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Splitting - Troubleshooting

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I'm splitting my first culm and am getting some weird strips. The enamel side of the strip appears to be splitting pretty evenly, about 3/8". Yet somewhere along the line, the split starts to walk toward the middle of the strip, making a taper in the pith side. I've been using a froe and I also tried the Bob Nunley hand-splitting method. I get a similar result either way. Any advice appreciated. (Paul Ausick)

Sounds as though you are allowing the culm to rotate about the knife blade, or to look at it another way, the knife blade is angled in relation to the culm. Can't help you with what you're doing wrong on the hand-splitting method.  (Martin-Darrell)

Try this.  Do your splitting by starting the split and then go to your workbench.  On your workbench screw a small 2X4 to it and drive a thin shaft screwdriver into the 2X4.  Now split the culm by pushing the culm along the shaft of the screwdriver.  If it starts to wander put pressure (sometimes real hard pressure) against the fatter side so it comes back to that side.  This is the best method I have found and I have shown it to many guys who have switched to it.  (Bret Reiter)

I think you are letting the froe angle to the center of the culm.  When you see the split start to angle in toward the pith, turn the back of the Froe back to the outer part of the strip. Are you splitting half, half and half. Hope this helps.  (Tony Spezio)

I'm in my first year of rod building and things are progressing OK.  On the first culm I split, there were quite a lot of small splits already on the culm, this also goes for most of my culms.  On splitting, because some of these splits were midway along the culm my finished sections of bamboo were somewhat truncated on some of the sections and were unusable.

Is this a common problem?  If not how do you get around the problem and save more bamboo?  I buy my culm in the UK and are the best I can find, I think the splits are either natural or due to loading during storage at the importer or during transfer by the courier.

I'd really like to save more bamboo, just got one rod out of my first full 12 foot culm?  (Nick Brett)

What you found is quite common.  Some bundles of bamboo are worse than others.

Splitting is one of those tasks that seems impossible at first, but with just a very little practice becomes second nature.  Students in my classes split their first culms into 28 tip pieces and 20 butt pieces.  On your second or third culm you will be doing the same.  (Harry Boyd)

I'm going to try to split my second culm next week and I'm going to use a knife in a vice instead of pushing the culm through past a nail.

On a secondary point, I do like the fact that its not easy and there's something to master here.  From my first culm, I'm currently final tapering my strips and the planing has gone OK but I know I've wasted a lot of bamboo.

Its good to know that this is a common problem, I paid as much as I could for the culms in the UK, around £150 for 6 12 foot culms, hoping that I would get some good sections.  The only other place I've seen culms for sale is of course the US but the shipping just kills the purchase.  (Nick Brett)

The random splitting is usually (?) the fault of rough handling, I think. Not much you can do about it, but it can ruin any reasoned approach to splitting.

I hand split, using a vice to control over runs, and usually split from the butt to the tip.  However I find that when you get one of these mashed culms, the splitting usually is on the tip end, so what I do is take each one of the existing splits  all the way through the culm.  This gives you a pile of funny looking biits of bamboo to deal with. By the way, it may be worth mentioning here that I always cut my culms into two 6' pieces  (or 3 four foot ones if it is to be a 3 piece rod) before I do any splitting at all.

At this point, I reverse them and split the pieces as best I can from the butt end to the tip end.  It is rare for me to be able to salvage as many regular strips from a culm as I would get when splitting an undamaged culm, but usually I get plenty for a rod plus spares, depending, of course, on the original size and condition of the culm.

I agree with Harry - there is no easy or royal road to splitting ; it's just a thing where you have to split a few and find out.  The good thing is that you will learn it quickly and get good at it., regardless of the technique you use.  I, for example, don't like knives or screwdrivers in vices as a means of splitting, as I find I can steer the split more accurately and easily with my hands;  but another person may find that that is quite wrong for him.  So go with what suits you.  (Peter McKean)

I'm still working on rod #1.  I'm nearly finished with the wraps. It was my experience that learning how to split was the hardest part of the process for me. I ordered the beginner's pack from Golden Witch plus an additional Grade A culm. My first attempts with a knife in a vise were futile.  Every strip ran out before the end.  I could hardly get even one strip out of two 6' half culms.

I read everything I could find on splitting:  Jack Howell, Garrison, Maurer, the Rod Makers archive. Finally, something Maurer said about an 'alternative' method of splitting did the trick.

After I start the split, I hold the culm up in front of me, usually between my legs, with the end braced against something.  Then, I split the strip, sometimes with a rotating movement, sometimes just putting pressure on the opposite side of where the strip wants to wander. 

It's counterintuitive, Syd Smith says, and he's right. 

It's Zen. What you think will work is wrong.

Now, if the force is with me, I can split a quarter inch strip into an eighth.

