Wood stability and how it is cut

Chopdoc

Chopdoc

AzB Silver Member
Silver Member
There is an interesting discussion in the main forum about how Paris snooker cues are produced by hand planing, not by turning on a lathe.

I posed a question there and thought I might toss it here as well for potential expert thought on the matter. I realize there may be no known certain answer. Then again, maybe you guys do know.


What I am curious about is this:

Producing the cue by planing cuts the wood with the grain. Producing the cue by lathe cuts the wood essentially at 90 degrees to the grain, across it.

What effect, if any, does this have on the wood. Does it have anything to do with stability of the wood?

Or is it in fact incidental?

Does it in effect have anything to do with stress relieving the wood? I understand it is only the surface fibers. But perhaps there is some cumulative effect?


Any thoughts on the matter are appreciated.

Lastly, have any of you heard of a "good" maple pool cue being made by hand planing? Or is there perhaps a maker that was or is known to produce maple pool cues in such a way?

I am very curious.


link to the discussion: http://forums.azbilliards.com/showthread.php?t=425411


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Cutting the wood by turning will leave 'tool-marks' on the surface of the wood
and as you've stated, at a 90* relation to the grain.
Those tool-marks are most effectively removed by now sanding WITH the grain.
This is done using varying grits of sandpaper, starting with the coarsest grit
and progressing to the finer grits until all of the marks are removed.
There is a phenomenon known as 'ghost-marks' which reside below the surface.
These are the result of 'shock' to the wood as it's being mechanically cut.
They follow the same path as the tool did and may not always be present.
Applying the sealer will generally confirm their presence.
Continued diligent sanding should remove them and the sealer is then re-applied.

HTHs, KJ
 
I see. I think I have seen these "ghost marks" on some of the cues hobbyists make and on lesser production cues. I wondered about them. It seemed to be a spiral in the wood under the finish.

It seems you are saying that how the wood is affected by cutting goes deeper than one might at first think. This is the "shock" you refer to.


Are you saying that proper finish sanding should negate any deleterious results of cross cutting the grain?




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Yes, if done diligently and with the knowledge that they could be present.

"Continued diligent sanding should remove them and the sealer is then re-applied."

Repeat as needed.
 
If you plane it, how does it become truly round?
By spin sanding the octagon?
That's more stressful to me .
I'm turning down .545" end shafts this weekend down to .535".
I use a thin kerf slot cutter on a cnc spindle.
Not one is warped so far.
 
Taking light cuts greatly diminishes the likelihood of ghost-marks. The wood hasn't been shocked as severely.
Repeated sanding can be a PITA but has to be done if you want your best finish.
One common distinguishing characteristic amongst CMs is : at what point do you say "that's good enough" ?
Ghosts are meant to haunt.
 
Hand planing is how snooker cues have been made for centuries. It is traditional and what has been and is still expected, It would be quite the feat to chuck up and turn a very thin 60" long cue. Europeans value tradition in a way that Americans disdain,. We are of the mind that newer is better as in Predator 314.....................................................z99., etc.

Cue makers sanding with the grain when there are variable speed lathes and dozens of different sandpapers available sounds like a snake oil sales man's pitch. I have done it both ways over 55+years and my results with a lathe are IDENTICAL to those without the lathe only a heck of a lot quicker. If you leave across the grain lines when you finish sanding, you skipped some grits. You are done with one grit as soon as the lines (Scratches) left by the previous grit are gone. By the time you've gotten to a well whiskered 600 grit, you're done.
 
Thank you for your input Mr Dayton. Your work and reputation are tremendous and I feel fortunate to have your participation here. I enjoy owning and playing with one of your cues as well.

It is a common misnomer that snooker cues tend to be longer than pool cues. 57-58 inches is the common size, even according to the Paris cue web site. They do also commonly use extensions as might be expected when playing on such large tables.

In fact, my own two snooker cues are a typical 58 inch length as I remember. I may have to get them out to confirm though as their dimensions are not in my cue collection database. An oversight on my part. To be candid, one is American made and the other Canadian. I did play in the UK for a year though, and their snooker cues were typically about the same length as my Joss pool cue. 58 inches.

