MacGyver-ing

I know, it's been a week.  But how many different ways can you say that we battled weather issues and laid up large pieces of fiberglass?  The weather has improved slightly the past week.  We've gone from way too hot to laying fiberglass during the day to it being too cold for fiberglass to cure at night (oh, and the battle with the dew on the canopy is a daily task, deploying heaters under the tent at night and in the morning). And then there is the occasional rainstorm that halts work from time to time. But we have been able to complete the two main layers of 1708 fabric that cover both sides of the foam as of yesterday.

In the process of completing this task, we've had to come up with some tools to allow us to reach the center of a 9 foot by 12 foot structure.  We've also had to figure out other tools we needed.  The usual tools like fiberglass layup rollers, plastic spreaders, and polyethylene mixing cups are always needed.  Paint rollers to spread resin are also needed, and trying to figure out what covers are compatible with polyester resin was fun.  In the case of the roller cover, we quickly gave up on the idea of cleaning the covers and determined the cheap foam rollers at the local Lowe's work well.

Fiberglass table, bucket on a stick, and more traditional tools.

To get a plastic spreader to the middle of the top, we found a cheap stain spreading pad that could be screwed to a painters pole and then taped, yes duct taped, a spreader to the end.  To pour resin at the appropriate spot in the middle of the top, I needed to create a bucket on a stick.  I found a large scrap hose clamp at the boatyard and screwed it onto the end of a scrap piece of wood.  I could then attach a quart size or smaller mixing cup and reach past the middle of the top from any side.

Tools aren't the only place where thinking outside the box is handy. I've probably mentioned it before, but one of the design features of the top is to have a couple of integrated wire chases (for lighting and solar wiring).  But how do you make a 2 inch by 4 inch hollow rounded rectangle on the underside of the top.  Wandering the local big-box hardware stores, we were asked several times if we needed help.  Unfortunately I've found that most people employed there aren't very good at thinking outside the box, and when I describe what I'm trying to do I usually get the "deer in headlights" blank stare.  So we wander the aisles and try to come up with inspiration.  What we found was a 4 inch square hollow plastic fence post.  If we cut it in half lengthwise, it should make two forms we can then fiberglass over to create the channels.

Jig for splitting PVC pipe into C shapes.

Another feature of the top is that I would like to make integrated hand-holds around the edges of the top.  I'd thought about taking some of that foam pipe insulation and sticking it over the edges of the top and then glassing over that, but discovered a better idea.  I was told of another blog, via a comment on one of my posts, where the couple built their own hard top.  They had the same idea for handholds, and they used PVC pipe split in half to create the form.  The neat thing about this approach was that they could then cut a slit in the PVC to create a bolt rope holder for installation of a dodger.  I quickly decided this was a great idea and incorporated it into the design.  But how do you split a piece of PVC in half lengthwise.  The other blogger I think used a hacksaw (and obviously a lot of time) to make the cuts.  I know I wouldn't be able to cut it straight enough by hand, so I came up with another option.  Using some scrap wood from the build of the form, I was able to create a jig I could clamp onto a tablesaw and it worked perfectly to split the tubes in half.

Of course, this presented a new problem I need to figure out.  I thought the thin wall PVC would be a bit more flexible once it was split, but I don't think I can bend it to match the compound curve along the front of the top.  I tried making some cuts in the C shaped PVC to see if I could get it to bend better...but if you think cutting a tube is hard, try cutting the sides of a C shaped bit of PVC.  I'm sure I'll figure out something, but it is another problem to deal with.

Meanwhile, I've got wire chases and other structure to install while the weather continues to somewhat cooperate.

Update: You are reading this fairly late because we were invited to dinner by new friends at the marina.  Yes, while the focus has been to get the top done, we have taken a few breaks. They made a multiple course Indian dinner that was absolutely awesome...thanks Stuart and Julia! The picture below shows the wiring chase and other structural foam just before I glued it to the top with polyester resin.  Hopefully tomorrow we can start glassing that in place.

The split "fencepost" and additional foam structure.

What Was I Thinking

I wonder how many times I've asked myself that question during this project.  Let's see...I probably average 3 times a day for...now how long have I been working on this project...never mind, I don't want to know. Anyway, work has been continuing in between oppressive heat and torrential rains.

