Which way to cut to avoid the dreaded wonkiness.....

[Zeddedhed]

Having got through three (yes, three) sets of stiles in a recent door build I'm now half way through prepping set number four.

The previous three sets developed varying degrees of wonk, wind, bow, twist etc either after or close to the very end of the prep process to the extent where they were no longer useable at the desired thickness.

Set number 4 have successfully been brought down to thickness (44mm) and now require bring to width (90mm) which means ripping off about 55mm and then a couple of passes through the thicknesser.

I've attached a few images showing the boards as they are now. You'll see that the LH board whilst mostly straight grained has several knots along it's RH edge. knowing that knots potentially mean stress points in the timber, which would be the best way to go here - remove the bulk of my waste from the knotty side, leaving the timber free from the knots, or leave the knots in. I'm really not bothered about aesthetics here. I simply want to avoid adding to my stack of bowed and twisted door stiles.

 

[Jacob]

Ripping an already planed board is a mistake (it'll move).
You should saw (crosscut and rip) to near finished size including length before you plane anything. So you have all your components sawn to near size first.
For your 90 x 44 finished size ideally you should start with 100 x 50 sawn (or a bit less if its good and straight, or short lengths) but leave it a while if you've ripped it from bigger boards. Best place for knots is within the width, not at the edges.
Oh, and buy drier wood next time!

 

[Zeddedhed]

Thanks for the quick reply Jacob.

Given that I've already planed them to thickness though, which way would you go with the rip? In other words which cut is least likely to cause them to bow on the face?

Normally I would always cut roughly to size first. The reason for changing the approach was the experience I've been having with the previous boards. The first set were fine until I rebated them. The second set went berserk after ripping but were then successfully flattened and squared up, only to turn into chunky longbows overnight. Set number three got all the way into the dry clamping stage. I then had to turn my attention elsewhere for the remainder of the day and when I came back to the workshop in the morning and released the clamps ready for the glue up they sprung into a horrible set of curves and twists. The workshop is kept at 15 - 17 degrees and is bone dry by the way. The (alleged) MC of the timber is around the 8 - 10% mark according to my Protimeter.

 

[Jacob]

Can't see the cut making much difference either way although there is the classic trick of trying to remove equal amounts from all sides to equalise released stresses.
Could be the timber then - either very wet and/or over hastily dried and with inherent stresses released with each step?

 

[Zeddedhed]

Could be the timber then - either very wet and/or over hastily dried and with inherent stresses released with each step?

Certainly for the first pair that went after the rebate. I actually felt it go as it was going over the spindle moulder. It was a 24 x 24 rebate and I took it in two passes so it should've been fine methinks, but no, halfway along during the second pass and 'boink' - we now have a kink!! It's amazing to think that just removing an extra 12mm x 24 mm of timber would make a lump of wood fold like that.

I'll give it a go taking an equal amount from each edge and let you know how that goes. Won't get done until tomorrow evening now as it's fishing day tomorrow.

 

[Trevanion]

I had a batch of 8" x 3" Accoya from a timber supplier recently because they didn't have any 4" x 3" in stock. I began ripping them down to 4" widths for door frames and the amount of stress released from the timber was unbelievable for something that's supposed to be super stable, I had about a 25mm bow in a 4m length. I managed to cut and plane the bow out since the size was generous and I thought "that should be all the stress pretty much gone", How wrong I was! Once I started taking a rebate out they were bowing as they were going through the spindle moulder and I had to set a couple aside as bead stock as they had just bowed too much.

Goes to show all timber moves!

 

[Zeddedhed]

I thought I'd let you know how I got on.....

With great trepidation I put the sections over the planer to create the reference edge. In the case of the knotty board, I edged the knotty side. Then a few quick passes through the thicknesser taking about 1.5mm off per pass.

Then I got all gung-ho and ripped off 20 or so mm on the TS. Everything was still looking good so I ripped again to within 5mm of finished size and finished off through the thicknesser.

Happily, everything stayed dead flat, straight, square and free of any signs of wonk.

I elected not to create a rebate for the glass as I felt this might unbalance things and send the wood all over the place. Instead I used the rip offcuts to make up two sets of beads, the first set being glued and pinned in place thus creating the rebate. The second set will just be pinned once the glass is fitted.

The door is being fitted on site tonight (I hate overnight work) and I'm now feeling rather relieved but nice and warm as the workshop woodburner crackles away, burning the remnants of the failed earlier attempts.