Ebony and Holly

[jrista]

It is NOT false, You think too much. Sanding leaves scratches even when viewing with micron microscopes because that is what sanding does; knife edge cutting with razor sharp tools is smoother because that is what knives do. Your premise runs against centuries of knowledge and skill, and wow, you haven't seen Japanese masters at work with knives, scrapers, swords, hand planes etc. Nope, sandpaper doesn't make it as smooth as a sharp edge can when cutting - and I am not talking about sawing. I have personally seen too much to the contrary of your premises.

IF sanding can make it finer and smoother, why are CNC and machine cuttings done with precision metal cutting edges on blades? By your presumption, they should sand it to make it more smooth.

The right hand plane can cut layers so thin in wood and even end grain that word from a book can easily be read through the ribbons. Sanding would only smear it and introduce scratches. Yep, I have seen it. I used to have a ribbon approx 2 1/2 inches wide and 3 ft long smooth as a baby's behind and clear enough to read a newspaper when the ribbon was laid over it. Knife edge sharp that sandpaper can't improve upon. I'm not making this up for the sake of an argument.

Since you believe that SP can do better than sharp knife edges, do you think that CNC/machining smoothness can be improved by sanding? Let's see now, my micrometer can measure 1/10,000. How was that machined to be able to measure that fine? Hmmm? Oh it was sanded. Nope, machined with very hard steel very precisely! AND this method can be applied to wood without the need for sandpaper.

So, aside from the fact that I've not said that sanding is simply better, "period"...or that I've said I actually agree that using a skew is the better tool if you have the skill.... IF you HAVE the skill. Not everyone does. As for thinking too much...its thanks to mankind's propensity to think and overthink and debate our thinkings that we have any of this stuff, woodworking and all our wonderful tools and sandpapers and finishes, at all. Its the reason we have any of what we have today. Mankind has thought for millennia and solved so many problems with our thinking. So I'm gonna keep thinking, thanks.

Lets ignore metal for the moment, as its an entirely different beast. Further, I'm not talking about sanding metal...I'm talking about sanding wood. IMO this distinction REALLY matters here.

With wood, your limiting fineness is the wood fibers themselves. Well, their cells. Wood cells are around 10-100 microns in size. They are straw like and brittle at the smaller scale with dry wood. They break and shatter easily. Sub-cellular structures are smaller, but in the long run, wood isn't capable of infinite smoothness, unlike metal. Metal is a malleable material that doesn't have a cellular structure, so its smoothness can be significantly higher (I mean, we can achieve perfect mirror like finishes with metal, we can't with bare wood.) So, after a point, NEITHER tooling NOR sandpaper, can actually achieve a smoother result...you'll ultimately hit a limit. Further, have you ever actually looked at wood that was planed or turned with a skew under a microscope? You absolutely 100% certain its not going to have any tooling marks at all, even microscopic ones? Or broken or shattered cells? (I'd bet good money there will be...but same as with sanding, these marks would be too small to matter, and encroaching upon the scale of the wood cells themselves.)

My point was, you proclaim its not possible at all to get as smooth a surface with sanding, as with tooling. I think you can. Especially sanding with the grain in your final passes. Sanding with the grain, with the cells, will eliminate cross-grain cuts, leaving you with a surface that doesn't appear to have scratches, and yet is still sanded.

But there is a limit to how smooth wood can get. Even if you fill the pores (unlikely with tooling), wood has a ton of small structure that is in the micron scale range, and none of it is going to be perfectly smooth in the end. Even with a steady hand, wood is a compressible material, and either the cutting edge or the bevel can potentially compress/crush the fibers, even when you are getting a nice streamer out of a hand plane. You may not be able to see the damage with the naked eye, there is no guarantee there isn't any damage/tool marks at a smaller scale. Not so much that you couldn't see imperfections with a microscope, no matter how you achieved your results. It's wood...

