Author Topic: Sanding beyond 320 Grit in Wood Working Projects  (Read 2897 times)

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Offline Steven Owen

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Sanding beyond 320 Grit in Wood Working Projects
« on: August 01, 2018, 11:55 AM »
How often do you go beyond 320 Grit paper for sanding a project?

Outside of polishing and french polishing, I can't imagine a grit higher than 320 making any visual difference in grain clarity on most projects.

Most of the time I use 320 for sanding the final coats of varnish when you plan to knock down a finish from gloss to satin/matte. 320 also get used for French polishing with Shelac.

Can you think of any scenarios where it would make sense to go beyond 320 grit for any wood working project.
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Offline Dick Mahany

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #1 on: August 01, 2018, 12:07 PM »
On flat work I rarely go beyond 320 on the bare substrate it self.  On some woods even 320 may make stains difficult to blend in and so 220 is sometimes used in those cases. 

For turnings such as platters and pens where trying to achieve a glass like surface, I will often sand as high as 800 for oils, waxes or other clear coats.  For some finishes such as lacquer 400-600 are used wet to level between coats.

 
« Last Edit: August 01, 2018, 12:30 PM by Dick Mahany »

Offline tjbnwi

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #2 on: August 06, 2018, 12:27 AM »
Farley do I go over 180.

Tom

Offline ScotF

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #3 on: August 06, 2018, 12:51 AM »
Depends on the project. I just made a set of dining chairs and table and sanded to 1,000 without skipping grits. It is how Sam Maloof did it and the finish and results came out very well. Lots of other projects go to 220 or even 180. Painted surfaces are 120 or 150.

Offline Pompeio

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #4 on: August 06, 2018, 07:24 AM »
You may also want to review the stain manufacturer’s instructions to see their recommendations as to what is the finest grit that should be used to adequately accept the stain.

Offline Cheese

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #5 on: August 06, 2018, 11:26 AM »
I recently made a black walnut countertop and went to 2000 just to view the results. I was very disappointed. [sad] The countertop has a lot of grain and figure to it but the polishing never brought that out, it remained rather flat looking. When I tried to oil it there were many areas where it refused to take.  [sad] [sad]

Consequently, I took the surface back to 220 and then applied Surfix. That came out real nice. [big grin]

I'll use 400/500 grit for hand sanding between coats of clear poly. Just a quick pass to eliminate the dust nibs.

Offline kevinculle

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #6 on: August 06, 2018, 11:34 AM »
Agree with Cheese, sanding beyond 220 or 320 is only of benefit in two situations:

1. Sanding endgrain with finer grits helps limit stain absorption, here I go 1 or 2 steps beyond the grit used on flat surfaces.

2. Sanding between coats of a hard finish like poly where it can be beneficial to go up to 800 or so to get a really refined final finish.

Offline ben_r_

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #7 on: August 06, 2018, 01:26 PM »
^^^^^ Im with these two. Same here. 120 or 150 for painted, 180-220 for stain or oil, up to 400-500+ for clear coats in between coats.
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Offline Peter Parfitt

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #8 on: August 06, 2018, 01:39 PM »
This is a very useful thread and well done to Steven for kicking this off.

I used to go too far and often beyond 240 grit. Very fine grades do make some stains more troublesome and going beyond about 180 grit can ruin an oil finish.

For end grain and de-nibbing then perhaps 320 to 400 are okay. If you are using a high end sander then other factors will apply. My friend's machine ($60k plus) can de-nib lacquer down to .01 of a mm (I think).

Peter

Offline HarveyWildes

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #9 on: August 06, 2018, 02:56 PM »
I often sand to 1200 grit or more on projects with a rubbed oil finish.  I dry sand to 400 - 600, and then wet sand through the higher grits.  I think it makes a huge difference in the small details - for example, cross grain flecks in quarter-sawn cherry or maple.  If you wet sand to that fine a grit, you are going to get more color variation because the natural variations in the wood are going to show more clearly.  Cherry is (in)famous for that.  If you stop at 220, the additional roughness in the surface over a 1000-2000 grit finish is going to mask some of the color variation.  Personally, I like to take advantage of the color variation, and I try to choose wood carefully for grain and color to get what I want.  Furthermore, it's not necessarily important to see all that detail in every piece, so I don't sand to that high a grit all the time.


