Prepping maple for finishing

[Phillip Ngan]

Hi Creekers!

I have some bird's eye maple that will be used to make a small cabinet which will be finished with a coat of BLO and then lacquered. I'm wondering what I need to do to prepare these boards prior to applying the BLO?

I've noticed that when the wood comes out of the planer it has a beautiful chatoyance, plus milling ridges. I use a 4 1/2 smoothing plane to remove the milling marks but the surface less uniform than when it emerged from the planer. (I also managed to tear out a couple of small spots because of the tricky grain.) So what should be my last step before applying the BLO?

1. be happy with the planing and go to the BLO
2. use a card scraper
3. use 320 grit sandpaper. After sandpapering, the beautiful lustre totally disappears. I know it will be somewhat restored after applying the BLO, but would I get a better end result if I skipped the sandpapering?

[Leo Graywacz]

Bring it up to 600 grit if you are going to oil and wax it.

[Al Wasser]

I take it you like your maple to get yellow fast. I hate yellow maple. Just use lacquer if you want to keep it light as long as possible.

[Scott Holmes]

Sand it flat... Flat and smooth are not the same. 220 grit is all you need on maple sanding past 220 on bare wood is a waste of time and sandpaper.

Hand sanding is always a good last step to remove any marks.

[Jeff Jewitt]

In tests that we did some time ago on curly maple, there was no difference between 220 grit and 600g with a film finish like lacquer. With BLO alone - there was some difference visible, but it disappeared after a year as the surface of the wood oxidized.

What you are seeing with 220 grit sanded wood is the efeect of the tiny scratches in the wood surface and they reflect light much the same way when you rub a gloss finish with steel wool or 320 grit - it gets duller.

When the wood surface has enough coats of finish to "wet out and "fill" the scratches, the effect is gone. 1-2 coats of BLO wet out the wood and don't fill the scratches on 220 grit sanded wood so you do see some luster differences bewteen that and 600grit sanded or hand planed wood.

[Mike Willeson]

One option is to find a mom 'n pop shop with a belt sanding machine and pay them a few bucks to run your board through after planning.

I had a few walnut boards I glue joined together to make a top for a shaker pedestal table I am making. Found a shop that ran it through their belt sander for $5. The top is beautiful. A little 220 sanding and I am done.

[Phillip Ngan]

@Jeff, using BLO and lacquer, will I get a better result prepping with a hand plane versus using sandpaper (220 grit or otherwise)? I guess I'm trying to make sense of the huge interest in using super nice hand planes sharpened to 8000 grit when going over it with 220 grit will suffice.

[Howard Acheson]

Phillip, a couple of years ago, I recall a woodworking magazine had explored whether there was any difference in the final finish when the wood was prepared by sanding, scraping or planing. After two coats of finish the test panel was unable to see any difference.

Here is some other info. It was originally prepared relating to the adhesion of finishes but there is some appearance data here too.

Sanding wood--hard or soft--beyond 220 does little more than burnish the wood making staining difficult. This is particularly true if you are using a pigment stain which sits on the surface and relies on "nooks and crannies" to impart color. Softer more porous woods can be sanded to to 220 but harder less absorbent woods may stain best if only sanded to 150. The best compromise is to aim for 180 grit.

A number of years ago a large cabinet/custom furniture shop I was involved with did series of adhesion tests with various finishes and sealers. As part of this test we explored adhesion based on sanding grit. We found about the same adhesion up to 180 - 220. Beyond 220 adhesion dropped off due to burnishing of the underlying wood particularly when non-linear machine sanders were used. This was tested on birch panels. We also found that the resulting smoothness of the first coat of finish was not materially affected by the smoothnes of the underlying wood for sandpaper grits between 150 - 220.. The smoothest surface substrate for final finishes was obtained by sanding lightly after the first coat of finish was applied and dry. Which makes the case for a thinned first coat of finish.

So our conclusion was that sanding beyond 180-220 was not necessary and could be actually detrimental.

But, most important was that there was a big appearance affect if the surface was not HAND sanded in the direction of the grain using the highest grit used on the sanding machine. A flat pad sander produced a much flatter surface than a ROS. However, both required final hand sanding with the grain for optimum appearence. If not hand sanded, swirl scratches could show. Final hand sanding using a sanding pad in the direction of the grain is a must.

[Will Blick]

Howie, as always, great post...

Question...

I often use my ultra sharp joiner hand plane after power joining a boards edge. Its quick n effective to remove the machine marks. The boards edge is glass smooth with just a few strokes, no sanding required of course... The edges are often exposed, as in book cases.

Based on what you mention above, I now think, I should make a pre-finish pass with 180 grit to rid the glass like finish.... I most often use maple, cherry and occassionaly some figured woods. Would you agree with this pre-finish 180 grit pass?

Like the previous poster, often I get carried away using a tool, and seeing how effective it can be, while loosing sight of the final goal :-)

[Phillip Ngan]

Will, you extracted the gist of my original question. Leave the glass like finish achieved with a plane or scraper, or go one step further and sand. Which will achieve a better looking result for an oil and lacquer finish?

Scott, Jeff, and Howie, thanks for the advice about sanding. I won't be going finer than 220 grit, preferably 180 if I do choose to sand.

[Will Blick]

Phillip, there is a big distinction here.....

When you say leave the glass like plane finish, my thought is, after reading Howies comments, you will end up with an inferior finish look....

It seems you need to rough up the glass like finish left by the hand plane with 150 grit to get the best - "after finish look"...

Correct?

If so, this really is a classic case of "less is better"....

And also, a glass-like hand planed surface, what "grit" would this be considered? My guess is, 1200 :-)

[Prashun Patel]

I'm WAY outa my league here with Jeff, Howard, and Scott in the room, but I'll chime in my limited experience:

On surfaces that are receiving light or no color, hand planing can take you from rough to finish-ready very quickly (sharpening time notwithstanding), quietly, and dustlessly.

I wouldn't bother experimenting with 'roughing' yr wood after handplaning unless you experience tearout, chatter, or track marks or if your test boards - always use em - aren't giving you the color you want.