i have a fundamental question 🙂 I have some 30mm thick oak board, 2.5metres long. I need to cut such a board to 3 pieces and glue a panel out of a single board such, that I get it to the maximum thickness. Now the question is, what shall be the order of the operations?
1) straighten the board first, then cut, then glue and just final planing
2) cut first, straighten individually, glue, final planing which will involve thickness reduction as those individual boards will have different thicknesses
3) cut first, straighten only one side, glue together such, that the prepared side will glue perfectly, then plane the other side such that all boards are the same thickness?
4) any other scenario?
I somehow feel that I could get the best results using method (3) but maybe i miss something fundamental there
This is how i do it.
If a board is twisted 5 mil over 3 meters, it is going to have much less twist over the final length. So I:
1. Cut into 3 pieces of the desired length
2. Make a reference face, and edge
3. I flatted the other face and edge
4. Bring to near final thickness
5 glue up
In step 4, I typically bring it to within a couple of mil of my thickness. After the panel is glued I like to use a smoother, and when I am done the new panel is pretty much the right thickness.
Hope that helps, others may have a different approach. I would be interested to read them.
I’ll second the vote for something like scenario 3. Like Joe said, it’s much easier to take a small amount of twist out of a shorter length of board. It’s also easier to straighten an edge of a shorter piece than a longer piece.
My order would be:
1, Cut the board in three pieces.
2, Flatten one face
3, Straighten one edge and make it square to the flat face. The middle piece of the glue up will need two square and straight edges.
4, Mark a thickness line a little thicker than your final (planned) thickness and plane the second face to the line.
5. Glue them up, being careful to keep the first flattened faces as even as possible with each other. Other things to thing about when gluing up include orientation of the boards for best appearance and grain direction. Sometimes when gluing up, I try to make it so I can plane the whole thing in one direction, rather than turning the plane around for one of the glued boards.
6. Plane the glue-up flat and to thickness.
3 is my routine. I think it’s worth saying that, in almost ALL situations, you want to rough cut to size before carrying out any planing because it ALWAYS reduces the amount of work and waste.
If you want to maximise thickness, and the board is not in too bad a state of warp, I think it’s best not to thickness your boards before gluing up – which is to say, you get your face side and edge (or edges) on each board and then glue up. With most glue-ups there is some misalignment that needs planing out, and if you plane both sides of your individual boards this means at best a little wasted time and at worst significant loss of thickness.
thanks for these fruitful comments. Strictly speaking, I thought that variant 3 will be the most viable, at the same time this is not what I did 🙂 So I ended with few panels warped such, that I have to get rid of half of the thickness to make them straight. So I will probably use them for something else and reglue new panels using approach (3).
Have a nice Christmas time!
Sorry to hear that! What method was it you used that resulted in the trouble?
Another bit of advice I might give about panels is that they will often move a little after final planing, so any raising or rebates on the edges or whatever else are best done straight away. So for example if you have eight raised panels to do for a door, I would plane each panel true and to thickness and immediately raise it to fit its groove to avoid the faff of trying to manhandle a warped panel flat.
All the best,
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