Bamboo tools

[Albannach Cuileag]

Guys and Gals,

is there a post or link decribing how to form a parallel hex similar to that required in bamboo rod making?
I want to make some custom tools using hex bamboo for the handles and caps as a gift for a mate of mine.

Thanks in advance.

[kengore]

If I understand your post are looking for a simple way to construct hex shaped sections of bamboo that don't taper, ie. the sides are parallel.

This is commonly done as part of the bamboo rod making proccess. 6 triangular shaped strips of bamboo are made in a 'rough planning form' and heat treated prior to final planning where the finished taper is created and the rod blank assembled.

Unfortunatly getting to this rough stage is 90% of the way to a finished rod. You may find that this it too much work for a few tool handles. Detailed info is available on several web sites. Here is a quick outline of the proccess...

1. Obtain a culm of tonkin bamboo, these are approx. 8' long and 3-4 inches in diameter. Prices vary, but expect to pay at least $40 plus shipping.

2. Split the culm into equal strips, the width of the strips depends on the final diameter of the blank. Butt sections usually make 24 strips while tips can produce up to 32 pieces.

3. Heat the strips with an alchohol lamp or heat gun and hand straighten them. The natural bamboo will have bends and sweeps that follow the power fibers as they grow through the nodes. If you are only interested in small pieces of finished blank for tool handles you could eliminate this step by cutting out the straight sections between nodes. This would yield strips 12-14 inches long, depending on the age of the bamboo.

4. Strips are then hand planed into a triangular cross section. This requires a good hand plane and some wooden planing forms. The planing forms are blocks of hardwood with a small groove running the length. The bamboo strip is placed in the groove and the protruding edge is planed flush with the top of the form.

Two seperate forms are required to get a perfect 60/60/60 triangle. The first form is used to put a 60 degree bevel on one side of the raw bamboo strip (which is almost square in cross section) the second form is used to put a 60 degree bevel on the opposite side. Note that material is only removed from the soft pith sides, the outer enamal surface is only lightly scraped or sanded to preserve the dense power fibers.

These forms are easily constructed from any dense straight grained hardwood and a table saw. Cut 2 pieces of wood 3/4" X 3/4" X 50" long (for full size rods, 20" long would work for small handles) Using the table saw you cut a small bevel off one corner of each of the wood pieces, then screw the strips together so the beveled corners line up to form a trianglular groove running the length of the form. Detailed info on angles and reccommended depths can be found in any bamboo rod building building reference, look for 'rough planing form' instructions.

The challenge with small lengths of bamboo is how to hold them during planing. There is lots of room on a 50" strip, you can easily hold it in place with your fingers. A 20" strip is a different matter, consider that the sole of the plane is almost 8" and you need some room for the planing stroke plus a couple of inches to hold onto the strip. That 20" will get used up fast.

5. The rough triangular strips are then bound together with twine (6 pieces at a time) to form a hexaganal cross section. These bundles are then baked in an oven to harden the bamboo and to give it the desired color. Small strips can be cooked in your kitchen oven, long strips need a special oven that can handle 50" pieces or longer.

6. During the heat treating proccess the strips will shrink, so they need to be planed again to the final dimensions. For full length rods this requires a special planing form with an adjustable groove. Usually made from metal these forms have screws every 5 to inches that adjust the width of the groove. The screws are adjusted to produce a precise taper in the finished rod. For a simple non-tapereded tool handle a short wooden form could be used, similar to the rough forms. The final form needs to be constructed with great precision, tolerances of 1/10,000 inch are required to produce blanks with clean near invisible glue lines. A dial caliper and possibly a depth gauge are required, as well as some kind of tool with a perfect 60 angle to use as a reference. Several common metal working tools can be used, such as a lathe cutting tool, a triangular file or a 60 degree threading cutting gauge.

7. The finished strips are then coated with glue and bound with twine. Once the glue has set the twine is scraped off and some light sanding or scraping of the 6 finshed surfaces will remove any excess glue.

Thats a whole lot of work! Perhaps justified for a fine bamboo rod, but maybe not for some small tool handles.

There might be another option. Bamboo blanks are typically made 6-8 inches too long and trimmed to size during the final assembly. Rodmakers also have the occasional mishap and end up with unusable pieces of hex shaped bamboo. With luck you can find a friendly rod maker that would give you some cut offs or a broken section to make into handles. By the time you invested in raw materials, tools and reference books you will easily have spent over $100, for that price you could find some broken rod sections on Ebay.

[jklett]

What kind of sizes are you looking for? If you give me the measurements for diameter(flat to flat) and length I'll see what I can come up with(I have some scrap that I can bevel and glue up along with some cutoffs that I was saving to make dubbing needles). All I would ask is that you pay the shipping and post pictures of the tools when they're done.