Author Topic: Why can't I scrape bamboo rind off without getting little nicks everywhere?  (Read 5472 times)

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Offline toomanyknots

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Anybody else have this problem? Anybody just use sandpaper? If so, what grit? I just always get these little nicks, no matter how sharp my scraper is, no matter how careful I am,...
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline PEARL DRUMS

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Scrape then sand the nicks aways
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Parnell

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Always just sanded it.  It gums up and wastes paper though.
1’—>1’

Offline bushboy

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I use 120 grit plumbers sand cloth,either way it's a lot of work.
Some like motorboats,I like kayaks,some like guns,I like bows,but not the wheelie type.

Offline Fred Arnold

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I sand mine too. IO may have tried scraping once with a knife but seemed like added work.
I found many years ago that it is much easier and more rewarding working with those that don't know anything than those that know it all.

Offline Tom Leemans

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I knock off the initial rough stuff on the nodes with the fine side of a hoof rasp, then I sand, but I use the thin sanding sponge pads. I guess the trick is knowing when to switch to each finer grit. My last grit is 320. Be patient and go light on the pressure.

Offline toomanyknots

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I'm just always afraid to sand the nicks away afterwards, afraid that I will sand too deep and compensate the strength of the back. I hate sanding typically, scraping goes way faster for me. And I don't remove basically anything on the nodes. I have never had a node break, or even a break near a node. It is always in the middle between the nodes if I have a break or splinter. The little nicks usually go away if I seal with a dull finish like tung oil, but I wanna use tru oil, and am afraid they will be even more visible with a glossy tru oil finish. 
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline Roy

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I use a scraper held almost flat, the nicks come from sitting the scraper down to hard and at a sharper perpendicular angle. I scrape maybe 80% off, then I go to 320 sand paper and only sand lengthwise on the boo. Do not try to get all the rind off... Usually there are long longitude lines/depressions in the boo that you just have to leave the rind on. You will skim the surface off it but if you try to get it all off, you scrape down into the power fibers on both sides of it, not good! Leaving those depression alone with a little rind in them, gives the boo a nice appearance when stained.
« Last Edit: August 31, 2013, 07:12:08 pm by Roy »

Offline toomanyknots

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I use a scraper held almost flat, the nicks come from sitting the scraper down to hard and at a sharper perpendicular angle. I scrape maybe 80% off, then I go to 320 sand paper and only sand lengthwise on the boo. Do not try to get all the rine off... Usually there are long longitude lines/depressions in the boo that you just have to leave the rine on. You will skim the surface off it but if you try to get it all off, you scrape down into the power fibers on both sides of it, not good! Leaving those depression alone with a little rine in them, gives the boo a nice appearance when stained.

Alrighty, I'll give that a try.
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline jeffhalfrack

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 I use a black or green Scotch brite pad JeffW

Offline Eric Krewson

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The first coat of finish on a stained bamboo backed bow held in the sun just right will tell you you left scraping nicks even after you think you had them all sanded out. I had some bamboo failures a year or so down the road that didn't make sense so I changed to sanding only for getting the rind off. I suspect some of those tiny nicks came back to haunt me.

Offline Mark Smeltzer

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I do just what Roy said.

Mark

Offline Ghost308

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Re: Why can't I scrape bamboo rind off without getting little nicks everywhere?
« Reply #12 on: September 02, 2013, 01:57:45 am »
I used my pocketknife and started always at the nodes, it worked very well for me the sanded it smooth ending with 320 grit.

Offline Dances with squirrels

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Re: Why can't I scrape bamboo rind off without getting little nicks everywhere?
« Reply #13 on: September 02, 2013, 05:09:50 am »
I do pretty much like Roy too... don't try too hard to get it all. It causes problems. Ive always preferred the looks of bamboo with a few whisps of rind left in those tiny valleys anyhow.

When you sharpen the edges of your scraper, roll the edges to varying degrees and then when it comes to scraping the rinsd off of bamboo, use an edge with a smaller hook on it. It will make less of a nick.

Also, as you work with the scraper, start it moving before it ever touches the work, then set it down light as a feather and always 'on the move', don't just drop it down at a 'starting point' and then begin scraping. That's how the nicks are created.  Use light pressure and always work towards the rind and away from the freshly exposed bamboo. That way you are sitting down on rind and  wiping away any previous nicks with the tail end of your strokes as you move from one end of the stave to the other.

Lift it in reverse of how you sat it down... gradually reduce pressure until it lifts off the bamboo... and still moving. This technique is subtly different and requires a little finess and you'll do it 'deliberately' and slowly at first, but will soon be doing it as fast as the other way. You should have to do almost no sanding when you're done with the scraper. I do minimal sanding on the bamboo, not much more than 60 seconds for the whole back most times wih 240 grit and have NO nicks visible any time afterwards, after dying or spraying, etc.

Hope this helps.
« Last Edit: September 02, 2013, 05:13:06 am by Dances with squirrels »
Straight wood may make a better bow, but crooked wood makes a better bowyer

mikekeswick

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Re: Why can't I scrape bamboo rind off without getting little nicks everywhere?
« Reply #14 on: September 02, 2013, 06:44:46 am »
I do pretty much like Roy too... don't try too hard to get it all. It causes problems. Ive always preferred the looks of bamboo with a few whisps of rind left in those tiny valleys anyhow.

When you sharpen the edges of your scraper, roll the edges to varying degrees and then when it comes to scraping the rinsd off of bamboo, use an edge with a smaller hook on it. It will make less of a nick.

Also, as you work with the scraper, start it moving before it ever touches the work, then set it down light as a feather and always 'on the move', don't just drop it down at a 'starting point' and then begin scraping. That's how the nicks are created.  Use light pressure and always work towards the rind and away from the freshly exposed bamboo. That way you are sitting down on rind and  wiping away any previous nicks with the tail end of your strokes as you move from one end of the stave to the other.

Lift it in reverse of how you sat it down... gradually reduce pressure until it lifts off the bamboo... and still moving. This technique is subtly different and requires a little finess and you'll do it 'deliberately' and slowly at first, but will soon be doing it as fast as the other way. You should have to do almost no sanding when you're done with the scraper. I do minimal sanding on the bamboo, not much more than 60 seconds for the whole back most times wih 240 grit and have NO nicks visible any time afterwards, after dying or spraying, etc.

Hope this helps.


Excellent discription of the best technique.
Make sure your scraper is very sharp  eg. glossy faces before rolling the burr. If your scraper is less than perfect you will use more pressure to make it cut.
The technique can also be likened to correct spraying technique.