In addition, we all know that one piece house cues for pool are commonly turned on lathes. So while unwieldy at such a length, certainly the machinery is not limited in such a way to prevent it.

I can imagine that to those used to turning much shorter two piece cue parts that full length cues are a bit unwieldy.

Thank you again so much for your thoughts. I can imagine that some can over-complicate even a simple graded sanding process, just as you imply.



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Paul Dayton said:
Cue makers sanding with the grain when there are variable speed lathes and dozens of different sandpapers available sounds like a snake oil sales man's pitch. I have done it both ways over 55+years and my results with a lathe are IDENTICAL.
Click to expand...

Sanding alternately with the grain and against the grain will remove the scratches quicker
and will remove less mtrl. in the process. Snake oil salesman's pitch; LMFAO.
Piloted Radial, now there's where it gets slick. Lol
 
KJ Cues said:
Sanding alternately with the grain and against the grain will remove the scratches quicker
and will remove less mtrl. in the process. Snake oil salesman's pitch; LMFAO.
Piloted Radial, now there's where it gets slick. Lol
Click to expand...

See here's a problem I have. My being raised around wood working tools and learning things, one thing I learned was to never, ever sand with the grain of the wood. If you put improper pressure when sanding with the grain, you can leave worse score lines in the wood than you are trying to get out. I would not sand with the grain with anything less than 400 grit because I've experienced the scoring issues with trying to finish cabinet doors too quickly. Yes it's an avoidable situation, but I avoid it by not using a technique that has been known to leave score marks.
 
Hits 'em Hard said:
See here's a problem I have. My being raised around wood working tools and learning things, one thing I learned was to never, ever sand with the grain of the wood. If you put improper pressure when sanding with the grain, you can leave worse score lines in the wood than you are trying to get out. I would not sand with the grain with anything less than 400 grit because I've experienced the scoring issues with trying to finish cabinet doors too quickly. Yes it's an avoidable situation, but I avoid it by not using a technique that has been known to leave score marks.
Click to expand...

Have you sanded shafts ????
 
Hits 'em Hard said:
See here's a problem I have. My being raised around wood working tools and learning things,
Click to expand...

How is it that you have a problem ?
You sand your way, I sand my way and others sand their way.
We all sand our different ways and are quite happy in doing so.
Was someone or something suppose to change because you have a problem ?
The only problem I see is the one that you have.
Can't help you with YOUR problem but thanx for sharing, we appreciate that.
 
Hits 'em Hard said:
See here's a problem I have. My being raised around wood working tools and learning things, one thing I learned was to never, ever sand with the grain of the wood. If you put improper pressure when sanding with the grain, you can leave worse score lines in the wood than you are trying to get out. I would not sand with the grain with anything less than 400 grit because I've experienced the scoring issues with trying to finish cabinet doors too quickly. Yes it's an avoidable situation, but I avoid it by not using a technique that has been known to leave score marks.
Click to expand...

Okay, I give up, if you don't sand with the grain, how do you sand? I ask because I've been finishing wood for 60 years and worked at it full time for 15 years, during that time I can honestly say that with the grain was the only way to hand sand. It has been since sanding started with the Egyptians Cross grain scratches on a piece of furniture meant it had to be done again. How do you leave score lines when sanding with the grain. Did some actual grains of sand get trapped under the sand paper or was your paper too coarse a grit?
 
I am far from any kind of expert on wood let alone pool cue construction.

I can say that in high school wood shop we were taught to sand with the grain. My parents were into antiques and they did a lot of restorations. I used to help some as a kid and my dad always had me sand with the grain.

Of course, we also had teachers that were getting high and sleeping with students so I am not sure how valid the information was.

I also have no doubt that there is more than one way to skin this cat.

But what I am really hoping to get at is how much if any the direction of the cutting, as in planing versus turning, might disturb or enhance the stability of the wood.

What we seem to have established thus far is that the cutting initially effects the wood to a deeper level than one might first suspect, but that the finish sanding process may negate that effect.