My advice?  Get your hands on some cheap culms and split them up until you are good at it.  (Reed Guice)

I have found that to split culms uniformly and efficiently, I need to clamp a culm strip at the successive nodes as I march down splitting the strip. This lets  the split open between successive nodes and permits me to control the split run through the node area; this is where the splits usually wander for me if I don't use this approach. I use a big old dull hunting knife that guides the split by twisting the blade to keep the split uniform. This means I clamp the strip at each successive node. I have tried all the ways in the books, but doing the clamping at the nodes and splitting between nodes is the best way for me to get the maximum number of usable uniform narrow strips from a culm. I use a bench vice for gently clamping the strip; the vice has hard rubber inserts on the faces so the clamping does not mar the bamboo strip. I hope this might help some newbie folks with their splitting problems. Just a procedure that I have evolved and that works for me.  (Frank Paul)

Many thanks for your email and good advice.

I split my second culm today to make the banty 4ft 4 wt rod in the latest issue of 'The Planing Form'.  I split by hand this time, instead of using a nail and pushing the culm through.  The split went much better than the first, which is good, still wasting too much bamboo and like you say, a lot of strips run out before they're long enough.

I guess as you say its down to practice and practicing on some cheap culms is good advice and something that I'll try.  (Nick Brett)

It's a learning process, and you will get better each time.  For your first rod you are doing fine.  Are you making a check spit along the entire length of the culm when you get it to keep it from developing lots of random cracks?  (Brian Creek)

Yes, I put a check split it each culm just after delivery.  The split in the culms were there when I received the delivery of the culms, almost rang the company I bought them to tell them but figured they could be a natural element of the drying process.

I feel pretty bad about wasting so much bamboo, what do other rod builders use it for?  (Nick Brett)

You should do a search of the archives.  This comes up periodically and the variety of uses is truly astounding. It makes great fire-starters. (Brian Creek)

Great, but expensive fire starters.  (Mark Wendt)

A small bag of shavings from planing is a great fire starter though.  (Neil Savage)

Much nicer than the little, white, waxy version.  (Brian Creek)

I keep all those errant pieces that do not work out anywhere else & make 4'0" to 4'6" one piece blanks for small streams.  I sell them on ebay & it is surprising how many I sell.  I usually get $85.00 to $125.00 for them.  Should have kept my mouth shut because I can see it now ebay bombarded with these blanks.  (Bret Reiter)

Andy Royer has made one shipment of bamboo to Europe and, I believe, is planning future shipments.  The first shipment was to a number of buyers, so you might be able to add yourself to a list.  At present Andy is out of bamboo, but that situation should change in the early spring.  Many of us on this list have bought bamboo from Andy.  (Tim Anderson)

I have been building rods for over 30 years, and I have had trouble with runouts and waste;  I still average two rods per culm.  I split now and for all of time I have been building by using Garrisons method:  With a sharpened tool. I split by hitting the tool in a node at a point giving me a straight line from one end to another. I don't worry about leaf nodes, but I split carefully to avoid wandering splits.  This is slower, but if you run the split from one node to the next,  you can't go far wrong.   One caution, use your splitting tool only at the nodes.  (Ralph Moon)

My first culm was a disaster but I did get a rod out of it. What I found with multiple splits is the split you make if close to an adjacent split that split will follow the split you are making.

When I do have multiple splits in a culm, I split down the split that is already started. This will not always give you equal splits but I find I can salvage a lot of bamboo by doing this. If the split is running off to a point.  Bend the  "FAT" side away from the split, this will bring the split back in line. If possible, split half, half and half.  Splitting in thirds will for the most part cause the split the veer off to the narrow side. If you put more pressure on the wide side away from the split the split will wander back in line. I use a post or the side of my workbench and a bit of Body English to bend the Fat Side away from the split. Start the split and do down just enough to open it. Put the tip of the Fat side against the post or bench and some body pressure against the middle making the Fat side bend away from the split. This will keep the split in line. It takes longer to try to tell how to do it than it takes to do.

To conserve bamboo on my 12' culms.  I first split the culm in half. Take the lower part of one half and measure up for the length of the rod I will be making and add one half of distance to the next node for staggering nodes. Cut the bamboo off there. Then do the same from the tip down. This leaves a nice section in the middle for three piece butts and tips. You are only cutting to length one half a culm leaving the other half for longer or shorter rods.

If this is not clear, I will be glad to send  you some photos of what I do.  (Tony Spezio)

To conserve bamboo on my 12' culms. I first split the culm in half. Take the lower part of one half and measure up for the length of the rod I will be making and add one half of distance to the next node for staggering nodes. Cut the bamboo off there. Then do the same from the tip down. This leaves a nice section in the middle for three piece butts and tips. You are only cutting to length one half a culm leaving the other half for longer or shorter rods.

This is a perfect example why those of us who really know Tony don't call him Tony......we call him Yoda!

He uses the Force to split bamboo, comes out perfect every time.  Hey, even a Jedi Master likes to fish.  (John Dotson)

I have to agree. Tony has helped out so many of us on this list. And every time I turn around I learn something new from him. Thank you Tony for your years of sharing your wealth of knowledge!  (Scott Bearden)