This is a quick overview of just some of the clear-coating varnishes that I know about and that I have used in the last few years. Basically they all fall into two kinds, modern hard varnishes and traditional supple ones.
If the furniture moves via floating panel construction, then you really have to use traditional varnishes, but if the wood is stable, as in most glued furniture, then you can use either traditional or modern varnishes.
Traditional Marine Varnishes
These are the traditional one-pack varnishes. As a general rule they fall into two types, the standard varnishes made mainly of alkyd like International ‘Original’, Blakes ‘Classic No 1’ and some other varnishes like MBM ‘Prima’ which I rather like.
Then there are the Premium Traditional Marine Varnishes like International ‘Deluxe’, Joton ‘Ravilak’ from Norway and the best Varnish in the World, the Dutch ‘Epifanes’. These varnishes tend to have a higher tung oil content, be darker in color and are certainly more expensive. They are not difficult to use and certainly have a good finish.
Mono-Urethanes & Single Pack Poly-urethanes
There are quite a few of these, (International ‘Schooner’ & Epifanes ‘Mono-urethane’ are two) however the only
one that I have really used much is the Blakes ‘Single Pack Polyurethane’ and that’s just great! Quite a few of them (including the Blakes single pack) are based on cyano-crylates, like SuperGlue – which is why they are so hard and use the moisture in the wood to cure them. I am a real fan of these. They set up like rock so you can polish it, which you can’t do easily with traditional varnishes, it dries quickly, is not particularly temperature dependant.
Make sure you have a respirator when using this type of finish. I do not deny that there is some furniture out there that was varnished with twin-pack Poly-urethane and they look gorgeous, they shine like a piece of glass. These type of finishes last twice as long as a traditional varnish. This stuff should really be used on furniture that is out in the sun and rain.
Really these are just the same as the Two-pack poly-urethanes. Everything I said about them is also true of Epoxy varnishes. They are just more difficult to work with because they can cure very quickly without warning.
I think that if you do allot of finishing of furniture, you can use these.
I do not recommend them for the first time furniture finisher. Remember epoxy does not like getting wet before it really hardens. Start early in the day so it can cure before nightfall if you are working out side.
My preference is to finish wood with a clear finish. However if you want a consistent color, wood stains make sense.
Now for me, when I think of a wood stain, I think of the spirit based dyes that we use to put back in a bit of color into our faded decks when they have seen just a bit to much summer sunlight without enough varnish but for some Some wood stains are a complete coating system and there are people that swear that these systems like the Dutch Sikkens Cetol system provide a better level of UV protection. Last far longer and are cheaper than any other system, after all they are designed for coating exterior wood on houses, where they guarantee many years of protection against all UV. They might be right….although these coating systems are still alkyd based, they have quite the highest solid content of any system I have considered here, which means that they need less coats and indeed should provide a higher UV protection. I admit that is the most important thing. I know people who have used them, and it seems that for large areas like table tops, it can be real good, but I do know people who have used them on smaller areas, and under closer inspection have been less than happy. One of the problems is that the sheer level of solids makes them less than completely clear, which is why they are stains!) they have a colored base (in various wood colors). When this color is even, there should not be too much problem, but sometimes you can see the streaks of color in the stain…..and this can be very ugly indeed.
This finish is favored by some furniture-builders in the Scandinavians countries. Wood oils are really good for furniture that are going to spend all their life indoors.
Outdoor furniture I feel, needs more UV protection. I’m not a big fan of wood oils.