Monday, February 28, 2011

More rehearsals: Fid needed!

Based on the the previous practice with edge tapes, I decided to go ahead and mock up an entire corner because the reinforcing patches will add even more layers besides the edging and I'd like to know just how far my sewing machine will take me.  Plus, if there's some hand sewing to do and I need to try that out.

Each corner will have three layers of reinforcement.  Both Emiliano Marino and Todd Bradshaw advise 1" of patch per foot of the sail's edge.  Of course, my plans are in metric so I'm going to just interpret the guidance as 10%.  These patches are not scaled to size, they are just scraps.

Mariano also describes a tradition of colored thread for seams and white thread for reinforcements.  He mentions this as a tradition with cotton construction, but I'm going to apply it to my tradi-modern GIS too.  Clearly, I can still use as much practice sewing as possible.

Unlike the previous tape practice, these are the actual tapes to be used.  The luff and the leech will be a tad heavier at 5oz.  The difference may be negligible, but the sewing machine might notice.  The foot and head will match the body's 4oz. weight.

So far so good.  No surprises here.

Now I'm, finding the limits of what my machine will handle.  The stitch on the left of the luff was with a thicker needle and the machine began to struggle at the third patch.  At the foot edging it balked.  I switched to a thinner needle for the stitch on the right and it got along farther.  Not happily, but it punched through all ten layers.

Now it's time to fit the hardware.  Spur grommets for the minor lashings, a brass ring for each of the corners.

The spur grommet is easy-peasy.  I used the small hole punch to nibble away the large hole for the ring.

The needle is no joke!  It's a three-sided shaft ready to do some damage.  Not shown is the sewing palm needed to ram this thing through ten layers of Dacron.  Cool stuff.

It's not easy to fully conceal the brass.  I'm not sure if I'm supposed to.  If so, I think I will follow Mariano's example of staggering the placement of alternating stitches so that they form more of a starburst pattern rather than a neat circle.

The other side.  Somehow I marked this side with pencil, but began stitching the ring onto the other side.  I can't even blame it on beer...

I started to get a little out of whack so I backed up one stitch.  I'd like to avoid this in the future.

So it became clear to me that my cut out needs to be neater.  I thought the tension would smooth everything out, but I also struggled to keep the ring centered over the hole.  More on that in a moment.

The back shows some of the tucking of ends, one of which formed an unintended knot.  I think I have a better feel for the length of twine required to do the whole ring with a single piece.

Dang it!  The hole was not large enough for the brass liner to pass through.  This could possibly by stretched with a fid, a cone-shaped tool that would be wedged and pounded in the hole.  Not gonna happen for this practice session.  Plus, I think the real remedy is to make the hole larger.  That would also alleviate the issue of pulling the ring out of place every time I pulled the twine taut.  So, for the real thing I will use the liner as my guide for marking the inner hole and will be sure to make it nice and smooth.

Not bad for a Sunday morning.

Friday, February 25, 2011

Rehearsals, rehearsals, rehearsals

One thing the Army taught me is that you can't rehearse often enough.  So in spite of the fact that I did some practice sewing already, I thought it would be wise to practice sewing with the actual sail materials.  Good thing I did because the sail cloth is nothing like the flag cloth I've worked with so far.

My first step was to create a practice seam.  I specified a 10mm seam width in my SailcutCAD design to accommodate the 3/8" wide basting tape.  Plus my sewing machine's maximum width zig-zag pattern is 7mm.  As I cut the practice seam , I also threw in a curve toward the end to get the feel for matching a curved edge to a straight line.  The result is the cupped shape shown above, although the plan will not have such a drastic curve to it.

So I was able to keep the stitching within the seam.  No big deal, though I did play around with the tension settings and other tweaks as I went along.

This is the top side.  I'm happy with how the pattern fills the overlap.

The "underside" was a little rougher.  Of course, unlike many sewing projects, there is no underside to a sail.  What this shows is that the bobbin thread is not being pulled up into the  fabric.  Normally that's adjusted with tension settings, but no matter what, I got the same result.  I'm going to call it good.

