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Bandsaw blade question.......

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Three-wheelers are another beast. They don't bend the blades double, so even though the wheels are smaller, won't have as much hardening effect. The big throat is the reason they still exist. Patternmakers used them a lot, but most every pure woodworking shop featured the 20-24" double wheel saw when I was a pup. Three-wheelers didn't resaw, but they could make patterns for molds of pretty good size, as long as they were no more than 4 inches thick.
 

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I think that some of the DoALL bandsaws where I worked might have been three wheelers because some had 36 inch throats and if I am not mistaken others had 48 inch throats. They were real behemoths.

BTW, when it comes to work hardening from flexing, it does not matter how far around a wheel a blade wraps if the contact distance is enough to flex a gullet to the curvature of the wheel. Determining that angle is not quite as easy as it appears because aerodynamic pressure makes the blade tend to float at one end and stick at the other.
 

odie

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Decided to order one 3/8" and one 1/2" alternate set, 3tpi, carbon steel blades from carbide.com.....and did that yesterday. If a bi-metal blade had been available in this configuration from this supplier, I probably would have gotten one of those, too......

Thanks for all the input here......it forced me to learn something I didn't know. This is the real reason I participate on this forum.....self improvement. I suspect there are a few here who are not of the same frame of mind.

I've used the 3/8" positive claw Timberwolf blade probably a dozen times since having any trouble, and it's been cutting smoothly and quickly......as it should. Since it's only been a couple of weeks since it was removed from the packaging, and is new and sharp.....those who keep suggesting I'm using a dull blade should take note of these things. I checked back on the bowl blank that was giving me so much trouble, and see that it was 26 percent MC, so that probably needs to be factored into the equation. I believe everything since then has been in the 18-22 percent MC range. The troublesome bowl block was sold to me as Goncalo Alves, but I've got suspicions that it's not......but, it could be. Grain looks similar, but I've done quite a few Goncalo Alves in the past, and it's not quite the same.

Note: It is per my usual procedure, to take bowl blanks that aren't completely flat on the bottom surface, to make a flat surface on the 6x48 belt. Occasionally I have to use wedges on very large blanks, to have a stable platform for bandsawing. Anyway, the troublesome bowl blank was flat, and not subject to tipping while being cut........best I can figure, is it had to do with the positive claw configuration, in combination with moisture content, and species.....(and, the species is questionable for positive identification.)

ooc
 
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Odie , don't take this the wrong way but your comment,
"Since it's only been a couple of weeks since it was removed from the packaging, and is new and sharp.....those who keep suggesting I'm using a dull blade should take note of these things."
makes little sense to me, since I find it to be out of context.
I don't know what or how much you cut in a couple weeks and a BS blade can be dulled in an instant. Just as everyone seems to have their own definition of sharp, they also have their own definition of dull.
I hope you have good luck with your new blades.
 
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I have found wet black walnut to be the worst thing for my bandsaw blades, It might be the high acid contend. They just go dull a lot faster when cutting it.

robo hippy
 

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Odie , don't take this the wrong way but your comment,
"Since it's only been a couple of weeks since it was removed from the packaging, and is new and sharp.....those who keep suggesting I'm using a dull blade should take note of these things."
makes little sense to me, since I find it to be out of context.
I don't know what or how much you cut in a couple weeks and a BS blade can be dulled in an instant. Just as everyone seems to have their own definition of sharp, they also have their own definition of dull.
I hope you have good luck with your new blades.

I was about to say the same thing, so thanks for saying it for me and possible others as well. Odie, I think if you view this from the perspective of those offering help that the rest of us do not have your advantage of actually seeing and using the blade nor do we fully know the extent of your knowledge and experience with bandsaw blades. As a result, we are to some extent, shooting in the dark and hoping that some of the shots hit the target.

Now that I have said that, I and others did spend some time and effort earnestly offering what we thought might be of help. It is obvious that not everything offered is dead on target, but so what? Weren't all suggestions genuine offers of help? Time to dismount from your high horse.

I am sure that everything mentioned was useful to somebody reading the forum. There are lurkers, you know. Maybe they don't participate because some of the regulars, including your's truly may be a little curt from time to time. I'll try to wag a more civil tongue (starting with my next post) -- and when I forget, you and other need to remind me.
 

