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Backing transparency problems, advice needed

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Backing transparency problems, advice needed

Postby einstin-7 » Wed Mar 11, 2015 8:51 pm

Hey there! I'm a noob here as well as a fairly new bower and the other day I decided to try my hand at a tri-lam longbow with mild reflex and all bamboo lams. I wanted to use a transparent backing so that the grain of the boo would be visible
"its not natural nodes intact"
Sooo I decided to go with ultra thin fiberglass drywall tape and smooth on epoxy to saturate it and form a kind of safety backing. Long story short after applying the epoxy and smoothing into the tape I then simply laid a single piece of clear packing tape over the top to keep from getting the epoxy on everything it happend to brush against and proceded to squeege the extra epoxy by running a dry knife down the length of tape.
When dry however the drywall tape was not transparent and in most places the epoxy wasnt either?? I'm not sure what to make of this since all the research I did beforehand suggested that the saturated glass fibers would become transparent and also the squeeze out of epoxy from the lams dried clear but the backing epoxy dried milky?

Would love to hear some theories...

Also despite the backing being less than attractive the bow did bend very nicely and I added a fourth lam to the limbs to increase the weight from 25 to 40#. I would like to hear some opinions particularly from more experienced bowyers though on advice for narrowing the outer limbs. The form had roughly 1.5" of clean arc reflex "handle outwards" and now the limbs seem to be bending smoothly in the rough inner 70%.
I left the limbs wide at the tips just under 3/4" and 10" back from them the width is 1 1/4".
On previous longbows the profile from the tip back was more like :: 1/2" @tip , 1" @10" and 1.5" @20" ...
I'm not sure whether to simply cut down from 1 1/4" to 1/2" tips or reduce the 1 1/4" to 1" as well and maintain a more linear front profile..
The last ten inches or so of the limb still has a little reflex and I'm not sure whether the smaller width would make it loose the reflex and possibly introduce a hinge? The taper of the overall limb is 0.005" per inch and If i understand right the general idea to a smooth tiller is a linear taper on thickness being mirrored in a linear taper of width as well...

I can't wait for the fireworks to start on this one :lol:
thanks all..! ;)
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Wed Mar 18, 2015 3:46 pm

Bump!

OK, so I decided to go ahead and trim down the profile to 1/2" tips and 1" at 10".
Everthing looks great and the bow shoots great here are some pics.
Image
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Would still like to hear some opinions for making the fiberglass tape and epoxy come out clear..
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Re: Backing transparency problems, advice needed

Postby 4nolz » Wed Mar 18, 2015 6:39 pm

Fiberglass tape and epoxy aren't clear.Cover it with snakeskin,silk or paint it I'd say.
there are 2 dates on your marker.Your life is the dash in between.
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Re: Backing transparency problems, advice needed

Postby Crooked Stic » Thu Mar 19, 2015 3:13 am

cant see the pics.
Prez of the Crooked Stic Gang
Image
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Mon Mar 23, 2015 10:39 am

Yes, I originally was thinking of silk or tape and decide on the tape because it was more easily available lol.. Next time I'll use silk!
As for the pics not showing I pm'd an admin and haven't gotten a reply yet.
Anyone with insight as to the syntax for pict links is welcome to enlighten me.
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Re: Backing transparency problems, advice needed

Postby 4nolz » Mon Mar 23, 2015 11:30 am

I mean just over the tape for cosmetic reasons but silk backing alone os OK just not going to increase weight like the tape-assuming the tape does?
there are 2 dates on your marker.Your life is the dash in between.
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Tue Mar 24, 2015 3:42 pm

Here's some of the pix...
Attachments
P1000519copy.JPG
P1000519copy.JPG (194.95 KiB) Viewed 5452 times
P1000516copy.JPG
P1000516copy.JPG (131.29 KiB) Viewed 5452 times
P1000503copy.jpg
P1000503copy.jpg (141.72 KiB) Viewed 5452 times
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Tue Mar 24, 2015 3:43 pm

and more..
Attachments
P1000509copy.JPG
P1000509copy.JPG (150.36 KiB) Viewed 5451 times
P1000510copy.JPG
P1000510copy.JPG (135.53 KiB) Viewed 5451 times
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Wed Mar 25, 2015 12:53 pm

4nolz wrote:I mean just over the tape for cosmetic reasons but silk backing alone os OK just not going to increase weight like the tape-assuming the tape does?


I'm not sure if the tape adds draw weight.. other bowyers seem to think not but since I applied it taut on the reflexed bow before any bending or tillering I'm assuming at least 3-5 lbs. maybe? :|
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Re: Backing transparency problems, advice needed

Postby einstin-7 » Wed Mar 25, 2015 12:56 pm

Funniest thing about this bow was I always think of bamboo as being light compared to hardwood but after weighing this one against a hardwood of the same style and length it weighs 1 oz. more.. lololol :shock:
Oh well it still shoots very smooth so I can live with that..
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