The economics of resizing lumber

[Anthony Whitesell]

Now that have all the necessary tools (bandsaw, table saw, jointer, and planer), I'm getting down and dirty. Last night I was attempting to quickly (ie., just a short fence and not a tall resaw fence) resaw some jointed lumber. I was resawing some jointed 5/4 yellow poplar in an attempt to make to finished 1/2" boards. Well that didn't work out so well. For the most part I got a 0.450" board and a 0.375 (3/8) board. Sometimes worse, ie. thinner than 3/8".

My thought was that 5/4 would be thick enough to be able to joint, resaw, and sand (drum sander or light planing) to make two 1/2" boards and there by saving some money on planing the heck out of 4/4 down to 1/2". Apparently that wasn't the case.

So before I purchase any more lumber, how much extra thickness do you need in order to convert rough cut to finish planed?

What size stock (4/4, 5/4, and 6/4 rough) would you buy to joint, resaw, and sand to make 1/2" or 3/4" boards?

Here's the economics part of question,
If 4/4 stock is $2.15 per square foot, 5/4 is $2.25 per sq. ft., and 6/4 is $2.40 per sq. ft, and 8/4 is $2.60 per square foot; which stock would you get for making 1/2" boards? What about for 3/4" boards?


P.S. and yes I mean per square foot not board foot. I believe that my retailer has compensated for thickness in the price, ie. a 6/4 board 2' long and 6" wide is 1 square foot (1.5 board feet) and costs $2.40 and not $3.60.

[Paul Johnstone]

P.S. and yes I mean per square foot not board foot. I believe that my retailer has compensated for thickness in the price, ie. a 6/4 board 2' long and 6" wide is 1 square foot (1.5 board feet) and costs $2.40 and not $3.60.

For me, it's not worth the hassle to resaw.

Also, it is normal for thicker wood to have a higher price per board foot.
I don't know why, but that is the case. My guess is that his rate is per board foot, not square foot.

As an example, 8/4 Walnut is almost double the price of 4/4 walnut from my supplier, and I know that is board foot, not square foot. Red Oak is roughly 60% more for 8/4 than 4/4. I am doing this by memory, so the numbers may not be exactly right.

[glenn bradley]

Different yards buy from different sawyers and this also varies on type of wood. Oak from here, maple from there and so on. My preferred yard has walnut and others where 4/4 is generally 15/16" but, their red and white oak are 13/16". If I want 1/2" material I usually buy 5/4 to allow for the original face jointing, resawing and planing to final thickness. We all have different tolerances for how important "flat" and "square" are depending on what we are building. Most of the stuff I build it is fairly important, some of the time 'off the rack' stuff is more than adequate. HTH.

[Larry Edgerton]

I buy rough 3/4 stock.

Just because you have the tools that can do the job does not mean that is the best way to do it. I am not being a smart alec, its just the realities of economy of time. I am better off doing something else, and they are much better at resawing.

I will do it with figured wood, but when making trim or T&G that is around a half, I buy rough 3/4.

You have to balance what they get against how long it will take you and figure out if you would do that particular job for that much money. 5/4 stock is more expensive per Bd. Ft. than 3/4 stock, so start with that and figure out your cost backwards. Would you work for say $5 hr.? That is what you need to figure out, what you are making with your time after all other considerations are considered.

[Anthony Whitesell]

I guess I should have made two posts. The most important question is:

How much extra thickness should you allow in order to convert rough cut to finish planed if you need 1/2" thick boards? How much for 3/4" thick?

My thought was that 5/4 would be thick enough to joint, resaw, and planer/sand to make two 1/2" boards and there by saving some money over planing the heck out of 4/4 down to 1/2". Apparently that's not the case.

[Anthony Whitesell]

I expect thicker to cost more for a few reasons. Supply and demand (less supply and less demand). Since there's only a given number of inches per tree there are few boards to put on the shelf to sell, and quality trees and lumber for thicker stock are less available, plus people and projects that require thicker stock aren't as common.

