Malahini Design

Malahini Design

Wednesday, February 2, 2011

Fairing begins

I started fairing the hull last Sunday but have a long way to go.  It is a slow and messy process as the sanders and planer make lots of dust and wood chips. The weather is also not cooperating.
What is fairing anyway?  Fairing is the process of shaping the frames, keel, chine and sheers to accept the plywood planking and create the final shape of the boat.  Here is a picture that shows what needs to be done.  This is the un-faired chine attached to a frame. I placed plywood on the joint to show that the corner of the chine sits above the frame.  Attempting to attach the plywood to this frame and chine would make a weak joint and also distort the plywood creating an unsafe hull.  

To create a smooth surface to accept the plywood, the chine must be rasped, planed and sanded to align with the frame.   To determine what needs to be removed, a scrap piece of plywood, as demonstrated in the picture above,  is pressed on the hull in the area you are working to illustrate the high and low spots. If you do have a low spot, it needs to be filled with either epoxy, if it is small, or a wood patch if larger.  However, in most cases, material must be removed.
Here's a chine that has been faired to match the frame.  As you can see, the plywood will lay smoothly, have uniform epoxy coverage and create a strong joint.  The lines are smooth and "fair".  The term fair is used a lot in boating and describes a surface or curve that is smooth and looks good.
This must be done on the entire hull so there is lot more to do.  The white oak is pretty tough and it takes a lot of work to get it shaped. 
The tools that seem to help with the fairing process are:
  • Angle grinder with 50 grit disk. This takes down the wood pretty fast but is difficult to control. It also throws a lot of sawdust into the air. 
  • Power planer. This helps take down long strips such as the chines. You have to be careful so you don't take too much or have the planer set at the wrong angle.  I angled my first chine incorrectly using my planer and will have to glue in some more wood to build it back up.  My dad, who was carpenter, would call a wood patch a "dutchman". There will be several dutchman as part of this boat, but hopefully not visible. 
  • Belt sander. I have a 50 grit belt and it cuts pretty fast.  You have watch for gouges, keeping the angle right, etc.  This also makes a lot of sawdust.  My garage is coated. 
  • Hand planes. Several different planes help the get close to the final shape.  A small block plane seems to work well. 
  • Rasps.  Mine are either dull or they don't handle the white oak.  I haven't been too successful using the rasp to make any significant progress. 
  • Sanding board.  I made a 3x21" board of 1/4" plywood and added handles.  I cut open a 40 grit sanding belt and glued this to the board.   This helps put the final shape on frames and such.  It works well on the curved frames because the plywood can bend to follow the curve.
The big snow storm of the Midwest is slowing progress.  It is too messy and cold in my garage to do any work. Temperatures are supposed to hit minus numbers tonight.  I'm pretty sick of Winter.

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