Author Topic: Anybody ever have a scrapper scrap unevenly across ring transitions?  (Read 2699 times)

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Offline toomanyknots

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What I mean is, take the gradual ring transition down the belly of a limb on a typical bow, where the rings feather out towards the nock. I have been having a problem where my scraper will sort of jump rings, and this will make a bump where the next ring starts. It is also pretty square, and not natural looking, it stands out pretty bad. Anybody know what I am talking about? I am using a straight scraper, it is probably not super sharp, but it ain't dull or nothing.
"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 Gordon

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #1 on: January 11, 2013, 01:13:52 pm »
Are you working with osage?
Gordon

Offline ionicmuffin

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #2 on: January 11, 2013, 01:22:02 pm »
i have a similar problem with mine! i think its very dull though. it mostly happens either at rings, or at knots or other hard sections.
Amo innectis arcus- I love crafting bows (latin)

Offline Pat B

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #3 on: January 11, 2013, 01:26:50 pm »
That is the softer early ring being scraped more than the harder heartwood. If you don't get too much of a dip you can even it up using a sanding block when you get to final sanding. It is a pretty common problem when using woods like osager, locust, mulberry, etc.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline MWirwicki

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  • The wood speaks to you; Listen with your eyes. GSD
Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #4 on: January 11, 2013, 01:28:43 pm »
Like Pat said.  I use a finer file to blend the two surfaces.  Then only finish it up with sandpaper.
Matt Wirwicki
Owosso, MI

Offline toomanyknots

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #5 on: January 11, 2013, 01:50:21 pm »
Are you working with osage?

 ;D, yup.
"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 toomanyknots

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #6 on: January 11, 2013, 01:53:30 pm »
That is the softer early ring being scraped more than the harder heartwood. If you don't get too much of a dip you can even it up using a sanding block when you get to final sanding. It is a pretty common problem when using woods like osager, locust, mulberry, etc.

Like Pat said.  I use a finer file to blend the two surfaces.  Then only finish it up with sandpaper.

Alrighty, sounds like a plan. Thank ya guys. Ya, it was on an osage bow I just finished it up. I thought I had sanded em down, than after finish sanding to 1000 grit, burnishing, and waxing, then I noticed that I still had some pretty big square indentations. Which thanks to the finish, are now painfully obvious,  ;D.
"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

mikekeswick

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #7 on: January 11, 2013, 02:00:26 pm »
The problem gets worse the duller your scraper gets. The less sharp the more pressure you have to use to 'force' it to bite. They should always be sharp enough to 'wipe' shavings off with one hand. ;)
The easy way to stop it happening is only ever use a super sharp scraper.
Then if this problems starts to form then flatten with files.

Offline SLIMBOB

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #8 on: January 11, 2013, 03:39:01 pm »
The key is not to let it get to deep.  As one appears, I use the sanding block as Pat said, and smooth it out completely.  Then back to the scraper, then repeat the sanding block and so on.  The thick ringed stuff is more of a problem as there is usually more early wood.  Sharper tools will minimize it.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.

Offline adb

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #9 on: January 11, 2013, 04:56:42 pm »
If I'm tillering osage, this happens. To prevent it, I alternate between scraper and rasp. The rasp will knock off the harder high spots, and then you can work with the scraper again. Keep the burr on your scraper fresh and it won't be as bad.

Offline dwardo

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #10 on: January 11, 2013, 05:15:27 pm »
Having two cab scrapers helps.
Sharpen both and when you start to question one, try the other and see if its you being too tired or the scraper blunting.

Offline Gordon

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Re: Anybody ever have a scrapper scrap unevenly across ring transitions?
« Reply #11 on: January 11, 2013, 05:17:10 pm »
It's all been said already - sharp scraper followed by a sanding block.
Gordon