Thread: 'Continuous grain flow' lesson fail.

So he cut the mitres with the grain instead of across it? Ahh, I get it now. Silly mistake, but considering you'd just given him a lesson.

Saw a video on YT of a guy cutting dovetails once, he cut them in the long grain instead of the end grain. When he tried to put the joint together all the dovetails broke off.

That's a very nice fail .

The problem I have with continuous grain is the effect of the saw kerf and cleanup of the cut faces after splitting the board. It can result in some mismatch if the grain/figure is at a significant angle. Is it just me or does the timber need to be carefully selected?

I purchased a fine kerf TCT bandsaw blade through Peacock Saws in Wacol west Brisbane. it lessens the amount of cleanup required only loose about 1mm from each board. Marking out is the key, cutting the miters on the correct face is the biggest trick.

Does this help? From a set of notes for a course I ran.

Figure 2.jpg

Originally Posted by aldav

So he cut the mitres with the grain instead of across it? Ahh, I get it now. Silly mistake, but considering you'd just given him a lesson. . . . .

Wish it was that simple but he cut the mitres so that the outside faces of the original board were to become the outside of the box

Originally Posted by labr@

. . .The problem I have with continuous grain is the effect of the saw kerf and cleanup of the cut faces after splitting the board. It can result in some mismatch if the grain/figure is at a significant angle. Is it just me or does the timber need to be carefully selected?

The kerf doesn't really matter if you don't cut right through the board when making the first cut between the side and end pieces. I set the blade so it barely breaks through the top for the first mitre-cut, then cut the mitre on the uneven side and the rest of the pieces so that only a very minimal bit of length is lost. (eg: less than 1mm)

Originally Posted by RGP

. . . . .cutting the miters on the correct face is the biggest trick.

And that's where he cocked up!!!!

Originally Posted by AlexS

Does this help? From a set of notes for a course I ran.

Figure 2.jpg

That's how I had the pieces taped together so they could actually see how it started out but they just can't picture how the inside faces become the outside of the box - must be a better way

Before making any cuts (excepting inserted strips) just mark the outside faces with a bit of chalk.

Make the cuts, then cut the mitres as though the chalked faces were inside the box.

I don't see how you could make it any simpler.

(It's the same as just telling them that the fresh cut faces go outside the box, but the chalk makes more of a point of it.)

Originally Posted by Skew ChiDAMN!!

Before making any cuts (excepting inserted strips) just mark the outside faces with a bit of chalk.

Make the cuts, then cut the mitres as though the chalked faces were inside the box.

I don't see how you could make it any simpler.

(It's the same as just telling them that the fresh cut faces go outside the box, but the chalk makes more of a point of it.)

Yep (but I use soft pencil.) It's a matter of being consistent. I always mark the face side on the inside, the face edge on the inside, then lay the pieces out end to end, inside down, in order, so that I can see that the grain is continuous. Flip the pieces over so they are inside up, and mark each end with 1, 2, 3 or 4 lines so that they go together in the correct order.

Originally Posted by Skew ChiDAMN!!

Before making any cuts (excepting inserted strips) just mark the outside faces with a bit of chalk.

Make the cuts, then cut the mitres as though the chalked faces were inside the box.

I don't see how you could make it any simpler.

(It's the same as just telling them that the fresh cut faces go outside the box, but the chalk makes more of a point of it.)

It really should be that simple although it wouldn't work for me because of the way I size the boards after ripping. In order to lose only the absolute minimum of the boxes outside faces, after ripping on the bandsaw, I clean each new face up and then re-thickness them in the drum-sander which would remove the marks - I am yet to master ripping anything 'dead-middle' so I would rather lose the difference off the boxes inside faces. Lately I've taken to marking where the mitres will be with fine felt-pen on the edges even before ripping - pen marks that aren't taken off with the mitre cuts disappear with sanding, levelling etc down the track.

This is my method,

Board long enough to cut 1 x long and 1 x short side + 30-40mm
Board thick enough to slice 2 x 12mm dressed boards = 28-30mm
Slice board at 13-14mm
Lay side by side so inside faces face up
swing one board around so it is end to end with the other and the grain matches
Permanent mark an arrow on the matching ends with the point directed towards the face
Run the back sides through the drum sander first to take off the bulk and even out the thickness
Sand the face last to ensure only the minimum is removed
Place the boards end to end again and Pencil = across the join and pencil ________________ to mark either the top and the bottom
Starting from the centre i cut the the shorter side first then the length on the left board then the opposite from the right board
Trimming the mitres with next to no waste will ensure a perfect match

I do have the odd occasion where once sliced the boards do not match, in which case the price of the box is reduced or the material is racked and used for dividers etc

Unless your drum sander is double-sided, it doesn't really take much effort to re-chalk or put a bit of low-adhesive tape or something on the top face as you remove each piece from the machine to transfer the mark.

It's why I like chalk... it's usually removed during the normal finishing process anyway and has low risk of 'scribibng' marks into the wood. (I say usually, 'cos some open-grained timbers really don't like it. )