Does the saw cutting the wood affect its quality

[lawyer_sawyer]

I was reading several things on this forum lately that had side comments on the pattern the blades make in the wood.  Circle saws leave a circular appearance on the wood and band saws leave straight lines.  I was wondering if there are any effects from the cuts.  does a bandsaw since it is always pulling wood grain one way loosen the face of the wood more than a circle saw or is this really a moot point.  I am just thinking in conjunction with cutting higher dollar woods to be used for mouldings does one type of cut create a more stable wood. 

I know cutting a wood quarter sawn tends to make it more stable but I guess I was just more curious about flat and rift sawn.

Thanks

[beenthere]

There is no effect to the wood below the surface fibers that are severed. The pattern talked about has to do with the size and number of teeth that are doing the cutting as well as the path the teeth take across the wood grain. If the teeth are not 'cutting' the wood, but instead tearing it loose, then the depth of the splinters can affect how much planing will have to be done to get past the damage.

[DanG]

I was reading, recently, on one of the Gov't or University sites about the effect of roughness on the service on the drying process.  Unfortunately, I don't remember exactly where it was.  Anyway, they were saying that planing the lumber before drying might reduce surface checking a tiny bit.  The theory was that moisture is more evenly removed from a smooth surface.  If that is true, then the band-sawn lumber might have a slight edge.  I have seen some circle-sawn lumber that was smoother than some band-sawn lumber, though.

[woodbeard]

One thing I noticed on wider boards I had cut on my swingblade mill with the double cut procedure is that a check was likely to start along the ridge where the two cuts meet, even if it was very slight.

[DanG]

Hmmm.  That seems to support what I had read about the rough surface.  I'll dig around and see if I can find that piece.

[IndyIan]

Woodbeard,
My guess is that the little step where your cuts meet acts like a stress riser in the wood so when the surface goes under tension as it dries the weakest point is on that step.
Its sort of like when you score glass or tile to break it, you've hardly done anything to the material but it still breaks there because that small scratch increases the effect of the stress you use to break it.
Also timber framers don't leave sharp notches on the bottom of floor joists where they rest on the beams for this same reason, they taper the cut back and this reduces the stress riser effect.
Ian

[woodbeard]

Yeah, that's kinda how I was visualising it, but wasn't sure if that was really what was going on. Makes sense, though.

[ARKANSAWYER]

   Yes it does!  Logs sawn on a WoodMizer mills are happy about it.


  All mills cut in one direction and as long as the tooth is sharp there is very little tear.  As for high dollar woods a band mill will waste less of it.  You would think a rough board would dry faster with more surface area.

[beenthere]

You would think a rough board would dry faster with more surface area.

Arky may be onto something here. If 'rougher' does dry faster, it may cause the surface checks because it is drying faster. Hmmm? 

[Bibbyman]

We've heard from our lumber broker that he really likes the band sawn lumber as it's easer to grade.  Using a sharp, well set blade makes for some pretty nice looking uniform lumber off the mill and that presentation may make some difference in how it's graded. 

I've also heard from a cabinet parts manufacture that dries and processes 10mbf of red oak a day that lumber sawn on a circle sawmill would need to be thicker because of the heavier saw tooth marks and the damage the sawing causes even below the dept of the saw tooth marks.

But I don't think it actually makes any difference in the real quality of the lumber. 

[Cedarman]

When we plane cedar that is well sawn on our bandmill, ( no humps and accurate) we can plane 1/32 and get a smooth board.  We usually take off 1/16 and get 99 per cent clean up because of a few missawn boards.  Circle sawn boards require between 1/16 and 1/8 to clean up.  Hence the reason to saw 1 1/16 to dry and clean up to 3/4 when using a circle saw.  As said before keep your blades sharp to reduce pull out.

[lawyer_sawyer]

thank you all for your answers
If I am reading this right it sounds as though the Bandmill while having a thinner kerf also saves money when it comes to the planing and so another saving in wood that could have been wasted in some form of sawdust or another.
Also it sounds like there is a potential for a more even drying process on the product coming from a bandmill.
Thanks again