hi roger, 

there are cetainly alternative approaches to sheathing.  the arctic hawk construction manual, for example, has everything sheathed on the interior before assembly (e.g., the panel interior side is glassed before they are stitched together).

that said, i would go with the proposed construction approach for the shearwater (yes i have built one).  it's not particularly difficult to get a very good layup on the interior with the hull (or deck) stitched and it also then avoids the need for taping the fillets/ensuring proper strength on the interior from panel to panel which is important and needed if you glassed the panels prior to assembly.

on your final question, if you just sheathed the inside of the panels prior to stitching, they would still bend just fine.  that is my experience based on building the arctic hawk which used that approach.

h

���When you say assembly, do you mean attaching the hull to the deck or the individual panels before stitching and filleting them together? On my WD 14, theres no way the panels would bend and twist to the proper shape if they were glassed first, the side panels in particular have almost a 90 deg bend in them at the stern.

i mean individual panels before before stitching and filleting them together.

i also mean only glassing on one side, the inside.

i can't speak for the wood duck, i am speaking for shearwaters which are not particulary curvy and certainly less curvey than an arctic hawk where i followed the builders guide which glassed the inside side of the panels before stitching them,

fwiw, on the old west river 180's (which i built as well) you glassed the inside of the deck prior to bending the deck and attaching it.  it really does not appear to have much of an impact until you start glassing both sides....particularly the outside.   glass is very rigid in tension (which is the outside). when you have it on the inside and you bend it, you are in compression.

the reason i am suggesting to follow the shearwater guide is when you assemble and fillet it, if you already glassed the inside of the panels, you now still have to put a layer of glass tape over the fillet to have the proper strength.  so it doesn't really save signifcant effort and the shape of a shearwater is pretty easy to glass the inside of the deck or hull after it is assembled/filleted (but before you attach the deck to the hull).

hope that helps

h

Many thanks, hspira, for the words of advice.  I will happily benefit from your experience.

- Roger

   After taping the interior seams of the Shearwater, the plans only call for laying glass in the cockpit area between the bulkheads. This method helps in the strength of the monocoque construction. If you glass the whole panel you would be adding unnecessary weight and probably have problems bending the panels to shape as you stitch.

PS