There is no question you have more skill with a skew than I do. I don't dispute that (please don't take any of my posts that way!) I may never have your skill (which ironically is part of the reason I posted in the first place!) Mastering a skew to the point where you can cut perfectly across the grain without any issues is not easy. But, as you so stated, I'm a thinker. I'm also a reader, a watcher (of videos and other educational content) and an experimenter. So, I have plenty of knowledge here, and a good amount of first hand experience (but not necessarily mastery) with a lot of this stuff. I've spent a lot of time over the last two years honing my sanding skills, and I can achieve some spectacular results. Beyond a certain point, whether the fibers are shattered at a microscopic scale or not, simply doesn't matter. At some point, burnishing comes into play as well, which will strip away much of the fragmented cells and compress whole cells, which causes a change in the nature of the fibers. The bevel of a skew can do this, as can high grit sandpaper (which is in fact where the shiny sheen comes from with super-smooth results.) However this won't leave a perfectly flat surface either, hence "sheen" rather than "gloss".

I guess you and I will just have to agree to disagree here. FWIW, there actually are microscope images of finished woods. Sanded, planed, bare or with some kind of sealant, with and without finishes. The ones I'm familiar with are in a book, but they are out there. The difference between planed and sanded wood to even a more moderate grit of say 400 or 600 is hard to discern. The edge at those grits looks like it goes slightly to the planing, but that's not a particularly fine grit, and you can certainly do better! (If I had the ability to get some comparison microscope shots here myself, I would....but, it looks like these are SEM images, which is certainly out of the realm of possibility for me.)



Now, talking about cell structures...this gets back into the stabilization question. If you stabilize, the nature of the wood, fibers, cells...would change... They would be filled with something other than easily compressible air, other than a natural cellular structure...a resin, a molecular polymer. The secondary point of my original post was to postulate that maybe there is an alternative to becoming a Japanese master with a skew, that would allow segmented blanks to be finished without needing to worry about sanding dust filling wood pores, while you lack the necessary fine touch skew, scraper, or gouge skill to get a perfect, "defect free" cut. I'm not saying I know for sure this is a solution...I only wanted to offer it as a potential option for readers who don't have years of skew skill. In my experience with stabilized woods, its an entirely different beast than wood. Much more like turning acrylic, than wood, although its not exactly the same either. I dunno...I think its a possibility. Some people may never have good enough skew skill to do what you and John propose. Even if it is better, some people may simply not be capable of it.


FWIW, there is PLENTY out there about say sanding metal surfaces, even machined ones. CNC machining doesn't leave a perfect defect-free surface a lot of the time either. At a micron scale, there are often ridges left behind that you may not be able to see with the naked eye or feel, but they are there. (Heck, in some cases you can both see and feel them.) Even the chromed steel CNC machined handles of my Powermatic lathe, have imperfections that were there out of the box. So the entire premise...is kind of bunk IMO. Beyond a certain scale, there isn't perfection...

 

[leehljp]

Jon,

I can agree with you in part and you have done some good study. I'll reply in part to some of the topics.

With wood, your limiting fineness is the wood fibers themselves. Well, their cells. Wood cells are around 10-100 microns in size. They are straw like and brittle at the smaller scale with dry wood. They break and shatter easily. Sub-cellular structures are smaller, but in the long run, wood isn't capable of infinite smoothness, unlike metal.

For me and the way I see it and do it:
Simply put, sanding no matter how fine, produces fibers that stick up. It does make it tactilely "feel" softer, but glass doesn't feel soft and is very smooth. Knife/razor sharp edges on skews and properly sharpened scrapers ( and on hand planes) will cut the wood so that the structures are as smooth as they can be by man's hands, and the structures are not destroyed. This is not about dull edged tools that rip or tear the structures. Hoadley's book on "Understanding Wood" has many many picts of pristinely cut wood, even end grain in order to see the cell and capillary structures. I have seen cells and capillaries like those from very sharp tools. I have long ago forgot my hand plane type, but I believe it is the "block" plane that will cut the end grain and cut it smoothly. Saws properly sharpened and block planes properly sharpened (which is totally understood in the wood working community) will cut the cells without destroying them. properly sharpened and used chisels of different types can do the same. And again, sandpaper creates and raises fibers up; razor edges cut them, in my opinion.

