Hi!
I would not use anything other than 2-part auto laquers like Sikkens, Dupont , PPG, Glasurite.
Or use 2-part boat urethanes that could be brushed on, like "International" (the above auto laquers have to be sprayed on)
Metanol softens 1-part enamels real fast...No so good if you want to keep the boat/airplane for many years.

Regards!
Jan K
Sweden