Monday, August 31, 2015

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.


  1. Hi Mike,
    Been following your progress- bimini looks good, too bad about the dry layup in spots. As far as doing the bottom, how would this series of steps work? It assumes 4 people can carry the top and frame out from underneath the 10' by 10' canopy in some way. And that the top will hold its shape with a little support. So here goes, (1) snip all the fishline ties while still on table (2) get two or more of those many walk by admirers to help you for 10 mins to carry top and frame out from underneath the canopy. (3) once out, use 4 previouly purchased swim noodles, each 6' long, string 2 together with rope and tie off on table so that they will support the up curved ends of the upside down bimini, (4) have those 2 or 3 helpers take the top off the frame, turn it over and walk it back under the canopy resting on the table and swim noodles. Just a thought, and you can reuse the noodles for swimming later.
    Doug in VT

    1. Hi Doug,
      The dry spots were a bummer, but easily fixable. I think 4 people should be able to carry the frame + bimini...two could easily handle the frame before. We can carry the frame out the side of the canopy, since it is 9' by 12' it will only go out two directions...and a boat blocks one of them.

      The noodle idea is a good one. Was wondering how to pad supports and that may work well. I'm not sure how well the top will hold the curve until the other side is glassed, so we may need to provide some support on the side opposite the arch mounting tab (I assume that bend will help hold the curve fine). Was thinking of using the curved scraps made when cutting the arch stringers out to help support as needed. May use a noodle, or maybe pipe insulation (it has a slit down it that could fit over the wood) to pad the holders.

      Since the frame could be carried by two, I assume 4 can carry the frame plus top. I can unclamp the frame from the stands and carry that out, then put the table top back in place on the stands, flip the top over and place it on the table, then remove the frame. I will probably need to remove the tarps so they don't get in the way...but we will figure it out.

      Thanks for the idea of the foam pads...think I will use that for sure.


    2. Hi Mike,
      You may have already started the process of laminating the underside, but here's my 2 cents. I think your idea of flipping the frame and foam top over together is a good conservative move especially if you are unsure that top with one side will hold its shape- such is the issue with DIY one offs. The weight of the frame should not press down or indent the foam. Supporting the upside down frame/top with several padded curved plywood stringers attached to a 3 or 4 inch wide plywood base allows you to adjust the supports and then cut the fishline and remove the frame. Take and mark depth measurements on the various stringers that are now part of the frame so you can potentially adjust the new underside stringers to bring shape back to design.
      Hope remnants of storms move quickly past your location
      Doug in VT

    3. Hey Doug,

      That would be ideal, except I'm not sure we can get the whole frame up on the table and then get it removed once the bottom supports are in place (just not sure exactly how heavy this thing is and getting to the ties near the middle would be a challenge. Still trying to figure it out this morning...meanwhile we are doing a little sanding of drips and such on the bottom side while we have it upside down (easier to reach the bottom middle when it is still right side up and we can crawl underneath). Will let you know...and hopefully remember to take pictures of the process. Also need to find a few helpers as I know my wife and I alone can't maneuver the 12' by 9' beast.

  2. Hi Mike.
    You must be happy with how it is looking. Doug's idea is a good one. The shape of the bimini is set however there will be some flex/spring in the job until it is done. The noodles will provide good shape support until the inner layup is finished. is it possible to remove most of the frame and leave one or two of the curved pieces in place? This will give a "comfort factor" that the bimini's curve is still correct. layup around the remaining curved pieces, then remove.

    1. Hey Alan,
      Happy with it so far. Don't really have a way of keeping the frame attached and still being able to lay up fiberglass on the bottom side. Was thinking of removing one of the curved stringers to see if I could do something with least use it as a gauge. The big issue is the shrinkage of the polyester. My hope is the application on the other side will even things out. Guess we will see.