But when the boards are marked for size and pricing, they are marked in square feet and charged based on that number with no compensation for the thickness (ie., no conversion done from square foot to board foot based on the thickness). Additionally, They only use whole square feet, so 3' x 6" is 2 sq. ft.

[Mike Gager]

i think what they might be saying is just because its called 5/4 doesnt mean its gonna measure 1-1/4"

if the board is actually say 1-1/16" by the time you resaw, joint, plane, etc, you will likely end up with a board closer to 3/8" then 1/2" just like what happened to you with the poplar

[Gary Herrmann]

Anthony, it all depends on how cupped or twisted the wood is. I've bought twisty 8/4 cherry before and considered myself lucky to get a 1.5" useable thickness when I was done jointing and planing.

I've been able to get 1/2" thick resawed boards out of 5/4 stock before, but it was pretty flat even in rough form.

[Robert Parrish]

What was the thickness after you planned the wood and before you did the resaw? 5/4 should have been thick enough to yield 2 1/2" boards. I usually leave 1/16 extra than use my drum sander to reach my desired thickness.

[Anthony Whitesell]

I only joint one side and one edge before I resaw. The board was almost 1.2" thick after jointing. The jointed side was 0.450" after drum sanding and after I jointing and sanding the other piece it was only 3/8".

[Jason Beam]

5/4 if it's rough.

6/4 if it's S4S.

And that's all assuming the stock is very well behaved and don't go warpin' on ya once you split it in two.



As for your lumber prices ... i would buy that man out of every inch of his 8/4 stock if he's selling it that way. $2.60 for twice as much wood as the $2.15 4/4 price?? That's a no-brainer. You are literally getting double the wood for 20% only more money. The scale you provided makes sense for board feet, not for square feet. I'm skeptical that anyone that deals lumber would not know better, but i have no problem with taking it off their hands for such a deal! :P

[Chris Padilla]

Anthony,

I'd go ahead and S4S a 5/4 board (or at least S3S with one jointed edge) if I planned to try and get two 2/4 boards out of it. One issue you have after the resaw is one board that is back to being more or less rough instead of having a good face from which to plane (thickness) down.

Next for the resawing is your choice of blade and technique. You only get good at resawing by doing it. I'm forever on the lookout for the best resaw blade. It is a compromise between kerf and finish quality.

The carbides are pretty nice but they eat up a decent amount of wood (Lenox Trimaster, 1" blade, 2/3 var pitch, 1/16" kerf, nice finish that needs drum sanded or lightly planed) and they are pricey (~$200 range for me: I need a 14' blade to wrap around my 20" BS).

Lately, I've been having a go around with a bimetal blade from Lenox called the Diemaster2. This one is a 1/2" blade, about a 0.038" kerf, 6 tpi, hook style, and cost me around $35. I have to admit that this blade is really doing me very well (or maybe I'm getting better at resawing) and it is fast becoming my favorite blade. I think I could resaw your 5/4 poplar boards in half with this blade and get you finished 2/4 boards...I think! :)

[Jason Beam]

Oh ... add to this ...

You can't form an opinion on resawing after just one or two tries. Give it some time to get good at it. Improvement means thicker yield and less sawdust. I did my dangedest to get 4 reasonably thick veneers off a single 13/16" thick piece of cherry the other day. You'd think i could get four 1/8" thick slices, no? Well the saw's new, the board was a little cupped and I didn't have a lot of confidence in it. It was the first time resawing on that saw, and I haven't had it long enough to get a feel for it's "personality" ... i got 4 slices, but they were considerably thinner after sanding - just a hair over 1/32" thick.

I am POSITIVE that I could get at least four 1/8" thick slices out of less because I could on my older saw. It just takes time to get there. All the patience and confidence will come once I have a better feel for how that saw cuts.

[D.McDonnel "Mac"]

C'mon guys you have to be darn lucky to get two sanded 1/2 inch boards out of 5/4 rough.

