Buying Lumber

[Don Dean]

I want to mill lumber down to 3/4" thickness. What size thickness should I buy for S2S, S3S? I heard that for S2S I should by 5/4 lumber if I wanted to mill it down to 3/4. Is there a general rule?

[Jim Becker]

Generally, 4/4 mills to 3/4" or thereabouts. If the board is actually relatively flat and straight, you can often get 7/8" finished if the 4/4 rough was generous.

[Jeffrey Makiel]

The 4/4 S2S lumber that I've purchased is usually around 15/16" but no less than 7/8" thick. Additonal planing (usually by me) is required to get it to exactly 3/4". This is a good thing assuming one has a planer. You should not need 5/4 to achieve a 3/4" dimension.

To me, S2S does not mean that the lumber is accurately dimensioned, but rather, the lumber's surface is smooth enough such that you can clearly see the grain.

However, the stuff at Home Depot is exactly 3/4". But I've never seen lumber like that at a lumber yard.

-Jeff :)

[Andrew Williams]

It depends on the degree of warp in the rough stock. I am currently preparing curly maple that is about 1 1/8 to 1 1/4 (sold as 4/4 rough) and it's pretty bad in terms of twist and bow (some cup too). I have been barely able to get 13/16 thicknessed out of it. After glue-ups and smoothing it will be slightly less than that. Sometimes I am down to my last pass through the planer to get a clean face at that thickness.

[Greg Cole]

Don,
To chime in and reiterate a little. The final dim's on a board are somewhat handcuffed to the status-quality of the board to start with. If the stick is pretty good to start, you can usually get by with 1" rough finishing up at 7/8", or 3/4 if it's a little more cupped, bowed etc.
I just worked up a small bunch of rough sawn lumber this weekend. I bought a lot of rough cut stuff from a private individual (no picking through it, just take it all)... before starting any milling, I sorted through the stack and sort of graded the sticks into 3 piles, good, ok, and umm.... maybe salvageable- maybe not. All were at least 1 1/8" in the rough, the good pile came out to damn close to 1", the ok pile worked out to right on 3/4" and some of the "maybe salvageable" finally was ok (after cutting some of the gnarly ends and picking out the straighter parts etc) to about 5/8".
Bear in mind some of this stock wasn't what I would have picked from a lumber yard, so there is a little more "shrinkage" there. But I rarely can find 100 bf of lumber for $2 a bf, so I don't mind the extra waste (and work).

[Don Dean]

Thanks guys! I now understand that the condition (how much milling required) of the lumber will determine the size I purchase.