Thread: Grain orientation for jointer and thicknesser

Good question Jill,
Hoping you don't mind me tagging along for the answer.
Cheers, Crowie

no problems crowie, we are all here to learn, and share our knowledge where we can. This is what makes this such a great forum

I just assumed you would feed in the direction of the grain rather than against it. No real reason other than the thought that to feed against the grain it would be more likely to lift,especially if the blades weren't up to par

Ian

You would feed the timber in with the grain, BUT, Pine being what it is can be contrary. I normally do a really fast initial cut about 1mm deep quite fast to orient the grain and see what it does and then adjust as needed. I have found that if you go fast on that first cut, it will tear out quite visibly without doing much damage and generally if you turn it around the next cut will fix the tearout.

I guess that there are as many ideas out there as there is woodworkers, but this is what I do.

Robert

You feed the wood into the surfacer with the grain running uphill and into the thicknesser with the grain running downhill. An easy way to remember this when you're starting out is "using the surfacer is harder, like walking uphill."

Please excuse my poor ASCII art skills, the slashes are the (exaggerated) direction of the grain.

SURFACER <---- \\\\\\\\\\\\\

THICKNESSER <---- ////////////

Originally Posted by Scissors

..... the slashes are the (exaggerated) direction of the grain.

SURFACER <---- \\\\\\

THICKNESSER <---- ////////////

That's a smart way of representing it in a hurry, Scissors! I assume you mean the slashes to represent the grain lines viewed fom the SIDE of the board.....?

Also for the newbies: imagine the blades rotating into the wood - for the top one (surfacer or jointer) the blades are contacting the under side, whilst it's the top side of the board that gets the treatment in the thickneser.

Use the same technique to "read" the grain of a board for hand planing. There are other ways to do it, but this is by far the easiest & most reliable (as long as the edge is clean enough to see the fibre orientation).

Cheers,

Yup Ian, I should have mentioned that that's looking at the grain from the side of the board.

Thanks Scissors, that is a neat way of remembering it

Most of the boards I work with look like this:

//////////\\\\\\\\\\\

Hello Jill

As specialist and Dovetail infer, grain orientation in some boards varies over the length and there may be no best (or even good) feed direction.
However, when grain orientation can be seen on the board edge I mark it in exaggerated fashion with felt pen or chalk as shown here. Then, on a planer/thicknesser combo, referring to these lines, the rule is: on top, top leads, on the bottom, bottom leads.
Hope the diagram explains this.

Originally Posted by JillB

Can anyone please refer me to a good reference on the correct grain orientation of boards being fed into 1) a jointer and 2) a thicknesser to avoid any tearout?

Are there any special requirements when using radiata pine on these machines?

Jill, do you own a hand plane?
the grain orientation is the same with a hand plane as it is for power tool -- you always try to plane "down hill"
so for the jointer imagine that you've got a plane clamped upside down in the vice -- which way is down hill if you were to push the board over the plane. This is the direction of feed.

for the thicky, imagine the plane is right way up the plane -- push the borad in the same direction you would push the plane

I've always heard the "pet the cat" method. The cutter should attack the surface as if it were petting a cat. You don't want to pet the fur in the opposite direction that the fur naturally lays down...or you'll have a really angry cat, or piece of lumber.

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Regards

I like the pet the cat explanation, especially as not all the fur goes the one way