Can I use this interior polyurethane varnish externally

[6ply]

I need to give a wooden house sign a quick lick of varnish and the only stuff I have is ronseal trade polyurethane satin coat varnish which says for interior wood. It is an oil-based paint that says high in vocs. Apart from what the label says is there any reason why I can't use it externally?

I would rather use this stuff and maybe recoat it annually than buy a new tin of varnish.

 

[RaceDiagnostics]

It may suffer from UV exposure?

 

[RichardM]

Try it and see how long it lasts.

 

[6ply]

It may suffer from UV exposure?

That's what I was wondering.

Try it and see how long it lasts.

Yes, I may just do that. Takes 5 mins to rub down.

 

[RichardM]

That's what I would do. If it doesn't last just sand it off and put some other stuff on.

 

[bricol]

Interior wood . . . anyone else notice the "use only outdoors" instruction on the side

(I know, it does say "well ventilated too )

 

[MetalMonkey]

As said, it will be mainly down to the UV resistance. If you intend to recoat it next year, then you don't have much to lose.