Bamboo Sealant Question

Hey everyone, I've got a bamboo questions. I'm about to use half poles as wall trim and chair rails (indoors). I'm worried about splitting. A few of my poles have just cracked and split sitting on my basement floor (I heard them crack!).

I've read changes in humidity can cause cracks, and that sealing the bamboo helps.

Would you agree sealing is a good idea, and if so, what sealant would you recommend?

nope its bamboo its going to split and crack as it dries. Thats just how bamboo works. It would be nice if you could seal it and prevent it but, nope.

I read somewhere just recently that it's the air pressure inside the 'nodes' that causes the cracking, so you need to make a hole in them. I'm guessing the only way you could really do that is by smashing through them with a long metal pole.

I wonder if you could tape (using super strong cloth tape) a drill bit to a metal pole (like a thin garden post) to one end and and a drill to the other to drill through each node.

You would have to go slow.

Maybe a spade drill bit?

Or to be safer:

https://www.totaltools.com.au/milwaukee-mania/119168-milwaukee-450mm-1-4-hex-quick-change-extension-bit-shockwave-48324534

If it is the air pressure, then forget about drilling the length. Just drill a very small hole in each section between a node. It can be at the back or somewhere that doesn't show but it will certainly allow the air pressure to change without any trouble. Lengthwise drill would be very difficult.

[ Edited by TIKIGIKI on 2023-01-15 12:51:40 ]

Ah yeah that would work as well 😂

In the Franks Cane and Rush catalog the bamboo they sell "is guaranteed to split" it is written.

But yeah, I think it will just split if it is going to split no matter what you do, can't hurt to try releasing pressure though.

Heck that stuff can grow up to over a foot a day.

Bill Sapp said that when they were building the Kahiki the Bamboo inside as it dried it would crack and when it did "it sounded like a gun going off."

I have some seven-inch bamboo from the Kahiki, so it was some BIG stuff in places.

Also, when we have a fire it is fun to make a bundle of fresh cut bamboo and throw it into the fire as it burns it sounds like firecrackers going off.

Bamboo gets its name because it goes BAM when in a fire..... https://www.youtube.com/watch?v=cTJtAa9DKNc

One more thing I think you can just grind some rebar to a point on one end and use that rebar to punch holes through the nodes in the Bamboo as well.

Good luck.

I'm a bit confused - we're talking about already split poles (now half poles) that develop cracks down their length. Not sure what one could drill that would help that.

Yes well I was "confused" too! It was mentioned that trapped air between the nodules was causing the problem and then a suggestion of puncturing the divisions internally was made. That could only be with completely intact poles so I too assumed that was what we were discussing, hence my suggestion. (In truth I do not hold much faith in air expansion being the cause of splitting.) If your poles are already in halves and now splitting it suggests to me that the bamboo was picked too green. There's not much you can do to prevent this as it will always split as the excess sap dries out. I have quite a lot of bamboo, both small diameters and large and have not found any splitting problems at all. Do you have central heating? That will definitely cause splitting as the heat dries the young bamboo even further. (Central heating is not good for any fancy veneer work either!)

Yeah, I do have central heating. Right now the bamboo has been inside and exposed to kinda dry temps for about a month (heats been running).

In a normal year, it gets more humid inside in the summer, and dries out a bit in the winter. I do have a humidifier so that helps.

I guess I'll just hang it and cross my fingers...

Yeah, in that case just let it dry a bit before you put it up and then don't use or cut out parts you don't like.

Or even use them behind a chair or down low.

Cracks in Bamboo can be cool too, I had to crack some bamboo for some lights once.

Good luck!

See the crack adds interest.