Michael Jones said:
Hmmm.... Varnish on an outside door? It'll crack and peel in no time at all.
Right now it has several coats of tounge oil on it. Hard to tell in the pic.
But I am wondering what else I could put on it to help preserve it.
Varnish is out though.....
The most traditional finish for exterior wood doors is a marine grade varnish, but you have to sand and recoat every year, and every 15-20 years you need to strip it back and start the process over. Nothing will give you better protection than a properly applied and maintained marine varnish. Some things may be as good, but none better.
There are numerous exterior grade water bourn varnishes out there these days, which are supposed to be more durrable, though I tend to think water bourn finishes look awfully blue. Lacquers would be a bad idea, as they do not like extreme temprutures. Also, there is no good way of applying lacquer short of spraying, and it's drying times can be long. Of course the most common, the cheapest, and the easiest thing is to paint the door.
No matter what clear coat you use (and you really need to use one, and an oil will not do) it is a VERY good idea to apply a very thin coat (about a 1 lb. cut) of shellac. This will act as a sealer, and will eliminate any problems with incompatability. What ever any manufacturer ever tells you, shellac will stick to anything, and any finish matterial will stick to shellac.
Light
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