Humbrol (and other brands) - do they fade in sunlight?

[TallBlondJohn]

No I'm not starting the pre-shaded debate again. I've moved a display case into a bay window - but is it safe to put models in it? I don't think they will deform in strong sunlight - I'm in Scotland - but will the paint fade over a period of years? Most of them are Humbrol painted, but there are a few Xtracyclics and Tamiya

 

Thanks

[Sierra Mike Sierra]

23 minutes ago, TallBlondJohn said:

will the paint fade over a period of years

I have asked myself the same question...

 

I don't have a representative contribution, but I have a very old Hasegawa F-4E built in the late 1980ies painted (airbrushed) with Humbrol Enamels in the Euro 1 camo scheme and it was sitting on a rack close to the window and was exposed to sunlight from midday to evening every day (if there was sun 😄) and I cannot observe any fading.

 

The white colour of another A-7A sitting next to it (for y couple of years less) has turned into smething creamy-white i.e. the bright white has become a bit yellowish. I am not sure though, what brand I had used for the the white, either Revell or Testors...

Edited September 3, 2022 by Sierra Mike Sierra

[Casey]

Lightfastness is one of main property of the pigments (usually in form of ASTM rating). Humbrol does not provide this information public, this is more common in artists world when you need to know what paint or pigment are better to use outside.

 

You can try to do educated guess based on pigments that should be used in the given paint but it is bit of a guesswork.

 

Nonetheless - direct sun exposure is usually a bad idea even for most lightfast pigments. You can try to minimize the effect of exposure by using UV protection varnish on your model. Glass is (usually) almost opaque to UVB but UVA still can get through.

 

If you are applying gloss/satin/matte coats over your model, check your product - it may already have UV protection, for example W&N varnishes do.

Edited September 4, 2022 by Casey

[TallBlondJohn]

Hmmm - I use future, which the manufacturer says "doesn't yellow" but that doesn't mean its UV resistant

[Paul Thompson]

I also live in Scotland, and believe me the sun can and will do nasties if going through both a window and a cabinet glass panel. Resin models I keep in the garage now (no windows) having had parts warp while sitting on the modelling desk in full sunlight for 20 minutes, but depending on the nature of the plastic they're also affected to a lesser extent. Also the joints can go due to differential heating of plastic, glue and filler. I've not noticed fading of the paintwork so much, but would expect it eventually.

 

As for yellowing, that can happen without the aid of sunlight, and is varnish brand dependant. I have 55 year old models that were finished with Humbrol varnish, and they've spent most of their lives in boxes. All have gone very yellow, the worst offenders being those done with Humbrol gloss varnish. Doesn't mean it will still be a problem though, because those varnishes have been reformulated over the decades more than once.............

 

Paul.

[Black Knight]

I used to cast car club badges for my vintage car club members. These were made in white-metal, i.e. a lead/tin alloy.

On these, as well as on other copies of the badges previously made in brass, I used Humbrol enamels to paint in the details. I used Humbrol numbers, 2. 3, 14, 15, 11, 16, 21, 22. I never used a primer or undercoat, just a few coats of the Humbrol gloss paint

These badges were about a 5 inch circle on a 2 inch long and wide mounting lug. They were attached, usually, to a badge bar across the front of the car. They were mounted and forgotten about. For a few years, at every car club event, I used to check every badge I'd made and/or painted to see how they were holding up. After a awhile I stopped checking. Other than the occasional very small chip in the paint, there was no flaking off, no change in colour at all

Our car club cars are not 'show cars' No spit and polish, but the cars are used for racing, hill climbs, trials, long and short distance rallies (short is about 100 mile, longest is about 15,000 miles), in all and every type of weather that can be thrown at us, from the freezing ice of Patagonia Andes mountains to the hot & dry plains of Mongolia and the warm rain of Ireland

The Humbrol enamels on the badges have survived it all with no change in colour after more than 15 years in some cases

[Pete Robin]

In "older" times when Humbrol, was really Humbrol, EVERY colour, gloss and matt, were painted out onto a very large metal plate. These plates were then placed on the roof of the laboratory facing the direction of most sunlight (south I reckon), and then left for very many months (sometimes years).

They were checked very regularly by spectrometers to make sure they didn't fade.

One would hope (not presume, cos I know where that leads), that the same thing is done with the new manufacturer?

However, as they have continually failed to keep to the correct formulations and consistency over the years, who knows.

Sorry. Just my threepence worth.

Regards

Pete

 

[Jamie @ Sovereign Hobbies]

24 minutes ago, Pete Robin said:

In "older" times when Humbrol, was really Humbrol, EVERY colour, gloss and matt, were painted out onto a very large metal plate. These plates were then placed on the roof of the laboratory facing the direction of most sunlight (south I reckon), and then left for very many months (sometimes years).

They were checked very regularly by spectrometers to make sure they didn't fade.

One would hope (not presume, cos I know where that leads), that the same thing is done with the new manufacturer?

However, as they have continually failed to keep to the correct formulations and consistency over the years, who knows.