After getting the top flipped over, we needed to start glassing the other side.  Of course, there is one little issue.  Fiberglass cloth doesn't really like to bend around sharp corners. If you did manage to bend it into a sharp corner you would break every glass fiber so the result wouldn't be structurally sound.  Now the mounting flange at the back of the top is a 60 degree acute angle, so this would be an issue for the glass. To resolve the problem I needed to fill the angle and make a radius the cloth could handle.

I took some of the scrap Divinycell foam board and cut little 1/2 inch isosceles-triangle-shaped filler strips using a table saw (borrowed from a friend at the marina) and a fine tooth blade.  I then mixed up some thickened polyester resin and glued the triangle strips along the edge of the flange where it meets the top.   Making some even thicker resin (near peanut butter consistency), I created little fillets at the edges of the triangle using Popsicle sticks so the cloth would have a more reasonable transition from the bottom of the top down onto the flange.

Triangle filler strip to curve fiberglass around the sharp corner.

That evening, after the triangle strips cured, we applied fiberglass along the mounting flange and around the corner onto the bottom of the top.  Due to the curves, and to make life a little easier on this step, the pieces of fiberglass were only long enough to cover the flange and about 18 inches of the bottom side of the top. As usual, we ended up working late into the night...I think it was about 1 AM by the time we got back to the boat.

In order to make sure the first layer along the bottom was one nice homogeneous piece of fiberglass, we wanted to get an early start so we could apply the two 12 foot long pieces of cloth that would complete the first layer. Apparently mother nature had other ideas .  This time, unlike the high temperatures that she had been throwing at us, we woke up to a thick fog.  Our hearts sank.  High humidity isn't good for fiberglass and water vapor, well it can ruin the stuff. Was all the work the prior night ruined?  I made my way out to the work area to inspect the project, bracing myself for the worst.

Fortunately, when I peeked into the tent, I found that the fiberglass had apparently cured well enough before the onset of the fog.  There were a few drips of water where it had condensed on the inside of the canopy and dripped down, but I was able to blot them up and everything dried out just fine.  Of course, thanks to the humidity levels, it took a LONG time to dry out and only the heat of the day ended up doing the trick.  By the time everything was dry enough we could continue, the temperatures at the work site were climbing past 95 degrees. We had to postpone the application of the second strip of fiberglass until it cooled off that evening.  We spent the evening applying the next strip, completing the task around 11 PM.  Oh, and the humidity levels the past day apparently hatched every sort of insect within a 5 county radius, so we were fighting off swarms of various insects attracted to our work light. I wonder what the acceptable number of insect carcasses is per square foot of fiberglass. Let's just say it was a trying evening.

After getting the second strip of fiberglass installed, we got up early the next morning in an attempt to get the final piece for the first layer on before the temperature got too high.  This time there was no fog, but there was a fair amount of dew on the boat.  I go back to the work area, and the canopy was covered in dew as well. A couple drips were again found on the fiberglass and foam and were blotted up with a rag. Then everything was left to dry for a bit.  Not wanting to wait until the evening, we started applying the fiberglass as soon as the foam was dry and the water spots on the fiberglass disappeared. It was a very different experience applying the glass during the day.  I thought that the added ambient light would help to find any issues during the layup, but it only helped right around the edges.  Everywhere else there was a fair amount of glare from across the top so it seemed visibility was about like working at night.

Yeah, a little warm for fiberglass.

There was another difference working during the day.  The higher temperature means the resin cures faster, even at the minimum catalyst amount recommended by the manufacturer.  When we started the layup, it was 84 degrees. The first couple feet worth of fabric went OK, then I noticed I was starting to sweat.  I checked the temperature and it had jumped to almost 90 degrees.  I could tell the resin was going to set up quickly so we had to work very fast.  In the rush to get the fabric wet out properly, we used a bit more resin and were unable to get it cleaned up or redistributed before it started setting up. As a result, the fiberglass has some excess resin floating on top of the fibers in a few spots.  Guess we will need to sand those spots down a bit so we don't end up with an overly resin rich layup. When we were done, I looked over at the thermometer and it was reading 104...no wonder the resin was setting up so quickly. That is why I was avoiding this process during the day but the lack of progress and forecast of lower temperatures convinced me to give it a try.  Guess we won't be doing that again for at least large layup areas.  The irony is that I think we actually do better work at night, probably due to the extended working time at those temperatures.

