MW's trade bow build...MORE questions 2/12/11

[Monkey Wrench]

I signed up for the trade-a-bow program, now that I've built a few successful longbows with a straight profile.  They have all been pretty straight forward up to this point. However, for the trade bow, I'm really trying to push the quality of this one.  So...I will have lots of questions.  

First off, I'm building a bamboo backed Ipe bow, r/d design similar to the one on Sam Harpers website.  So far I have cut the fade profiles into the ipe, 7/16 at the handle and 1/4 at the tips.  The bow will be 68" nock to nock.  I also have the bamboo in hand.  Supposedly it is ready to put on the bow, but I want to check that.  I got this a few months ago, it will need to be spliced in the middle.

Here's some pics, where I'm at now, and questions.  I know I don't have many posts yet, but that means I need EVEN MORE help, so oldtimers please don't think you are wasting your time.

Now that the profile is cut out, I'm planning on going ahead and cutting the shape of the bow into the ipe.  Since the back of the bow is flat, it will lay in my bandsaw well and be easy to cut for a beginner.   Is this a good plan? See pic 1...

       


Next lets move onto the bamboo itself.  It is 1.25 inches wide, has been "heated", flattened, and tapered.  At the end (which will be the joint in the middle), it is 1/4" think at it's highest point.  At the end where the nocks will be, it is about 1/8".  Is this ready to glue on?

       

       


Next is the joint at the handle.  This is where it might get hard to follow.  The bamboo pieces together are about 74" long, so I have some room to play with.  If I put the joint in the middle of the bow, and let the two ends fall where they may, I get a node on the bamboo that will hit right about where I am planning on nocking it.  See the next two pics.

       

       


But, if I overlap the joint a bit (cutting about 2" off of the splice end of each piece), I will be able to get the bamboo node off of the nock point, and also have no node interference at the handle.  See the next two pics...

       

       

 Which method would be better?  I would prefer the second alternative, just so I don't have to mess with the nodes.  Since there will be no node interference at the handle, this will also let me select which which end of the bow will be the top after I tiller it.  Kinda seems like a no-brainer, but maybe there is something I'm not considering here.


Last questions...
I'm going to be using URAC glue, so I don't have to heat it.  This will allow me to build a few pieces at a time, and not have to glue the tip overlays on at the sime time I'm gluing the bamboo to the ipe.  I can also put the layers on the handle seperately.  I can glue up the handle one night, and the add the bamboo and the profile the next.  Sound like a plan?

My plan is also to go ahead and cut the shape out of the ipe, glue the bamboo on, and then trim the bamboo to match the ipe.  Sam's website has him doing it the other way, but I think that because it's one continuous piece of bamboo, and you have to string it to find the center.  Since the bamboo was centered before it was cut, I don't have that problem.

What type of splice do I need to do at the handle.  My thinking is since it will be at the handle, there will be no bending, so I can just butt them together.  I will be covering the splice with a leather handle when I'm done anyway.

Thanks for the help!!!

[Monkey Wrench]

Hmmm...doing something wrong posting the pictures.  I uploaded them to photobucket, then used the image tool to put in the url???

[John Scifres]

They're too wide.  Must be less than 640.

You should flatten the bamboo and then lay out the bow on the bamboo.  Cut it out and then thin it so that all sides are less than 1/16th".  This makes it naturally tapered.

Taper your slat from 1/2" at the handle to 3/8" at the tips.  Glue the belly onto the bamboo without cutting out the shape.

Then cut the profile out of the belly slat using the shaped bamboo sides as your guide.

[AKmud]

Make sure you put the right code in the IMG box.  Copy the "Direct link" code for it.

[SubXeroArcher]

it helps to preview your post before you actually post it too...you can see if the img is going to work or not

[KellyG]

sounds like you have plan, Hope you get the PIC thing going. I really want to see how you are doing the BBI.
Happy building,
Kelly

[Monkey Wrench]

Originally posted by John Scifres:
They're too wide.  Must be less than 640.

