Glassing the Hull and Fairing - Part 2...

Draping the Fabric...

First layer - working our way aft
smoothing out wrinkles.

Here is where we ventured into uncharted waters... sort of.  We had never used Xynole fabric before but expected two things from all we had read:
One, it ate copious amounts of resin during wet out; and
Two, it would drape wonderfully over tight curves and irregular shapes.  Both proved true. The initial wet out used close to 6 gallons of resin (filling ate 2 to 3 more) and using soft drafting brushes it was easy to move the cloth into position and push into corners with a few caveats...

Figure 2 - completed fabric
 ready for epoxy

The problematic joint between keel and hull was tough to get flat and smooth.  It wanted to pull away from the joint and create an air pocket under the fillet.  We had draped the cloth up to the point you see in Figure 2.  We didn't realize this until we tried to wet it out.

We made a few decisions along the way.  The first was to allow the fabric to overlap at the chines.  The first layer was centered over the keel and overlaps at the back and front.  There is enough "cling" that allows the fabric to stay put with little to no securing along its length.  We secured the fabric with blue tape around the transom to keep it from sliding forward as we brushed and smoothed the cloth out.  It went quickly and within a few hours we were ready for epoxy.  We had a combination of squeegees and 1/4" nap rollers to spread. The temp had dropped being October and the shop temp was around 70.

Disaster strikes (learning event)...

We mixed around 24 oz of epoxy resin, divided it and took our stations. We had visions of us working opposite sides of the hull starting at the bow, working the bottom and progressing toward the sides.  The epoxy was thick and we poured it on and started trying to work it. It disappeared like we had just poured it in a sponge.The rollers we had at the ready just grabbed the fabric and pulled it up, distorting it. The squeegees did much the same and the fabric was hardly wetting out where double layered, just sort of floating.  We knew that this was not going to work.
We stopped, contained it as much as possible and left it.  The biggest mistake we made was not leaving ourselves enough time to do this.  We both had a 2 hour window and this was not going to happen.  We backed up and punted.

Tools for the job...

So, I needed to tackle a few issues.  One was the wet out of the doubled layers.  I could have backed
up and peeled off the side panels and wet out the bottom first.  We kind of messed ourselves up with a few square feet of hardened epoxy (24 oz) locking both pieces together and to the hull.  I have seen folks using laminating rollers and decided to order two 6" long x 1" diameter rollers.  They look like stacks of edge sharpened washers and spacers stacked on a paint roller frame.  The beauty of it is that you can put pressure on the fabric and mash it into the epoxy without having surface area that would lift the fabric back up.

Also, I needed to get the shop temp up.  The next time around I would have it around 80 which totally changed the wet out properties of the epoxy.  Viscosity was totally different.
I will also mention my hot knife cutter which was used to trim the fabric as we draped it the first time but also came in handy for cutting along the keel fillet, thereby, separating the keel drape from the hull bottom.  It worked good.  Xynole is a polyester fabric, not fiberglass, so it was possible to "hot knife" it instead of cutting with a razor.
The last piece of the puzzle was needing more help and my son in law Adam stepped up to help. Thank God!  Adam is active duty Coast Guard, home for a short while while we celebrated the birth of our second Granddaughter, Emma.  The Redwing will be named after our first Grand baby, Addy Beth, so I guess there is a second build in the future so older Sis can't rub baby Sis's face in it. Anyway, Adam has spent (as most do full time on any ship) his fair share of time painting (and mixing paint). He says the commercials say its all about diving out of helicopters to rescue floundering sailboats or chasing drugs dealers and terrorists from our shores, but its really mostly chipping, scraping and painting.  He had become a master of those skills whether he wanted to be or not. His help was crucial in a "wet out" this large and we owe him big time.  The batches were mixed in 2 qt quantities and he rolled them out over and over and over (and over). In between, he grabbed squeegees, rollers, whatever and helped move it around. I admired his extremely thorough mixing technique and have tried to duplicate it ever since.  My epoxy batches seem more consistent now anyway.

Wet Out...

