Thread: Trouble with A2 Blades - please help.

Originally Posted by Yxoc

..... Or maybe the wood has some silica - Has anyone else worked NGR with handtools and had the same problem?

Hi Derek - I have worked a moderate amount of NGR and always found it to be moderately soft & pretty easy on cutting edges in the broad shceme of things. Batches vary, of course, but grittiness has never been a problem for me - my complaints would be its rowed & variable grain directions - some pieces can be a real challenge!

Grit getting into the surface seems the likliest cause, alright. That will certainly wreck a fine edge in a hurry...

Cheers,

Yes, I'm told that a tree that grows in sandy soil may have a higher level of silica.

Some species are notorious, like Brushbox. Finishing hollowing cuts on a 10" bowl had me resharpening after every pass.

lwilliams, nitride say on a turning gouge flute would still offer some benefit wouldn't it?

I suppose a coating on a fluting tool would help but here's a link to an abstract about coatings for woodworking:

http://tinyurl.com/ykztdw5

couldn't see a comparo of coated and non-coated

btw it's a coating on a turning gouge i was referring too; obviously the bevel gets ground at first use so only one plane retains the coating

I looked at the information on Brent's site again - a wealth of painstakingly collected accurate data for the benefit of woodworkers worldwide, what a fantastic resource. He is somewhat negative towards A2 steels and the chipping at the edge in his photos does look bad. I remind myself of two things to put it all in perspective: we're talking about 150 passes of a four foot board and secondly the photos (which shows rather dramatic chipping) is magnified 200 times or something. Certainly a bigger load than a couple of passes on a short NGR board.

Ian - thanks for your input, other than the chipping problem on the blade the NGR does work rather easily except for the reversing grain. I have found that an effective planing angle of 59 degrees still leaves occasional fine tear out but increasing the angle to 64 degrees handles just about everything and the result is sensational! The resulting surface shimmers like the reflective coating on road signs and worksite high vis jackets. I am in a quandry as to how I will fill the very porous grain without destroying the planed look. I fear it will have to be sanded someway or another.

I think the problem is definitely a workshop hygiene problem - there's been long stretches between working on pieces and the pieces have been moved around the shed a bit which is also our garage. I guess I have just managed to pick up bits of grit and muck and brushing the surface is not sufficient to remove it. Lesson learnt I will have to be more careful in storing lumber.

Coxy

IIRC Brent's test of the V. A2 block came up better than the other 2?

Assuming batch consistency then there's something to do with bevel up??

Originally Posted by Yxoc

I have ... New Guinea Rosewood... but very shortly thereafter, tiny but perceptible (and visible) tracks appear on the surface.

I agree with the later discussion that a contaminated workpiece is the most likely culprit. However, if after removing a few shavings thickness from this board the problem persists you should provide further information about your sharpening process.

You said nothing about how you grind the blade. You mentioned the stones you use but not whether you use a jig or not. If there is a problem with the blade edge it could be the steel itself, or the grinding, or less likely the honing.

Brent