First layer applied...might need a little cleanup on the front section.

Making this top has been an interesting, if not incredibly slow, process.  I wish I had been able to find a place were I could do this work indoors as I think it would have alleviated many of the issues that slow down the process.  I should have chosen a different time of year as well, but the desire to head to the islands in the fall only left the summer (hurricane season) to get the work done. Of course, ideally I would have found a reasonably priced top I could have just had installed.  What was I thinking.

Turning Turtle

I came up with a design for the finished top and made some plans for how to get there.  But, as they say, the devil is in the details.  I've spent a lot of time at just about every step of the process thus far figuring out some detail related to the build. How do I create the desired arch, how do I calculate and lay up the complex angle that makes up the mounting flange at the arch, and even how to apply 9 to 12 foot long swaths of glass fabric (particularly when you can't really reach the middle of a large surface).

The last couple days haven't been any different.  With the main layers of fiberglass applied to the top of the top, it was time to flip the thing over so we could start applying the glass to the underside of the foam.  Now it sounds like a relatively simple task to flip the thing over, but there are some catches.  Once the foam core of the top has fiberglass on both sides, it becomes rigid and can support weight.  With the fiberglass on only a single side, the expectation is that it is still rather flexible.  And if it flexes too much, I could imagine that the bond between the foam and the fiberglass skin could be weakened (I don't know if this is true, but it seems like a possibility). When the top is upside down, I expect that it will not retain the curve without assistance too.

Then there is the frame to which the foam was attached.  It held the foam at the desired curve (mostly) with a number of loops of 30 pound test fishing line. While this was sufficient for holding the foam above the frame, what would happen if we flip it over?  Would the lines pull through the foam? Can we keep the frame attached or will we have to remove it before turning it over? And will we be able to control this huge piece of plastic and foam as we flip it end-over-end?

Oh, and did I mention the canopy top?  It is a 10 foot square (measured at the feet, so the top is actually only about 9.5 foot square), and the bimini top is 9.25 foot by 12 foot at its widest points.  Can we maneuver the top out from under the canopy or will I have to disassemble all of the tarps and move the canopy first?  All of these problems to work through on the flip are similar to what I've had to figure out at every step of the process.

We thought about it for a while and came up with a plan that seemed like it would work. We recruited a few friends at the marina (6 of us total) to help with the task.  Naturally, as we were getting ready to flip it over, storms started brewing on the horizon.  As the fiberglass is still rather raw and water soaking into the foam would not be a great idea, we had to button everything back up and wait for it to blow over.  After the rain, I was able to get everyone back together and we were ready to go.

The process was that we would first move the top and frame off of the boat stands that had been holding it up, maneuver it out the side of the canopy, and carefully set it aside.  Then we would place the tabletop I originally built back on the boat stands so we would again have a table.  Using a bedspread we bought at a local thrift store, we added a bit of padding to the tabletop and then covered it with plastic so no drips will glue it to the top. We would pick the top and frame back up, carefully set it on the rear edge (where the fiberglass wrapped around the foam) and then continue flipping it over supporting the top with the frame just sitting on top.  The next step would be maneuvering the upside down top back under the canopy and carefully setting it on the table.  We would then use the scrap curved pieces of plywood, padded with pipe insulation foam, to cradle the top on the table and help maintain the curve.

Surprisingly, the move went about like we planned.  At first we didn't get the boat stands supporting the tabletop well positioned, and the tabletop started to pull apart after we set the top down.  We quickly went around and lifted the top and table to reposition the stands.  After slipping the padded cradle wedges into place, the top has successfully become a turtle laying on its back. Our friends Stewart and Julia brought a bottle of champagne to celebrate the event, and then we adjourned to our boat for some drinks, snacks, and conversation to complete the evening.

Working on the support cradle.

The next morning I went out to adjust the position of the top on the table and tweak the position of the cradle wedges before attaching them to the table.  We also cut up some foam pool noodles to help add support and distribute weight.