Mahogany transom after epoxy seal coat

Wet out hull - 6 gallons later

This was much more straight forward once the missing pieces were plugged in.  Adam started mixing batches and we started pouring.  This time we paused after the pour.  We knew that we needed to wait and let the fabric soak through and get heavy as it penetrated the plywood underneath.  This was one mistake on the failed attempt and I had forgotten that you had to be patient and confident about the process. We had plenty of buckets and as we finished one we would turn it upside down to drain off.  Hot work in the Tyvek suits and respirators but it progressed.  The sides ended up being easier than the bottom.  The keel sides were the toughest at a 90 degree angle. The sides were just a matter of pouring along the chine and working it around with the squeegees.  It would seem to be running toward the edge but as the fabric soaked it up, it would slow to a crawl.  Easy.  Then rolled out the overlaps with the laminate rollers.
It took the three of us about 4 hours of solid mixing, pouring and working the epoxy in the cloth.  By
the time we got done it wasn't very stressful to make a pour down the sides and we kept working the doubled up layers.  We also laid a coat on the transom to be covered with clear finish in the end. We left it alone and called it a day.

Final Sanding and Fairing...
This took some time and honestly has been a learning experience in what we thought was going to be a pretty straight forward process from all we had read.  I'll explain...

Lots and lots of dust...

From what I understood, we would just roll an additional 3 coats on and sand down flat having built the surface up sufficiently not to get back into the cloth.  I had also read that sanding into the cloth was very difficult and would be a hard thing to do given its abrasion resistant qualities.  I agree with this to a point, but folks you can sand through an edge or corner in a second so be careful.  Using Ruel Parker's instruction in his Sharpie book on finishing an xynole covered boat, I used a 4-1/2" grinder and flap disk pad to grind the overlapping joint edges down.  This was very aggressive and would have been better off doing this with a belt sander.  It chewed through the fabric just fine without leaving the irregular dips along the fabric edges that the grinder did (careful here too, but don't waste your time RO sanding to level). I will say that the polyester was very nice when it came to the itchiness that sanding glass cloth causes.  Orbital sanding takes forever on hard cured epoxy and the temptation is to get on the sanders edge to "speed" things up a bit. This will only leave a wavy surface.

My recommendation on leveling is... use a belt sander (good technique) with 80 grit belt, then 60 grit RO then 80, then 150 grit. The 80 grit orbital didn't remove the 80 grit belt sander scratches but the 60 did a nice job of it. We did not use the belt sander on the sides once glassed.  Our overlap was primarily on the bottom where it should be. We rolled out two fill coats once the heavy leveling was done on the bottom, sanded with 80 grit to level bottom and sides as much as possible and then switched to a knife edge steel trowel (kind you use to work concrete) to skim coat the surface using US Composites Fairing Filler mix.  It is a proprietary blend of fillers and worked really well.  Use small batches (12oz at a time) because a little bit goes a long way.

Note the faired and sanded surface on right
and irregular rough surface on the left before skim coat of filler

At this point it was a lot of my Dad doing the heavy lifting on the sanding duties as my elbow was in a brace after having the triceps tendon reattached to the bone.  I did what I could left handed and he took ibuprofen.
After roughly 12 to 16 hours or more of sanding we are down to the final spot fill and touch up before priming.  The surface looks fair and flat but a coat of epoxy primer will tell on us.  That should come over Christmas week with me coming out of this brace and taking a week off work. It isn't shown here but we put one last fillet along the keel/hull joint.  It still needs to be touched up with 150 and I'll amend this page to reflect that before posting the "Paint Posting" so stand by.  Injury and all, I think we will get her flipped after New Year's!

Light band on bottom running under the sander's dust bag is the overlap of material.  the dark bands on
either side of it is the skim coat fairing filler that leveled up the thickness difference.

 Gratuitous Injury Update...

5 days after surgery

2-1/2 weeks later - healing like a young pup :)
Gray headed old dog that is!
A product of my wife constantly telling me to "Put that down" or "I'll get that you idot!"
It worked!

