Author Topic: some newbie ?s  (Read 2410 times)

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Offline Tom Kurth

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some newbie ?s
« on: September 14, 2013, 12:13:17 am »
As a woodworker I hold to the philosophy that every piece of wood has a particular destiny so when I came across a piece of red oak 3/4" x 3 1/2" x 56" with straight, flat growth-rings, it spoke to me of a flat bow though I knew it was probably beyond my meager skills as a novice bowyer. I shaped it as a pyramid style bow (2 5/8" wide) and added siyahs (sp?) to make it 60 3/4" nock to nock. At this point it weighs 53# at 28".

My questions: 1) As I've tillered it, I mark a spot that needs work and take a little off. I check it and all seems well--problem area solved. A few short draws and check again. Same spot needs work--over and over again. Is this typical? Or am I doing something wrong? Or am I just an impatient so-and-so?

2) It has taken some set--about 1 1/2". I've read so much here and elsewhere so I get a little confused sometimes. Red oak has a tendency to take set? Am I right? And can I help this by heat treating? Can somebody direct me to a nutshell on heat treating?

3) When it comes time for finishing, I like to use a home-made wiping varnish (one part varnish, one part mineral spirits, one part boiled linseed oil) on many projects. I know it's not the most durable, but is it otherwise a reasonable choice for a bow that probably won't see harsh weather?

Thanks for any help. I'll post some pics when I can nail down the teen-ager in this house for some computer help.

Best,
Tom
Best,
Tom

Escape to Missouri

Offline huisme

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Re: some newbie ?s
« Reply #1 on: September 14, 2013, 12:35:57 am »
1) It happens, don't sweat it too much. You might try turning the bow around so you're not getting used to expecting any one flaw.

2) Yeah, in my short experience with RO (don't like the stuff) it takes some set. I think if you heat the belly and trap the back it'll help.

3) Yessireebob.
50#@26"
Black locust. Black locust everywhere.
Mollegabets all day long.
Might as well make them short, save some wood to keep warm.

Offline cdpbrewer

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Re: some newbie ?s
« Reply #2 on: September 14, 2013, 07:53:02 am »
1)  Tiller not changing after wood removal can be due to not exercising the bow enough after wood removal- or not removing enough wood.  It's real boring, but pull the bow on a tillering tree at least 30 times.   
Details:  Mark areas for wood removal and note draw weight (not to exceed intended final bow weight), draw length and where the tips are vertically.  Remove wood.  Put back on tree with scale.  Exercise 30 times at intended weight while watching for hinges- don't worry about tiller.  Assess tiller and see if tips position or draw length have moved.   If no change and you think there should have been, consider shooting a heavy arrow 10 or so times but don't exceed latest tillered draw length.  Sometimes that works better than juts pulling the bow. 

2)  As George T says, set happens.  I'd be real proud with having only 1-1/2" set for a red oak, 53# at 28", 60-3/4" ntn!  I've only tried removing set once on a red oak board bow by heating and bending in more reflex than I should have.   It didn't have any crystals but the bow broke anyhow while doing so.  YMMV- others have reported success.   
Details:  Set on red oak and most other bow woods is due to the wood on the belly's surface being crushed.  This is due to red oak being stronger in tension than compression.   Toasting the belly won't remove the crushing damage and set but it will strengthen the belly and help prevent more set- and usually add a few pounds in draw weight.    If the set gave the bow too much string follow for your taste, consider bending in some reflex after the bow has been floor tillered on the next bow.

3)  That finish is fine for a bow that won't see lots of rain and such.   Consider waxing after the finish is fully cured (tung oil instead of the linseed oil in your recipe will speed curing).   I use regular old floor wax- no silicone just in case the bow ever needs refinishing. 

c.d.

Offline Del the cat

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Re: some newbie ?s
« Reply #3 on: September 14, 2013, 10:27:27 am »
Removing wood and nothing happens is good... it's much better than removing too much and creating a hinge.
Experience is what teaches you how much to remove at any time.
It's a balancing act... too little and the job takes for ever... too much and it's ruined.
Pretty obvious, the former is the option to go for, it's all about patience.
The 'no change' you think you are seeing is probably just a very small change. If it was an obvious change it would prob' be too much.
I always say take off half as much as you think it needs :laugh:.
The whole tiller ing process is one of teasing it back by successive approximation.
If it takes less than a few days to get from floor tiller to full draw you are doing it too quick. Never try and do it in one session.
I reckon increasing the draw by say 2" at the target poundage is enough for one session, even if you just take a break for tea and toast (or your equivalent regional snack  ;) ). It's easy to get 'tiller fatigue' where you can no longer see what you are loking at.
When in doubt, step away from the bow :laugh: .
Doubtless some will dissagree, but I've never broken a bow by going too slow.
Del
BTW What are you removing wood with? A cabinet rasp or scraper are prob' favourite at the tillering stage, but it needs to be a good sharp scraper to have any real effect. I tend to use a rasp and then clean up with the scraper

« Last Edit: September 16, 2013, 12:07:16 pm by Del the cat »
Health warning, these posts may contain traces of nut.

Offline SLIMBOB

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Re: some newbie ?s
« Reply #4 on: September 14, 2013, 11:02:56 am »
Great advice, well said and spot on by Del (except the tea and toast.  Shiner Bach and a dip of snuff for this Texan).  20 lite strokes with my scraper, exercise and check the tiller.  No visible change is what I'm after.  Repeat and check it again.  And then again, again.  Little tiny moves each time is about perfect, otherwise you'll blow right past your target.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.

mikekeswick

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Re: some newbie ?s
« Reply #5 on: September 14, 2013, 05:53:15 pm »
Removing wood and nothing happens is good... it's much better than removing too much and creating a hinge.
Experience it what teaches you how much to remove at any time.
It's a balancing act... too little and the job takes for ever... too much and it's ruined.
Pretty obvious, the former is the option to go for, it's all about patience.
The 'no change' you think you are seeing is probably just a very small change. If it was an obvious change it would prob' be too much.
I always say take off half as much as you think it needs :laugh:.
The whole tiller ing process is one of teasing it back by successive approximation.
If it takes less than a few days to get from floor tiller to full draw you are doing it too quick. Never try and do it in one session.
I reckon increasing the draw by say 2" at the target poundage is enough for one session, even if you just take a break for tea and toast (or your equivalent regional snack  ;) ). It's easy to get 'tiller fatigue' where you can no longer see what you are loking at.
When in doubt, step away from the bow :laugh: .
Doubtless some will dissagree, but I've never broken a bow by going too slow.
Del
BTW What are you removing wood with? A cabinet rasp or scraper are prob' favourite at the tillering stage, but it needs to be a good sharp scraper to have any real effect. I tend to use a rasp and then clean up with the scraper


And amen to that. :)
Listen to what you've been told and all i'll say is it's good to have a questioning mind ...the rest will come with experience! Keep making shavings.