Jointing lumber question

[Brian Runau]

I have a Grizzly G0586 8" with a decent length table. I got some quarter sawn white oak from Frank Miller lumber near Richmond, IN last fall and it has been in my basement shop since then. I have a dehumidifier in the basement. Frank Miller does a lot of QS and is known for it and very reasonable prices.

My problem. I took down a 4-1/2 to 5" wide @8 ft board today and cut off about 8" on one end that had a knot and discoloration. I cut two 39" pieces out of what was left to mill for a drawer front. I like to work so I can cut out the sap wood where possible. Both these board went through the jointer in a very weird way.

I mill through cupping side to side and end to end etc... but these pieces hit the blades on the first 6" or so then no contact, then 6" or so in the middle of the board then no contact, and then hit the blades on the last six inches on the first pass. I was able to mill them flat, but I've never seen a board that had undulating cupping in it and not two piece cut from the same 8ft piece.

Any idea why it did this?

Thanks.

Brian

[Mel Fulks]

I’m not sure I’m understanding all of that. But, it’s best to face with convex side of board on the machine. Because that often makes the
board move straighter . All advice to face the other way is based on liability....not science.

[Brian Runau]

I’m not sure I’m understanding all of that. But, it’s best to face with convex side of board on the machine. Because that often makes the
board move straighter . All advice to face the other way is based on liability....not science.

Mel. The board was wavy from end to end and this was on the sanded one side of the board as it came out of the mill. Thanks brian

[Paul F Franklin]

Perhaps you were pressing down hard enough to cause the board to flatten enough in the middle to contact the knives again. When jointing bowed boards, especially 4/4 or thinner, you have to be careful to use minimum downward pressure and focus on pressing the board forward, not down. For a board that is bowed enough that it will require more than one pass to flatten, you don't even want to press down hard on the outfeed side except where the board is in full contact with the outfeed (the ends if you are jointing concave side, or the middle if doing it Mel's way).

But I have seen wavy stock before so it may have just been the board. Normally sighting down the board will give you a reasonable idea of what to expect.

[Andrew Seemann]

Wavy stock is not uncommon. White oak can be cantankerous during drying and, despite its stable reputation, quarter sawn can be ornery also. Years ago the old man had some white oak milled up. One of the pieces was 1/2" thick quatersawn. It was like a three foot by eight inch potato chip.

[Mel Fulks]

Brian, Glad you got the help you needed! Like Wagner’s music ...this post is “better than it sounds”. You are wise to ask
about anything you are not absolutely sure of. Stay safe.

[Jim Matthews]

Did you already joint one side to have a reference face?
If one is not available, some handplane prep might help. An alternative is to build a sled; longer than the board to be planed, narrower than the planer bed - to establish a reference face.

https://thewoodwhisperer.com/viewer-...s/planer-sled/



A properly Quartersawn board should be the most stable sample. Have you verified with a known good straightedge that the board is planar?

If it's twisted over the length, the planer rollers will try to keep the span between the rollers flat on the bed below the knives.

If the thickness of the board varies greatly, the rollers may have too much slack to take up which would tilt the board "up" toward the loose roller.

[Bill Space]

It sounds like that board was cut on a bandsaw mill, when the blade was getting dull and started to wander slightly as it was cutting.

[Tom Bender]

Wow, what happened to that tree?

[Brian Runau]

It sounds like that board was cut on a bandsaw mill, when the blade was getting dull and started to wander slightly as it was cutting.

Bill I think this is it. Thanks. Brian

[John TenEyck]

It sounds like that board was cut on a bandsaw mill, when the blade was getting dull and started to wander slightly as it was cutting.

This is most likely the problem. It happens when I mill lumber on my bandsaw mill if the blade gets duller on one side than the other, especially if I hit a nail like I did yesterday. Holy cow, the rest of the cut looked like waves. Milling lumber is not as easy as those who don't mill lumber typically think. There are at least 100 ways to fail, and counting.

As long as your stock is thick enough to face joint out those waves all will be well. It's just a problem with milling, not with the wood itself.

John