One of the things I haven't really mentioned yet is an issue we discovered while doing the layup on the top side.  Polyester resin shrinks when it dries.  As a result (we think anyway), we noticed that the side edges of the top pulled away from the frame a bit, stretching the fishing line as it did.  The movement was about 3/4 of an inch.  Since I assume applying fiberglass to the other side of the top will result in it curling back the other way, I set up the cradle wedges so the ends of the top were held about the same distance from the end of the frame.  My hope is this will allow for any shrinkage of the fiberglass laid on the bottom of the foam...and if the bottom doesn't shrink that much it is OK as the only place the curve is critical is at the arch, and the laid up tab at that position seems to be holding the curve well.

Removing the mold/frame.

Up to this point the frame was still mostly attached to the top in order to make sure we got the cradle positioned well.  But it was time for that to change.  Using some wire cutters, I carefully clipped all the fishing line flush with the foam.  We then tried removing the frame.  Unfortunately, but not surprisingly, the frame was stuck along the back edge.  When I made the frame, I intentionally didn't glue the back piece to the rest of the frame, it was only held with screws.  I removed the screws so we could remove the rest of the frame...but it still wouldn't budge.

Don't let anyone tell you that polyester resin doesn't make a good glue.  The resin that dripped through the holes we punched in the foam managed to glue the back lip of the mold to the rest of the frame despite my best efforts to not do that.  In the end I had to cut the supports to move the rest of the frame.  Using flexible putty knifes we were able to work the last piece of the mold free.

Almost ready to glass.

Now with the top free of the mold, it is time to clean up (sand down) any remaining drips and bumps, clean the PVA off the back of the mounting flange so the next layers of fiberglass will stick, and then we will be ready to apply more fiberglass.

More Glass Pains

The last couple of days we have managed to apply the two longest pieces of fiberglass yet.  Two different 12 foot long (52 inch wide) sections were laid across the width of the top to complete the second layer of glass on the top of the top.  I'd love to say everything went well, but I would be lying.

Dry fitting a 12 foot long piece of fiberglass cloth.

We were once again working mostly at night because of timing and temperature issues for the first piece.  We did a process similar to our first large piece of fabric.  My wife would make up 16 ounce batches of resin, I would roll part of it out on the top, then roll the fabric over the wet area and finally use the remaining resin to wet out the top of the fabric.  We would then roll and work the fabric to make sure the resin was penetrating the thick fabric.  When the next batch of resin was mixed, we would roll the fabric back a bit so I could wet the bottom of the next section and continue the process.

Trying to do the best work we can, it takes us about 4 hours to apply, wet out, and roll a 12 foot long swath of this fabric. I think things would go faster with a 3rd person so one would mix up resin, another could apply the resin and wet out the fabric, and the third would work the fabric with the fiberglass roller and squeegee. I tried getting the dogs to help out, but they keep objecting due to the lack of opposable thumbs. I think they are just smart enough to know better.

Doesn't it look pretty at night.

As you might guess, the problem with working at night is the light.  We have a couple work lights (a 500 watt construction work light and a clip-on LED light that we can attach to the canopy right above the top) but, as it turns out, this just isn't enough light.  By having only one or two point sources of light, it is nearly impossible to see bubbles and dry spots inside the fabric layer.  We did the best we could and everything looked great as best we could tell when we were done (do I know how to spend a Friday night or not...heh).  It wasn't until the next morning that we discovered some issues in the layup.

The first issue was that there were dry spots in the layup.  The dry spots seemed to occur in a line, and I believe it was caused by the dry roll of fiberglass.  When we would roll the fiberglass back so I could apply more resin to the top, the roll would soak up some resin while sitting on the wet edge.  Then once we rolled it on, we didn't see that some resin was sucked out the area.  The second issue were a few bubbles that we both swore weren't there the night before.  Fortunately, repairing fiberglass isn't difficult.

When we did the second long sheet of fiberglass, we started a bit earlier and so we had the advantage of daylight for much of the process.  I paid particular attention to the spots where we stopped the roll, making sure to use the fiberglass roller to rebed the glass in those areas.  The result was much better that time.

Grinding down bad spots in the second layer layup.