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I have found wet black walnut to be the worst thing for my bandsaw blades, It might be the high acid contend. They just go dull a lot faster when cutting it.

robo hippy

There is not much black walnut around here, but I discovered a couple years ago that sometime it can dull tools almost instantly. Alan Lacer was at our club for a week of hands on classes and one of the things we were doing was using a skew to turn some green black walnut. It was giving everybody in the class fits. Alan said to me, "Your skew isn't sharp", so he sharpened it. Next, he said, "You must be using the skew wrong", followed a bit later by, "Let me show you", followed by, "there is something wrong with the steel in your skew", followed by, "I'll show you with my skew", followed by, "what the heck is going on here .... ?" The problem was the black walnut. One of the guys in the class had access to a scanning electron microscope in the lab where he worked and what he saw looked like sandpaper -- large crystals of silica. He brought some photomicrographs to the class the next day to confirm the silica problem.

Well my project was a tool handle for a Thompson bowl gouge and I was not going to let that little bump in the road deter me. After the class was done, I decided if you can fight fire with fire then why not fight sandpaper with sandpaper. That's what I did and that's why sandpaper is a turning tool. :D

By the way, the tool handle looks pretty good and nobody would know how it was turned unless I told them.
 
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odie

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I was about to say the same thing, so thanks for saying it for me and possible others as well. Odie, I think if you view this from the perspective of those offering help that the rest of us do not have your advantage of actually seeing and using the blade nor do we fully know the extent of your knowledge and experience with bandsaw blades. As a result, we are to some extent, shooting in the dark and hoping that some of the shots hit the target.

Now that I have said that, I and others did spend some time and effort earnestly offering what we thought might be of help. It is obvious that not everything offered is dead on target, but so what? Weren't all suggestions genuine offers of help? Time to dismount from your high horse.

I am sure that everything mentioned was useful to somebody reading the forum. There are lurkers, you know. Maybe they don't participate because some of the regulars, including your's truly may be a little curt from time to time. I'll try to wag a more civil tongue (starting with my next post) -- and when I forget, you and other need to remind me.

No "high horse", Bill.........what about the dozen, or so bowl blanks I've cut since the problem bowl blank? You did understand that the blade has cut well before and after the problem bowl blank, didn't you? Those cut fine and smoothly, as I said before. All I'm saying is the band saw blade is sharp......if you are disputing that, well, I don't know what to say, other than the blade is only a couple weeks old, and cutting like a sharp blade......you can take my word for it.....or not.

Let's take it from there, and just assume my band saw blade is sharp. There are other factors that are subject to discussion, and/or speculation.

At this point, I'm feeling confident that the problem is the tooth configuration of the 1/2" blade I was using, and the current 3/8" blade I am using, in conjunction with the species and moisture content. I have some new blades on the way with alternate set. If I have the same problem with those, I'll be sure to restart this thread and open it up for discussion. Thanks to some independent internet searches, and links you posted, I did learn something, and I thank you for that.

ooc
 
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No "high horse", Bill.........what about the dozen, or so bowl blanks I've cut since the problem bowl blank? You did understand that the blade has cut well before and after the problem bowl blank, didn't you? Those cut fine and smoothly, as I said before. All I'm saying is the band saw blade is sharp......if you are disputing that, well, I don't know what to say, other than the blade is only a couple weeks old, and cutting like a sharp blade......you can take my word for it.....or not.

Let's take it from there, and just assume my band saw blade is sharp. There are other factors that are subject to discussion, and/or speculation.

At this point, I'm feeling confident that the problem is the tooth configuration of the 1/2" blade I was using, and the current 3/8" blade I am using, in conjunction with the species and moisture content. I have some new blades on the way with alternate set. If I have the same problem with those, I'll be sure to restart this thread and open it up for discussion. Thanks to some independent internet searches, and links you posted, I did learn something, and I thank you for that.

ooc

I'm glad you learned more information about bandsaw blades, but the main point Bill and myself are trying to make is, don't admonish people who are genuinely trying to help with a question you posted.
 

odie

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I'm glad you learned more information about bandsaw blades, but the main point Bill and myself are trying to make is, don't admonish people who are genuinely trying to help with a question you posted.

Ed......I think you and Bill are reading something into what I said.......:D

.....and, thank you for trying to help.

