants-Fast

Cheers weave

It wasn't gin by any chance??

chrism · January 11, 2020, 06:43:48 AM

Quote from: emjaybee on January 10, 2020, 11:11:39 PM
I'll apologise for being a little off topic, but it has some relevance.

Henry Ford offered his Model T Ford's in "any colour you like, as long as it's black".

The reason for the colour choice was simple.

Black was the only paint colour that dried fast enough to keep up with the pace of the production line.

Interestingly until five years after Henry made that statement, they weren't available in black at all, only grey, green, blue or red. It wasn't until 1914 that they switched to black only.

To move back more on topic for the forums, the standard wheel track width was 56" which enabled them to be fitted with flanged wheels to run on standard gauge railway tracks. Models with a 60" track were available as a special order to allow the same to be done for use on the remaining pre-Civil War Southern railways, which were 5' gauge.