After things cured some, I went back to the first piece and ground down the bad spots with a die grinder fitted with an abrasive sanding wheel.  After smoothing the edges of the ground down spots, I cut patches of cloth that overlapped the ground down areas and applied them to the spots.  As of this morning, they are looking much better.  Unfortunately, it does make a bit more work to smooth out the top surface.

Cut out repair patches.

So, the top now has a minimum of two layers of fiberglass across the top side, with three layers along the back edge and the mounting flange, and up to four layers where the sheets of fiberglass overlap.  The next task is to smooth things out as best we can on the top side.  Since we will be applying nonskid across most of this surface and the thickened gel coat we will use will easily hide most of the minor smoothness imperfections (like wall texture does in a house), it shouldn't be too difficult.  The hardest part will be reaching the center of the top (until we get a layer or two of fiberglass on the other side of the foam as it still can't support a lot of weight the way it is now) to smooth things out.  I'm thinking a drywall pole sander may be my best bet.  I might use a thin layer of resin to help smooth things out as well.

Top side patched and ready to be smoothed out.

I am not looking forward to sanding this stuff down as fiberglass dust is the equivalent of itching powder. Then I need to come up with a plan to disassemble the canopy and tarps and figure out how to remove the top from the mold and flip it over so we can start applying glass to the other side. There is always something new to figure out with this project.  But it is starting to really look like a bimini top for the boat and even gets compliments from those who stop by to see the project. Hopefully that will be the case when this project is done.

A Pain In The Glass

As every sailor knows, your life is dictated by mother nature. We rely on the wind for propulsion, the sun for power (or I will once I finally get the solar installed on this bimini), and the seas for a smooth highway or bumpy ride, and we try to hide from things like thunderstorms and hurricanes. Those further south than I are currently bracing for Erika (a storm that formed right behind Danny and looks like it will be heading to Florida). But even when sitting in a marina and working on projects far from the storms, the weather still dictates my life.

Tropical Storm Erika, National Weather Service Hurricane Center Image.

If I had been smarter, I probably would have held off on this project for a month or two, but the timing just didn't work out that way. So instead, I continuously wait on weather windows in order to continue the fiberglass work. Water contamination is a concern, so it can't rain. Dew that collects on the shade canopy most mornings can drip down and make a mess of things. By using polyester resin I can adjust the speed of the cure by the amount of catalyst used...but only to a point. Using the minimum amount of catalyst, I can get about 25 to 30 minutes of working time out of a batch when it is 90 degrees Fahrenheit. The only weather problem I haven't encountered thus far is the minimum temperature of 60 degrees...they say you shouldn't try laying up fiberglass below that temperature either.

Like in many days past, we have been somewhat cool overnight, at least to the point that the temperature and dew point meet. About the time it dries, the temperature is shooting past 90 degrees in the yard. So that only leaves us with the evenings. And that is the time slot we have been using. Around 4 or 5 PM the temperature drops back below 90 F, and if there aren't any storms, we can finally start applying fiberglass to the big foam sheet that makes up the core of the hard top.

Front curve of the top now cut.

Unfortunately, as the light fades, it gets more difficult to see what we are doing. The 500 watt work light helps a lot, but it is no replacement for the ambient light during the day. Not wanting to spend the rest of our lives at the boatyard, we press on. Over the last couple days, we have managed to cover the remainder of the top side of the bimini foam with one layer of fiberglass and with two layers along the rear edge where it will mount to the arch.

On the first new panel we started, we wanted to do the whole section with a single 9 foot long by 52 inch wide piece of cloth after laying up the 18 inch wide strip at the back/mounting flange. Wetting and applying that much fiberglass at one time with two people simply cannot be done in the time it takes for the resin to cure (at least not for us novices). In order to put down a sheet of glass that long, we need to do it in stages.

Positioning the rear mount reinforcing strip.  Note the black alignment marks.

