Small craft(7)

The next step was making a hull with ply wood.  At the first, prepaed a long and thin MDF. Drew a straight line on that. Put the MDF down on the frames and measured the distance from the line of the MDF to the centre line of  the boat. As the same way, found the distance between the MDF line and chine. I found evey length of frames fallowing the same procedure.   And then, I transferred them onto the plw wood which is going to be a real hull of our boat. I drew a long straight line on the ply wood again and marked every station lines on the long line. Pointed the distance which I found before on the each station lines. Nailed on these points and drew a line with a long and thin batten.

  My mate and I were in charge of this job. We thought that we did our job very accurately.  However, one of tutor said that it did not look right. We had to recheck it, even though it took a long time.  Fortunately, I found that we made a mistake. We fixed and redrew the line. 

  Finally, I obtained one of the bottom hull. I laid two ply woods together and cut them out along the drawing line. I gave some offcut just in case of mistake.   

   When we made side of our boat, I realized that the ply wood was shorter. As a result, we used the scarfing procedure. 
  
   Scarfing is one of essential boatbuilding skill that extending the size of timber by beveling and joining two(or more) timbers.   Generally speaking, 12 to 1 ratio is desired. Also, 'The Gougeon Brothers on Boat Construction' book recommends that 8:1 to 12:1 as a common rate. However, small vessel such as a dinghy, sometimes, reduce the ratio. We did scarfing as ratio 7:1. 

  On the wild clean worktable, we set the timbers up. Lined up perfectly and clamp down with a long lumber stick. We used a nice sharped plane and dressed very carefully.  

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During the job we need to consider about grain unevenness. If the scarfing surface is not even, it will be bumpy when we glue. We completed saftly, and glued two timbers at the end.