All I was trying to point out is the blade is sharp. I've been using a personal band saw for much longer than the 30 years I've been turning bowls on a lathe, and I may have had something to learn about tooth configurations of band saw blades......but, I know when it's cutting well enough to call it sharp.

ooc
 
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Can anybody here tell me the difference of bi metal and carbon blade in terms of performance.
Sorry . I didn't mean to hi jack this post.
Thanks in advance.
 
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It would be about the same difference as there is between carbon steel turning tools, and the high speed steel turning tools. They hold a good sharp working edge a LOT longer.

robo hippy
 
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Bi-metal blades have HSS alloy tips on a flexible back. Not quite like carbide tips, which are also available, but ahead of induction-hardened teeth on standard blades.

For fresh wood, even if you wash it, I think you'll find it's the grit in the bark which dulls. The alloy will be scored just as rapidly as the carbon with the dirt, though it's more resistant to heat and wear, which makes it dandy for dry and clean work. Excellent for metals.
 

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It is surprising how much silica some wood contains. Black walnut may be among the worst, but white oak is up there too. When you get a piece that is especially high in silica, it can dull a blade rather quickly.
 
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It is surprising how much silica some wood contains. Black walnut may be among the worst, but white oak is up there too. When you get a piece that is especially high in silica, it can dull a blade rather quickly.

Since I took to WD40ing the blade after use with those acid woods, blades have lasted longer. Corrosion is a player.
 
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Well, I don't do much oak, but have been through a lot of walnut. It really does dull the blades and turning tools faster than most other woods. I always figured it was because the wood has a higher acidic level than other woods. Not sure about the silica though. I did have a board of Ipe, and if you laid it out in the sun, it would glitter.

robo hippy
 
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Saw it, but since I have not experienced what he claims, I let it go as hearsay.
 

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Saw it, but since I have not experienced what he claims, I let it go as hearsay.

OK, but Alan, I, and five others were there in the class at the shop of one of our club members. Beyond that there is not much "evidence". Alan was as sceptical as you are about silica until the classmate used the SEM where he works to get the images that showed a huge amount of silica. My piece of the black walnut is now a handle for a bowl gouge and I am not willing to surrender it to the advancement of science by destructive analysis to confirm or discredit my wild haired claim. Several years ago I turned one other piece of black walnut in a swap with someone from up "Nawth" on Sawmill Creek. I sent him a piece of mesquite in return. I don't know if it could be something like the alkaline soil here that was responsible for the difference, but that first piece of Yankee walnut turned without any problems that I recall.
 
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Several years ago I turned one other piece of black walnut in a swap with someone from up "Nawth" on Sawmill Creek. I sent him a piece of mesquite in return. I don't know if it could be something like the alkaline soil here that was responsible for the difference, but that first piece of Yankee walnut turned without any problems that I recall.

It's the arboreal version of Don't mess with Texas.:D
 
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bk walnut causing dulling of gouges

I have turned a few (10-15?) pieces of bk walnut-some green and some fairly dried out. I normally use 5 gouges at a time before re sharpening. Haven't really noticed a problem with BW dulling quicker than others. Must be the midwest clay/sand soil!! Gretch
 
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Hmm, the silica got me thinking about myrtle/california bay laurel. It does dull the tools fairly quickly. Always figured that since the best stuff comes from the coastal areas there was more silica in it than normal woods.

So, if a wood has high silica content, is that some thing that the tree produces, or some thing that it sucks up from the surrounding soil?

robo hippy
 

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I did some Internet searching and found that there are 21 species of walnut. The piece that I got in the Alan Lacer class which was cut locally seems much denser than the walnut that I got in trade from another turner in the northeastern part of the country. The few walnut planks that i have bought were comparable to the lighter walnut. The piece that I got in the class is also much darker in color compared to other walnut that I have seen.

I have found next to nothing about silica in wood although i know that local white oak (primarily post oak) is moderately high in silica.

UPDATE: Rather than silica, the mineral deposits seem more likely to be calcium carbonate. That would seem more logical since the ground water in north Texas is quite hard. Apparently most hardwoods can get calcium carbonate deposits. In an urban forest, it is more likely where the water source for the trees is from deep aquifers where the water is hard. However even shallow wells are likely to be hard with a high calcium content due to shallow limestone formations.
 
