Bow form clamping options w/TB3 glue.

[eflanders]

I would like to build an all-wood r/d longbow utilizing multiple laminations and using TiteBond 3 glue. As you know there are many options as to the clamping methods (bands, airhose, wood clamps, etc.)& the corresponding form designs that one could use.  Given the type of glue that I will be using, what do you all feel is the best form and clamping method to use?  Please note that I plan to make multiple bows from the form and clamping method chosen.

[ChristopherO]

I've made all wood laminates with TB3 and any method you choose should work as long as the glue joint is tight.  TB3 does not fill gaps such as an epoxy glue but it does a good job when tolerances are tight.

[okie64]

I've  made several bows using tb3 with spring clamps and pressure plates and they all turned out nice. The main thing with tb3 is that your joints fit tight.

[rbbhunt]

Another tthing is TB3 needs to be exposed to air to dry.  In other words, don't wrap with saran wrap.  I speak from experience  :(

[eflanders]

When you folks say "tight joints", are you suggesting that I do not use a toothing plane on the lamination glue joint faces for preparation?

[PEARL DRUMS]

No toothing with TBIII, smoother is good. I learned that the hard way.

[Roy from Pa]

For wood to wood or wood to Bamboo, all I ever use is Urac185. It is $5.49 for a pint and a pint will do 3 or 4 bows at least. It is bullet proof, and I have never had a glue joint failure with Urac. When making a bow, and with the cost of materials and all your time involved, I would go for a good well known glue like Urac185.
  http://www.nelsonpaint.com/glue

[fujimo]

urac is my first choice-keep it in the reefer- will last longer, and when it is cool it has a way longer open time.
i dont think that tb111 gives you a very long open time- but whatever it is, i am sure that it is enough- as plenty of people use it!!!
dont over clamp with urac- i built a perry reflex- hickory on hickory- used the string and wedge method for clamping- we over did the wedges in the handle area- the bow eventually failed there- on analsys we saw that it was a glue starved joint.- but never had one fail since- all i use is the stationary grade rubber bands on my form- works super well.
g'luck
wayne

[Pat B]

Urac is the best of the best with wood/wood glueups. I've had good luck with bicycle tire tube bands wrapped around the glue up and then put into Perry reflex.

[tradbower]

I have to agree with Roy , Fuji, and Pat. Use Urac 185.

[7 Lakes]

Urac is great but it doesn't fill voids like epoxy.  If you can run everything through a thickness sander then use it with confidence.
  If you are using Bamboo and the backing isn't perfect then use epoxy.

[7 Lakes]

I'll get you a few pictues of a simple, inexpensive form for all wood bows.  It can be adjusted easily for different amounts of reflex / deflex or you can introduce both.

[Inuumarue]

For me I use strips of inner tube wrapped around the glue up. Then I clamp it into reflex. If I were doing multiple lams I'd probably clamp them up in stages.  TB3 sets up too fast for me to do much more than two or three lams.

Adam

[7 Lakes]

This is a simple form for all wood bows with a backing or multiple backings.  By moving the blocks you can decide how much reflex / deflex or combinations you want.  Keep it wrapped to keep off the glue dribbles and you can use it over and over.  

The yellow thingy on top is a yardstick for a pressure plate.  Pay no attention to the black magic marker marks on the edge.  They are in the wrong place for this type of bow.  

   1st picture has everything clamped and ready to put in the oven.  
 

[7 Lakes]

I started with a perfectly straight, flat 2/6 and trimmed it down to fit between a set of weights I had handy.  

Here's a few more pictures.

Clamping in a little deflex, notice riser is already curved.
 

Notice the epoxy squeezing out.  PS If you are going to go through the time and trouble to build a bow don't be cheap on the glue.  Use Epoxy.  But with any glue you are looking for it to squeeze out when clamped.
 

Notice all the spring clamps on one side, Build your heat box wide enough to handle clamps on either side.  I use my oven designed for glass bows and it's not wide enough.  Clamps are on sale at our Lowes store for $1 each.  You can never have enough clamps.
 

Black Walnut Overlay, don't stick it far outside the working part of the grip.  This is an 8" riser and 8" overlay.  
 

Simple wooden blocks, easy to experiment with, simple to build to any height.  Just keep them straight across the board so you don't introduce twist.
 

Put your curve in the riser before glue up if you are going to introduce deflex.  You can bend and clamp the core and backing this way without having to go back and fit a riser.
 

With only two laminations the blank will spring off the form.  In other words just because you glued in 3" of reflex doesn't mean you will end up with 3".  You'll just have to experiment.  I like a slight deflex leading into a reflex that comes just about even with the riser.  It's easy to tiller and a great shooter.
 

I hope this helps.

[7 Lakes]

In the last picture the bow is cut out and trimed down it actually comes off the form with glue dribbers hanging off the bottom.  You can see where about an inch and a half of reflex disappeared.  The glue line of a thin lamination introduced between the core and backing would have held more reflex.  
 

[eflanders]

Mike,  That is great information and the pictures help a lot.  If you don't mind me asking about the lost reflex:  Would using more and thinner lams allow for less loss of the reflex?  Can one calculate or estimate the amount of lost reflex? Is the amount of lost reflex fairly consistant from one type of wood to another wood?

[7 Lakes]

The thicker and heavier the core the less reflex remains.  To some extent the thinner the backing the more reflex is lost.  The easiest and best way of saving reflex is to substitue some of the Ipe with a thin bamboo lamination.  An extra light weight lamination will reduce the limb weight plus give an added glue line to prevent reflex loss.  I wanted a lightweight bow and didn't have room for a third lam on this bow.  

I'm also not a huge fan of alot of reflex it puts alot of compression pressure on the core while subject to a tension blow up on the back.  Hickory in all it's wonder as a bow wood just can't take it like glass.  Besides a bow that comes out straight or with a slight deflex is the best shooter in the all wood catagory.

[Sal]

Mike, thank you for sharing that info,its very helpful.  I'm glad to see you here, you really know your stuff.  I still have a bow I bought from you about 8 years ago through the auction site.  Its a great shooter, all bamboo.  

I'll make a copy of your form, its exactly what I was looking for, I also like the gentle reflex deflex.

[7 Lakes]

Hey Sal, good to hear from you.  If you are going to copy this form do at least one thing different than I did.  Make your hot box wide enough to handle the spring clamps, clamped on either side of the bow.  The clamps would be easier to take on and off the form if they alternated sides.  You can also get more clamps on that way.