Glassing the Hull - Part 1... Prep

Long time, no post....
Its not that we haven't been doing much, its just that we were hoping to get this hull finished and flipped a lot quicker than it has happened. I was holding off on the posts so that I would have a true "transitional point to bring this blog up to (the "flip" seemed perfect) but that will be postponed a little.  I have had a setback in the "elbow department" that has thrown a wrench in things.  Seems that about three weeks ago I somehow tore about 2/3's of the

triceps tendon off the end of the elbow. rare injury I am told by the orthopedic surgeon.  I never felt anything at the moment but within a day or so of the injury (best guess), it swelled and hurt and became hard to use (pushing).  Finally had the MRI and I am scheduled to have it reattached to the bone on Tuesday the 18th.
Dad and I worked off and on the past three weeks but were not able to make too much progress on final sanding and prepping for the paint.  At this point we are limping along.  As of today I am trying to sneak in a little left handed sanding (literally with the left hand) and figure it will be a good week before I can pick it back up with help.  As of today 11/16/2014 we are on the final skim coat of epoxy filler and are really close to paint.
Prepping for glass...

Cured patch ready for sanding

Areas like this are best handled
with the RO sander

Looking back at the blog it looks like we were up to patching and filling screw holes with epoxy filler and getting ready for an all over sanding and shaping prior to laying the xynole fabric over the hull and wetting out.  Lots to cover so here we go. Using a mixture of fillers, specifically phenolic micro-balloons (accounts for the brown color) and silica for its thickening and non-sagging properties; we went around the hull patching all the screw holes and joints.  Once fully cured it came time to sand and level these surfaces.  Folks, do what you want but we don't mess around trying to fine sand at this point and find a random orbit sander the wrong tool for the job.  Instead, reach for your trusty belt sander and if you don't own one,stop and go get one.  They are not cheap, but with the right technique, they are great at leveling and prepping a surface. Fast too.  The belt sander is your friend!!! Remember, you are getting ready to build a thick surface of epoxy and fabric over this surface so level it, fair it even, but don't waste your time making it baby butt smooth.


Belt Sander technique and expectations...

1. Keep the sander pointed in the direction of the grain (in this instance front (fore) to back (aft) and keep it moving.  the sander is aggressive and that is what scares most folks off, but as long as you keep it moving in lazy figure eights and keep the platen (flat piece that the belt rests on) flat and let the weight of the sander do the cutting. You will find the time it takes to accomplish what a RO sander will to be diminished nearly half or more. Moreover, the surface will be much fairer and flatter, basically emulating what a long-board can accomplish to a point.
2. Expect a lot of dust...  I mean a lot of dust. It would be a good idea to go ahead and find a 1" tool hose and adapter to attach to a Shopvac.  The epoxy/wood dust buildup can overheat the belt and get in the motor. Strap or tape the cord 
3. You can use the belt sander in other ways as well...  Fun tip! your sander has a "slack belt" portion than can be used for shaping outside curves.  Between the front of the plate and the front drum is an unsupported portion of belt that will assume a natural arc.  Two things to note: One, the belt may tend to wander left or right.  If it does, it only means that you are applying too much pressure on the opposite side of the belt.  Two, most sanders have a portion of the housing that extends down to protect this portion.  You will have to remove this before you can use this technique.  We relied on this, in combination with a 45 degree chamfer router bit to remove the bulk of the edge, to help create the rounded-over edge at the chine (where bottom meets side).
4. Grit... On a tabletop that we are leveling we are cautious about going too coarse in grit and creating more work for ourselves down the road as we try to sand out scratches.  At this stage were are not worried about it.  Start with a fast cutting 36 or 50 grit belt and keep it moving. Sand wood and patch alike to a fair surface.  It will go quick and you will be ready for the cloth in no time.

Epoxy fillet around end of keel

Final Filling and Sanding...

Bondo squeegee with cut radius  edge.

Following the techniques and suggestions above, we finished pre-glass sanding of the hull.  The only step left was to round the joint between the keel and hull bottom so that the cloth would smoothly flow between the two perpendicular surfaces. Xynole drapes better than just about any cloth out there, but it has its limits.  This was basically a matter of filling up a Ziploc pastry bag with thickened epoxy and laying a generous bead along the joint.  Once accomplished, run a bonding spreader with a radius corner along the joint to create a fillet.  Let it set and clean up the excess squeeze out with a sander.  An RO would be fine for this work if the joint is pretty clean.  Just a suggestion: Feather sand the radius cut on the squeegee.  The trailing edge of the squeegee is done this way as manufactured and we think it would help out when trying to press it hard into that  90 degree corner.

At this point we are ready for cloth.  On to Part 2.

Design Changes...

Hang on. We have an update...

Pictures are worth a thousand words, so here you go.

