The longbow back laminate
Making a thin back laminate for a longbow of e.g. hickory without a band saw or circular saw is hard and it would take a very long time. When selecting a suitable piece of wood for the back laminate, more knowledge is needed when using hickory compared to using bamboo. I therefore recommend that you make the back laminate from bamboo.
Bamboo is very strong in tension and you hardly have to worry about the grain running off the edges of the laminate. Bamboo is in fact a type of grass, but from now on I will refer to it as wood. “Then you saw and file the grass”, just does not sound right.
You need a bamboo log about 10 - 15 cm (4 - 6”) in diameter and the finished bamboo laminate for your longbow should be 193 cm (76”) in length and must have an equal distance from the ends to the top and the bottom node of the laminate.
If you buy green bamboo you will have to season it yourself.
The longbow belly laminate
You need an Ipê plank 193 cm (76”) long by 3.5 cm (1 3/8”) wide by 2.2 cm (7/8”) thick. The planks are also available with a thickness of 2.5 cm (1”), which is fine.
Ipê is used for decking and will make a durable and great looking sun deck but more important, it is also a very strong and compression resistant type of wood. This makes ipê ideal for the belly of a longbow or as core wood when making a multi laminate bow. Ipê is widely available and sold by many hardwood dealers and will make an excellent belly wood.
When searching for the belly wood for a bow avoid knots if you can!
Glue for gluing the laminates together:
Types of glue, which may be used, are UHU plus endfest 300, Smoothe On, Resorcinol etc.
A bow form
To facilitate the best possible bond you need a straight form to strap the laminates to, when gluing them together (p14). The form will also ensure the bow stave is still straight once the glue sets.
There are several ways to make a bow form. The more professional versions, however, take time and demand some serious power tools, which is why I will use a simpler version in this guide. The form I use for illustration purpose, is a ready planed pine board 4.7 cm x 15 cm x 200 cm (1 7/8” x 6” x 78 3/4”). The exact dimensions of the form are not important, but the form needs to be firm and stiff enough for it not to change its shape, as you strap the laminates to it and the glue sets. The board used as a form should thus be fairly oversized like mine is, especially when a softer type of wood like pine wood is used.
Leather for the handle of the longbow:
A soft piece of leather.
The string nocks
For ipê reinforced nocks you need two small pieces of Ipê, which you will have plenty of once you have cut out your bow
if you choose to make horn nocks you will need 1 or 2 pieces of buffalo horn depending on their size. Other types of horn may be used.
Making the laminate longbow
Making the ipê belly laminate
The ipê plank I acquired was 14 cm (5 1/2”) wide, which made it possible for me to make 4 belly laminates of 193 cm (76”) long by 3.5 cm (1 3/8”) wide by 2.2 cm (7/8”) thick.
Start by marking out the belly laminate for the longbow. In order to get the laminate as straight as possible, I use a chalk string to mark out the sides.
Cut out the belly laminate. If you have power tools available, use them as we have 0.5 cm (3/16”) of room to play with as our finished bow only will be 3 cm (1 3/16”) wide.
I am starting out with a bow length of 193 cm (76”), which may be a little oversized. However, if you want to be on the safe side, when it comes to achieving your desired draw weight, this is the way to do it. If your bow turns out too weak, you can shorten it to achieve the desired draw weight.
Making the bamboo back laminate
1. Fix your bamboo log in working height. I use a foldable workbench (p1).
When you buy the yellow/light brown bamboo, like the log in the photos, you will be buying seasoned bamboo. The disadvantage is that the logs virtually always have several cracks. You do not have to season it but you will waste some bamboo, as the areas with the cracks cannot be used for your bow. Therefore, you have to find all the big and small cracks in the bamboo and mark them in some way (p2). When you have done that, you will be able to plan where to cut the back laminate of the longbow.
When you have found a spot with no cracks that will fit a 3.5 cm (1 3/8”) wide back laminate, make a straight line down the length of the log representing the first edge of the laminate (p3+4). The line is NOT allowed to twist; it has to be straight down the length of the log as otherwise the grain will be cut (p4).
Cutting the bamboo laminate for the longbow
Use the jig saw to cut along the line that you just made (p5), but first make sure that the blade of the jig saw can work freely inside the log, which should be no problem.
When you have made the first cut down the length of the log, grab one of the ipê laminates from earlier as we know they are straight, and align it with the cut that you just made. Then make a second line to represent
the second edge of the bamboo laminate (p6). To be on the safe side, use a string to check whether the line is straight (p7). Cut once more with your jig saw and you now have yourself a very rough bamboo back laminate (p8).
Instead of using the jig saw you may split the bamboo using a knife and a soft headed hammer, but it takes longer and you waste more bamboo. If you decide to do it this way, always start splitting the log at the end with the smallest diameter. When splitting the bamboo you should always make room for error, because the split might run off to one of the sides.
2. The bamboo must now be worked down to the correct thickness. The length of the finished bamboo laminate is 193 cm (76”) but I do not cut the laminate at this stage, because it is nice to have some extra length when working the laminate down in thickness.
The thickness of the finished bamboo laminate is 4 mm (5/32”) at the handle and then it tapers down to 3 mm (1/8”) at the tips. The measurements are made between the nodes of the bamboo (p9). The taper of the bamboo laminate is not of vital importance as you will still get a great working longbow without it. The rationale for tapering the laminate is to try keeping the ratio of bamboo to ipê about the same throughout the length of the bow.