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As you no doubt encountered in your searches, silica has some solubility problems. Wants pretty acid conditions to get into solution. Unless it's in solution, the tree can't transport. Silica is an abundant (#2), albeit weird element. If there's a non-carbon-based life form somewhere in the universe, it's probably based on silica, with silanes that mimic carbon chains. Tree likes it if available, perhaps because of the structural mimicry.

Calcium, as you no doubt discovered, is more soluble. It'll get into the tree and you'll find it pretty much where you find silica - those places where the water transport slows so that it can combine and stay behind. Calcium oxalate is the poison in a lot of leaves, the stuff of mineral stain in maple, and kidney stones. :mad: Look at that greenish cast in the confused grain under a branch. Probably calcium salt of some sort, likely oxalate.
 
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Thanks for the more in-depth information on silica and calcium.
Please correct me if I'm wrong, but all trees are susceptible to either or both of these elements, which can make them more difficult to machine and dull tools much quicker than usual. Which brings us back to Odie's OP, where he had a piece of Goncalo Alves that was much harder to cut than normal. The blank he was cutting may have a very high mineral content due to where it was growing. Also there are two different species of Goncalo Alves.
Goncalo Alves South American {Astronium fraxinifolium}
Goncalo Alves Central American {Astronium graveolens}
One, the graveolens species, is the harder of the two.
 

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As you no doubt encountered in your searches, silica has some solubility problems. Wants pretty acid conditions to get into solution. Unless it's in solution, the tree can't transport. Silica is an abundant (#2), albeit weird element. If there's a non-carbon-based life form somewhere in the universe, it's probably based on silica, with silanes that mimic carbon chains. Tree likes it if available, perhaps because of the structural mimicry.

Calcium, as you no doubt discovered, is more soluble. It'll get into the tree and you'll find it pretty much where you find silica - those places where the water transport slows so that it can combine and stay behind. Calcium oxalate is the poison in a lot of leaves, the stuff of mineral stain in maple, and kidney stones. :mad: Look at that greenish cast in the confused grain under a branch. Probably calcium salt of some sort, likely oxalate.

For the benefit of others who may not have been "into" chemistry since high school, a minor clarification should be made. From the early hour of your post at 4:22 AM (or possibly a really late night post :)) and the probability that you were still waiting on Mr. Coffee, it would be most reasonable to assume that you intended to type "silicon" rather than "silica" given that you made reference to the element and not the compound "silicon dioxide" which is the chemical name for silica, AKA sand.

Maybe there actually are silicon based life forms all around us and we don't recognize it (them) because of the absence of any characteristics that we identify with "life". I think that Dr. Asimov entertained such an idea in "Planets Have an Air About Them".

Regarding calcium carbonate, I am coming to the conclusion that there is no particular species of domestic hardwood that is more likely to contain deposits of the mineral, but rather, it depends on where the tree grows. Limestone is likely to be found either on the surface or not too far down where a tree root system gets its water around here and in much of Texas. My assumption that post oak and other white oak species contain a lot of mineral deposits is probably because they are the predominant native species of tree around here and not that it is an oak characteristic. It could also be that oaks prefer growing in this type of environment which sort of makes mineral deposits a characteristic of the wood. Likewise, the urban black walnut that gave us fits would be more likely to contain mineral deposits because of where it was grown and not some characteristic of the species.

I found only a small mount of information about mineral deposits in wood in Hoadley's book, "Understanding Wood", but nothing related to an association with species. Similarly, the FPL Wood Handbook briefly mentions mineral deposits in domestic hardwoods only from the perspective of workability in Chapter 3:
Hard deposits in the cells, such as calcium carbonate and silica, can have a pronounced dulling effect on all cutting edges. This dulling effect becomes more pronounced as the wood is dried to the usual in-service requirements.
I noticed that the current online version of the handbook has been updated with many changes since my 2003 and 2006 editions that I have on my computer -- something else that I need to download and clog up my hard drive.

Along a similar line of thought, many of the folks from the panhandle area of west Texas never had a tooth cavity because the ground water is naturally fluoridated and not because they are a different species (possibly silicon based :)).
 
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Along this line I have turned some elm, maple and cottonwood that have really stunk up my shop and other logs of the same species that weren't to bad. I conclude the really smelly stuff grew by sewer lines and the others didn't.:D
 
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At least I was half awake. Coffee was a nice Italian roast to compliment the cinnamon toast, BTW. Silica does have solubility problems, but it is composed of silicon and oxygen.