We decided on this change for a few reasons but primarily due to the fact that the cockpit was starting to resemble a broom closet. It was going to be encumbered by a continuous roof that would limit fishing and other possible recreational opportunities and may force everyone into the pilothouse.  The motor well just ate up too much room and I don't like a notched transom. Gone is the extensive Mahogany veneer layer on the pilothouse.  I fear a maintenance nightmare.  I'm limiting my use of Mahogany trim on the outside and using glass and paint.

The movement of the outboard aft is one I struggled with due to the outboard's weight being moved behind the boat but decided that it shouldn't be an issue for a few reasons...

1. It is only a 110lb 20hp outboard to start with.
2. I intend to use an Armstrong style bracket with a positive flotation chamber.
3. I intend to move the house batteries forward, beyond the center of gravity.

The benefits are...

1.  Much, much larger cockpit for recreation.
2. Nice swim platform behind the transom (again recreation).
3. Most folks that have them, like them. 
4. I can move or add ballast to trim the boat once we are in the water.

Interior Arrangement has changed a little too...

Changes...

1. Pilot and Co-pilot's chairs
2. Stove/Oven and sink.
3. 12V Refrigerator under seat (see below)
4. Gone is the dinette (extra seating can be had in the cockpit)
5. Propane onboard to run the range/oven and a Yamaha 2400 generator.

Inboard Profile:

Inboard Profile

Transom and Stem

Milestone... outer hull construction is complete!

Except for a very minor bit of construction along the sheer (more nautical boat parts named which, by the way, is the top edge of the hull) marks the last of the "parts" that we installed before the laborious task of sanding... sanding... and more sanding.

The Stem...

Lamination before planing.
Notice the black plastic in the
background for glue up.

Trimmed up you can see
the lamination layers

The stem of which we refer is actually the outer stem.  You could call the inner stem the "Apron" if you wish, and would be technically correct.  Loosely put, the outer stem is the wedge shaped piece that forms the front edge of the hull.  In this version we are laminating this using 4 layers of 1" thick yellow pine (yes, old friend the pine) and a center lamination of AB Marine Ply.



We generously slathered all layers of lamination with the same epoxy glue mix we have used all along as they sat on a piece of black poly sheet, and wrapped this up before clamping.  The piece just falls away from the sheet when cured and is ready to be squared up and thickness planed.

Note the Stem on this pretty little sailboat.
See how it turns square at the top....
very pretty

Now comes the tricky part, and we did take a shortcut or two, but can live with ourselves... unless you have read this blog, you'll never know in the end.  We show the little sailboat "Ashley Grey"so you get an idea of the stem treatment planned.  See how it is angled up to the sheerstrake (a strake is a board and the sheerstrake is the uppermost board along the sheer or upper edge of the hull).  We have "short-cutted" this carving and elected to rip the angle that forms the wedge shaped stem in one pass.  We couldn't figure out how to do it any other way on the tablesaw.

Let me digress a minute and I will speak for myself (no we or us) just "I"...

I appreciate a hand tool.  If I have an (that means one or two) edge to round over, or a very small piece of wood to part, I will use a block plane or Japanese saw to plane or cut and they are a pleasure and faster. However, I do not waste (and yes it seems a waste with so little free time available for this pursuit) a lot of time adhering to a purist notion of always having to hand plane this or hand cut that OR that it is somehow better.  If there is a power tool that will answer, I reach for it.  I have more silly, specialized versions of power tools than hand tools and I do use them, although it can be months or even years between.  I do believe that a deft hand with a power tool takes some skill and can be used with artistry.  I also believe that some of the adherence to doing it all with a hand tool is founded in trying to do it like my Great Granddaddy did, or trying to emulate those fantastic craftsmen of yesteryear.  That's fine, but I am willing to bet "dollars to doughnuts" that if they had access to a decent saw, jointer or power sander back then, they wouldn't have reached for that hand tool to start with.  They were professionals that wanted to do their job to the level expected of them and get home in time enough to see their family or go fishing every once in a while.

Stem shown with the proper angle.
Notice the off-cut on the floor.  It will
be saved for later and glued back and shaped
to form the square top.

Stem fit and rounded over where it
meets the keel... heavy sucker!