Longbow draw weight
My aim is a draw weight of 50 pounds at a draw length of 80 cm (31 1/2”). A draw length of 80 cm (31 1/2”) will require a little more from the wood than the more conventional draw length of 71 cm (28”), but this bamboo/ipê combination should handle the extra stress without any problems. You have to make the bamboo laminate a little thicker for larger draw weights and thinner for lighter draw weights. By tillering the bow to the longer draw length I shall have the option of a full draw to the ear.
When working the bamboo down in thickness I free-handedly cut most of the excess bamboo away with the band saw. Then I sand it down to the exact size using the belt sander and 40 grit sandpaper. Do frequent checks with your calibers. It takes some practice to free-handedly cut the bamboo with the band saw and I would suggest that you practice on some scrap bamboo.
If you do not have the power tools available, you will have to do the work by hand. Use a plane, surform and a sanding block. It takes longer but it is certainly possible.
Wear protective gloves when working with bamboo because it does have a tendency to create some nasty splinters.
Cutting the back laminate
3. The back laminate is now ready and it fits nicely on the ipê belly laminate (p10). Get your form ready (p11)!
The distance from the top of the laminate to the top node should be the same as the distance from the bottom of the laminate to the bottom node. You therefore need to work out this distance before you cut the laminate to its final length of 193 cm (76”). In my case this distance is 5.5 cm (2 5/32”) (p12) and I will thus cut my bamboo laminate 5.5 cm (2 5/32”) from both the top- and the bottom node. In photo (p12) you see one of the top nodes of my laminate (the end of the laminate is to the left in the photo).
Cut the ipê laminate to a length of 193 cm (76”) if you have not already done so.
The laminate is now 193 cm (76”) in length; it has the correct thickness and an equal distance from the ends to the top- and bottom node.
Gluing the laminates together
4. Before I glue the laminates together, I use sandpaper to rough up the surface of the ipê, which will be facing the bamboo laminate. Ipê is a very oily type of wood, and wiping the newly sanded surface with acetone will aid the gluing process.
Let the acetone vaporize while you prepare the form. Cover the form with seran wrap. In doing so, you will prevent the form from becoming a part of the bow, should you spill any of the glue.
I prefer to do a test run before I mix the glue, just to make sure everything is aligned and I have all the things I need ready. So, try to clamp and bind the laminates and the form together without the glue, especially if this is your first time making a laminate bow. When the glue is mixed you only have little time to finish, before the glue sets in, and if you do not have everything in place by then, it is tough luck. The amount of time at your disposal does of course depend on the type of glue which you use.
Another precaution that I take is to make some opposing marks on the laminates (p13). This way, if I lose the orientation of the laminates when I apply the glue, all I have to do is to align the marks to get back on track. An alternative to the opposing marks is to mark the handle section at this stage.
Glue the laminates together (p14).
5. Let the glue dry. In the photo (p15) you can see that plenty of glue oozed out like it should.
Marking out and cutting out the longbow
6. Mark out the back of the bow according to Fig. 1 (p16). It is important to place the center line at the crown of the bamboo throughout the length of the stave.
When the center line is in place, mark out the rest of the bow with reference to the center line and not to the edge of the stave.
Cut the back tapers of the bow.
7. Mark out the belly tapers according to Fig. 1 and cut once more.
Dealing with the nodes of the bamboo
The Split Cane Fly Rod makers are a group of people with a great deal of experience working with bamboo. They make flexible fishing rods meant for fly fishing, using split bamboo. When dealing with the nodes of the bamboo I use knowledge acquired from a Danish rod maker. Some rod makers totally even out the nodes, but we will not be doing that.
8. Use a file meant for metal work to work the nodes of the bamboo down to the dark discoloration just above the node (p17+18). Only just remove the dark discoloration. File diagonally (p18) in one direction only (I think, it has to do with tearing the grain). In the photo (p19) I have removed half of the dark discoloration above the node (furthest away in the photo). Work down all the nodes like this and be careful not to damage the bamboo next to the node.
Removing the rind and shaping the bow
9. Carefully remove the rind of the bamboo using rough sandpaper and/or a card scraper. Only remove the rind, do not damage the grain underneath, this is very important. Take care when working close to the nodes as this is usually where mistakes happen. The photo (p20) shows the rind partly removed. If you do not remove it, you can and will probably get into trouble when trying to glue something onto the surface of the bamboo or when applying the finishing lacquer.
10. Sand the back of the bow with 120 grit sandpaper and carefully round off the edges of the bamboo making everything nice and smooth.
11. Flip the bow over in the vise and take off the edges of the ipê with the rasp (p21). Then round off the edges of the ipê still using the rasp (p22). Use the card scraper or some rough sandpaper to remove the tool marks made with the rasp.
Tillering a longbow
Tillering roughly means to make your longbow bend nice and evenly by removing wood in the right places. There are more aspects to the art of tillering than getting the bow to bend nicely. You also have to arrive at the desired draw weight and draw length, all in the same process.
12. Get your bow ready for the tillering by making some temporary string grooves (nocks) and fitting an overlong bowstring. Then start doing your magic!
The photo (p23) shows my longbow on the tiller before beginning. In the photo (p24a) my bow is starting to bend nicely. The photo (p24b) shows the bow after I am done with the tillering and after the first shooting session. The amount of string follow is about 2.5 cm (1”) when compared to the starting point in photo (p23). When the bow is left to sit for a short while, it is down to only 2 cm (25/32”), which is not too bad for a 50 pound bow with a draw length of 80 cm (31 1/2”) with no initial reflex curve to compensate.
13. Create the final string grooves reinforced with horn or a piece of ipe. See the images below.
14. Sew on a sweet looking leather handle and you are ready to go shooting p(41)!