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In one of your photographs you showed a table saw, which looked to have at least a 10 inch blade capacity. With that you can resaw up to a 6 inch wide board by cutting full depth of the blade (3 inches) then flipping the board and cutting the other 3 inches. For a 16 inch wide back you could resaw two 4 1/4 inch wide pieces (extra 1/4 inch for joining) to give you 4 pieces. By orienting them properly you could maintain the appearance of a two piece book matched back.

I have resawn wood in that fashion using a tall fence and a simple jig using a spring loaded hinge to hold the board against the fence and perpendicular to the saw table.

It is a 12" saw. I could try building the jig. Do you have any tips on building it? A springed dowel against a tall fence right before the saw blade?

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Going to change the blade for a 100-tooth blade.

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being an in the field carpenter I resaw stuff all the time with my 10" table saw...being that it's a jobsite DeWalt model I only raise the blase 3 turns of the handle max for each pass...slowly working my way to the middle of the board I'm thinning down.

this is problematic because repeated passes certainly introduce the repeated chances of error...YMMV with your table saw pertaining to its ability to cut through x amount of wood in one pass. big problem arises when your right at the crossover point as the waste will fall away creating its own issues with holding the desired wood against the fence...

just last week I had to make 7 custom router bases...3 for my PC 7310 and 4 for my PC 310...4" squares...every single one had a little error on the resaw situation...no biggy as I put the planed end against the metal bases and the other on the bottom...why no biggy? because except for the one left flat for the 310 (special size hole in the middle to spin a 1 3/8" diameter rabbet bit) all the others were custom shaped to deal with a hybrid straight/spiral/straight/spiral handrail I got stuck with fabricating...custom bases required for the spiral sections of course and the transitions were humps/valleys that spread across 12" in a flowing fashion...those also had some aspects of spiraling...so I put PSA sandpaper on the top/bottom of the rough blank and sanded back and forth until the base conformed to the situation and was square to the sides (helixes are a real PITA...at any given point in the spiral the square of the tangent at that point must create a square edge relative to the top/bottom and sides)...further info is this: I created the rough blank out of that wacky wood that's been talked about for easy guitar making: http://www.puretimber.com/ ...trust me, it's not suitable for guitars really...during its drying process it shrinks in all 3 dimensions...width, thickness, length...pfffftttt...just bend the woods on a pipe or using a blanket!...

anyway, on the first day I totally failed on simultaneously bending around the spiral (easy) and also bending at the point of inflection of straight (32 degrees pitch) and spiral (46 degrees pitch)...so i created joints at those points with the wood...overnight I came up with an idea of how to pull the 15 degree bend across the 6" width of the material...sure, took over an hour to do the bend slowly, having to overbend to 22.5 degrees to allow for spring back to ~15 degrees, and 2 of the old style Irwin Quick Grip XP600 clamps (rated at 900 lbs. of force with 2 hands...the new Next Generation ones are a joke..they totally fail...stop squeezing and just slip...lame) along with a DeWalt squeeze clamp (beats out the new Irwin ones hands down)...I estimate over 1,000 lbs of force needed to make that type of bend...over a 4 day period I got 4 layers of that stuff bent up and clamped in place...after about 2 weeks of drying I realized the middle 2 pieces would never dry and took it all apart and stickered each layer by 1/4" to allow air to get to the middle layers...eventually glued it up...and that was the end of my obligation...or so I thought...hahahaha

ended up with the obligation to first create a 'perfect' blank of 2 3/8 tall and 2 1/4 wide...sure...yeah...righto...that took almost 2 weeks straight to pull off (7 days a week...worked 20 days in a row on this jobsite)...after the first rough cut off the top I realized various things (sorry, even though I've taken a LOT of math, way beyond anything I'll ever use as a carpenter, I was never exposed to helical math)...first, the concept of squareness and how important that would be...second, this was going to be a nightmare...third, try as I might 'perfect' was NOT going to happen...sigh...anyway the custom bases were required to run a router along this blank the bring it from 2 5/8" to 2 1/4" thickness...used a 5/8" top bearing flush cutting bit with a 1/2" bearing to remove 1/16" each pass...again, one has to have a level/square top to pull this off...and now it's quite apparent that there never was a master carver willing to take this job, so presently I'm having 3 custom made router bits to profile the blank to a 6010 hand rail profile... ...again a perfectly flat top required to even begin to pull that one off...many thanks to Al Carruth for having the Ultimate Scraper put into production...any type of sander left a slight hump across the top/bottom...hand held planers ripped out chunks of wood because of what we carpenters refer to runout in the grain (not the same as runout in a top of a guitar)...so I was stuck with grinding/beltsanding/scraping to get those planes correct...and the planer just don't work across a spiral (well, unless you create a custom riding surface I guess)

sorry...yeah, I know, this is a luthier's forum...the above is carpentry...