Okay. Whew... enough of that.  Now, we (yes back to "we", the "team", and it takes a team) ripped the stem as shown here and checked the fit against the apron or inner stem. Guess what, my apron isn't exactly square to the center-line.  Here is another admission of failure on my part. I (taking full blame) missed square by a quarter inch and if the inner stem was planed off to square it up, it would bee too wide for the outer stem to fit.  Well, I got ahead of myself here and had actually figured this out before beveling so I was able to mark the amount to be removed and ran it through the planer with a wedge matching the angle.

Countersunk hole in stem with
1/2" threaded rod showing.

We attached the stem with three 10" lengths of 316 stainless threaded rod, flat and lock washers that went clear through the inner and outer stem.  Also, while the countersink and 12" drill bit were chucked in, we drilled and attached 5 - 8" lengths of the same rod through the keel and hull bottom as a little extra insurance if we ended up on a lee shore, no power and a reef trying to grind our bottom out (Patrick O'Brian fan). Also used an 8" lag at the keel joint to firmly attach the  stem to keel.
I stated this under the picture description above but I'll say it again. We will glue back the off-cut from the tablesaw and shape the pretty little transition curve after the hull is flipped to resemble the sailboat's stem shown above.

Transom "Veneer"...

Milled Mahogany ready to be glued and installed.

Bar clamps holding the board together while the screws
are driven home.

There is a lot of brightwork (clear finished wood... in this case mahogany) on this version of the Redwing.  the intention is to look reminiscent of those gentlemen's yachts from the Gilded Era.  You know, something that may have ferried Clark Gable or Charles Lindbergh around on their honeymoon.  At the same time we are making some serious "faux pas" in this stylization by adding such comforts and modern propulsion accessories as a rooftop AC unit or even more hideous, a transom bracket and outboard (yes, there have been some shifts since this design was introduced as concessions to practicality and usefulness). We do plan to make these seem more "yachtish", if that is a word, by decking the bracket's swim platform with teak veneer or choosing a low profile version of the AC.  One important piece of brightwork is a mahogany transom which is currently two layers of 1/2" Marine Fir ply. We elected to mill enough lumber to add a 1" layer, epoxy glued and screwed from the inside.  By the way, the transom was already notched for the intended outboard motor well.  That will be filled and glassed from the inside after the "flip" and another layer of ply added to reinforce this area.  You can see from the pictures that we glued these up one at a time, by first laying them into place and marking the shape to be sanded flush later.
1-1/2" stainless screws clamped the boards in place (probably useless once the epoxy cures).

Mahogany sanded and shaped so it looks fairly light.
Note the uneven wood tone. Pretty common and why I like to dye
the wood to get an even tone.

All that's left is to cut the arched top (bottom in the picture), sand and dye to even the wood tones between boards before coating with epoxy and final finishing.
That does it for the construction itself, by that, we mean adding components before the hull is flipped.  Once flipped it gets really busy.  The next post will talk about the preparation of the hull for cloth and that is where we are now in the process.  We hope to have that finished by this weekend ( around the first of October) and begin glassing the hull next week.  After that, another round of sanding and fairing (nautical for smoothing and evening surfaces), then final paint. Thanks for looking!

The Keel

What the %&! is a Keel? (and why do I need one)...

Answer:  the longitudinal structure along the center line at the bottom of a vessel's hull, on which the rest of the hull is built, in some vessels extended downward as a blade or ridge to increase stability.
Okay, that's all for now... Good night everybody...

Seriously, a keel adds stability and in this flat bottomed design it adds even more.  It should improve the tracking of the boat so it isn't as prone to slip sideways in the water and will help the pounding that can occur in choppy water.  The designer proposed a box keel.

Keel shown in yellow... Grey man contemplating why his toes turn up.

That is a hollow "box" attached to the bottom of the boat.  A box keel doesn't add any weight down low (which we think will add to stability) and seems a place that could be subjected to water infiltration that we would not be able to inspect.  Instead we opted to make it a solid timber, glued, screwed and bolted to the bottom. We also liked the idea that if ever grounded it would be our first line of defense, and a seriously substantial one. So, lets build this thing.

Milling and Material...
Again, we turn to our familiar, favorite southern wood, Yellow Pine.  Yep, they are all around us and we love spreading their needles around our holly but did you know its a "heckuva" boat wood?

