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Building Tips and technical articles. => Paint and finishing => Topic started by: John Hammonds on May 23, 2012, 05:22:43 PM

Title: Apologies if this has been covered before but. . . Decals and sunlight
Post by: John Hammonds on May 23, 2012, 05:22:43 PM

What is the best top coat for protection against sunlight? I make my own decals (Usual way with decal paper and an ink jet printer). I have just printed off a sheet for my new model and noticed a similar decal on a model several years old had faded really badly when compared to the fresh transfer.

I am 100% electric so not worried about fuel proof properties but really disappointed with the level of "fade" I am seeing on decals a few years old. The existing decals are coated with an acrylic spray coat (Just to allow the decal to be immersed in water to free from the backing paper without the ink dissolving)..

What should I spray over the decal once it is applied to keep it's colour?

I'm based in England but don't mind doing the leg work to locate a US equivalent product on this side of the pond.

Thanks in advance

TTFN
John.

Title: Re: Apologies if this has been covered before but. . . Decals and sunlight
Post by: Tim Wescott on May 23, 2012, 06:33:21 PM

There's a Krylon clear product that claims to be UV protecting.

Title: Re: Apologies if this has been covered before but. . . Decals and sunlight
Post by: Randy Powell on May 23, 2012, 08:02:26 PM

The Krylon clear with UV protection works, but it has the unfortunate side effect that it can make the decal ink bleed a bit. You get sort of a halo around letters and such. Better off to just use the regular acrylic clear on the decal then use a catalyzed polyurethane as a top coat. It has a ton of UV screens in it.

Title: Re: Apologies if this has been covered before but. . . Decals and sunlight
Post by: Avaiojet on May 24, 2012, 07:14:32 AM

Frog juice.

Charles

Title: Re: Apologies if this has been covered before but. . . Decals and sunlight
Post by: John Hammonds on May 24, 2012, 03:31:17 PM

Thanks all, I had not come across Krylon over here but a quick search shows it is available from plenty of craft outlets so I'll give one of them a ring and try out both the UV protection and standard versions. I don't have access to a spray gun and can't find catalyzed polyurethane products in rattle cans.  :(

I guess another thing which would at least slow the process down would be to make some protective covers for wings etc so the decal is only exposed when I'm actually out flying. I have to admit generally my models don't last long enough for it to become a problem  HB~> but this one has sneaked through somehow despite plenty of air time.

Frog juice. . . Well, that bought up some interesting websites when I typed it into Google.  n~ Finally found what you were referring to, it looks really good. I presume I can use it to seal the decal  prior to putting it in water or should I only use it as a top coat after applying the decal to the model?

Thanks again all.

TTFN
John.

Title: Re: Apologies if this has been covered before but. . . Decals and sunlight
Post by: john e. holliday on May 25, 2012, 09:56:24 AM

If you have an old blanket laying around, cover the plane while it is out in the sunlight.  Uncover only long enough for appearance point judging.   Had a young man do that to his stunter at a SIG contest one year.   Only time you seen it was when he was ready to fly.  Blew his competitions mind so bad that they were not even close to scoring like he did.    H^^