sail taping - © Frank Ellinghaus -
My sailing- / -rowing dinghy was designed as a family boat with sail area of only 39 sq. ft. I wanted
more - (my actual sail has 57 sq. ft. and it could be even a little more). So
how could I as an amateur, alter this design without paying a fortune in failed
sails? The solution was to choose cheap material for the sail and do it by tryal
and error. Besides not beeing a good taylor (or not at all) I wanted my sail as
soon as possible.
Searching through the web I found Jim Michalak´s article on
polytarp sails. Jim sews the sails from cheap polytarp and he has a point in
doing it that way, since it should be much more durable than a glued/taped sail.
But for me, speed and ease of taping (and my impatience) was the reason to try
it with this method first. There are other sites on the net which promote taping
too one even sells white polytarp and white tape. Click here for their site ... but
come back soon :-) . They seem to use only onesided tape for glueing while for
me double sided with carpet tape for outdoor use, looks like the better way.
(Tell me if I´m wrong.) Though I don`t know how long it will hold it sticks very
well to polytarp and is a pleasure to work with. But it should hold better
because both sides stick and there is no covered area without glue as with duct
tape. My actual sail has now (August 99) more than 30 sailing hours and only a
little tape has lifted on the top.
The following method seems for me the best way to have it last as long as
possible. Now here is the description:
Step 1:
Place the carpet tape on one side of the precut polytarp
sail at the edge.
Step
2
Step 2:
Remove the carpet tape´s wax paper and
place the boltrope on its middle. The boltrope should be much longer than the
sails side. Both ends should extend far enough out of the sides so that you can
fix the sail to the spars with the boltrope´s ends. Than fold the sails end with
the carpet tape, tape around the boltrope so that the rope with its wrapping
becomes the edge of the sail. Do this with all sides so that you get 4 boltropes
each extending out of the sail at both ends. If you think the boltrope would
disturb the air flow on the leach, use a smaller boltrope for the leach. Since
this rope doesn´t have so much load to carry it could be rather thin.
Step 3
Step 3:
Put two narrow rows of carpet tape on
polytarp and than cut this double row out. With this you´ll get strips which
fold easily in the middle to wrap around both sides of the sails edges with the
bolt rope inside. Remove the wax paper and fold the strips around all four sides
of the sail. Now you could fix this sail on your rig without grommets since the
boltropes take all of the load. But I normally do some grommets on the luff and
foot sides. But these grommets are only for adjusting the sail not for taking
load! Don´t use grommets in the corner patches to tighten the sail. This should
be done only through the boltropes. The grommets transfer the load to your tarp
and your glued seams so they could weaken your construction.
here you see the
stripe around the sails edge, with the boltropes extending out at the side. The
small unused strips on the sail are intended for the grommets but they easily
could also find a use in a sail repair kit.
Step 4 - placing
the grommets:
For the grommets put only one strip of carpet tape on polytarp,
cut it out beforehand and cut pieces of about 5 inch. Fold them around the edge
where you want to install the grommets. So you´ll get 5 layers of tarp under the
grommets (one original with two on each side through the taped strips).
Step 5
edge gluer
Step 5 - placing
corner patches:
Take a double row strip of carpet taped polytarp of about 1
foot and fold so that you get 1/2 foot folded strip. Cut the free end of that
strip round. Than remove the tape and fold/glue it around the sails edge at the
end of a corner. Than do the same with another strip from the second side of
this corner.
Step 6 - placing white duct tape:
Here it comes
the duct tape. You can use it and place 2 rows on each side of the edges over
the carpet taped strips. I do this on the leach and the head of the sail because
I think it will deflect the sun a little bit so that the adhesive will not melt
so easily.
The large picture
click
here for a bigger drawing of the rig.
The last picture
sail on mast
here you see the
stripe around the sails edge, with the boltropes extending out at the side. The
small unused strips on the sail are intended for the grommets but they easily
could also find a use in a sail repair kit. 
Step 5
sail on mast