Bow Build Along.......let the fun begin

[initialimage]

I was able to work on the project again today.  Here is what I got done.

I laid out the riser.

 

After bandsawing just outside my lines I start sanding:

 

I ground my lams today.  These are 3 thinner lams that are alternating colors.

 

I have a thicker lam(belly lam) that was ground also and I have it clamped to my form to line my riser up against. You might not be able to tell from the picture but there is a very small gap in one area so the riser needs to be tweaked so that it fits flush.

 

This riser is not going to work on this bow.  For a fiberglass bow(which this form is designed for) the riser should work great, but for this bamboo backed bow it is too severe and the bamboo backing won't easily bend around it.  I played around with some scrap and even tried heat bending it, but there is too much strain on the boo to follow this riser.  

I'll be modifying the riser tomorrow.  I'll cut it so it's not so pronounced and everything should bend nicely.  

More tomorrow..................

[LazerRay]

Lucky you

[Osagetree]

I expect a fast shooter if you pull it off,,, keep it coming!

[Shaun]

Thanks for posting as you go. Looks like the riser is gaping to the left of center, is that the adjustment you mentioned? Also, it looks like you are going to have the riser the same thickness as the middle lamination and butt into it. Or are you leaving the ends thick until you get the shape done and then feather it out?

I am really enjoying this build along. I picked up some lam bow working pieces, a hot box, couple of forms and hose stuff at an auction a while back and am looking forward to working with it. Threads like this give me a lot of info for when that time comes.

[initialimage]

I won't normally post unless I have something to show but decided I'd answer Shaun's(I enjoyed reading about your recent adventure) questions.

There is a slight gap to the left of center which you pointed out.  That is the area I need to tweak to get fitting a little better.  The riser is still thick at my fades.  I like to get the riser fitting flush along the bottom and then I'll fade them to a feather edge from the top side.  

I am hoping to glue the bow up tonight and have some more pics to post.  I don't know how many I'll be able to take because I'll have my hands full at glue up.

Osagetree.....If I can pull it off(not sure if I'll succeed or not.  I'm pushing my limits with this one)

[Shaun]

Jeff, thanks again for this tread and answering my questions. That is a great idea to leave the riser tips thick until all else is fitted. I have read that paper thin, tapering to nothing tips are important on a riser and they must be very fragile when at that stage.

I'm looking forward to seeing how this one turns out, but even more to seeing/sharing the learning process that it is providing.

There is one school of thought that follows fact and engineering statistics. There is another that relies on something more elusive. This second is summed up in a phrase I've heard, "Intuition is the highest form of reason." There seems to be some intuitive as well as practical application going on in your design process. Keep it up.

[initialimage]

I have the bottom surface of my riser lined up to my form.  When I start making fiberglass bows off this form, I'll machine a jig that I can use for sanding the riser and make it a no brainer.  I had to do a lot of test fitting and sanding to get it right without a jig.  What you can't see in the picture is how the bottom surface lines up with the belly lam.  I just put the riser up for the picture.  You can see how much I cut off to get the raw bamboo piece to bend over the riser.  I was going to add a little more walnut to the belly side of the riser anyway(later after removed from the form) so I'll just make up the difference I cut off by adding a thicker piece.  I also realized that my side stops are the right size for a fiberglass bow thickness but not for this bow.  I had to machine some larger ones.

 

Here is a shot now that the riser piece has been sanded out.  Notice how thin it gets.  You also have to make sure it is a very gradual taper.  You can sand a feather edge, but if the angle is too severe, the lams won't make a smooth transition over it.

 

I've got a few more things to do and another trick to show before I glue up.  Looks like I'll be working all night so hopefully I'll be able to work in gluing up the bow tonight.  I have my tripod here, so maybe I can get some pictures while I'm doing the glue up.

[NorthShoreLB]

I like the new riser much better  

[initialimage]

I was finally able to get the bow glued up.  I'll have to wait until it comes out of the form to see how it glued up.  I've never glued up a bamboo backed bow in hose form before.  

Here is a little trick I use when I glue up a bamboo backed bow no matter what method I use for glue up.  I glue little pieces to keep the raw bamboo from sliding off to the side once pressure is applied.  

 

Before I lay out everything for gluing up I get the form ready along with the air hose.  I don't like using saran wrap on the form since it clings to itself so easily.  I've got some plastic material(can get at Home Depot) that is much thicker than saran wrap and you can see how it holds its shape better.  The airhose is different.  I like to protect the hose from glue as much as possible.  I like to wrap the hose and saran wrap can easily work for this though I use shrink wrap material I have in my shop. Wrap loosely because the hose will expand when aired up.

 

Now that I'm about ready to glue up everything, I lay out a protective material(saran wrap or shrink wrap) on top of my work surface. I spread out all my pieces for gluing.  I made some notes on these just for the build along.  I like to tape off the belly and the raw bamboo backing.  This makes for a much easier cleanup of the blank when it comes out of the form.  

 

Ready to glue......................

