Heya
So I ripped some cherry for the small side table featured in the latest issue. I oversized the parts a bit at 1 1/8” x 1 1/8” cause I figured I would get it to final size on the planer.
Well there is a bow that just won’t go away. My technique has been with the bow side up(center high) push it over a light cut on the jointer only applying pressure to the front. Weirdly, I’m still getting cuts along the entire length of the part.
These parts will be the legs. I went with the bow since I was running out of material and tapered them down to 1/2” square from 1” square. It’s a little wonky but hopefully not too noticeable. Needless to say the tapered bits didn’t come out perfectly square. Hoping some finally clean up with a handplane can get them pretty uniform.
Any tips on flattening skinny parts like this? Should I have flattened the board perfectt before ripping? It seems the bow is coming from internal pressures. The board is also plain sawn. Does this just not really work for legs?
I have some ash on standby if this doesn’t work out, although I’m not sure about ash legs/cherry apron combo. Maybe ash pulls to balance?
Replies
In my experience a part that is bowed or twisted WANTS to be bowed or twisted and will find its way back to its own form in time. If you are at final thickness and the part is still moving bit the bullet and move on.
Riftsawn lumber is nicer for legs (to me) because you'll have straight grain on all 4 sides. If the table you have in your head is cherry, go get some more cherry. Nothing is worse than a nicely built piece that you hate because of a compromise.
Echoing MJ....you should consider just moving on. With the Covid lockdown, my local wood supplier closed up to walk ins. They pick, you buy it or don't bother to come back again. Purchased two cherry 6/4 boards for this chest of drawers. Got one beautiful curly piece that I resawed for drawer faces. The other was supposed to be for legs and top.
I got the four legs from the second board (not much reduction in thickness), but when I began to resaw the boards for the top, I knew I was in trouble. Not only did I not get the boards for the top, but I chased twist with the jointer/planner until I finally accepted that the best I was going to get were a bunch of short, thin boards for boxes.
You more experienced woodworkers probably detected another mistake I made. If I wanted a 3/4" top, I should have bought 4/4 to start with. Life is all about learning, right?
I would ask a few questions about your techniques and processes because you should be able to resaw the boards the way you wanted.
The first mistake many woodworkers make is to pick up lumber for a project and immediately start cutting it. What you should do is allow it time to acclimate to the humidity conditions in your shop first. The thicker the boards the longer it takes. I like to purchase the wood for my next project when I start the current one giving the wood a month or more to acclimate. Your local climate can affect this dryer climates without large humidity swings may not need to wait as long.
The next thing to understand, when you resaw wood you are exposing the center of the board which will always be holding more moisture than the faces no matter how long its been acclimated so you are going to create a situation where the two faces have unequal moisture content which is what often causes wood to bow and twist. To help mitigate this I resaw then restack and sticker the boards and weight them down if possible and let them sit another couple of weeks before milling.
When I do start milling I always face joint first, I fortunately have a 12" jointer which accommodates most boards I work with, but here you need to understand the board you are working with and your jointer. If your jointer has nice long tables (72"+) joint the board bow up but be careful not to exert too much downward pressure, you don't want to artificially flatten the board, this is why a planer can't reliably flatten boards, just take cuts off the high points until the board is flattened.
If on the other hand you have more of a hobbyists jointer with short tables and you try to joint with the bow up you may find the board simply rolling along the table and never truly flattening anything. In this case I recommend jointing bow down and maintaining pressure only in the center of the bow letting the leading and trailing ends go uncut while you take off the high spot in the bow until it flattens the board and you are taking cuts the entire length.
Once you have flattened one face, I run it through the planer using my jointed face against the table for 2-3 passes roughly trying to remove the same amount of wood that I did in the jointing process after which I will alternate faces so that I don't expose more of the boards moist core on one side than the other. I continue this until I have milled the wood to approximately 1/8" oversized upon which I restack and sticker the wood for a few days to reaclimate before final milling and cutting.
It seems like a lengthy process but if you integrate it into the project you are currently working on, say after glue up when you waiting for the glue to dry, it doesn't seem so odious and can be quite efficient.
You've commented that you're a bit of a newbie. That is not a newbie project. It looks damn nice.
Well thanks for the push guys.
I think it’ll turn out okay.
We learn a little every time, I reckon that’s the allure!
The other thing is, maybe it isn't the wood, but the jointer or technique. A jointer can make all sorts of shapes in a hurry.
chuck...looks good in the pic !
I don’t get too crazy with legs, you’re never going to see a slight bow and it doesn’t affect anything.
It’s harder when you’re taking light passes. That said, jointer technique is an aspect. You want to avoid pushing down on the board as it goes over the cutter head, or else you’re duplicating what happens in a planer.
I use a push block with a heel & I put down pressure just on the front of the board once it passes cutterhead I maintain contact along the bed, resist the temptation to keep the pressure just in the other side of cutterhead (which is what you normally do taking a deeper pass).
If you don’t do this you’re pushing the bow flat. Again, matters most with a light pass.
As I get close to the end, I’m putting down pressure with the push block. This effectively puts more pressure at cloth ends of the board and less in the middle.
I lay the board in the bed and check for gaps, repeat as needed.
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