As you know we decided to head to a marina after arriving here in the Chesapeake Bay. We were looking for a place to get some work done because...well...we own a boat and the list if things to fix never seems to end. My original goal was to replace our soft bimini with a fiberglass hard top I can walk on. In addition to having a great place to mount much needed solar panels, the top could be set up to collect rain water and provide for a safer access to the boom should something go wrong while underway.
Of course the top wasn't the only problem. I've had another seacock freeze and, in fact, I was able to break the handle off of it while trying to open it during our trip up. So, the idea that I should just replace all the through-hulls (that I originally wanted done when last in Deltaville but the yard failed to accomplish) is back near the top of the list. And that project requires that the boat be hauled out of the water again. In addition, we have a variety of other problems that we have discovered need attention,
Not having much luck in finding a yard that could both haul our catamaran (the 21' 3" beam limits options) and allow us to do our own work (my experience thus far indicates that yard work is often expensive and below my quality expectations...if you can get them to do any work at all), we decided to alter our plans a bit. We were able to find a regular marina that was nearby and not overly expensive. This would allow us to get some in-the-water repair work done on the boat and could tick another task off the list. You see, my parents have never seen our boat or gone sailing with me and if we could stay put for a little bit, they could come out for a visit.
So, after confirming space at the marina, my parents were able to set up a trip to come see us. About this time the "unusually hot" weather I previously mentioned started up. We were able to get some things done, but it always seems to go slower than you expect on a boat. When I owned a home, the most pesky repairs always seemed to involve plumbing, where I would have to run to the hardware store at least three or four times to get parts I either didn't foresee I would need or that were different than I anticipated. Boat projects all seem to go the way my plumbing projects did. Even having cars at our disposal, a project you think should take a couple hours seems to take all day. Still, I managed to get the AC pump, an electrical plug, and our spinnaker halyard replaced.
While I have had internet access, I've been researching options for building that hard top. I seem to have new ideas on structure and materials every day. One of my biggest problems so far is finding good engineering data so I can construct a lightweight top that will support my weight. I even considered building the top on the boat right at the marina, but decided that building a 10 foot by 8 foot top in place would be tricky at best and a potential disaster at worst. I am confident I can build the top for a much friendlier price than the pre-built option, if I can only get the engineering right.
My parent's trip would encompass both Father's Day and my dad's birthday so I also tried to set up something for him. I know he likes fishing, so I tried to see if there was something I could do to take him both sailing and fishing during his visit. Unfortunately, I just don't have the knowledge or experience and after a couple days worth of looking at equipment and supplies, I threw in the towel on that idea.
New pressure tank and water filter |
Then a day before my parents were to arrive, my usual luck with things crops up. Our galley sink had a Brita drinking filter attached to it and it started leaking, spraying a stream of water backwards and in the general direction of the microwave. Thinking it was just a simple seal problem and knowing that electric appliances don't like taking showers, we went to the hardware store to find a replacement gasket. Two hardware stores later we managed to find the washer, only to discover that didn't solve the problem. Using a bright flashlight and magnifier, I was able to find out that the leak wasn't with the gasket but a pinhole that developed in the sink spout itself...and our attempts to fix it have only made it worse. So, I ended up having to replace the entire faucet. Three trips to three different stores to find a faucet that could be made to work. Adding an under-sink filter to the cold water supply because no faucet we found would support the old filter, and replacing the water system pressure tank because it was old and rusting and if I was going to have to do all this other work anyway, might as well fix that too. About 12 hours spent collecting the various parts needed for the fix and two hours actually installing the parts, and the sink worked once again. No more filter hanging off the faucet, a larger filter hiding under the sink, and a pull out faucet that fits well with the boat so I'm happy with the results.
New galley faucet |
Then we found some bugs in one of our food storage bins. Not ants, weevils, or roaches but a bunch of small moths...and moth larvae. Fortunately for us, we keep our food stores in a variety of plastic bins and the moths seem to have been limited to one bin, with a few escapees in the locker itself. Best we can tell the moths hitchhiked their way in by hiding in some boxes of cake mix that we were gifted. Yep, we broke the rule of no paper/cardboard boxes on the boat and the result was a few dozen unwanted guests. We pulled everything out of the locker, cleaned up the locker, cleaned up the storage box with the moths, THREW AWAY the paperboard boxed cake mixes, and then put everything else back together.
New halyard for the spinnaker. |
We completed the fixes and cleanup as my parents got to town. And I still had other things I wanted to get done. We needed to actually clean up the boat some (it always seems to be a mess and two dogs currently shedding isn't helping the situation) and we were due for an oil change before I take the boat out again (which I wanted to do with my parents).
Then this past week we've been playing tourist and tour guide...but more on that next time.
I've often wondered about the prohibition against cardboard containers on board. After all, we don't prohibit cardboard containers in our house/apartment.
ReplyDeleteI think it is more to do with where the cardboard came from (i.e., how clean was the store, where on the shelves, and how long was it in storage?)
In Mexico we typically abided by the "no cardboard" rule, but not always. Never had an infestation... fingers crossed.
David
sailing-pelagia.blogspot.com
I don't know for sure, but I can guess that the cardboard/boxes could provide both shelter and food for some types of bugs.
