--- In email@example.com
, charles.k.scott@... wrote:
> --- You wrote:
> >Thanks Corky
> Can you tell me how is the glass laid upto or over the stem ,Do you
> trim the glass to the very tips of the stem or fold them both over
> slightly .
> --- end of quote ---
> Mike, two things: 1. The outer stem is pretty typically faired into
the hull such that it is an extension of the hull, not a protrusion,
which means that the fiberglass should lay over it without much
difficulty. 2. Several of the websites I've culled through show how
the outer hull fiberglass is laid up, they do slit the part that lays
over the bow and stern curves, then trim that such that it follows
the curve of the hull line, but overlaps by 3 inches or so on both
sides. The bump this creates when the resin cures is eventually
filled in with successive coats of resin with some sanding in
between. If it's not possible to manage that, then the long edge
should overlap the short edge. The short edge is still long enough
to overlap, or fold all the way over the leading edge and lay on the
opposite side, but the long edge should then overlap it, which will
hold it down.
> The same thing happens with the interior fiberglassing, again ably
demonstrated on John Michne's website.
> Speaking of fiberglassing, there are several schools of thought
regarding the process. Some folks recommend coating the hull with a
coat of resin and letting that partially cure prior to laying on the
blanket of fiberglass. Then the fiberglass is laid on and coated
with resin which then bonds to the first coat. But timing is
critical here. If you do not apply the fiberglass within the proper
time, the sealer coat will cure to the point where the fiberglass
will not properly bond to it. But attempt to lay on the fiberglass
too soon and you could run into problems with the fiberglass sticking
to it. Leave it to cure for too long, and you will have to resand
the entire hull to give the next coat something to bond to. But a
chemical bond may be achieved by laying on the fiberglass before the
sealer coat has fully cured. This is as opposed to a mechanical
bond, which is achieved by roughing up the first coat to give the
next coat something to grip.
> Some folks say it's just too much trouble to seal the hull prior to
fiberglassing and recommend laying the fiberglass on the bare hull
and then just applying the resin to bond the fiberglass directly to
the hull. That does work, no question, but there are issues. The
resin can wick into the wood, especially if you have some fairly
porous cedar, pulling the resin away from the fiberglass and leaving
it white rather than transparent.
> But either way works.
> Finally, I've noticed from ads in "The Wooden Boat" that there is a
vendor advertising really thin resin that wets out the fiberglass
well. That's important for the first coat, you want it to wet out
quickly so you can apply it to the entire project before things start
curing. It is not important that the weave be filled with the first
coat. The thing that needs to happen is for the fiberglass to bond
properly to the cedar. The later coats can be thicker, or more
viscous so that they fill the weave to make the outer shell smoooooth.
> But I'm not sure I want to be the pioneer who tries it when there
are plenty of systems that basically do the same thing and are well
proven. But I won't be there for several months so I have plenty of
time to think about it.
> If you have the time and the days lined up, you can do all the
coating without any sanding, if you use a resin that doesn't cure for
24 hours or so. But check with the manufacturer to be sure and
remember, the hotter it is in the shop or wherever the project is,
the faster the resin cures.
> Finally, from accidental experience, the blessing of fiberglass is
that almost any mistake can be fixed with lots of sanding and
application of a patch. With further coats of resin and maybe
another thin layer of fiberglass you can fill in almost any gouge
such that it blends in seamlessly with the original fiberglass.
> But beware, some are allergic to the particles of fiberglass and
especially to the cleaners such as Acetone or Laquer Thinner. These
solvents are extremely toxic so wear a proper mask when using them
and wear gloves.
> Corky Scott
Really great response, Corky!