Tabletop finishing questions

[Chip Byrd]

I am in the process of finishing my first tabletop. It's made from QSWO and will be top-coated with WP. I have grain filled it and put down a wash coat of shellac.


I have heard that it is a good idea to finish both sides of a tabletop. I have learned a lot from this site and was hoping that someone with experience might be able to answer a couple questions.


1) Do both sides need to be finished with the same number of coats? I suppose what I am asking is if 2-3 coats on the bottom will suffice if I plan to put 4-5 on the top?


2) What stages do you use to finish the two sides? Do you finish the bottom completely and then do the top? If so, how do you avoid getting overlap lines?


Thanks in advance for any help or suggestions.


Chip

[Mike Ontko]

You'll want to wait till others who have more specific experience chime in, but I've been reading that just one coat on the unseen sides would be sufficient. The point of the coats in those unseen areas is simply to seal off the wood from the effects of moisture/humidity, whereas the parts that are used or seen also have to address protection (physical and UV) and aesthetics. So, as long as you're certain that you're getting complete coverage, then one or two coats in those unseen spots should be enough.

[Prashun Patel]

1) No. That's what I do. More critically, I don't sand or plane the bottom as thoroughly as the top. THAT's the real time saver. Wiping on another coat doesn't take all that long.
2) Bottom completely, then top. I consider it a test to identify any gotcha's when doing the top side.

[John TenEyck]

I do the bottom, too, but only 2 or 3 coats. More importantly, for me at least, I put 2 or three coats on the top and edges first. I tried doing the bottom first but had some runs go down the sides and onto the top. If you don't scrape and resand the top until those drips are completely gone, they will show forever. So I now do two or three coats on the top and sides first to seal them, then do the bottom, then come back and do however many additional coats on the top and sides until I'm satisfied.

John

[Kent A Bathurst]

I do the bottom, too, but only 2 or 3 coats. More importantly, for me at least, I put 2 or three coats on the top and edges first. I tried doing the bottom first but had some runs go down the sides and onto the top. If you don't scrape and resand the top until those drips are completely gone, they will show forever. So I now do two or three coats on the top and sides first to seal them, then do the bottom, then come back and do however many additional coats on the top and sides until I'm satisfied.

John

This is precisely how I have done all of my QSWO table tops - many of them[except I put down shellac seal coat, and I think J10 does not].

As soon as I have put on a coat on the sides/edges, I use a folded cotton rag to run under the top, along the edge, to pick up any that has moved around the edge onto the bottom face, without disturbing the varnish on the edges.

When I am doing the bottom - I use the cotton rag along the edges to pick up anything that had dripped over the side of the bottom.

Like Prashun, I bail on the surface prep early - rough sand with ROS at 100g and stop. Then - usually 1 shellac and 3 coats of varnish on the bottom, and the top gets more. I don't care how the bottom looks. It is all messed up with trial/test shots of dye and gel stain anyway. Anyone that would look under there and criticize the finish on the bottom of a table top gets tossed out of the house immediately.

[Chip Byrd]

Thanks Guys,

That definitely gives me some ideas. I will follow a protocol similar to John T's.