Yup, that must be it.  I thought most websites automatically size now-a-days.  No biggie, I'll trim them down at lunch.  Thanks for the help!!!

What about the splice at the handle?  Will a simple butt joint work, since there will be a leather handle?

[John Scifres]

Yes.

[Monkey Wrench]

Finally got the pics to work.  Thanks for the tips.

Last question and I can get this weekends work done.  What do you think of removing some of the material at the splice, so the nodes line up better?  I will cut off the overlap that is shown on the second to last picture.

[hova]

i think if youre going to butt splice your ipe , maybe an angled scarf would be a good idea on the boo , just so you dont have a couple butt joints right on top of each other.


lookin good so far though .

-hov

[Monkey Wrench]

Not splicing the ipe, just the boo backing.

John, I get why I should cut the boo and then sand down the edges to 1/16 which will produce a natural taper.  Wasn't thinking about that, thanks for the tip.  As the boo gets wider, it will automatically get thicker...ah...yeah....

[KellyG]

Well MW,
looks like you have a plan and a mentor.
Happy Building,
kelly

[Monkey Wrench]

I've got the boo cut, sanded and ready for glue up.  Two questions...

1)  Since the boo will be spliced in the middle, can I glue up one side at a time?  This way I won't have to buy so many clamps just yet.  I'm planning on using urac, and then just letting it set-up inside the house (at 70 degrees).  I could make it warmer if necessary, not sure what I need to do here.

2)  I've seen people refer to sanding the rind layer off of the boo so it does not pick up a splinter.  The following pictures shows where I have sanded the boo for the tip overlays.  Is this how much I should sand down over the whole bow before tillering?  I guess, the question is the "rind" the very top layer only, or does it include the middle layer that is lighter in color.  (all three layers can be seen in the photo).

   

[hova]

the rind is usually meant to be just the protective enamel on the outside. any deeper than that and you risk nicking the power tubes , and causing a splinter just the same.

-hov

[KochNE]

As much as clamps cost...just buy a cheap bike innertube if you can't pick one up for free.  You'll get better glue lines w/ the tube than clamps anyhow.  

Yes, the rind is just the VERY outermost waxy layer.  If you sand past this you will break the power fibers & increase chances for backing failure.  And whatever you do...stay away from the nodes with the sandpaper.  Once glued up, only sand from the boo to the ipe.  Never the other way around.

[Monkey Wrench]

So it looks like I dug in too far on sanding flat for the tips?  I don't think I would have gotten it flat if I had backed off.  Maybe I shouldn't have sanded it out so far.

Think I'm heading for imenent failure here, or is it OK since it's close to the tips?

Thanks!!!

[KochNE]

If tips are non- or little-bending and you saturate the sanded parts w/ glue well, after staining the boo, if you plan on doing so, it'll have a better chance of surviving.

[Monkey Wrench]

I have all the handle pieces, tips, backing, etc ready for glue-up, but I have a question.  Do I need to sand the kerfing off of the peices, and then scuff them up for glue-up?  I'm thinking if I do all that, why even sand the kerf out?  

Thanks for the help!!!
Brad

[No-sage]

Depends what kind of glue you're using.  Titebond like smooth surfaces, so if that type of glue is what you're using, smooth everything out and glue up while everything is freshly sanded.

if you're using a gap filling type of glue (epoxy, URAC), they need space for a good bond.

I'd still remove the kerf marks though, mainly because they're usually uneven and you'll get bad looking glue lines.

[hova]

i tried a neat trick the other day on some scrap , where i got carbon paper , taped it to a piece about the size of an overlay , then rubbed it on a scrap tip from a broken bow.  

it would transfer the graphite right where there were high spots , and i could then use my scraper to flatten both pieces. i would alternate the overlay then the tip , and mark each piece and clean em up.


it resulted in the cleanest glue line i have done yet. i wish i had just did it on the handle i glued up last month , that glue line looks like michael jacksons plastic surgeon did it...


-hov