First we positioned the dry cloth on the top, rough trimmed it so there was only an inch or two of overhang, and made marks using a permanent marker to act as guides for placement. We rolled the fiberglass onto a section of 2 inch diameter PVC pipe. Then we applied a coat of resin to the foam and allowed it to begin to gel. For the rest of the process my wife would mix up 16 ounce (1 pint or approximately 473 ml) batches of resin. I would apply some to the resin to the pre-wetted foam, we would position the end of the cloth on the roll using the marks, and roll out a couple of feet of the cloth. Using more resin I would wet out the top of the cloth.  My wife would make more resin, and I would roll the cloth back up to the wet area, apply more to the foam, and then roll more of the cloth out and wet the top side of it.  Then whoever wasn't busy at the time would use the fiberglass roller and squeegee to embed the cloth in the resin, work out bubbles, and move any excess resin toward the dry roll of cloth. This process of mixing some resin, wetting the foam, rolling out some glass, wetting the top of the glass, and working the glass was repeated until the entire piece was done. By the time we completed the last section, the polyester was starting to gel in the first sections.

Initial dry-fit of the long piece of fabric. Note PVC "roll".

The key to this approach is to stay well ahead of the resin that is starting to gel. You also need to make sure that the section of cloth is well wet out and in its final position while the resin is still wet. This process is a bit nerve-racking the first time you try it...or at least it was for us. Making sure to stay ahead of the curing resin, getting the cloth to wet out well (particularly on more vertical surfaces) and making sure the resin isn't too thick means you have to move fairly fast. Oh, and remember we are doing this by the light of a single 500 watt bulb, outside, where the light is attracting every insect within 5 miles to our little oasis in the boatyard. I'm sure if anyone had been watching, they might have found the whole ordeal quite entertaining. It took us from around 6 PM to almost midnight to complete the mounting flange band of fiberglass and the 9 foot long sheet (and clean and pack up the work area for the night).

The second side panel was done the following night and went about like the first, except that we ran out of material on the roll before we reached the end of the panel. So, in this case we had to pre-cut another piece of cloth and during the layup process it had to be positioned and integrated into the first piece as we went along. Having done the process once, the second time it did go a bit faster, and I think we made it back to the boat just a little after 11 PM.

The morning after each layup, we were finally able to see our prior night's work in the light of day.  For the most part, it looked good. There were a couple small spots that had bubbles or were not wet out well and we will go back and repair them before the next layer, but overall I think it went well. At least we are making progress towards the goal.

The first layer of fiberglass on the top.

As a side note, a few bugs (mosquitoes or similar) did manage to make it into the wet resin. They actually look just like the fossilized "fly in amber" you might have seen in grade school. Maybe a 1000 years from now some grade school kid will get to see a 2015 mosquito perfectly preserved in glass fiber reinforced polyester resin...wonder how the teacher would explain that. But hey, at least those are a few mosquitoes that won't be biting us again.

While The Weather Cooperates

Hurricane...or is it tropical storm now...Danny doesn't look like it will be headed our direction. (I do hope all my friends and fellow cruisers in its path are OK).  Meanwhile, the weather has been at least somewhat cooperative here so we've been putting in a lot of time on the hardtop project. So, sorry that posts have been a bit sporadic, but if there is one thing that this project has taught me, it is that we need to work when the weather allows.  By the end of the day today we are ready to lay more glass, but there isn't enough time so I'll finally see if I can catch up on the blog.

Work space or refugee camp? Attempting to keep things dry.

When we left off there were a couple days of unsettled weather that arrived.  After the storm that hit at the end of the last post, we mopped up the mess and tried to get everything dried out. They called for 70% chance of rain most of the following day and that usually means we will get soaked (water and laying fiberglass just don't mix).  So we did some shopping and other preparation while we waited on the weather...that never came.  The ominous looking clouds finally just fizzled out about 3 PM. We cut the two smaller pieces of foam that need to be glued to the ends of the 8 foot panels so we end up with 9.5 foot panels and punched holes in them, but that was it.

The next day the forecast was similar, but we decided we wouldn't be fooled again.  This project was already taking a lot longer than I had hoped, so we didn't want to sit around waiting for weather that may not arrive. We pulled out the two remaining foam panels and spent the day punching holes in them.  The 9 nails in the tool make this a much longer process than I would like, but it does work.  Well, until a nail breaks off. You see, you tend to bend the nails after pushing them into the foam so you have to constantly straighten them.  Eventually the bending weakens the nails and...well...you end up digging one of them out of the foam panel with pliers.  Good thing I had the remaining piece of the original longer board full of nails so I could just cut another 9 out of it and finish up. Again, thankfully the rain never came.