As to sewer lines and smells. The willow that cost me several hot, fragrant summer hours with a hatchet and hook to get the roots out of my septic tank smelled pretty much the same under sandpaper as the one that grew out front. I think it has more to do with the amount of water captured in the heartwood and how log it's had to stagnate.
 
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band saw blades

Silica SiO2 is sometimes thrown around losely. It will precipitate out of solution with no crystalline form and be rather soft. The hard form of it most common is quartz which is quite hard. There are 4 other forms, crystabolite and tridymite, similar to quartz. The other two, coesite and stishovite are high pressure forms found only in metorite impact craters. I have heard but cannot verify that teak from Indonesia is rich in quartz giving a very dulling effect to tools. Now that the USGS has an organic branch maybe they will investigate the chemical uptake and reactions of trees with the soil.

One other important item. When I lived in Texas we would take a piece of Texas quartz and boil it in coffee all night. Come morning it was soft as a donut and tasted like hambone.

Correction the correct spelling is cristobalite.
 
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Bill Boehme

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... One other important item. When I lived in Texas we would take a piece of Texas quartz and boil it in coffee all night. Come morning it was soft as a donut and tasted like hambone.

Hey, Wayne. how well does the quartz donut wash down with the trail coffee? :D I hear that a dried cow chip is even better than chicory. We Texans are known for spinning a yarn now and then, but I try to keep 'em believable. :D

Thanks for the information on the various forms of SiO₂. When I looked at the USDA Forest Products Laboratory site I got the impression that the bulk of their research now is to support the lumber industry in areas such as engineered wood products rather than more academic questions such as mineral deposits in wood.
 
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This thread has actually become very interesting. A number of us here in Hawaii ponder many of the blade issues brought up here. The worst wood I have ever put through the bandsaw is Sausage tree. Takes a new blade to garbage real fast. The wood is so nasty it rounds over state of the art tool steel in moments. We have volcanic soil so nothing really nasty in the water. But all of us seem to use the term silica. Something nasty has to be in the wood. Next is Ulu(breadfruit). Both these woods are pretty soft in comparison with say Koa. And very fibrous. And most of us assume coconut palm has piles of silica in in it. Tough on blades and tools. so it seems that sand can not get sucked up into the pores? Do I got that right or am I missing something? Very micro perhaps and then getting lodged like a log jamb? Any one help clarify that? Seems I am reading different answers and ideas.
 

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Decided to order one 3/8" and one 1/2" alternate set, 3tpi, carbon steel blades from carbide.com.....and did that yesterday. If a bi-metal blade had been available in this configuration from this supplier, I probably would have gotten one of those, too......

Thanks for all the input here......it forced me to learn something I didn't know. This is the real reason I participate on this forum.....self improvement. I suspect there are a few here who are not of the same frame of mind.

I've used the 3/8" positive claw Timberwolf blade probably a dozen times since having any trouble, and it's been cutting smoothly and quickly......as it should. Since it's only been a couple of weeks since it was removed from the packaging, and is new and sharp.....those who keep suggesting I'm using a dull blade should take note of these things. I checked back on the bowl blank that was giving me so much trouble, and see that it was 26 percent MC, so that probably needs to be factored into the equation. I believe everything since then has been in the 18-22 percent MC range. The troublesome bowl block was sold to me as Goncalo Alves, but I've got suspicions that it's not......but, it could be. Grain looks similar, but I've done quite a few Goncalo Alves in the past, and it's not quite the same.

Note: It is per my usual procedure, to take bowl blanks that aren't completely flat on the bottom surface, to make a flat surface on the 6x48 belt. Occasionally I have to use wedges on very large blanks, to have a stable platform for bandsawing. Anyway, the troublesome bowl blank was flat, and not subject to tipping while being cut........best I can figure, is it had to do with the positive claw configuration, in combination with moisture content, and species.....(and, the species is questionable for positive identification.)

ooc

Just a note to let those interested know.......I have received the two band saw blades from Carbide, and have not used them yet. I'll continue to use the Timberwolf blade until there is a problem, or until it becomes dull.

