Re: [SCA-Archery] painting/finishing wood bows
- I have sought the oppinion of a professional.
First, my appollogies. Resin IS waterproof. The issue of removing gelcoat
is one of exposing void spaces and creating voids between fiberglass fibers.
Second, bows may typically have the sides exposed and just have a
polyurithane or varnish finish which can break down and allow moisture to enter
and/or leave the wood, requiring maintainance periodically.
Third, stress fractures in the resin over time and repeated bendings may
allow moisture acces to the wood.
Fourth, the matting material used in fiberglass construction makes no
difference to its abbillity to TRANSPORT water. Fiberglass matting won't absorb
water into the fibers, but it will allow water between the fibers. I was not
refering to boats constructed with matting or with roving in particular as they
bath have the same properties if not fully resinned.
I think, however, that we are striving for the same point, which is; if
fiberglass is not aplied correctly or breaks down in some way, the wood
underneath is at risk. Oiling wood is a good way to restore moisture. If resin
begins to crack, a repair to the fiberglass is necessary for the strength of the
bow and for the protection of the wood underneath. You may want to seek the aid
of a professional in repairing the fiberglass if you are unsure of how to do it
Greg Christensen wrote:
> The epoxy resin is waterproof if it was not then my wood strip canoe would
> be waterlogged which it is not. Yes if there are void spaces as below there
> will be problems....You are right about the gel coat (a special blend of
> epoxy resin) if it is removed the fiber glass breaks downs if it is not
> protected from UV rays or in your case water freezing in the voids. Your
> also referring to boats made with fiberglass mat material which is not the
> standard fabric that has a weave to it, but the strands go in all directions
> like wool felt.
> I don't know if oiling will actually go through the epoxy resin and
> fiberglass, but I do know that if there is moister in the air then the wood
> will pick some up.
> Gregge the Archer
> This happens
> >if there are any void spaces, or there is any of the fiberglass fabric
> >which did
> >not completely absorb the resin.
> > I've seen many a boat go to the crushers because someone sanded
> >through the
> >gelcoat while trying to get all the bottom paint off and then just put new
> >bottom paint back on without repairing the gelcoat.
> > I would not rely on a semi-rigid coating to keep your bow waterproof
> >over a
> >long period of time. Repeated oiling is better because you are
> >replenishing the
> >moisture in the wood.
> >Calum McKay
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- I think we are all on the same page here essentially about
fiberglass and its need to be sealed.
The use of fiberglass cloth to make bows stopped about 40 years
ago and I've seen way too many accidents with them at Pennsic where they
delaminate in a very dramatic way, even after a thorough inspection
which they passed.They dry out, get old and fatigued, and delamination
is almost impossible to detect,until it happens then, BOOM!
The type of fiberglass laminations used on most modern bows is
where the fibers are laid out it vertical strands(much like the way you
lay out sinew for a sinew backing) and then adhered to themselves with
the resin,The bowyers purchase these pre-made laminations. These lammys
are then adhered to other lammys including the wood ones with a heat
cured synthetic resin glue. The way it was explained to me by some of
the bowyers I spoke to about my unfortunate accident with my hunting bow
in the early 1980's is that microscopically, there are passages between
the fibers which will eventually allow moisture through the fibers. The
fiberglass and resin are not absorbent but porous, the wood is absorbent
and almost acts like a wick.This is why all good bowyers seal all of the
bow, not just the edges and recommend that the owners continue to oil or
preferably wax on a regular basis.
Now before I go out hunting, I thoroughly wax my bows with a
beeswax paste, or Johnsons paste wax or Butchers wax and I carry some
with me into the woods.
On my self bows I use linseed oil.
But people PLEASE continue to care for your bows! I don't mean to
burst any bubbles here, but just because your bow is made with
fiberglass. it is not invulnerable to moisture.
Geoffrei St. Albans of Eastwood
Canton of Lions End