Start with 5/4 = 20/16

Saw kerf = 1/16

Joint: 2 faces (one each board) at 1/32 each = 1/16

Plane: 2 faces (one each board) at 1/32 each = 1/16

Sand: 4 faces at 1/64 each = 1/16

Total loss = 4/16

Thickness remaining = 16/16 two boards = (2) 1/2" boards

All above assumes ideal conditions and machine setups. Any deviation caused by warp, twist, cup, tearout, imperfect setup or thin rough stock will doom you! Also be aware that straight stock can also cup/warp twist when resawn or planed a lot if it was not dried properly.

I figure on 6/4 to get two 1/2 inch boards and 8/4 to get 3/4 plus boards.

However having said all that if your prices are indeed square foot prices then you will do well to buy thick and resaw.

It is a good skill to have when dealing with expensive highly figured wood that you want to resaw and make your own thick veneer.

I use the Highland Hardware Woodslicer and am pleased with it for doing my resawing.

Good luck,

Mac

[Todd Crawford]

I was just adding the same stuf up when I saw your post Mac..... It's tough.....

[Chris Padilla]

I was just adding the same stuf up when I saw your post Mac..... It's tough.....

...but doable with experience and the right blade.... :)

[Kevin Godshall]

There is so much variance in what you might get from a "rough" 5/4. Cupping, bowing, twisting.. all of it reduces the final size that you are going to be able to start re-sawing. The wider the board, the more the potential for variance.

If I'm looking to re-saw and finish at 1/2, minimum start is 5/4 S4S.

[Jim Kountz]

I agree with Mac on this one. The thickness just isnt there to do this with any kind of repeatability. That to me is the key to this. Yes you might be able to pull it off once, maybe twice who knows, but would you want to take a risk and "try it" on some valuable lumber just "hoping" that the Gods are with you that day? Not me, I need something thicker to start with or like Kevin said start with s4s 5/4. I can resaw extremely accurately on my saw and it leaves a finish that usually only takes one or two passes through the drum sander. Even with that though I would be hesitant to do this on anything with value @ 5/4 rough.

[Jack Briggs]

I guess I should have made two posts. The most important question is:

How much extra thickness should you allow in order to convert rough cut to finish planed if you need 1/2" thick boards? How much for 3/4" thick?

My thought was that 5/4 would be thick enough to joint, resaw, and planer/sand to make two 1/2" boards and there by saving some money over planing the heck out of 4/4 down to 1/2". Apparently that's not the case.


If you're talking 5/4 rough sawn, I have no problems getting 1/2" final thickness from resawing 5/4 lumber. There's a full 1/4" (usually more with rough sawn) for the saw kerf and planing. Should work with no problems.


Cheers,

[Thomas Bennett]

I gave up on 4/4 lumber. I always buy (or have cut by a Woodmiser) 5/4 or thicker. For resawing , as some of the other posts have stated ,I start out with 5/4 S-4-S at 1 1/8 or so, cut to approximate length and width. Start with a thin kerf blade on the tablesaw and resaw in several passes to the maximum height of the blade. I just found a Freud multipurpose 12 " blade on sale, works great. My Paolini slide saw will cut about 4" high, times 2 is 8 inches already cut out . Then I go to the band saw and cut out the waste, not more than 3 -4 inches or less. I have a 12" throat on my bandsaw and usually don't resaw anything wider than 11". It works great. I could never set up my bandsaw to get consistent cuts this accurate, although it does generate a lot of steps. The whole point is to end up with bookmatched 1/2 thick panels.
For stile stock I pre-rip the stock a little wider than needed and surface every peice completely flat on the joiner, then plane. I target 7/8 for the stile and rail stock. I found I was always fighting the 4/4, unless it was very flat. I find paying a little extra for 5/4 is well worth the money,

[Joe Chritz]

Assuming accurate 5/4 board and drawer sides at 20" long.

5/4 is also 20/16 so 20-2 (2 passes to flatten one face)=18. Minus 10 (1/2 stock and two passes to ensure it cleans up only leaves 8/16 or 1/2". You still need blade kerf, top clean the other piece on both sides.

