Can you "un-yellow" yellowed decals

CaptainHawk1 · Post by **CaptainHawk1** » Mon Jan 01, 2007 3:34 pm

I have purchased quite a few kits recently off of ebay that jus tdue to their age have come with decal sets that were yellowed. Most of them, I would just assume order after market decals for anyway, but the Revell/Monogram Voyager SE I would like to salvage.

Is there any way to do this?

-Shawn

tonyG2 · Post by **tonyG2** » Mon Jan 01, 2007 3:37 pm

The best way I have ever tried - or seen recommended - is to place the decal in a clear plastic cover - standard self sealing baggie will be fine - and tape that (decal facing outward) to a window with a reasonable level of sunlight and and wait.

Solar UV will bleach out the yellowing. There will be some bleaching of the decal as well, but the yellowing die to age will go first.

CaptainHawk1 · Post by **CaptainHawk1** » Tue Jan 02, 2007 12:34 am

tonyG2 wrote:The best way I have ever tried - or seen recommended - is to place the decal in a clear plastic cover - standard self sealing baggie will be fine - and tape that (decal facing outward) to a window with a reasonable level of sunlight and and wait.

Solar UV will bleach out the yellowing. There will be some bleaching of the decal as well, but the yellowing die to age will go first.

I live in vegas so the sunlight is not a problem. About how long does this process take?

-Shawn

Digger1 · Post by **Digger1** » Tue Jan 02, 2007 2:03 am

probably best to check it after a couple of hours in bright sunlight just in case it bleaches out too much of the ink.

tonyG2 · Post by **tonyG2** » Tue Jan 02, 2007 6:03 am

I've had it take up to a week. But then I do live in England......

CaptainHawk1 · Post by **CaptainHawk1** » Tue Jan 02, 2007 12:29 pm

Thank you, gentlemen.

-Shawn

Go Flight · Post by **Go Flight** » Tue Jan 02, 2007 2:01 pm

Fixing yellowing decals was brought up before and the decals in a clear, plastic bag was suggested. Someone did this and the decals stuck themselves to the inside of the bag because of humidity. so be careful.

In a recent FSM (the Decal issue) there was an article about this. What the author did was simply tape the decals (with just one piece of tape), decals side facing out to a window, and let it hang in the sun for a few days - no bag. I would check it a few times a day to make sure all's going well.
Also make sure to use the decals promptly for if the carrier yellowed once it will do it again.

CaptainHawk1 · Post by **CaptainHawk1** » Tue Jan 02, 2007 4:43 pm

Go Flight wrote:Fixing yellowing decals was brought up before and the decals in a clear, plastic bag was suggested. Someone did this and the decals stuck themselves to the inside of the bag because of humidity. so be careful.

In a recent FSM (the Decal issue) there was an article about this. What the author did was simply tape the decals (with just one piece of tape), decals side facing out to a window, and let it hang in the sun for a few days - no bag. I would check it a few times a day to make sure all's going well.
Also make sure to use the decals promptly for if the carrier yellowed once it will do it again.

Humidity... no problem, but I was thinking the same thing (why not just tape them to a window w/no bag?). Now, since you brought it up, how long would it take for the yellowing to occur again and how can I stop them from yellowing afterthey are applied?

-Shawn

Go Flight · Post by **Go Flight** » Thu Jan 04, 2007 9:47 am

CaptainHawk1 wrote:
Go Flight wrote:Fixing yellowing decals was brought up before and the decals in a clear, plastic bag was suggested. Someone did this and the decals stuck themselves to the inside of the bag because of humidity. so be careful.

In a recent FSM (the Decal issue) there was an article about this. What the author did was simply tape the decals (with just one piece of tape), decals side facing out to a window, and let it hang in the sun for a few days - no bag. I would check it a few times a day to make sure all's going well.
Also make sure to use the decals promptly for if the carrier yellowed once it will do it again.
Humidity... no problem, but I was thinking the same thing (why not just tape them to a window w/no bag?). Now, since you brought it up, how long would it take for the yellowing to occur again and how can I stop them from yellowing afterthey are applied?

-Shawn

Hey Shawn,
I only mentioned it because thats what the article said - BTW it was the Sept. 2006 issue of FSM if you want to get the back issue.
They wanted to stress the point that once you get it white (or clear) don't leave them lying around for another 10-15years.
Having said that I don't know the answer to your question, but if I had to guess I would say they would stay non-yellow for at least a few years. But if you get them white, use them and seal them onto the model then I would guess that the problem is solved.

MillenniumFalsehood · Post by **MillenniumFalsehood** » Sun Jan 14, 2007 4:10 pm

Whew, glad it's not the same problem as yellowed plastic. On an aside, when I first read the post I thought, "So the yellow contest got to you too, huh?"

Whiteraven_2001 · Post by **Whiteraven_2001** » Tue Feb 06, 2007 8:13 pm

I seem to recall reading somewhere that it was a good idea to trim as much of the "clear" part off a rehabilitated decal as possible, since this is where the yellowing appears/is most visible.

DX-SFX · Post by **DX-SFX** » Wed Feb 07, 2007 9:50 pm

I'm actually experimenting with this as we speak. I've got a couple of old Airfix decal sheets and a couple of old Aurora decal sheets taped to the window in sealed plastic bags. The only problem is that we're in mid winter with little sun but so far it does appear to be working slowly with the odd hour or two we get. So far they've been up there a couple of weeks. I've left one half of one sheet in shadow to act as a control. It might take a couple more weeks at this rate but early signs are promising. Obviously in summer, the bright sunshine will act much quicker I imagine.