Gluing the extensions on the large panels.

Then it was time to start gluing the remaining panels together.  Since I don't have a full mold and only stringers, I had to attach the two side panels to the mold so the end would lay over one of the stringers and then glue the small pieces to them.  This would keep them properly aligned and holding the curve. Using polyester resin that I reinforced with some chopped glass fiber and fumed silica, I created what I could only describe as "hairy polyester mud" to glue them together.  I smeared the concoction into the joint, then pushed the smaller piece into position and held them in place with sandbags covered in plastic.  I used a plastic spreader to remove the excess that squeezed out in order to minimize later sanding.  It is much easier to scrape off wet goo than sand down hardened polyester.

After the two side panels cured, it was time to adhere them to the center panel.  Now one might think that the edges of a 4 foot by 8 foot foam panel would be straight, but they did not line up with the center panel very well.  I discovered that the center panel had pulled up from the mold a bit, I assume from the shrinkage of the polyester.  It seems that the 30 lb. test fishing line I was using stretched or the knots slipped a bit.  I was able to pull it back down with some wedges between the frame and the line. This shrinkage may have given the center panel a slight curve along the edge as well. so I then had to sand the panels a bit to get a better fit.

Panels tied to the frame and glued together.

Once the fit was better, I used a similar concoction to glue the side panels to the middle panel.  We tied the edges that are closer to the seam to the mold so we could slide the panel back a couple of inches.  I also threaded ties for the other side through the panel but left them untied so we could move it.  By sliding the panels apart a couple inches, I was able to apply the hairy mud from underneath the mold.  We slid the panel into position, checked the alignment, and tied the free end down to the frame.  Since there was one spot on each panel that didn't line up flush, I used boards wedged underneath the mold to hold them even.

All the panels are attached. This thing is getting big.

When all of that cured, we had a foam panel roughly the size of the final top with a fiberglass strip down the center. All that was left was to finish shaping the foam construct so it would be the final shape of the top and ready for glass.  Using a razor knife, I roughly carved the back edge of the two new panels and then sanded them so they matched the needed curve for the mounting flange. In order to protect the back edge of the mold, I slipped a sacrificial piece of heavy plastic between the foam and the mold and adjusted its position when sanding would start cutting through it.  This worked well and allowed me to get the curve to match up very well with the mold.

Rough cutting and then shaping the back edge.

The final step was to cut the curve at the front.  I used the trick I originally figured out for creating the curves on the stringers.  Taking a boat stand, some line, and a pencil, I created a crude compass to draw the arc.  In this case I didn't have a radius (for some reason, SketchUp wouldn't tell me the radius) but I had the intersection points on the edges and the length at the center, so I figured it out where to place the boat stand (a.k.a. the compass pivot) using trial and error.  I then cut the curve using my jig saw fitted with a fine tooth (32 teeth per inch) metal cutting blade. Where the foam intersected one of the mold stringers, I switched from the saw to the razor knife to keep from damaging the form.

Scribing the arc with a boat stand and string again.

A little sanding and it is now ready for applying the remaining fiberglass on the top side.  If the weather continues to cooperate, that will likely be what we will start tomorrow.

It Begins

Finally.  Working on the actual hardtop.  Can't believe how much work has been put into this project just to get to the starting point.  Building a workshop, a work table, a frame mold, a fiberglass roll holder/table, trying to make the workshop a bit more weatherproof and other improvements took a long time. But now we are making a little progress toward actually creating the top.

It started with dragging two panels of foam to the work site,  One was the piece I cut the test panel from and I used it to cut another 15 inch section off of the end. Then we started poking holes in the face of that piece and the full 4 foot by 8 foot section.  The hole poking tool that we started with had 36 nails in it and we quickly decided it was difficult to work.  Those 36 nails, when pushed into the foam, hold on pretty well and you really have to pry it back off.  So, the tool was reduced to just 9 nails and that worked better.  Another problem with the tool was that the nails were pushing back out of the back of the board, so I mixed up a bit of polyester resin and glued the nails in with it.  After that it was just a matter of using a 6 inch square took and slowly poking holes in all that foam.  Did I mention it takes a while?

The new 6 inch square foam hole poking device.