Establishing a center line

Hard, heavy and rot resistant; perfect for a keel.  The bottom is curved and we didn't feel like finding a timber big enough and long enough to suit and end up at the surgeons office scheduling a "repair".  The same frame material was readily available in 12" widths  and we knew that we could probably horse a 1" thick board down into that rockered bottom's shape.  We only milled the 12' boards enough to even up the thickness and width, leaving as much meat as possible.


Cutting and Laminating...

Taper on Masonite.

First Layer

There is one more step before we attach the keel and that is to shape the fore and aft ends (gonna start using nautical terms now).  The fore end of the keel must butt into the stem at an angle and tapers down to the stem's width.  To accomplish this we measured back 3' from the end of the pattern and sprung a spline that tapered a gentle curve from a 12" width to the stem's 4" width on a piece of Masonite.  We then cut that curve with a circular saw and transferred it on each side of a center-line, then cut the pine boards to match the pattern. To laminate, we used a combination of epoxy glue thickened with milled fiber and silica and 2" 316 stainless screws.  We also staggered the joints just starting from the aft end on one layer and the fore end the next.  Both fore and aft ends get the same taper.  This process repeated itself for 5 layers with a final keel measuring 5" x 11".

5 Layers High

Final shaping...

This shows the stem but note
the keel angle.  Stem is next.
Can't wait huh?

Okay, almost ready to do something else but one last little bit of work.  We need to give this keel some shape. Lets start with the stem end.  Simple enough, just need to transfer the same stem angle up keel.  Cutting was roughed in with a reciprocating saw and final shaped with a planer and belt sander.  Constantly checking with a straight edge.
Now, turn 180 degrees and walk to the back of the boat.  Good, let's shape the stern end of the keel.  This gets a little different shape and when conversing with the boat's designer, Karl Stambaugh, he suggested a rounded, tapered bulb to clean the water as it rolled off and reduce turbulence at the outboard prop.











Here's the steps.

1. Taper at a 45 degree angle and trim with a saw (again for me reciprocating).

Mark the angle

Trim off but for God's sake get closer than I did.

2. Belt sand to the line (get closer than me, too danged much sanding here).

Freehand an arc

3. Round a line and belt sand to that line. This just takes a little time and I finished off with a 6" orbital.

Well that's about it for the keel.  We ran a 3/4" round over router bit around the edge and it still needs a fillet of epoxy around the base to help the polyester cloth to lay smooth and the whole thing needs filling and smoothing but more on that later. Stem to soon follow.

BTW, in real time as I'm posting this we are in the final stages of sanding in preparation of glassing the hull. The stem and transom are done and a lot of shaping is finished. We'll follow up with successive posts to catch us up rapidly so check back every few days.  Thanks for looking!

Covering the Bottom with Ply

Fig 1. - Clamping down a sheet to mark the shape

Marking and Cutting...

Now that the frames and sides are trimmed its time to apply the bottom plywood.  There will be two layers of 1/2" ply installed for strength.  The first layer will be glued and screwed to the frames and the second layer will be glued and screwed to the first.  The first step is to cut a half sheet and line up with the closest frame toward the stem (or front) that will cover from side to side.  From there its pretty simple, just a matter of clamping down the ply and marking the cut where the outside of the side ply intersects the bottom (Fig 1).
Once marked, cut to the line and set aside.  We opted to do all of the cutting at once since there was going to be a lot of glue mixing and screwing down once we started.  We suited up in coverall suits to protect our clothes and skin.


Installing...




Fig 2 - Squeezing bead with Ziploc pastry bag.

Installation was messy, awkward but simple. The epoxy was mixed to a peanut butter consistency using fumed silica and milled fiber for strength.  We used a short cup to fold a quart Ziploc bag in and dumped the mixture, forming a pastry bag to squeeze along the frame edges (Fig 2). 



Fig 3 - Brushing the drainage holes to seal the wood.
Also note the bead of epoxy spread along the frames,
ready to receive the plywood.



We also took the time to saturate the limbered drainage holes in the frames which would be tough to get to once the plywood gets installed (Fig 3).  The plywood was screwed down, one after the other and now we are ready for the next layer of ply.