The conversation causes me to reflect on the shaft straightening tool we have seen advertised and demonstrated in the forums. It seems to work by altering the surface stresses of the wood fibers. It is a matter of some controversy but it does come to mine.


I would like to invite further thoughts on how or if the type of cutting may contribute to or detract from the stability of the end product?




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Re Ghost marking in wood,
This will occur when the cutter is cutting fine and still appears sharp but in fact is generating heat into the layers below the finished surface. Hand planes will do the same thing if you really push a dull plane. Hand planing also readily identifies the grain direction. Depending how the router is set up, the direction of cut is the vector of the work piece rotation velocity verses the cutter surface velocity and the velocity it is being feed along the work piece. An incline or decline depending on direction can reduce the apparent angle of contact with the wood, but really becomes more academic. Very sharp tools that cut cool have the lease stress put back into the material and that does not just apply to wood either. Sanding if it gets hot between the paper and the wood will put stress back into the wood surface. For some things this becomes desirable, for some it not desired.
Neil
 
Paul Dayton said:
Okay, I give up, if you don't sand with the grain, how do you sand? I ask because I've been finishing wood for 60 years and worked at it full time for 15 years, during that time I can honestly say that with the grain was the only way to hand sand. It has been since sanding started with the Egyptians Cross grain scratches on a piece of furniture meant it had to be done again. How do you leave score lines when sanding with the grain. Did some actual grains of sand get trapped under the sand paper or was your paper too coarse a grit?
Click to expand...

The growth rings of wood are harder than the sapwood, so when you sand with the grain you are removing more sapwood than growth rings leaving an uneven surface. Sanding across the grain puts more emphasis on leveling out the growth rings with the sapwood. Go test it for yourself. Get a piece of 400 grit and sand with the grain on a scrap pice of wood longer than you normally would. You should then be able to drag your finger across the grain and feel the growth rings. Do the same thing sanding across the grain and you won't feel the growth rings protruding.

As for the scoring lines, that can be the result of multiple reasons. Too fast of sanding. Too coarse of grit. Or the most common, you accidentally rip the sand paper and an edge folds under. But no matter what is causing the scoring, sanding with the grain has an increased chance of scoring. Such an increase, I avoid sanding with the grain because of how bad it can be.
 
conetip said:
Re Ghost marking in wood,
This will occur when the cutter is cutting fine and still appears sharp but in fact is generating heat into the layers below the finished surface. Hand planes will do the same thing if you really push a dull plane. Hand planing also readily identifies the grain direction. Depending how the router is set up, the direction of cut is the vector of the work piece rotation velocity verses the cutter surface velocity and the velocity it is being feed along the work piece. An incline or decline depending on direction can reduce the apparent angle of contact with the wood, but really becomes more academic. Very sharp tools that cut cool have the lease stress put back into the material and that does not just apply to wood either. Sanding if it gets hot between the paper and the wood will put stress back into the wood surface. For some things this becomes desirable, for some it not desired.
Neil
Click to expand...
So heat is a factor. I would expect that.

As you say it becomes academic.

But in the real world can it contribute to or detract from stability? Would the the the thoroughness of finish sanding determine this?

I was given one piece of advice by a master cue maker as I await my lathe. Patience. This may seem to apply.
 
Hits 'em Hard said:
The growth rings of wood are harder than the sapwood, so when you sand with the grain you are removing more sapwood than growth rings leaving an uneven surface. Sanding across the grain puts more emphasis on leveling out the growth rings with the sapwood. Go test it for yourself. Get a piece of 400 grit and sand with the grain on a scrap pice of wood longer than you normally would. You should then be able to drag your finger across the grain and feel the growth rings. Do the same thing sanding across the grain and you won't feel the growth rings protruding.

As for the scoring lines, that can be the result of multiple reasons. Too fast of sanding. Too coarse of grit. Or the most common, you accidentally rip the sand paper and an edge folds under. But no matter what is causing the scoring, sanding with the grain has an increased chance of scoring. Such an increase, I avoid sanding with the grain because of how bad it can be.
Click to expand...
So you spin sand shafts only?
You don't sand them lengthwise at all ?
 
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