Once the holes were poked, the next step was to position the foam on the frame and tie it down with some fishing line so it would retain the curve.  It needed to be positioned over a stringer so we could tackle the next step, joining the small piece of foam to the end of the large one.  With some fiddling, we got the large piece positioned and figured that we could use some light sandbags covered in plastic to hold the smaller piece in position.  I mixed up some resin, thickened with fumed silica and a little chopped glass fiber (in my spare time I've taken some of the small pieces of clean scrap cloth that were cut away from the test piece and cut the fibers into 1/4 inch or so strands), and we glued the two pieces together.  After a little curing time, we had a 4 foot by 9.5 foot slightly curved panel.

Hand sanding the curve at the top back edge.

After that, the panel had to be re positioned to it's final location on the mold and re-secured to the frame. Then the rear edge needed to be shaped so the fiberglass would curve over the edge of the foam and continue down the back of the 60 degree angle that makes up the mounting surface.  Since it is a compound curve I hand-carved the foam with a razor knife and then hand-sanded it into the correct contour.  Another labor intensive and time consuming process, but it did turn out well.

There was much debate about how we were going to fiberglass the middle of a 9 foot by 12 foot panel. We decided that we would start by putting a band of fiberglass down the middle section before we attached the side panels.  This way we can be up close and inspect the initial layer's bonding between the glass and the foam.  So, the next step was to actually lay up some glass.

Naturally, the...ahem...cooler dry days we had the last weekend were no longer in sight.  Now it is supposed to be nearing 100 degrees Fahrenheit with chances of rain in the afternoon.  Not exactly the best conditions for doing fiberglass work.  We got up yesterday ready to do some fiberglass before it got hot, we just needed to run to the store to pick up a couple of last minute things.  By the time we got back to the yard the temperature was soaring over 95 degrees. Too late to get it done until it cools off in the evening.  So, we did some other things in preparation for later steps like punching more holes in more foam panels. And we bought a work light. Remember how I lamented doing fiberglass work in the dark? Well, it seems like that might be the only time conditions are favorable for doing the layup.

It finally got back down to around 90 F after 5 P.M. and we were able to start work.  With the panel in place, I started by putting a strip of glass along the frame that will become the mounting flange along the arch of the boat.  I had previously laminated that surface of the mold with cellophane tape and sprayed it with PVA so it wouldn't stick. I coated that with some thickened resin, let that get tacky and then applied a little more regular resin and the glass.  Applying resin on a surface that is 30 degrees past vertical is a real pain in the butt.  I think I ended up wearing about as much as the fiberglass mat was.  But I was able to get it laid up with a little work.

Yep, doing fiberglass at night again.

Before the strip we applied had cured, we applied the first layer over the back part of the arch.  This was a square of the mat that was 52 inches long and 46 inches wide. It was applied to the top rear of the the foam sheet and wrapped around to the mounting flange at the back.  This left the sides of the foam clear so we can easily bond the next sheets of foam without any interference from the fiberglass mat.  Of course it was getting dark at that point, but we were a bit more prepared than just a hand-held flashlight.  This time we had a 500 watt worklight and a LED clip light to help light the work space. By the time we got that piece done, it was getting late. We packed everything up and headed back to the boat...getting there about 10 P.M.

The next morning we awoke to a good coat of dew on the inside of the work canopy.  Since I didn't like the idea of it potentially raining on me while working, we setup a fan and waited for the canopy to dry.  It did...finally...around 10 A.M. or so.  The same time it was approaching the 90 F temperature mark again.  But we did lay up the two final pieces of glass to complete the covering of the center panel of the top.  And it wasn't even dark yet.

The top of the center section with the first layer of glass.

Feeling like we might get more accomplished today, we stopped for a late lunch and were rushed back to the tent with the sound of thunder.  We get back and start buttoning things up and as we are getting things closed, the downpour starts.  And it pours.  Trying to tie things up, I'm getting soaked and the panel does get a little wet.  We quickly dry it off (the glass had cured by that point, so blotting up with towels did seem to work) and my wife re-positioned a tarp to block the rain.  Hopefully it won't cause any issues with the surface of the laminating resin so we can continue the layup when the weather improves.

It feels good to finally see something that resembles a top starting to form.