[initialimage]

I'm surprised I was able to take as many pictures as I did.  I had my hands full during the glue up.

I like to run a bead of glue down the length of each piece and then use a seam roller to spread the glue.  It works really well.  You can purchase one of these in the wallpaper section at Home Depot, etc.  One thing I always do on both sides of the riser(at the fades) once I've spread the glue is to pool a little extra over the fades but don't spread it out.  I leave it thick to make sure I get a good joint there.  Any excess will get forced out.  I am using Urac 185 from Nelson Paint Company for this glue up.  I'll use Smooth On when I do a fiberglass bow.  

 

On a fiberglass glue up I use strapping tape around the lams and the bottom of the form to pull everything tight before putting the form together.  I didn't have enough hands to do that with this bow because my belly lam is thicker and has to be forced down onto the form.  You can see my solution to this.  I put a couple of wooden dowels through the form on each end and used inner tubing to easily stretch and hold my lams down to the form.

 

Once everything is in place and my side stops adjusted to the right height I put one more layer of plastic on top of the pieces and then assemble everything.  

 

Here is the form with the hose aired up.

 

When I decided to make the riser smaller I needed to make up that missing space so the air hose would keep the right spacing.  You can see my solution.  I just took the cut off riser section and taped it to the top of the form.  

Now it's time to wait.............This is the worst part of bowmaking for me.  I'm always very tempted to pull the blanks off the form much too early.

[Shaun]

I can't wait either, go ahead and pull it off the form so we can see. No, better wait.

The little pieces glued to the bamboo to keep it centered are at the tips only - past where you plan to cut to length?

[initialimage]

Forgot to mention something about the airhose.  You should always check it for leaks.  This hose hasn't been used in years.  I aired it up and in turn put each end into a large cup of water.  I had small bubbles coming out of each.  I tightened the clamps that hold the plugs in the hose and tested them again.  No leaks.  The last thing you want is a hose that goes flat before glue up is complete.

[initialimage]

Shaun...I only put the small glue on pieces at the ends.  That seems to hold everything right where it needs to be.  I've thought about putting some at mid limb but never needed to.  The pieces that are glued on can be handled two ways.  If the raw bamboo is left longer than it will end up being the ends can just get cut off and they are gone.  Once I get the blank off the form I use the bandsaw to trim just outside of the boo backing.  This cuts away almost all of those small glued on pieces and they completely disappear when I sand the sides.  I'll probably show that step with pictures later.

[initialimage]

I was asked a question offline that I'll address here and it has to do with the air hose.  I bought my plugs and hose from Binghams.  You can see on one end it has a normal schrader valve incorporated into it.  I just use a normal attachement in my airhose for airing it up.  I have a regulator setup within my airlines in the shop.  I turn it down all the way so there is no pressure.  I then press the air fitting onto the hose and slowly raise the pressure until it's where I want it.  All it takes is a bicycle pump with a pressure gauge on it.  

 

I'm going to dinner to celebrate my younger son's 6th birthday.  After the festivities I'll come back and pull the form apart.  I've got my fingers crossed.

[Crooked Stic]

Looking good so far.

[initialimage]

The blank is off the form and glue up appears successful.  I only hope the rest of it is.  Here is a shot showing what to be very careful of.  These edges of dried glue can be extremely sharp so either wear gloves at first or use great care when handling the blank.  

 

The next two shots show why I like to tape off both the belly side and the back of the bow. I like to use the blue tape because it shows up much better, but the regular masking tape is so much cheaper.  Glue will find a way to get on them.

Back
 

Belly
 

My next step is to take the blank to the bandsaw and carefully cut away the majority of the glue that has hardened over the sides.  After that I like to take a file and file the edges of the belly so that any leftover glue is flush with the belly.  This way it will sit flat when I cut the profile on the bandsaw.  I cut just outside of my raw bamboo piece.  After that I sand the edges to the raw bamboo.  

DON'T REMOVE THE TAPE UNTIL YOU HAVE SANDED CLOSE TO YOUR FINISH PROFILE.  It will pull off much easier than if you try to do it before sanding the edges.  

Here is a shot once the tape has been removed.
 

CAN YOU SAY TILLERING NIGHTMARE BOYS AND GIRLS?
 

I've got my work cut out for me now.

[clintopher]

Good luck.  I know I wouldn't be up for the task of getting those limbs to bend right.

Clint

[Lewis Brookshire III]

Man, those limbs have some MAJOR bend in them. ALmost looks like its strung backwards. This is gonna be a cool little bow for sure. I would LOVE to do this. Good luck!

[NorthShoreLB]

HOLY CURVES !!!

I wouldn't know where to start tillering that pappy.


Manny

[initialimage]

Just thought I'd throw this in for reference.  It is the glue up profile of my previous bow.  I got good tiller on it but had to take my time and it challenged me a couple of times.  I know this new one will be lots of fun.  Ha ha.  I seem to get more radical with each bow I build though I don't see myself trying to out radical this one.

 

 

Please send good karma my way.  I'll need all I can get.