You should be able to easily resaw 6/4 down to get 1/2 finished sides.

I go through this every time I do drawers since I actually like the finished material at 5/8 in most applications. It is almost never economically feasible for me to do any resawing for drawer sides.

I keep threatening to get a bunch of soft maple rough cut at 3/4 and just keep it in the shop.

Joe

[Jim Becker]

I generally make 1/2" material (for drawers) from nominal 8/4 yellow poplar and get three pieces out of it. But it's absolutely true that the quality of what you start with is going to affect your ability to extract final dimensioned material from it. Mac's math is spot on and as you see, nominal 5/4 material "could" yield two 1/2" boards, but only if the material you start with is pretty darn good. 6/4 would be safer for two 1/2" boards as output, but it's not common on the retail racks. (easy to have if you're having your own stock milled, however)

[Anthony Whitesell]

That's pretty good. 3 pieces from 8/4.

1 1/2" finished from 4/4
2 1/2" finished from 6/4 (or really good 5/4)
3 1/2" finished from 8/4

The yield from the 8/4 sounds really efficient (and economical). I'll have to check that out tonight at the lumber yard.

[Lee Schierer]

I guess I should have made two posts. The most important question is:

How much extra thickness should you allow in order to convert rough cut to finish planed if you need 1/2" thick boards? How much for 3/4" thick?

My thought was that 5/4 would be thick enough to joint, resaw, and planer/sand to make two 1/2" boards and there by saving some money over planing the heck out of 4/4 down to 1/2". Apparently that's not the case.

I would say that you should be able to get two 1/2" boards from a piece that actually masures 1.25 thick. Many places sell 5/4 S2S lumber that is actually only 1" thick in actual dimensions (they already did the finishing to remove 1/4" to provide the two finished surfaces). No way can you get two 1/2" thick boards from an actual 1" thick piece of wood.

Because the grain doesn't run straight all the way from one end of most boards to the other, you'll have better luck resawing if you mark the cut line with a pencil and use a curved resaw finger that allows you to move the uncut end left and right witht eh leading edge of the blade as the pivot point to stay on track as you cut the board. Otherwise the blade will tend to follow angled grain and get off center on portions of the cut. Red oak is particularly prone to doing this.

[bob hertle]

I'll saw 2 finished 1/2 inch drawer sides from a 5/4 rough board, but nothing longer than about 20-24 inches. Any longer, and you risk losing too much to the jointer. Agree that it's best to saw 3 pieces from 8/4.

Bob

[Anthony Whitesell]

Now that you mention it, I already tried cutting red oak on the bandsaw. I won't be trying that again any time soon.

[J.R. Rutter]

I guess I should have made two posts. The most important question is:

How much extra thickness should you allow in order to convert rough cut to finish planed if you need 1/2" thick boards? How much for 3/4" thick?

My thought was that 5/4 would be thick enough to joint, resaw, and planer/sand to make two 1/2" boards and there by saving some money over planing the heck out of 4/4 down to 1/2". Apparently that's not the case.

From your experience, you now know to allow " 1/4 " per board that you want to net. So 2 ea x 2/4 = 3/4 per half or buy 6/4 lumber to start with.

You can save some money, but only you will know if it is worth it. One benefit would be sets of bookmatched boards, which is nice for things like doors. The math goes:

6/4 = $2.40 / BF
so 1 SF = $2.40 x 1.5 = $3.60 / SF
cut in half to net 1/2" boards = $1.80 / SF
so you have saved $2.25 - $1.80 = $.45 / SF

[Jeff Willard]

Also, it is normal for thicker wood to have a higher price per board foot.
I don't know why, but that is the case.

It's all going to depend on the drying properties of each species. Compare the price of 4/4 and 12/4 stock of any given species. Walnut and maple-lots of degrade in thick sections-big price discrepancy. Then compare 4/4 poplar or mahogany to 12/4. These woods kiln well in thicker sections and the price per board foot is much closer.