Help with keeping a ripped board straight

[David Fagan]

I'm fairly new to woodworking (most of my projects have been building garage cabinets and stuff out of plywood). I'm starting to work on a project and bought some mahogany. Just looking for some help on technique and order of operations. I had some 7/8" x 7" boards, that I had planed down to 1/2" thick. I used a planer sled to get one face flat, and then planed down to 1/2" This worked well. Since I don't have a jointer, I next used a straightedge and router to get one straight edge. My next step was to rip the boards down into 2" wide strips. The first board went pretty well, when I went to rip the second board the tension in the wood caused it to warp after ripping. Should I have ripped it wider (say 2 1/4" or 2 1/2") and then re "jointed" and ripped to final thickness? If that's the case then I think the jointer I've been wanting to buy anyways is nearer in my future than originally planned.

Thanks for the help.

[John Coloccia]

If I need them precise, I'll always rip oversize and then trim to proper size (joint if necessary and re-rip on the table saw). I don't know if that's considered a "best practice" but almost everyone I know sneaks up on the final dimension when they want precision.

[Todd Crawford]

If I need them precise, I'll always rip oversize and then trim to proper size (joint if necessary and re-rip on the table saw). I don't know if that's considered a "best practice" but almost everyone I know sneaks up on the final dimension when they want precision.

Same thing I do as well.

[Dave Verstraete]

Same procedure here, too

[Larry Fox]

If I really need them to stay put (or have a better chance of it) I rip them oversized and let them sit for a week or so and then rip them to final dimensions.

[Jay Allen]

Same here, and if it moves quite a bit, I try to give it some time before I use it. That 's not always possible, but I try, or move to a different piece of stock, if possible.

You did cut quite a bit from where you started. You planed it to nearly half of the original thickness and then down to 2" strips. That is quite a bit of stock removal. Some species are more likely to move than others and some of it could be the fault of the drying process.

[Bill Davis]

Another solution, because thid is not an isolated instance of this type of defect ocurring, is to buy your wood in the widths you ultimately need. That way you can pick the straight ones. Not always possible but something to think about. I believe that is why they usually sell larger boards. Internal tensions are 'masked' or less of a problem.

I usually over buy my wood so there is more likelyhood of ending up with straight pieces. Also a possible way to get a glimpse into the lurking tensions in a board would be to do the 'case hardening' test on a couple of end piece cutoffs before ripping to width. If the piece shows obvious case hardening expect more likelihood of warp, cup and crook type defects.

[Neil Brooks]

Time and sneaking up on your final dimension seems like the right answer to me.

Much of the wood that we get does NOT have a consistent moisture content, through-and-through. It's not at all uncommon for the inside to have more moisture than the outside.

Which means it will move when cut -- particularly if you don't plane each side identically, or -- much worse -- if you only plane one side.

If you have a moisture meter, you can see this for yourself by checking the moisture as you shave away fractional inches.

I've heard some say that they clamp the planed piece TO (or between) a board(s), while it's acclimating after being planed (or resawn). It might help; probably won't hurt :)

[glenn bradley]

I too cut parts over size, let them relax for a day of two and then final size them.

[johnny means]

I like to rip to approximate width, joint, then plane to final width. This leaves a better surface on both edges, is safer, more consistent and ,by gang planing, can be done very fast.

[Mike Cutler]

David
Sneaking up on the final dimension is pretty much tried and true. Along with that though you may also want to factor in time for acclimating to your environment.
A jointer in this instance would not have helped, other than to speed up the process to get the board releasing tension as it passed through the saw.
I personally would have joined one face, and an edge, then stacked them for a few days. I would have then ripped them, let 'em sit again, and then planed them to final thickness.
On boards that I know will be critical in the final dimension. I do everything I can to obtain as close to Quartersawn as I possibly can get. Even then, sometimes internal stress wins.
You didn't do anything wrong. It's just kind of the nature of the beast.