UV cure for yellowing varnish?

[Weaver]

I noticed on my recent Skyhawk build that Humbrol clear varnish went on very yellow (over white), but then cleared up as it dried, particularly if placed in strong sunlight.

Now I have a model of a swept-wing Magister which is mostly white, and it's yellowed so badly over the last few years that I havn't been taking it out of the box at shows. So, seeing as UV worked for the Skyhawk, I thought I'd give it go with the Magister, and it worked! It's had about ten days on a window sill, being turned every day for even coverage, and the yellowing has almost gone.

I'm now trying it with a yellowed canopy from a Frogspawn Sea Venom.


I suspect either or both of two mechanisms may be at work here:


1. The clear coat doesn't really dry properly without strong UV exposure,

2. Sitting in a box with a load of other painted models causes yellowing due to residual fumes (I don't take my models out of their transport boxes between shows).

[NARSES2]

I knew sunlight worked with yellowed transfers but not with kits. Good to know

[kerick]

I wonder if that would work on white paint that has yellowed?

[Rick Lowe]

I knew sunlight worked with yellowed transfers but not with kits. Good to know

Doesn't the yellowing of the carrier film return? I seem to have heard that somewhere.

[PR19_Kit]

I knew sunlight worked with yellowed transfers but not with kits. Good to know

Doesn't the yellowing of the carrier film return? I seem to have heard that somewhere.

Eventually, unless you've used the decals, but it takes as long as it did the first time around.

[Rick Lowe]

Oh, great! That's good to know.

[zenrat]

I wonder if that would work on white paint that has yellowed?

Chances are you have a windowsill painted with gloss white (oil based) enamel in your house.  Has it yellowed?
I have a pearl white '60 Pontiac convertible which is now cream due to the clear.  I'll be finding a windowsill and trying this.