If I'm putting on a hard finish, I sand to 400-600 and call it a day, because wet sanding a hard finish may affect the look of the finish, but it's not doing anything to the wood.


On a more philosophical note, there was an article a while back in Scientific American on the aesthetics of Jackson Pollock's paintings - the guy who splattered paint on the canvas.  In a blind experiment, people were shown a Jackson Pollock painting and a respectable wannabee Jackson Pollock painting, and asked to choose which one they preferred.  Regardless of whether liked Pollock's style or not, there was a very clear preference for Pollock over the wannabee - and this was true over a selection of Pollock and wannabee paintings.  Since it seemed like the style didn't really lend itself to that kind of preference ("just" splattering paint on canvas, after all), the authors tried to analyse factors that might account for the preference.  One of the things they analyzed was the fractal complexity of the paintings.  They found that Pollock's paintings were an order of magnitude (i.e. over 10x) more complex, more detailed, than the wannabees.  Their conclusion was the Pollock painting engaged the viewer's brain in more unconscious analytical pattern analysis, which translated into a more pleasing aesthetic at the conscious level (again, regardless of whether you really like Pollack to begin with).  No one at the time the article was written knew what techniques Pollock used to get more detail - he worked behind closed doors.


Now think of that in terms of wood grain.  As you sand through successively higher grits, you bring out more detail.  The detail is patterned due to the way that wood grows, but it's not geometrically regular, so the fractal complexity metric would seem to fit.  If you apply the conclusions of the Pollock article, the increased detail of the grain should result in a more pleasing piece even if the viewer is not really aware of the grain patterns.  That's good -if- the focus of the piece is the wood.  So that's the idea that I'm playing with by sanding to higher grits, and I think it plays out pretty well.


That's not saying that every piece will look better if it's sanded to higher grits.  You just have to decide how to balance the detail of the wood vs. the lines of the design vs. the utility vs. whatever other design factors you have, and work appropriately.
« Last Edit: August 06, 2018, 03:09 PM by HarveyWildes »

Offline Cheese

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #10 on: August 06, 2018, 04:04 PM »
I often sand to 1200 grit or more on projects with a rubbed oil finish.  I dry sand to 400 - 600, and then wet sand through the higher grits.

If you’re wet sanding the higher grits, do you dry sand at some time to not raise the grain?

Offline grbmds

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #11 on: August 06, 2018, 04:24 PM »
Rarely go above 220-240. In fact, the General Gel Poly I use, recommends 150 in the directions. I usually go beyond that  but have sanded to only 150 and it works well, but I use Satin poly rather than gloss. With a glossy finish I would think there might be  good reason to go up to 400, but I don't believe beyond that would be necessary (might be some advantages).

Over the time I've been a woodworker, I've sanded to various grits. I think that is the best way to determine what works best for you with the finishes you commonly use; oil, poly, or any others. Pick the one that looks best to you, label it, keep it as a sample, and add any notes that might help you duplicate it in the future. Then, you will get what you want in most situations.
Randy

Offline rst

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #12 on: August 06, 2018, 08:36 PM »
My first job out of school,1971, was as a hand stainer in a PA custom kitchen factory.  Back then the average price for one of their kitchens was $15,000.00 (they are still in business).  Any finish available was done, from stain to paint to unfinished.  The woods utilized were oak, maple, cherry, and pine.  Excepting pine which blotches when wet, all woods were sprayed with water just like a finish.  The woods were sanded to 180 before wet and stained.  Painted finishes were not wet.  The stains would penetrate deeper into the wood and give a much richer appearance.  Nitrocellulose laquer sealer was applied, sanded with 220, sprayed with regular laquer, sanded again with 320, final spray was then wet oil sanded with 400, then 800, and hand rubbed with 000 steel wool.  Johnson wax, machine polished was the final step.This resulted in a bullet proof finish that lasted forever.  I still use this process today with water, oil or solvent finishes.

Offline HarveyWildes

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #13 on: August 06, 2018, 10:09 PM »
I often sand to 1200 grit or more on projects with a rubbed oil finish.  I dry sand to 400 - 600, and then wet sand through the higher grits.

If you’re wet sanding the higher grits, do you dry sand at some time to not raise the grain?

