Tearout

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TobyB

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Am I being cack-handed - or is this just how it goes ...

Trying my hand at a bit of "cabinet making" to make a small occasional/hall table about 50 cms square and a metre or so high. Bought a big plank of 1 1/4" beech for the top and rails, and a smaller length of 2" stock for the 4 legs. Handsawn and bandsawn the components to length. Now preparing the boards by hand to get them smooth and square and the right thickness. This is going to be the largest amount of hand planing I'll have ever done

The 4 side rails have been OK - used my Clifton 5 1/2 to get them flat etc (it has quite a curve on its blade and will cut a thicker shaving to shift the excess wood), and final finish with a Veritas LA BUJ which cuts a broader fine shaving for a nice finish.

Struggled with the legs however. On the first, most of it was OK, but one corner (ie affecting an edge and face) for about 10 cms I had loads of tearout problems. Re-sharpened the blades, checked I was going with the grain (and just to be sure tried the other direction and confirmed I was right because it was even worse!), tried using the plane skewed in both directions, and also tried oblique strokes. Got most of it OK after all this - and have marked that corner as the bit to loose when I cut tapers onto the legs.

On to the second leg. Aaahhh! A whole face is like this. A slightly "pippy" or "quilted" appearance emerges from the rough sawn surface as it's got smoother - but tearout all over, and quite deep. Tried doing some really light cuts with the BUJ and it's even worse - although the blade was set for a very light cut it ripped out a huge area - dreadful. Tried all the "tricks" I could remember reading about - no joy.

Anyone recognise what I'm doing wrong, or what I could do better? Are some bits of beech just like this? If I was turning a bit of spalted I might accept that a whole load of sanding was the only way I could get a finish in an area which tore out like this ... is that the way forward here?
 
Hey Toby

Not sure what sharpening technique you employ, but David Charlesworth's Ruler trick gave my number 5 plane iron a sharper blade than I have ever been able to achieve and greatly reduced some tear out I was getting.

I think a back bevel is sometimes recommended for tear out problems as well (which I guess the ruler trick is a microscopic version of?)

Good luck
 
Hone the blade of your BUJ to a steeper angle to give a higher effective pitch. This may be sufficient to deal with the tear out. Or use a scraper.

Cheers :wink:

Paul
 
Paul's right. Try honing at 45 deg to give 57 deg pitch and fine shavings with a narrow mouth. The blade still wants a slight camber but much less than the Jack. I keep two blades for the 60 1/2 one for low angle (e.g. end grain) and one as above.
 
Modernist":376hyxg8 said:
Paul's right. Try honing at 45 deg to give 57 deg pitch and fine shavings with a narrow mouth. The blade still wants a slight camber but much less than the Jack. I keep two blades for the 60 1/2 one for low angle (e.g. end grain) and one as above.

I keep my LAJ and BUS with that blade angle and they seem to deal with pretty much everything without tearout.

Ed
 
I will be demonstrating a steep effective pitch, or back bevel at the Oxford show.

David Charlesworth
 
So - try a much steeper angle seems to be the advice ... thinking about it, the Clifton "conventional" and Veritas BU are actually much of the same ... where a steeper angle blade (pre-set for the BUJ maybe?) might be a solution ... or an even steeper angled cabinet scraper might work if they don't ...

Thanks for the help ...
 
Rob bought some Indian Laurel to the Talking Tools event. This is his deffinition of "the wood from hell" for tearout.

I managed to get it almost perfect with a tiny 25 degree back bevel in a number 5.

This gives an effective pitch of 70 degrees.

Many timbers will respond to a slightly lower effective pitch of 60 degrees. Some experimenting is advised, but the blade must be very sharp and the shavings very fine.

best wishes,
David Charlesworth
 
This was all good advice - I got hold of a 50 degree blade for the BUJ - which I think puts the planing angle right up where David is suggesting - and no tearout ... job well done.

Thanks everybody ...
 
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