Why does it look like this?

[Tenson Ashton]

Hi,

I just got some Beech from a supplier and two planks look like expected but one looks somewhat 'patchy' and darker than the others. If it just dampness or what? I have attached a photo that seems to show up the patchiness. The top one is the normal one and the lower one is the odd looking one.

http://img410.imageshack.us/img410/9308/wood.jpg

By the way, any tips on the best way to dry planks like this (~3m long 20cm wide 18mm thickness)? In the past I have just left them inside for a week or 2 before planing them to thickness, fixing and finishing them. They have already been dried in a kiln before I got them but they always warp a bit coming inside. It seems to work, but I was just reading in another thread about painting the ends when drying? Should I cut them to length before drying too, or should I let it dry as one long piece and then cut to length afterwards?

Thanks!!:)

[Mitchell Andrus]

I've seen this happen on boards that come out of the planer when the knives are dull...

I'm pretty sure the planer is picking up chips and instead of cutting through them, the knife just forces the chip into (onto) the wood making a small compression. This disturbance changes the way the light bounces off the surface.

....or sunspots. When in doubt, blame sunspots.
.

[Kelly C. Hanna]

I agree....planer chips. They will sand out nicely. A change of blades will eliminate that.

[Chris Gombola]

+3 My planer is doing that now and it's dull knives (I just haven't had the time...)


I agree....planer chips. They will sand out nicely. A change of blades will eliminate that.

[Cliff Rohrabacher]

When my J/P is mashing chips against the wood making little dents it's because I forgot to put the DC on .

[Rod Sheridan]

When my J/P is mashing chips against the wood making little dents it's because I forgot to put the DC on .

I thought I had the patent on that?

Regards, Rod.

[Tenson Ashton]

Thanks for the replies. It makes sense, the odd looking board has quite a few snipe marks. I will be thicknessing them anyway so its not a problem.

[Dave Hale]

I thought I had the patent on that?

Regards, Rod.

I want fair-use rights on the patent then. :)

[David G Baker]

When I buy red oak from the Borg the boards always have planer marks on them that have to be sanded out by me. When I buy it from my regular supplier he runs the wood through the sander prior to my leaving with it.

[David Keller NC]

By the way, any tips on the best way to dry planks like this (~3m long 20cm wide 18mm thickness)? In the past I have just left them inside for a week or 2 before planing them to thickness, fixing and finishing them. They have already been dried in a kiln before I got them but they always warp a bit coming inside. It seems to work, but I was just reading in another thread about painting the ends when drying? Should I cut them to length before drying too, or should I let it dry as one long piece and then cut to length afterwards?

Well, you're not exactly "drying" them - you're just letting them come to equilibrium with the average humidity in your shop. Some movement (warping, twisting, cupping) is normal with any species, it's just that beech is one of our less stable domestic woods. And what you've shown in the pictures was cut from a relatively small tree - there's both face grain and edge grain in the same board, and that generally accentuates the movement issue.

Generally it's unnecessary to paint the ends of the board - one does this when sawing up logs into boards, but that's an extreme case of moisture removal.

You should definitely leave the boards as long and as wide as possible for a couple of weeks until they come to equilibrium with the humidity in your shop. When you do start in on them, cut off the first 3 inches or so of either end of the board and throw that away - this part will likely be case hardened or have end checks that will propogate if used. Once you've cut the boards to rough length/width and straightened out the surface on jointer/planer, stack and sticker them overnight in your shop. Sometimes the act of taking wood off of either side and ripping the boards to width will allow them to distort a little, so if you're making something out of them tha must be absolutely straight and flat (like drawers sides, for example), you want an opportunity to give them a final pass on a planer before using them.

[glenn bradley]

Originally Posted by Cliff Rohrabacher http://www.sawmillcreek.org/images/buttons/viewpost.gif (http://www.sawmillcreek.org/showthread.php?p=1062436#post1062436)
When my J/P is mashing chips against the wood making little dents it's because I forgot to put the DC on .



I thought I had the patent on that?

Regards, Rod.

If you do, I owe you royalties.

[Andy Pratt]

Don't want to hijack the thread, but why is it better to leave the boards in larger sizes as they come to equilibrium? I would have thought that the smaller the board, the more it could essentially "show you what it's going to do up front" if you let it dry in smaller size as opposed to as part of a larger board.

For example - as you're bringing a large board to equilibrium, a small section of the board wants to cup, but the holding force of the larger board (assume less warping tendency in the rest) reduces the amount of cup in this small area. You cut up the large board and dimension it, now the small portion is on it's own and completes the rest of it's cup after you've already brought it down to rough size.

I suppose on the other hand, you don't know what it's going to do exactly, or to what severity, so how would you know how much in excess to cut each piece. You might waste more lumber doing it by the way in my example. By the way, I bring to equilibrium in large size too, but I never thought about doing it a different way, now I'm curious.

Andy

[David Keller NC]

Well, there's certainly a reason to saw a log thinner if you want thinner material, or thicker if you want thicker, because the thinner material will certainly dry faster.

From the standpoint of already-dry wood, I suspect the answer is a bit more nuanced. Wood does exhibit some plasticity that will "set" over time, so I would guess that having the board stay as one large piece to keep smaller sections of it from cupping, bowing or twisting until the whole thing "sets" would be beneficial.

But I think the reason most of us leave our lumber in the largest size possible is that we really don't know what we're going to use it for, and there's nothing worse than discovering that all of your mahogany stock is 4" too short for the case side you want to make...