Thursday, October 27, 2016

Paddle Fail: Warped shaft on Sassafras Paddle

Hoping that folks reading will learn from my mistakes, I've posted a few failures over the years in this paddle making journey. One such example was my doomed attempt at carving a paddle from a piece of downed cedar or the first sassafras tripper that snapped after aggressively testing the flex.

Well, here's another learning experience to share. After completing a sassafras version of the recurved cree blade,  I had decided on doing a negative burn of the simple original decoration of bars and circles. In order to visualize the result, an image of the paddle was tinkered on with photoshop.

Visualizing the burning pattern

The plan was to do a full on burn with a propane torch on both sides of the paddle with a few spots left bare in order to complete the fine details with pyrography pen. After testing and doing a single side burn on a new Sassafras Tripper this seemed like it would be without problems.

Unfortunately while burning through the shaft area on this paddle, it began to warp ridiculously so now there is a pronounced bend, both curving laterally and back to front as evident from the pics below.

Severe warp of shaft to the right

Shaft bent back from blade

Guess without planning it, I created my very first "bent-shaft" canoe paddle.

Luke McNair had sent a warning about the risk of warping if heat was applied unevenly. Did my best to consciously avoid this, but the results here are pretty dramatic. I suspect the fact that the shaft was carved down to 1" and the blade thinned down more than usual for some flex contributed to the warping. The lumber stock was also flat-sawn instead of being quarter sawn.

Either way, all is not lost. I plan to practice some etching on the burned blade and will figure out some other usage for this failure so the wood (and my efforts) aren't wasted.


David said...

Thursday October 20th, go have a look at your entry... :)
We all learn from mistakes... Some are worst than others but all are mostly with low consequences( in the woodworking world anyway) Grab an other piece of wood, make sure it is really dry before you try to torch it. If the moisture content was some what hight, like more than 6-8% it might be one of the reason for the excessive warping. The one I made was a really thin shaft and blade and did n't have problem, but it also was quarter sawn and bone dry!!
good luck and thank you for sharing your mistakes with us, we can all relate in ne way or an other!!

Murat said...

Thanks David! I'll be sourcing out some quarter sawn lumber next time I hit the mill. You're right though, mistakes in the wood working world are usually pretty low consequence. Already have the next few paddle blanks being worked on and am also trying to fix up an old broken one like you did with your wife's favourite paddle.

David said...

We sure wouldn't make mistakes if we didn't do nothing!!
Keep up the great work!!

Luke Mcnair said...

Hello Murat, sorry to hear about the paddle! Did you try burning the other side of the blade and shaft? I've experienced the same back to front bend in shou-sugi-ban paddles; it's often possible to straighten it out by equally burning the other side. I imagine it's because the wood fibres are massively contracting on the burnt side, but staying the same on the non burnt side. I reckon the bend to the side in the shaft could be fixed by steam bending; I've got a couple of paddles I need to try that on. I have to say that I'm probably not going to use the burning technique for working paddles again, due to the risk of warping, checking on the end grain, and the fact that it ends up looking really tatty after heavy use. It's great for display paddles with high contrast chip carving though. Really enjoying the blog. I've been meaning to email you for ages with canoe and paddle photos; will try and do it soon.

Murat said...

Thanks Luke. Yes, the whole shaft and the other side of the blade were burnt too. In fact, the warping began to get extreme when burning the other side. Strange. I'll give your idea about steam bending a try. I wonder if the warping is worse on woods that steam bend very well in the first place, like ash and sassafras. Looking forward to seeing your paddle and canoe photos.

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