Here is an edge tape folded over the body to create a 1 1/2" finished edge.  That's three layers of cloth.  In this case it's all 4oz. cloth, though my actual tape is 5oz.  The machine handled this well.

The luff of the Lugs'l requires a considerable amount tension--downhaul--so the luff needs additional reinforcing to handle the load.  My plan is to quad fold a 6" tape as shown above for a total of five layers of fabric (four from the tape plus one from the body).

But... there are places where the layers will add up even more.  If the corners were simply intersecting edge tapes, there would be seven layers.  However, each corner will also have reinforcing patches of at least three layers.  That means ten layers total in some spots.

Stitching through these seven layers was clearly taxing our sewing machine (a fairly expensive model that does lots of cool computerized stuff like the three-point zig).  So I think I'm going to have to hand sew some of the edging and patches.  I planned to hand-sew rings in those spots anyway, so...

Next up will be practice grommets and hand-sewn rings!

Wednesday, February 23, 2011

Materials arrived!

So now that the holidays are behind us, I ordered and received my sail making materials.  Exciting!  Here's the inventory of goods:

At the top are the panel development plans as generated by SailcutCAD, my GIS notebook filled with Michael Storer's plans and helpful tips from other builders, the roll of 4 oz. Dacron, spools of V69 thread in chestnut and white, metric tape measure and stick, edge tapes of different widths, double stick seam basting tape, sewing palm and sail twine for hand sewing, spur grommets with die set and hole punch, brass rings and liners with die set.  Yay!

So this is what SailcutCAD creates as plans.  It has been noted by seasoned sailmakers/designers that a computer program is little good if you don't have a plotter to print the design directly to the cloth.  That would certainly make things easier.  But I'm not an "easier" kind of guy!  So I will transfer these coordinates onto the cloth by hand using rulers, straight edges and beer.

These rings will reinforce the corners of the sail (peak, throat, tack and clew) as well as the intermediate tack and clew of the two reefs.  The technique is to cut the hole, place a ring over the hole, then hand sew twine around the ring and the hole's edge in a wrapping manner so that the ring gets encased in twine.  Then the brass liner slips through the hole and is pounded flare so that it remains in the hole.  The liner protects the twine from chafing from what ever is used to lash the sail to the spar.  This technique is overkill for the rope lashings and the sort of loads I expect for this sail, but I think it will be fun.  Way too expensive, but fun.

Because the ring and liner approach is so expensive (each ring/liner combo was several dollars) and so labor intensive, I decided to use spur grommets for the multiple lashing points along the sail's head and foot.  These are not the sort found at arts & craft stores.  These are sold by sailors for sailors.

Here are my planning notes on rough measurements, construction, etc.  I will actually use fewer reef points and they will be holes only, no attached strings (nettles).  The holes will be reinforced with hand-sewn rings.  Similar to the brass ring above, a hand sewn ring is made of twine instead and in stiched to the hole's edge in the same manner.  No liner for these as they will normally be out in the flow of the wind.  When conditions require a reduced sail area, these reef point will simply act to gather up neatly the folded cloth as the sail is reefed.  But the stress is carried at the intermediate tack and clew at each end of the boom.

So that's enough salty talk for one post.  It's all I can do refrain from jumping in and pulling an all-nighter lofting, cutting and sewing.  This blog entry will have to satisfy my sailmaking itch for now.  Plus I have a post to add on the Storer forum.  Ciao for now...

One more post about flags...

I put my sail project on hold for awhile, but I did spend some time sewing.  These flags serve two purposes: practice sewing and outfitting the family fleet.  From top to bottom are burgees correctly sized for: my brother's J24, my dad's 20' speedboat, my future Goat Island Skiff, and the family Sunfish.  After the second flag I gave up on doubling the white cloth.  I also experimented with different techniques for fusing the cut edge of the cloth.  In the end, there's nothing better than hot knife approach.  Ok, enough flag crap... it's time to post about sails!