Friday, May 24, 2013

Corkin' and the oar factory.

The team has split into two groups the first is corking the seams on the boats and the second is turning out oars.

I'll start with the corkers. Corking, corkin', or caulking is a method of sealing plank seams where cotton or oakum is driven into the seam in order to make it water tight. First the seam is cleaned, then raw linseed oil is painted into the seam. Next the cotton or oakum is pounded in and painted. Finally the seam is covered in seam compound.

The above description is for boats whose seams are tight enough to take the corking. The problem with the Powell boats is although they were planked extremely tight the planks have shrunken grossly due to the use of very green oak. (the selection of this wood was a huge amateur mistake, none of the instructors at the school thought it would be a good idea.) With the shrinkage a solution had to be decided upon.

The above photo shows the solution. As you can see there is a cedar spline in the seam with the cotton or oakum. The cedar is quite soft compared to the oak so when the planks begin to swell the cedar, cotton/oakum mix will simply crush together sealing the plank seam.

Were not reinventing the well here. Some older boats who have had damaged plank seams and were unable to spend the money to replace every other plank have been corked up this way with success.

In the back corner of the shop team oar (which i am a part) is hard at work carving the crap-load of ash oars that will accompany these boats down the Grand Canyon.

Its really fun work, lots of layout and hand tool work. Ash is a little stiff to work so the key is razor sharp blades in all the tools. With that the strips of wood just peal right off.

Oar making is an interesting project when your trying to make a bunch of oars that are identical. It all comes down to repeating every step every time.

By the end of the day today one boat was corked up except for the garboard seams, the other was close behind and there were six finished oars stacked in the corner of the shop.

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