Thursday, September 17, 2015

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.



8 comments:

  1. Hi Mike,
    great to see bottom of bimini covered with layers of glass. And wire chases structures.
    Love the tools. As far as curved front rope bolt holder, here are a few ideas- Pex or poly/vinyl tube. (may be too squirrely and nothing sticks to it) , PVC electric conduit Sched 40 at 3/4" or 1" dia... may be more flexible than what you have due to thinner wall ...10' max length for 3/4" , 20' for 1" dia (at an electric supply store not Lowes). Cord and Wire Channels, (usually max 5' long) ,split wire loom flex tubing. What you really want is 3/4"-1" pipe made out of what they make plumbing riser tubes out of.
    Doug in VT

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    1. Hey Doug,
      The PVC tubing I have is not schedule 40, it is thin wall...but apparently still a bit too stiff to form the complex curve. Wondering if a curved track is actually a good idea anyway since we will be making the dodgers at some point and simpler may be better. Still weighing options. We'll figure something out.

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  2. Hi Mike,
    Wondering if a heat gun or even a hair dryer on the tubing as you placed it on the curved section.
    cheers,
    Alan

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    1. Another friend suggested heat. Will need to give that a try. I just need to be careful not to apply it right next to the fiberglass and foam...I assume the foam won't like it and I know "green" fiberglass isn't supposed to like excessive heat.

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    2. Perhaps using one of the curved plywood supports that has the same curve as the front of the bimini would serve as a subsitute. Heat the tubing and curve it to match the support. Best to be on a flat horizontal surface like your table. You might actually be able to wire the tube or 1/2 tube to the curve to keep curved shape while it cools. Note full tube curved would be a bitch to saw length wise.
      Doug in VT

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    3. Hey Doug,
      The supports I have mimic the curve in the Y axis but not the X axis along the front of the top. The tubes are already split in half...have a whole stack of C shaped pieces of thin wall PVC. Need to figure out how to brace the for the curve along the X axis (the split stuff flexes fine for the Y component now, just not the X). Hope that explanation makes sense.

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  3. Hi Mike,
    Hope the already splt pieces work for bending- all the youtube videos of people bending PVC from 1" to 4" dia and using hairdryers to propane weed torches,use a complete pipe filled or mostly filled with sand to prevent kinking and taped ends to keep the sand in. Both X and Y axis - yep got it, curved to have a higher crown and you rounded the front edge. On a few other notes- check out the Oct CW- article on "Homemade Hardtop" same cloth disinergration reason but no need to stand on- your story/project would be just as interesting/informative. Other article on "the many uses of Battery Switches"- struck a nerve per my comment on solar. Great to see project moving along and cooler weather.
    Doug in VT

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    1. Hey Doug,

      Just tested the idea this afternoon once the rain ran me away from more fiberglass. The heat gun works and gets it soft enough (actually can get it very soft...like a wet noodle) and you can keep the shape reasonably intact if you are careful...but I'm trying to think up a way to make a small-ish jig that can hold the curve and keep the edges of the C at the proper locations (this stuff is a bit hot on the fingers) ;-)

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