1/4 Sawn vs flat sawn for laminates

[DC]

I'm confused(what else is new). I'm looking at the last two pictures of the flat sawn wood. Don't those flames mean grain run-out? Am I missing something?

[Stick Bender]

Don when you flat saw you get that cathedrale grain pattern it doesent follow a ring it will be the belly side for bamboo backed bow !

[Hamish]

DC, With all types of backing lams you need to look at the grain on the sides to get true picture of how straight the grain really is.
Flat sawn lams can look like they have too many steps on the back. Check the grain on the side and if the run off  1:16 or more you have viable backing strip. For practical purposes a 1/8" thick backing strip, the grain needs to run from back to belly at no point less than 2" along the length. 1:16     1/8":2".

Same again for a quarter sawn board. At first glance  the edge might appear straight, have a very close look at the grain and the grain(use a loupe if necessary) may be skewed too much. Use the 1:16 ratio again.

Rift sawn is easy to see the grain lines on the edge. 1;16 ratio still applies.

For core or belly laminations you can get away with less, but always a best bet to use the straightest grain available.

[Stick Bender]

Hamish did a better job of explaining then I could but here is a couple of ruff pics ,the first is a side profile you can see how the grain is runing down the lam in betwen the chatter marks and a end view pic of the grain !

[Stick Bender]

End view

[willie]

what do you use for a grinder?

[Stick Bender]

I joint them flat on the jointer and run them threw ether the drum sander or the thickness planer the thickness planer is quicker and better tolerance for these thicker lams but for any thing under 1/4 in I have to use a sled with it and the drum sander becomes more accurate with thinner lams  at least for me.

[willie]

Sounds like a good plan, is your sander as precision as your planer? Factory built? sounds like taking lighter cuts helps with the consistent thicknesses.

Don.  If the ring count is up there, having flames is almost unavoidable, and if the flames direction alternates, then you are not doing so bad either.

[Stick Bender]

The drum sander is actually more precision then the planer but with longer lams you can't avoid the conveyor belt seem but with wood +- 2/1000  is about the best you can hope for .

[willie]

if the conveyer belt seam causes a divot in the sanded face, I would think you have a warranty claim

[Stick Bender]

Most conveyor feed systems have some kind of seem on the belts ,there are so called seamless belts but they usually don't come factory installed  at +- 2/1000 is splitting hairs with wood , raised grain or a speck of saw dust would cause that to ,in a perfect world you would like 0.000 but it's never happened for me with wood . there are guys that claim they get tighter tolerances by grinding there conveyor belts and trueing there drum paper.