Sorry. Just my threepence worth.

Regards

Pete

 

 

I'm pretty confident nobody does that any more, not least because it would imply an absolute minimum gestation period of many months if not years before a product could be released for sale in which time the commercial supplier of the pigment tints could have changed some aspect of their product invalidating the whole experiment.

 

It's also not really perceived as a concern by the vast majority of the market. Virtually the only topical complaint one does see is that of yellowing whites and clearcoats, which as you will know tends to be the binder aging.

[Black Knight]

On car paints they do rapid simulated tests

Samples of paints are put under strong UV lights for days. Dusty air is blasted over panels of the paints. Drops of ammonia are sprayed on and washed off, day after day. And many more tests.

ICI used to have a paint test facility in Co, Antrim

[Casey]

5 hours ago, Jamie @ Sovereign Hobbies said:

I'm pretty confident nobody does that any more

Golden Acrylics still does that - https://justpaint.org/lightfastness-testing-at-golden-artist-colors/

Edited September 13, 2022 by Casey

[Pete Robin]

10 hours ago, Jamie @ Sovereign Hobbies said:

 

I'm pretty confident nobody does that any more, not least because it would imply an absolute minimum gestation period of many months if not years before a product could be released for sale in which time the commercial supplier of the pigment tints could have changed some aspect of their product invalidating the whole experiment.

 

It's also not really perceived as a concern by the vast majority of the market. Virtually the only topical complaint one does see is that of yellowing whites and clearcoats, which as you will know tends to be the binder aging.

Hey Jamie, quite understand why no one would want to carry out these long term tests. I think that at Humbrol, they did the severe testing because in the beginning their paint wasn't just aimed at modellers. It was intended for use in every type of craft/hobby. They even marketed a lot of the gloss colours in fairly large tins. The advent of the Authentic Colours range changed their direction considerably, and I guess, led to today's huge choice, not only in colours available, but also in type of paint.

The yellowing was, and I guess still is to some extent, a massive problem. I can remember being given the first lot of varnishes to test "on the bench". Oh dear Lord they were bad. It was like using brown glue and it didn't really thin very well. It got better, but I am positive that even after many iterations and tinkering, there are much better and friendlier products out there. What the future will bring is fascinating.

I am happy that there are now many brands and new techniques etc as it's led to the extremely high standards we see in our hobby nowadays. 

Regards,

Pete

 

[Jamie @ Sovereign Hobbies]

Apologies I should have been more specific!   I meant paints aimed at modellers in particular. Artists' products are a whole different ballgame since there is no research element to it, only the long term stability of the wide range of generic colours since art is expected (hoped?) to endure for hundreds of years. I expect it's still done in the automotive world too before publishing the colour brochure for new cars under development (but definitely not for repair work which will usually use different brands of paint products to the original manufacturer for obvious reasons). For paints aimed at modellers, the MO is to limit production to a small number of pigments known to behave themselves well longer term (hence why I'm unable to make a specific RN colour as discussed in the Maritime section on a thread the other day which absolutely needs a certain pigment) and the focus goes into the as-new colour. I do think there's good merit to UV protective clear coats though. I'm not sure that lightfastness testing would change a model paint brand's perceived ranking amongst its competition whereby for most serious modellers they're judged on how much thinning range they have, how smoothly they lay down and how quickly they flash off after delivery from an airbrush at low pressure and close range. If they do that well, they'll sell and be popular with modellers.

[Bertie McBoatface]

Slightly off topic but UV radiation can craze and fog some clear plastics. Actually I think I degrades opaque plastics too but more slowly and without visible symptoms. 
 

I wonder what it does to CA glue and resins over time?

[Black Knight]

On 04/09/2022 at 10:50, Black Knight said:

I used to cast car club badges for my vintage car club members. These were made in white-metal, i.e. a lead/tin alloy.

On these, as well as on other copies of the badges previously made in brass, I used Humbrol enamels to paint in the details. I used Humbrol numbers, 2. 3, 14, 15, 11, 16, 21, 22. I never used a primer or undercoat, just a few coats of the Humbrol gloss paint

. . . 

Just a wee up-date;

Last Saturday my car club had it autumn rally

I looked for club badges I had made and painted. I found only one

The Humbrol enamels on it have dulled, i.e. they are no longer glossy, the colour has faded a bit but its still the same colour. That badge was made and painted about 2007

Of the repainted brass badges I could not discern which were mine or were the very original badges, all the colours looked good

[treker_ed]

I assume that they are stuck to the cars? Therefore would any dulling be down to the fact that they are exposed to outside factors (wind, rain, sun etc) rather than what the OP was initially asking about? I have about 30 or so lots placed on a case which is in direct sunlight on a small landing. All painted with acrylics, but then coated with various varnishes, future, tamiya x22, xf86 (flat varnish) x35, (satin), xtracrylic varnish, Vallejo, and a few Humbrol Clear. None of them have faded (yet!!) having been placed there, and they have been there for about 3 years.