Bamboo Recurve Build Along

By Sam Harper

Doing a dry run

It's a good idea to do a dry run before you slather glue all over everything. That will help you anticipate any problems. Whenever unexpected problems arise in the middle of glue up, it causes panic and foul language. Doing a dry run will alleviate some anxiety and reduce the number of cuss words you say later on.

You should have a center line drawn on your form from when you made it. You should also have a center line drawn on all your lams, including the bamboo backing. That'll help you keep everything lined up when you put it on the form.

Of course you don't have to draw a center line where those butt splices are because that's obvious.

Seeing everything all stacked together like that made me think maybe I should've made the tapered laminations thinner. This bow may come out kind of strong. But this is the middle, showing the power lam and all. It gets thinner as you go out beyond the power lam and the core lams taper.

I start putting the rubber bands on from the middle, like this.

I think the easiest way to put the rubber bands on is to use needle nose pliers. Start by hooking the loop on the back, then pulling it up, over, and toward you, then put it over the dowel in the front.

Don't freak out if you break a few rubber bands. Just remember how cheap they were and how easy it is to cut more from your inner tube. I broke six of them today.

Once I've got a few rubber bands in the middle, I put a clamp on the deepest part of the curve before putting the rest of the rubber bands on.

That makes it easier to put the rest of the rubber bands on. Don't put much pressure on that clamp. You need the bamboo to be able to slide as you apply pressure with the rubber bands.

Once you get all the rubber bands on there, check for gaps between your lams. If you see any, you can just add more rubber bands on top of the ones you've already got. That'll give you more pressure.

Once you've got that all situated, you can add clamps to the curve. I start with the one at the bottom and work my way out, placing a clamp wherever I need to to close any gaps.

These kinds of clamps will leave dents in your bamboo if you squeeze them too tight. You can avoid that by using a piece of leather or something for padding. But if you get a little dent, it's not too big of a deal. You're going to sand or grind that rind off later, and the dents will go with it.

The glue up

There are almost as many gluing surfaces for this bow as there are for a fiberglass bow, so I'm going to measure out almost as much glue. Just like the fiberglass bow, I'm going to use two 3oz paper cups (Mickey Mouse is optional), fill one almost to the top with Smooth On epoxy, and fill the other almost to the top with the hardener.

Then I'm going to squeeze those into a plastic bowl and mix well with a stick of scrap wood.

To prepare for glue up, I put the form near the back of my table and tape some wax paper to the table nearest to me. I also drape some plastic wrap over the bow form. I put all the lamination on the wax paper in the order I'm going to stack them.

Starting with the belly lam, I dab glue on it with my stirring stick, then spread it with my handy dandy seam roller.

I also put glue on one of the tapered lams, then place it on the belly lam to where both glued surfaces are pressed against each other. I press down with my hands all along the length. That helps minimize the amount of sliding later on.

I couldn't show you all this because I had glue all over my hands and didn't want to handle the camera. But I basically just kept gluing and stacking. The second to last piece was the power lam. Be sure to get those center lines all lined up.

The last thing to apply glue to is the bamboo backing. This was a little tricky because of the curve, but still manageable. Be generous with the glue around the curve in case you don't get a perfect glue line. Smooth On will fill any gaps, and although it may not be beautiful, it will be fully functional.

I put that all on the form and get it basically centered. At this point, I took my rubber gloves off since I'd just be handling the plastic from here. With glue-free hands, I could take pictures again.

Notice how the tip of the backing is bent up while everything else is straight. That makes it impossible to wrap the plastic around it right away. So I just wrap the plastic around the middle at first and put the first few rubber bands on.

See how the ends are still unwrapped? As I put the clamp on the curve, I can wrap the rest of that plastic around the ends, being careful not to get any plastic between the laminations.

By the way, don't wrap that plastic tight. Leave it kind of loose so that when the glue gets squeezed out it has somewhere to go. Otherwise, it'll pop the plastic and glue your bow to the form.

From here, I follow the same procedure as when I was doing the dry run. Be careful to keep all the laminations lined up as you're applying clamps because it'll want to slide. Here it is all clamped up and ready to go in the hot box.

Having it all clamped and rubber banded like that makes it blurry. It clears up when you place it in the hot box.

This is a new hot box I made with plywood. It's a lot sturdier than the one in my 'how to' thingy and gets a little warmer. It still has three 100 watt bulbs in it. I attached foam board insulation all over the inside. It gets to around 170F in the summer or 150F in the winter.

I cook it for four hours, then turn it off and leave it in there over night. Or, if I do the glue up in the morning (which I did today), I might take it out that evening. Just make sure you give it plenty of time to cool off.

to be continued...

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