I've never had a lot of problem with raising the grain with the oil finish I use.  It's a homemade brew of more or less 1/3 poly, 1/3 oil, and 1/3 orange oil (as a mineral spirits or turpentine substitute).  I start with a mix that is high on orange oil and low and poly (say 40% orange oil, 35% oil, and 25% poly) and decrease the orange oil and increase the poly over time  I usually wet sand with 600 after dry sanding with 600, so that takes care of any sanding nubbins  that raise after the first coat.  After the first coat, the poly starts to harden the wood and I've never had an issue with roughness after that.  Then I work up through 800, 1000, and 1200 over 4-6 wet sanding passes.  If I'm not too burned out on sanding and finishing by that point, and the piece is worth the effort, I might take it up to 1500 and 2000 with 3 (or more) passes.  I try to do 2 passes with the final grit.  After that it's wax and polish.

The most compulsive ever?  A bathroom countertop out of African Mahogany that took 26 coats of wet sanding goodness to 1500 grit before it was more or less waterproof.  That was about 6-7 years ago and I just noticed a little roughness where the granddaughters left water sitting multiple times - they are pretty sloppy.  So it's coming due for a pass with 1500 Granat and another couple of coats of oil, and it'll be good for another 6-7 years.  I'm really happy with how it looks, so more or less think that it was worth the effort.  It's not a way to make money if you're doing it commercially though.

As an aside, I don't worry about how wood soaks up stain or not, because I very rarely use stain, and usually then only to match a color of some existing piece.


« Last Edit: August 06, 2018, 10:13 PM by HarveyWildes »

Offline SRSemenza

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #14 on: August 06, 2018, 11:53 PM »
Well it certainly makes a bit of a difference on the type of finish, but man some of you guys are really going fine. 

If I am doing stain, 180 or 220 for the bare wood depending on the stain and wood.  Raising the grain and sanding with 180 if using a water base stain.

Between coats of poly (oil base) 320 or 400. By hand or power depending on the piece  and number of coats going on to get the desired look.

For paint I sand the wood to 150.  And 220 between coats.

Those are the norm. It goes all over the place if I need to play around and match something existing.

So to answer Steve's question ...... I hardly ever go beyond 320.

Seth

Offline HarveyWildes

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #15 on: August 07, 2018, 09:20 AM »
Another factor - using smoothing planes with good sharp blades shears the wood rather than abrading it.  The same can be said of scraping.  In theory this should yield a super smooth surface.  I've had some luck with this approach for small, flat surfaces like panels or boxes, but overall I get better results with sanding.

For the proficient hand tool users that can get a finish ready surface with planes or scrapers, how does the work involved compare to sanding?  If you are doing multiple coats of oil, do you end up sanding between coats anyway?

Offline Peter Parfitt

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #16 on: August 07, 2018, 01:28 PM »
Another factor - using smoothing planes with good sharp blades shears the wood rather than abrading it.  The same can be said of scraping.  In theory this should yield a super smooth surface.  I've had some luck with this approach for small, flat surfaces like panels or boxes, but overall I get better results with sanding.

For the proficient hand tool users that can get a finish ready surface with planes or scrapers, how does the work involved compare to sanding?  If you are doing multiple coats of oil, do you end up sanding between coats anyway?

Hi Harvey

In my limited experience based on French polish work, some commercial varnishes and various oil products scraping does leave a good surface which still leaves the wood pores open to accept the finish. Sanding at very fine grits can result in a shiny surface which cannot absorb the stain or finish product.

Peter

Offline Steven Owen

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Re: Sanding beyond 320 Grit in Wood Working Projects
« Reply #17 on: August 07, 2018, 05:02 PM »
Another factor - using smoothing planes with good sharp blades shears the wood rather than abrading it.  The same can be said of scraping.  In theory this should yield a super smooth surface.  I've had some luck with this approach for small, flat surfaces like panels or boxes, but overall I get better results with sanding.

For the proficient hand tool users that can get a finish ready surface with planes or scrapers, how does the work involved compare to sanding?  If you are doing multiple coats of oil, do you end up sanding between coats anyway?

The wood whisper feels planing is faster than sanding on smaller project.  Like anything, I’d think it would depend on the desired results.  Planing allows more grain detail to show up in surfaces and planing allows the grain to absorb more stain creating a darker gain when staining or using wood dyes. 

Your choice of wood and desired look will impact the choice to sand or plane a project. 

Ex: Zebra wood projects look a lot better if you use hand planes vs sanding.  You might not notice much a or difference between sanding & planing with a Sugar Maple project since Sugar Maple doesn’t have very dramitc grain to begin with.
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