Steve22
Established Member
If by hand with typical sawn boards I'd use a 5 1/2 mostly, and/or a 7 for finer flattening/straightening, both with a cambered edge.
A long board evenly bowed, cupped and/or twisted has an area in the middle which is co-planar with the best flat surface you can get. So you work out from the middle and extend the flat to the ends. This means starting on the convex side and taking off the hump, as you can't start on the concave side in the same way. Machine or hand planing the same but other way up.
Over the planer you keep all the pressure in the middle of the board concave side up, as you take off the hump on the other side and extend the flat from the middle to the ends. You can see how you are going by the areas left un-planed. Ideally your last pass removes from the whole board including the last remaining un-planed areas at each end on opposite sides.
If not so evenly distorted you have to adapt the process. The easiest is to pencil mark high points/areas and plane to remove the marks, then repeat.
The thing to avoid is just thrashing away at it and seeing how it turns out. Much better to identify where waste needs removing and then remove it.
It's a proactive process, the machine doesn't think for you!
I’mJacob makes a good point. Well worth making some light marks over the faces with a pencil, then you can see exactly what is going on. But for 2.4m you really do need rollers or similar to support it. If the marks you are getting are fairly regularly spaced across the width then I would check the blades, they may need sharpening or replacing.
the blades are brand new been used once on the wavy board I think I will try to get rollers and have a look around to see if I can find a no 7 plane I’ve seen a faithful and Stanley also seen a no 6 Stanley. I would of said about Eletric planers but the vibration really kills my hands. I have an aggressive form of rheumatoid arthritis Which has tu both my ha 90 degrees outwards so it does present some challengesJacob makes a good point. Well worth making some light marks over the faces with a pencil, then you can see exactly what is going on. But for 2.4m you really do need rollers or similar to support it. If the marks you are getting are fairly regularly spaced across the width then I would check the blades, they may need sharpening or replacing.