I am building desks for my children: a wooden slab on a standing desk frame.
The wooden slab is 160 x 80 x 2 cm and is made of smaller pieces of oak (probably) glued together. They form a nice flat and smooth surface (I can swipe my hand on it slightly, there may be very small shards)
I want to varnish it but this is the first time I am going to do it. So my constraints are:
- the work will be done on-site in the room where the desk will stand afterwards
- I am an unexperienced DIY-selfer (but willing to learn). This is to say that I am looking for more forgiving solutions
- this is intended to be a desk for teenagers, so for books, copybooks, writing, computer etc. → it does not need to be industrial-grade resistant but smooth and still relatively protected
I am now faced with the choice of the varnish. When reading about them, I see that there are three categories of finish : brilliant, satin, mat. It seems that brilliant is the most resistant one.
There is also the problem of the solvants: water and white-spirit based - this is what I saw in France. This OldHouse video (US) mentions another one based off polyurethane. This video (linked to the moment where this is presented) also mentions "lacquer" - whihc does not translate to anything I saw in France.
My main problem is that all these information are complete (even over-complete) but do not address my context: a working desk (or a dinner table - the kind of table where you do everyday things)
EDIT: I also saw that everyone uses a brush, while in the shop I went to a roll is suggested all the time.
FINAL EDIT (for those who may have the same concerns as I had)
I went for a water-based varnish. It has a pseudoplastic behaviour which frankly is more annoying in that case than anything else. It may be useful when varnishing a ceiling (I am not sure this exists at all, but anyway).
I used a 11 cm foam roll. I was at the limit of slipping (as opposed to rolling) so if the surface was smaller (as it was on the edges) I would have had a problem.
I made three layers, grinding first with a 200 paper (I am not sure if this is universal - it is a fine-grained paper, but you still feel the grains). The last two layers were ground with a 500 paper (it feel rather smooth). This includes the last layer - I was wondering whether to leave it as it or to work the sandpaper on it and I finally did. That was the right decision, the surface is very smooth now.
Final effect below, if my children do not get excellent marks this year I would really not understand why :)