My point was, you proclaim it's not possible at all to get as smooth a surface with sanding, as with tooling. I think you can. Especially sanding with the grain in your final passes. Sanding with the grain, with the cells, will eliminate cross-grain cuts, leaving you with a surface that doesn't appear to have scratches, and yet is still sanded.

Again, in my opinion, Properly sharpened tools will not leave scratches that can be seen even with a 5x or 10x loupe. My background: Grew up on a farm, dad not wealthy, bought broken down machinery and tractors are repaired them to use as his tools and machinery. I learned from an early age to "fix" things. Excelled at welding by age 10. Did sports in school to get out of farm work. Had 2 uncles that built houses. Spent time with them occasion. What I learned in all of this carried forth to help through the ages for me, even though my life's work is not in this field. Concerning pen making. I had the need to find away to prevent sanding dust in segments and be smooth enough that sanding would not be required. And remember, I am obsessive and want perfect smoothness without tool marks. Even erasers spread create and spread sanding dust, and DNA does not remove it.

I am obsessive in working to get clean and smooth finishes (and obsessive about other things too). This led me to one day contemplate an alternative method that I had not yet read about, but after posting my findings here nearly 15 years ago, some very knowledgeable pen and bowl turners agreed with it, although there were initially a couple who said tools could not make it as smooth as sandpaper. I spent about an hour sharpening my modified scraper, made to my own specs by me. I pulled on my knowledge of what I could remember from my uncles in sharpening planes, and from what I learned from skilled masters in Japan. I took my scraper and ground it to a specific angle, then took different sandpaper grits and swiped the tool on 6 or 7 micron SP and down to .3 microns, and then applying a fine rouge on a leather strop and then on a non-rouge strop. (Japanese masters have a different method and it works well too.) Lastly I swiped the tool 2 or 3 times with a little pressure on the .3 micron SP on glass from a vertical perspective. Although I could not see it, it was in my mind similar to wood scraper tools that create the burr, which is what does the cutting and smoothing for hand scrapers.

Then, when I put this on the already turned to size segmented blank, I was blown away. SMOOTH and no smearing. While the No-Smearing was my purpose, I learned how smooth I could get a stabilized or hard wood blank without sanding. I was Blown Away!

In line with your discussions on cells etc, I used this method on some padauk. Padauk has some of the largest cells of any wood, and are visible to the naked eye with properly cut and or sanded blanks. Numerous times over the years, there have been pictures posted here with questions if the circular "sand lines" or circular tool scratches are showing up in the finished pen. Most of the time the answer was NO. It is the cellular structure that is being seen. The first time I turned a padauk blank, I was surprised that I could see the cells. Yes I was sanding then and used MicroMesh 12000 for the final sanding. That is the nature of most padauk.

I apologize for saying you think too much. I do that too, or rather used to do that every day. I have a dual router - router table that I made after thinking about it for a year. I had every dimensions and thickness of wood totally in my mind before I started cutting and building. I could picture every piece and knew its dimensions. When I started building and cutting every measurement came to me. I built the basic carcass and 5 drawers in a day. I have several pieces of furniture that I made by getting all the dimensions in my head before cutting and building. (BTW, I aced Geometry in school. I could mentally picture the problems and was often accused of cheating when I finished tests in half the time of the rest of the class.) I can't do that now.

Keep at it!

 

[jttheclockman]

https://www.penturners.org/threads/turning-blanks-sanded-smooth-with-only-a-skew.177564/

https://www.woodcraft.com/blog_entries/using-scrapers-for-a-smoother-finish

 

[jrista]

Just for some reference:

SEM image of some wood. I suspect sanding stopped around 320, 400, or 600, and didn't go anywhere near 3000 grit. Suffice it to say, at a microscopic level? There is no such thing as "smoother with this or that". Now with the medium fine grits sandpapers, you might not have as nice a looking edge to cells with sanding, which get broken and fragmented by EITHER planing or sanding, but my argument all along has been that you need to sand to a higher grit to achieve that silky smooth sanded feeling anyway.

