finishing an oak desktop - Woodworking Talk

kjhart0133 · 10-10-2009, 12:29 PM

I just completed fabricating and sanding an oak top for a desk I'm building. The desktop is a laminate of 3/4" red oak veneer and 1/2" birch ply. The edging is solid red oak as can be seen in the pictures below.

I don't plan to stain the top, I'd like to retain its natural hue. What would be a suitable finish that won't be sticky or glossy, but still provide some durability? I'm trying some Minwax Clear Satin Wipe-On Poly on a test piece right now, but I wonder if Tung Oil or even a rub-on wax would be more appropriate.

Any advice is greatly appreciated.

Thanks,

Kevin H.

Julian the woodnut · 10-10-2009, 01:03 PM

Stick with the wipe on poly. Wax and tung oil aren't very good moisture barriers compared to poly, or varnish.

phinds · 10-10-2009, 01:12 PM

Because I'm familiar w/ it and trust it, I'd go with the clear satin poly that you are trying out, but I'm an amateur at finishing and you'll likely get better advice from some of the pros here.

JW_in_Indy · 10-10-2009, 09:47 PM

Oak is a very pourous wood. Quite hard, but still very porous. What I would do if it were me, is I would pre-treat the oak with three or four coats of pre-wash consisting of 50% denatured alcohol and 50% de-waxed shellac before applying the poly. Sanding between coats with 320 I would also do multiple coats of thinned poly (about 70% poly to 30% thinning agent - mineral spirits if oil based, water if water based) sanding with 320 between coats. Don't use a tack cloth to remove sanding dust.... they contain sticky wax that leaves a residue behind. Use a soft cotton rag dipped in mineral spitits (again, if you are using oil based poly) and wrung out to pick up the sanding dust. Between the final few coats, sand with 400 or greater.

That will fill all of the open pores fairly well and give you an incredibly durable finish. But, if you want a furniture grade ultra smooth glass like finish with zero pores like you see on fine cabnitry, you will need to use a pore filler. I've never used one and they all have their followers who are pretty loyal to each brand. But, I can't seem to separate the wheat from the chaff when it comes to them. I do know they work, but some are supposedly WAY better than others. With some, it's ease of application or use. Again, you are just going to have to do some research on them, unless some one here is familiar with them.

rrich · 10-11-2009, 12:34 AM

Kevin,

If you are looking to retain the natural appearance, try a test.

Wipe the top with mineral spirits, paint thinner or turpentine. This will give you an idea of what the results of poly or a curing oil will look like.

I would first go with a curing oil (Minwax Antique Oil Finish) which will impart a warming effect to the finish. Then followed with a poly. If you want a satin finish do a couple of gloss coats of poly for protection and then a coat of satin for the final coat.

If you just go with an oil based poly, the final result will have a warming (Color wise) effect. A water based poly will have a cooling effect. (Almost a blue tinge?)

If you have some scraps left, this might be a good time to start your finishing scrap book. Finish the scraps and write what you did on the back of the scrap. They will make a wonderful reference for you in the years to come.

ditto · 10-12-2009, 03:24 PM

Why not just finish for the look you want and then just get a piece of glass cut to put over it? This is a desk after all, it's going to get used and abused. Food/drink spills, pen marks, nicks, dents, all kinds of stuff. Glass will protect you from just about anything. I built my desk as well (maple, stained /w poly) and that's what I did. Looks great, relatively cheap, easy cleanup, and looks exactly the same after 4 years of daily usage.