Fig 4 - Glue spread waiting for next sheet

Next layer of ply was marked and cut the same.  We were sure to stagger the joints so there wasn't a weak spot formed.  Each sheet took between 12oz and 36oz. of epoxy mixture.  This was mixed to mayonnaise consistency with a notched trowel.  The awkward part was just trying to hover over the glue long enough to get the panel lined up before dropping into place.  Fig 4 also shows the previous sheet edge to the right and the pencil mark on the left that was used to line up the sheets as we went along for cutting; as well as, a stopping point for the glue.  We didn't attempt to glue all of this at once.



Filling out the Tyvek suit to its breaking point...

Extending the side angle through the bottom ply...

Just as the title states the bottom ply must be cleaned up by following the side angle.  Not much to say here, no real tricks.  I used a power plane and belt sander to do this.  The following pictures show how this should look when finished. The stuff on top is curls from the power planer. Next up, the keel...







Prepping To Cover the Boat's Bottom

Fig 1.  Marking board that is the same width as the frame and is notched
to clear
the protruding chine and plywood edge.  The darker board is there to help hold it in alignment.

Now that the sides are finished, it's time to prepare those sides for the bottom ply sheathing.  Because the chine and plywood edges are 90 degree edges. We have to trim those edges at an angle to match the boat sides so that the bottom plywood will lie flat.  We also need for the plywood sides to assume a nice, close fit to the bottom and not have humps and bumps that keep them from lying tightly on the frame bottoms.  Just as the frames created a nice fair curve for the plywood sides, we need for those same frames to create a nice fair curve on the bottom.  How to accomplish this?...


Figure 2. Frame bottom transferred to outside surface of side.

To prepare, we need to mark the outside plywood surface with the frame's bottom edge, basically extending that edge through the plywood.  This was accomplished as seen in Figure 1.  Once finished we will end up with a series of marks that look like the ones shown in Figure 2.  One thing to note is that the bottom of this boat is a continuous curve from front to back.  This creates rocker.  In a boat's design it provides maneuverability.  You can spot this gradual arc by the horizontal frame pencil line in comparison to the edge of the plywood. See how the left side is closer to the edge of the ply than the right edge of the line?  And obviously the bottom is sloping from left to right.  That bottom ply will contact that left edge of the frame.  When the boat is flipped upright, we will fill in that gap with epoxy creating a structural joint, as well as, using screws to hold the bottom to the frames.


Now that we have all of the lines drawn we will place one screw at the end of the line closest to the plywood edge. (in figure 2 taht would have been at the left edge of the pencil line).  Again, this represents the edge of the frame closest to the bottom and the one that the bottom ply will come into contact with when screwed and glued down tight.



Fig 3. Screws driven along pencil line temporarily to rest the batten on to drawn a fair curve.

Figure 3 shows this.  This particular screw is located in the middle of the line as it represents the Station 12 frame, the middle and flattest part of the boat's bottom.  What this picture also shows is the spline or batten strip resting on top, not attached.  We prepared this by ripping a 1/4" thick strip out of some scrap 3/4" pine, 12' long.  When bent along the tops of the screws, the spline gives us a nice fair curve that gets us much closer to what the finished boat's bottom will be.  We will used thickened epoxy along this joint which is gap filling but the closer the better.

Figure 4. Line marked along top edge.

Now that we have a line to follow its is time to chose a way to cut down the edge protruding above the frame level to that line.  It's a good bit of material to remove and we wanted to get it as cut as quickly and accurately as possible.  We eliminated a power planer since the amount of waste to be removed varies and might be hard to keep level. We eliminated the jig saw because it was such a gentle curve and decided on the circular saw.  It can handle gentle curves easily and has a foot that can be adjusted at an appropriate angle to handle most of the cut.  Things get steeper near the stem so we will have to use the planer to level down to the frame.  We used a bevel gauge to establish the angle and transfer that to the circular saw foot.  Unplug the saw first.  We used a clamp to keep the guard back while we transferred the angle to the saw.  See figures 5 & 6.


Fig. 5  Getting the angle using the bevel gauge



Fig 6  Transferring to the saw to set the angle.

 Now its a matter of carefully cutting along the line and getting used to the flavor of marine plywood with a hint of epoxy.  By the way, wait till the epoxy is fully cured. Green epoxy will gum up your tools and is still unhealthy to breath when not fully cured.  Here (final few pictures below) is the result with some minor hand planing to finish off.  Note that it is fairly level now and ready to provide a fair surface for glue and screws.  This wide edge will provide a nice glue surface for the bottom ply.