My point is, there is a limit to how smooth things can get. At the 1 mm scale here (1000µm), the sanded result "looks" smoother to my eye. Similarly, the planed result clearly shows that the wood fibers still get shredded, you can see that plain as day (I guarantee you, if you look at your own wood at this scale, you'll see the same thing!!! Regardless of how sharp your tools are...) At the 30µm scale, you can see that the cellular structure still fragments and breaks with planing. The structures themselves are also clearly a limiting factor on how flat and smooth the surface of wood can get...big cells or small, they are the limiting factor.

Again...I'm not saying a super sharp plane or skew isn't excellent. That's never been my point. I know they are highly capable tools that will slice wood beautifully. They just won't do it perfectly. Perfection is an illusion that would be quickly shattered with some microscopy.

I understand what you guys are saying. I get it. I understand your preference. I'm an out of the box thinker, and I know many people can't skew to save their lives, or even if they can skew, they can't necessarily get a superbly smooth result. For their sakes, is why I am still posting. There is almost always more than one way to solve most problems. I've got a bunch of spalted maple to stabilize. I'm going to stabilize some other woods as well, and then do a bit of segmenting and see if the stabilized woods (which would have filled in cellular structures, that's the entire purpose of stabilizing) eliminate the problems with sanding dust. If there is nowhere for the dust to get lodged....then logically, the dust shouldn't get stuck in the wood. Now, maybe during the sanding process, you might see that the lighter woods don't look great, but with some proper cleaning (say with compressed air and DNA), I would be willing to bet that a skew, despite maybe being a better option, isn't the ONLY option.

Alright, I'm out.

 

[jrista]

https://www.penturners.org/threads/turning-blanks-sanded-smooth-with-only-a-skew.177564/

Since posting that, the whole stabilization thing came into play, now that I have all the equipment. Hence...this thread...

 

[leehljp]

Just for some reference:

View attachment 362151

SEM image of some wood. I suspect sanding stopped around 320, 400, or 600, and didn't go anywhere near 3000 grit. Suffice it to say, at a microscopic level? There is no such thing as "smoother with this or that". Now with the medium fine grits sandpapers, you might not have as nice a looking edge to cells with sanding, which get broken and fragmented by EITHER planing or sanding, but my argument all along has been that you need to sand to a higher grit to achieve that silky smooth sanded feeling anyway.

My point is, there is a limit to how smooth things can get. At the 1 mm scale here (1000µm), the sanded result "looks" smoother to my eye. Similarly, the planed result clearly shows that the wood fibers still get shredded, you can see that plain as day (I guarantee you, if you look at your own wood at this scale, you'll see the same thing!!! Regardless of how sharp your tools are...) At the 30µm scale, you can see that the cellular structure still fragments and breaks with planing. The structures themselves are also clearly a limiting factor on how flat and smooth the surface of wood can get...big cells or small, they are the limiting factor.

Again...I'm not saying a super sharp plane or skew isn't excellent. That's never been my point. I know they are highly capable tools that will slice wood beautifully. They just won't do it perfectly. Perfection is an illusion that would be quickly shattered with some microscopy.

I understand what you guys are saying. I get it. I understand your preference. I'm an out of the box thinker, and I know many people can't skew to save their lives, or even if they can skew, they can't necessarily get a superbly smooth result. For their sakes, is why I am still posting. There is almost always more than one way to solve most problems. I've got a bunch of spalted maple to stabilize. I'm going to stabilize some other woods as well, and then do a bit of segmenting and see if the stabilized woods (which would have filled in cellular structures, that's the entire purpose of stabilizing) eliminate the problems with sanding dust. If there is nowhere for the dust to get lodged....then logically, the dust shouldn't get stuck in the wood. Now, maybe during the sanding process, you might see that the lighter woods don't look great, but with some proper cleaning (say with compressed air and DNA), I would be willing to bet that a skew, despite maybe being a better option, isn't the ONLY option.

Alright, I'm out.

LOL, I have seen the same thing in Japan but the opposite of those picts. And I also saw videos with closeups of which form and angle of planes produced what kind of cut crunched and super smooth with capillary veins clearly visible. BTW, the sanded pics with the capillary holes, I have seen clearer ones done by block planes. Hoadley's book has some super photos of capillarys and grain.