flattening – board flexing
Welcome! / Forums / General Woodworking Discussions / Wood and Wood Preparation / flattening – board flexing
- This topic has 7 replies, 4 voices, and was last updated 7 years, 6 months ago by noho.
-
AuthorPosts
-
Hello,
i have some pine boards that i have been trying to flatten with a jointer plane. my issue is the following :
The boards are slightly bowed, meaning that when put flat on the bench, the front and back are touching, but the middle section isn’t. But when I plane with the jointer, the weight of it makes the whole board contact with the bench.
Thus, when I put pressure on the middle of the board, it is very flat, but without any pressure/weight, the board keeps its hollow in the middle.Do you face the same issue, and how do you manage that ? what is the best or most common approach for that ?
Thanks for your inputs !
Christophe
On the cupped side, focus your efforts on the ends, the high spots. You make have to put away the jointer plane and use a number 4. Use your eye to check for straightness.
generally, when I have a long board I cut it to approximate lengths for my project pieces, it’s much easier truing up shorter lengths.
Thanks BrianJ. It’s what i have done, using some shavings. What is weird is that the board isn’t really thin (18 mm thick pine) and length is about 80 cm. So not really very long…
It’s really the first time i notice that. Never saw this issue on Paul’s videos, or any other videos…
Glad it worked, if you look up the terms or view the stock prep videos typically bow is used in reference along the length of the board and ‘cup’ when across the width.
Either way, you got it figured out.- This reply was modified 7 years, 6 months ago by BrianJ.
- This reply was modified 7 years, 6 months ago by BrianJ.
🙂
but what is weird is that I never saw this issue discussed in Paul’s videos or other woodworking programs. Though i think it is quite a common issue, isn’t it ?
(ps : this pine was a nightmare. quite a lot of heavy knots and some areas full of resin… I think i’ll keep working with poplar, much nicer and fun to work with…)
25 October 2016 at 5:03 am #141901This is very common for us hobbyists who don’t typically buy (or know how to buy) premium wood. When I have a board that is bent along its length, first I’ll cut it down to a little larger than needed for the project – it’s much easier to true up a smaller board than a longer board. If the board is still bent along its length, I’ll start on the concave side. This way the middle of the length is touching the benchtop and the ends are not. I use shims to hold up the two ends – this can be small wedges, but what I use most often is small plastic cards like old insurance cards, expired credit cards, etc. You want something that is not compressible. Shavings are not good enough. Once the board is shimmed properly you can flatten it. After it is flat, you can run a gauge line for thickness, turn it over and work on the other side.
Hope this helps.
-
AuthorPosts
- You must be logged in to reply to this topic.