Thread: Problem with continuous grain alignment

https://www.google.com/search?q=medu...t=firefox-b-ab
A tree is basically tapered in height and as explained in the above link, it depends how the original pieces were milled ie: quater sawn or live sawn
https://www.google.com/search?q=quar...t=firefox-b-ab
https://www.google.com/search?q=live...t=firefox-b-ab

As RW said its the way it was milled. In basic terms the grain on the right hand side of the board is higher than then left due to the cut of the timber and where the growth rings run along the timber. you will never get grain alignment this way. for best alignment use the full length not thickness sliced in half. see attached pic the first shows an exaggerated grain pattern nd how its off once sliced. 2nd part is how to best align grain.

Sorry, Joe, I didn't even look at who posted this thread. Has the postman been yet? AP can be hit and miss, unless they are all on Queensland time!! Hahaha

This happens to me on the odd occasion but as you say i just trim them and lose a bit of height.

Originally Posted by Dengue

Can anyone please explain why this is so, and how to get around it?


Resaw-1.JPG

in the photo of the timber going through the bandsaw, you will notice that the growth rings are running in a diagonal direction from top left to bottom right. The width of the kerf is causing the same growth ring to be slightly higher on one piece than the other.

Hi Joe,
The first picture shows you slicing the wood long grain in the bandsaw....the second shows you joining the two pieces endgrain as you would normally make a mitred box. Are we looking at the same piece of timber?
I understand your issue about different heights but the pictures have me puzzled.

The wider the kerf, the greater the grain misalignment unless the rings on the end-grain are nearly perfectly flat across the board. (ie. perpendicular to the face, as in theoretically perfectly quarter-sawn.)

Originally Posted by Ruddy

Hi Joe,
The first picture shows you slicing the wood long grain in the bandsaw....the second shows you joining the two pieces endgrain as you would normally make a mitred box. Are we looking at the same piece of timber?
I understand your issue about different heights but the pictures have me puzzled.

I believe he's book-matching the faces on the inside of the cut. That way you can get the grain to match on all four corners of the box. 1 end & 1 side from one piece, one end & 1 side from the other.

If you just dock one length into the 4 pieces you can get 3 corners beautifully matched but the 4th corner where the two ends of the board meet?

Hi Skew...
I can see the book matching but that does not explain the two pictures....

Hey Ruddy, these are two pics from an article on making mitre boxes with continuous grain, so I cannot verify that it is the same piece in both pics. I chose them because it was a good illustration of the problem ( a pic worth a 1,000 words). And the timber is beautifully quarter grain cut, so there should be no mis-alignment.

Skew, you are right. I only try to match the two inside surfaces that have been cut during the resaw, and these form the outer sides of the box. Also, spot on with the one thin length of board for a box. You can only get 3 of the four corners continuous. I always select the front long side first, with the nicest grain, then the two side pieces either side of that, and make sure the mismatched joint is at the rear of the box. Not always easy, depending where the good grain is located on the board

Finally, an admission. I still can't get my head around why the two boards are misaligned It is something I often experience with my boxes, and quite annoying. And I have been using a Laguna Resaw King blade with 1.0mm kerf

The grain in the boards become misaligned because the growth rings are not always running perpendicular to the faces. Often they run slightly out with quartersawn material. In the photo you used, the growth rings are at about a 50° angle (riftsawn). Riftsawn material will give usable boards so long as you resaw the board and then rip the boards to width afterwards. Backsawn material will be unusable for a 4 corner bookmatch, it won't even look like it was bookmatched at all.

Below is a few images I cooked up to try to help explain what is going on with riftsawn material.

The first is an image of a 150x35 board with the growth rings running at 45° to the faces.
box side misalignment3.jpg

Then I have resawn that billet into 2@150x15 losing a whopping 5mm kerf.
box side misalignment2.jpg

Now I can measure the growth ring offset between the two inside "bookmatched" faces. To align the grain after resawing, I will need to remove 5mm from the top edge of one board, and 5mm from the bottom edge of the other.
box side misalignment1.jpg

Thank you Kuffy, that is now crystal clear. Many thanks for taking the time and effort to do the drawings. Another case of a picture worth a 1,000 words. I particularly like the isometric view with shadow, very classy