still...even resawing the poplar blanks of 11/32" (to allow for material removal and end up at ~1/4") thickness was problematic to a degree...and the point really is first experiment with a trial piece before you run the real thing through a table saw...you'll learn a lot I think...

have fun and keep your fingers on your hand!

rsfjr, I would use a ripping blade instead of a 100 tooth. You will get a lot of burning, and will have to take more passes to do the resaw. If you leave 1/4-1/2" uncut in the middle, you won't have any problem with the off-cut piece getting gouged by the blade. Finish the cut with the wood in a vice and a hand saw.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I understood what was meant by ripping the board. But still, folks. Some of the stuff I'm seeing suggested here is just plain dangerous. And probably no where near worth the risk. Btw, has anybody done the calculation on the kerf removal give the table saw approach? The ONLY idea that seems worth a try given your setup is to rip the boards, sand to proper 0.2" thickness and glue. The sand to 0.12". Everything else involves major, unnecessary risk. It will look great.

An underpowered table saw would be a danger when resawing, but it can be done safely, otherwise I wouldn't do it or suggest it to others. I've done it with a 14" blade, but started with thicker wood, and got good results.

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

Thanks all. It is a 2 HP makita. I won't resaw this time. I find it hard to run it smoothly through the fence. Knowing me, I know that I am going to end up with a piece with some paper-thin sections.

Since it is not the best wood (slab cut), by far, gonna try thinning it with the tools I have. Gonna sharpen my planes to #6000 stone and give a try. Gonna sacrifice the cupped side first, if everything goes fine gonna end with the scrapper plane set to an angle near 90°, to avoid tearing the cross grains.

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I think ur missing a good point. How wide is the board? Rip it in half and you halve the cupping. Less sacrificial sanding.

I missed that, Mike. Thanks!

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

The board is 9.4 inch wide. I have two of them.

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Yep, that's what I'd do.

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Wah-wah-wah-wah
Wah

So I am going to cut both boards in 4 to lessen the cupping effect. This weekend going to start built the mould.

Thanks again all for the patience!

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I'm going to try this again. Since you have two boards, maybe they came off the same stack in the right order? So to a degree they are bookmatched? Post a picture side by side.

Next, before you cut, try to flatten. Heavy weights. A little moisture. Some time. Why? Because your boards are 9.4", perfect for sizing a two piece back. 4" might turn out to be a be shy for a side depending on your design choice. And nothing stays the cut size. I would try flattening first before other idea. What do you lose but a little time?

They came from the same stack. Not that bookmatching, there are a large cathedral in each side.

Tried to flatten by applying hot stem then placing 4 pieces of 1" plywood on the top. It is cupped a little less, but still cupped.

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When I resaw with the table saw I use a rip or combination blade. Fewer teeth and larger gullets allow the saw dust to clear better than a high number tooth blade with smaller gullets. I like the Freud 10 inch thin kerf blades. I think the coating and thinner kerf is a plus. I raise the blade to the full depth I want to cut and go slower as needed. I found multiple passes, raising the blade each time didn't work as well - more chance of wood movement between passes. My jig for holding the wood against the fence consists of two boards fastened together with a spring hinge as used on a self closing door. One board fits in the miter slot and the other springs against the wood and fence.
Although I am fairly sure I could get two usable slices from the thickness of the board you have I can understand your reticence, never having done it before.

It will take weeks for the board to flatten.

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Maybe it was too little time. Left for 1 week about (since I started the topic). But the climate here doesn't help we are at drought right now, so it dries too fast, about 15%rh inside the house today.

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Yup. Lots of potential there. Spritz with water. Heavy weights. Over and over.

Shooting from the hip here, but how about dampening it, then wrap in Saran Wrap? Not too wet. Don't want to create a biological experiment.

Nice idea. Just going to make some micro holes in the wrap to assure the water escaping the wood.

But the critical point is to wait the wife goes to sleep.

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