Resawing

[memzey]

Hi everyone.

Quick question from me: I have a squared up length of oak, 23” long by 8” wide and 1” thick which I’d like to use as the book matched top for a box I’m making. The top will be captured in grooves. If I were to resaw this as planned what would my likely final thickness be? I’m assuming I’d lose some thickness to bandsaw kerf and subsequent cupping but not too much I’d hope. MC is about 7% throughout the board.

Thanks in advance.

 

[Racers]

As a rule I usually aim lose at least 3mm from each piece, you might get less waste if you are careful, but its a rule that works for me.

Pete

 

[custard]

+1

I'd reckon on about 6mm in total. So your 25mm thick Oak board ends up at around a 9mm thick top. Structurally that's fine, I make drawer bottoms to similar dimensions out of 8mm thick wood, and they're Cedar not Oak. You'll likely get some cupping, but given it's captured in a groove all around means you can live with a little bit of cupping.

Good luck!

 

[memzey]

Thanks everyone. That’s just the info I was looking for. I’ve a nice sharp 6tpi 3/4” tuffsaws blade in my bandsaw (an old but good 352) so I’m hoping that with a slow and steady feed rate I’ll get something approaching the figures you state.

 

[custard]

6tpi is a bit fine for an 8" cut. It's do-able, but the feed rate will have to be at a snail's pace or else the gullets will clog with sawdust and the blade will wander.

 

[memzey]

Like a snail with a limp :mrgreen:

 

[memzey]

Just checked my sales receipt and the blade is actually a 3/4” x 3/4” varitooth. IIRC that was meant to be better for resawing than the 6tpi I thought it was. Not sure if it will make a huge difference though?

 

[HOJ]

I have just done this with some W/E 1" Oak, it came sawn at 30mm, cut it to 2.4m long X 180mm, P & T'd down to 25mm, resawn to about 11mm, hoping to finish at 9mm, which will be done tomorrow, for some ply laminated door linings.

 

[memzey]

Let us know how you get on HOJ.

 

[custard]

Not sure if it will make a huge difference though?

Still think "snail", but now it's a really athletic one!

Incidentally, when I'm deep ripping boards on the bandsaw I usually make a cut that's a few inches long, then pull the board back and watch what happens.

If the cut starts to close up, or opens wider, then it's pointless proceeding any further with that particular board. It's still a useful board, just it's not suitable for deep ripping. Pressing on would just turn it into firewood.

But if the kerf remains stable then you can complete the cut. This is particularly relevant with Oak, as unfortunately so much Oak nowadays is forced through the kilning process, which increases the risk of internal tensions that will reveal themselves during deep ripping.

 

[memzey]

Thanks for the tips everyone.

Last night I set about doing the deep rip/resaw. First I had to fabricate a taller fence for that purpose as although the cast iron fence on a 352 is rock solid it is only a couple of inches tall:

Getting this right took a while as I had to ensure it was square and parallel to the blade in both planes. I also had to do the setup twice as I tried it on a scrap piece first to make sure that the cut wasn't sloped from top to bottom. I got there in the end though:

It seemed to work a treat as both leaves were even in thickness across their width. In order to minimise cupping I then put them in stick and clamped them down on to my bench top:

I'm not sure if this is actually going to help but I figured it was unlikely to hurt. As Custard says, if there is a little bit of cupping I'm not too worried as the top will be held captive in groves. I'll try to post up some pics once the cramps are off - possibly tonight.

 

[custard]

Looking good Memsey!

=D>

Incidentally, I have a similar gap in my bench to allow cramping from the back, like you I find it very useful for all sorts of jobs.