Milling Question

[Art Davis]

Suppose I want to make a project (let's say a cutting board) with a particular thickness and want to use unmilled lumber. What thickness lumber do I buy so that I wind up with the desired thickness of the final project?

I don't think this is a real simple question 'cause it depends upon the bow and cup, etc, of the raw wood. So I guess my question is this: how do I assess the raw lumber to get an idea of what I can get out of it?

Thanks for any words of advice.

Art

[Brent Ring]

Obviously, when you choose your lumber, try to pick out the straight boards, with as little cupping, twists, or bends as possible. It is awfully hard to set a standard. and the length of the board will have somthing to do with it. If your project requires longer stock, AND the rough lumber you purchase has a fair amount of defects to be milled out, you may end up with thinner, usuable stock.

Most of the comments I have seen here say it is reasonable to purchase 4/4 rough, and get a good 3/4" board from that. From my own experience, and the rough lumber I have acquired, 1/4" of loss is about right. Sometimes you will do better, other times you won't. So, from my experience:

4/4 = 3/4" approximately
5/4 = 1"
6/4 = 1 1/4"
and so on and so forth....

I know that there are some in this forum that have better expertise than I do. This is just been my experience.

[mike holden]

Art,
The additional quarter inch is a good "rule of thumb".
Just want to add, that since you can mill it to final thickness yourself, you no longer have to work in specific thicknesses. This can really free you up when designing and building. After all, who takes a caliper to someones finished project to see what the thickness is?
Mike

[Cliff Rohrabacher]

If your rough lumber is really cupped you can rip and glue it flipping every other piece to get the Median thickness that will be substantially more thick than it would have been had you just milled all the cup off from each side.

[Chip Lindley]

Cliff is right On! Ripping cupped boards allows them to be utilized with much less waste than *wishing* the whole width of a 10" plank would flatten to 3/4" Many times this is just not the case.

After jointing and thicknessing, I often re-glue the halves back together to retain the original grain lines of a Nice board, with only the loss of a saw kerf or two. Flipping negates this! In my experience, I have found no need to flip, except in very wide panels, if the wood is well seasoned and relatively straight grained.

[Steve Sawyer]

One other thing to take into consideration. If you cut your stock to rough width and lenght - say an extra 1" in length and an extra 1/2" in width - BEFORE milling, you will get better yields from your stock.

I cross-cut by hand or using a jig saw, and rip using a band saw - it's safer than trying to work with twisted, cupped etc. stock on a table saw. Then I head for the jointer and planer

[Rod Sheridan]

One other thing to take into consideration. If you cut your stock to rough width and lenght - say an extra 1" in length and an extra 1/2" in width - BEFORE milling, you will get better yields from your stock.

I cross-cut by hand or using a jig saw, and rip using a band saw - it's safer than trying to work with twisted, cupped etc. stock on a table saw. Then I head for the jointer and planer

And who would argue with someone who has the surname of Sawyer when it comes to cutting wood?:D

I also rip rough material on the bandsaw, it's one of the safest ways.

Of course if you have a Euro slider, then you can straight line rip rough material.

I often leave a few inches extra in length if it's the end of a board to take car of hidden checks in the end.

Regards, Rod.