Since that one bowl that gave me so much trouble, and was the initial inspiration for this thread, the Timberwolf positive claw blade continues to perform perfectly. Although not the same species as that one troublesome bowl, (sold to me as Goncalo Alves, but I've got some doubts that it was labeled correctly), yesterday, I roughed three bowls that were well above 30 percent MC. Since starting this thread, I've roughed about 10-12 bowls.....all with no issues.

I don't know what can be deducted from all this, but this particular Timberwolf blade doesn't appear to be the problem.

An alternate set tooth blade is the best overall choice for my purposes......

Thanks to those who contributed to the content of this thread.

ooc
 

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This thread has actually become very interesting. A number of us here in Hawaii ponder many of the blade issues brought up here. The worst wood I have ever put through the bandsaw is Sausage tree. Takes a new blade to garbage real fast. The wood is so nasty it rounds over state of the art tool steel in moments. We have volcanic soil so nothing really nasty in the water. But all of us seem to use the term silica. Something nasty has to be in the wood. Next is Ulu(breadfruit). Both these woods are pretty soft in comparison with say Koa. And very fibrous. And most of us assume coconut palm has piles of silica in in it. Tough on blades and tools. so it seems that sand can not get sucked up into the pores? Do I got that right or am I missing something? Very micro perhaps and then getting lodged like a log jamb? Any one help clarify that? Seems I am reading different answers and ideas.

I think that the exact mechanism for mineral deposits in wood is still something unanswered ... at least for woodturners. Maybe some one in the Forest Products Laboratory knows.

I am sure that any minerals would need to be in solution in the ground water in order to be taken up by the roots. In addition to SiO2 being the largest part of volcanic soil, I know from the smell of vents when I visited Hawaii in 1974 that there is also a lot of sulfur so the ground water is probably acidic where these trees grow which I think would help dissolve some of the minerals. Any mineral that can be dissolved to some degree, even if only a very small amount, can amount to something significant considering the huge volume of water that a tree drinks. I believe that most of the water ends up in the leaves, at least in deciduous trees, but I can envision some minerals building up in the wood sort of like hardening of the arteries.

Anyway, that is my story until a wiser person comes along and sets the record straight.
 
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bandsaw blades

Kelly-This is my attempt. The Hawaiian Islands are composed of a rock that is basaltic, about 52 percent SiO2 by chemical analysis. This does not mean that there is a mineral SiO2 in some form that comprises 52% of the rock. It means that there is Si when combined with oxygen would total 52% of the rock. It could be from one mineral or a dozen minerals combined. The magma when ejected cools rapidly and the elements do not have time to segregate into various minerals , the rock is homogeneous, rather like a glass , individual crystals are not visible.

Now take this rock, grind it up and spread it on your flowers or your tree. Will the tree take up the particulate material or only that that dissolves . I don't know but if it takes up particulate material it will be abrasive just like the rock is abrasive.

If the rock were granitic it would contain 72% SiO2, some of it in the form of quartz which is quite hard and abrasive.

Finished - excuse the verbose Odie
 
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If the plant could somehow push solid material through its vessels, how would it discriminate? It would take in any stray grain of whatever, not just silicates. The mechanism of uptake is known. http://www.eplantscience.com /bota...ficial_elements/silicon/silicon_in_plants.php

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC42876/ et cetera As this article reminds us, we can thank silicon for the first sandpaper - horsetails - which preferentially pick up silicates. Note, also that one of the silicon-loving plants is sugar cane.

It's only a bit of chemistry to produce our friend SiO2 and others in, as the first article states "nanometric, microscopic and macroscopic dimensions." I'm going to go out on a limb and say that the first two probably don't play a large role in abrading our edges, but the third might.

I once picked up a few hundred BF of hard maple from a kiln near an iron mine. The trees had grown downwind of the operation for many years, and the surface looked pink. If ever there was a chance to get solids in wood, that was it. Sadly, it was only casual surface dust from the kiln which was located in old concentrator buildings.
 

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This has become a most interesting and enlightening thread that has "evolved" from a bandsaw blade question and I think that we have all learned more about wood in an unexpected way. I have had a few "aha" moments as more dots got connected.

Odie, I hope that you don't mind too much that your thread has been hijacked, although I have a feeling that you also have appreciated the evolution. In a sense, the subject has not really changed -- it has only delved deeper into what make some wood hard to cut and why does some wood dull cutting edges so quickly.
 
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