DeleteGetting stuff out of a box and into a ziplock freezer bag seems to make the most sense to me. It gets rid of the cardboard, provides a sturdy and easy to stow sealable container. And if anything is contaminated, it prevents the spread of the contamination beyond the bag...so cleanup becomes throw the one bag away.
This is definitely what we should have done with the cake/brownie mixes. No idea how these moths got in there, but somehow they sneaked in without us catching them and the only guess I have is in the paperboard boxes. Lesson learned.
Hi Mike,
ReplyDeleteBased on what I've read, look for 1" Dinivinyl (sp) at around $250-$300 per 4'x8' sheet. You would need 3 sheets and try for local supplier to avoid high shipping costs. Make thin bent plywood mold/form plus 2x3s and cover plywood with poly sheeting to eliminate any posibility of epoxy sticking to form. Make 1/64" slits that go 2/3 way thru 1" foam so it can bend over plywood form. Lay foam slit up over form and thickened epoxy glue cut foam pieces together and weigh down foam to keep shape. Once epoxy hardens, cover slit top with epoxy and 1 layer of bi-axial cloth. Once hardened flip over foam and coat what is bottom with 4 built up layers of epoxy and bi-axial cloth. Flip over so top is up and using left over foam make foam handhold strips on top edges plus one strip going down center fore to aft. Epoxy down , then build up 2 more layers of bi-axial cloth. This makes 3 layers on top 4 layers on bottom. this should easily hold your weight plus any solar panels. Where you attach to legs or targa, foam should be hollowed out in that area and replaced with thickened epoxy for strength. Same type of procedure where you attach solar panels.
Doug From VT
Hey Doug,
DeleteCurious where you got the information to base the recommendation? What I was seeing indicated that 1/2 to 3/4 should be sufficient with the stringers embedded in at 1/3 the width/length intervals.
As for method, I was looking at cutting 4 or 5 temporary curved stringers out of plywood or 1-by-?, attaching the foam to the temporary stringers to create the curve and then doing the layup on one side to "set" the curve, Flip over, remove temporary stringers, apply plastic tubing or conduit to create the form for permanent stringers, then glassing over that. I was told that the foam should be able to bend to the minor curve without the need of slits...but I've never played with the stuff so we will see.
Not sure if all of that makes sense, but seemed a bit easier than building full molds for something that will get the non-skid treatment anyway. Buying a thin sheet of plywood or laminate to cover the stringers would turn that into a mold...so maybe that is the way to go anyway. As for finding a local supplier of Divinycell...lol...I don't know who may carry it...but I can barely find marine ply local so I don't hold out much hope on that...I'm sure it is only in stock somewhere in the hurricane belt. ;-)
Hi Mike,
DeleteSeveral locations for info
1) Hacking family- he tried 1/2" thick (all he could find) and glued 2 together for thickness- said he'd go with 1" afterwards given his problems glueing 2 sheets together
2) West System site and Bertram31.com site for strength and layup and Jon Hacking based on him being engineer and having built one that's doing fine
Seems bottom (compression) having more layers is important and bi-axial has good strength/wetting and curves/forms ok
Design
1) Don't think you want embedded stringers- rely on the inherent strength of a composite fiberglas/foam/fiberglas sandwich
2) you want H80 divinycell at 5 lbs per cu ft. good for medium stuctural strength, stands up to heat and has good standalone compression strength
3) Think you'll probably want hardtop to crown in center along boat axis and probably to dip a little in front - hence need for some sliting- preslit stuff goes 90% way thru but that's for tight curves which I don't think you need,and you might need grid slit in forward 1' if you are going to have it curve down. Depending on the curves you want may only need minor sliting, but you don't want a lot of inherent tension in the composite that you might get with no slitting. Epoxy will fill in the slits
4) center 1" ridge gives more strength and hand hold 1" ridges on all sides have 2 functions- increases strength/rigidity and directs water to a few locations for possible fresh water collection.
5) Rec cheap thin plywood and cheap 2x3s or 2x4s for mold, it gives a more solid surface than just stringers
Suppliers
Jamestown distributors (RI)
Fiberglass supply.com
Fiberglast.com
Merritt Supply FL
Defender CT
Boat builder central
Blue water supply in Apex NC with H80 4'x8' at $297
Maybe a boat builder/marine supply center nearby can steer you to distributor closer
Doug from VT
Hey Doug,
DeleteIn composite construction the core is all about the shear stress. Choosing to glue two panels together I'm betting didn't gain them much of anything over just using a single core. The stress points of having the skins in the middle combined with voids in the bond resulted in a structure that would have likely been less rigid than if he had only used one layer of the foam with the proper skins bonded on each side. It wasn't until he filled the voids (with over a liter of resin...big weight gain...and I wonder how complete the bond was even then) that he was able to strengthen it up.
The "mold" the folks on Ocelot did is pretty much what I was considering if I didn't do a full negative mold of the outside of the top (if that makes sense). They used temporary stringers attached together to hold the foam in place while they did the layup...unless I'm missing something in their described process. The fiberglass layup schedule I intend to use will depend on which way I go with the mold...since starting with gel coat would necessitate the use of CSM for the first layer to prevent print through. The rest will be biaxial non-woven cloth for strength with a minimum of 2 layers to produce fiber strands at 45 degree intervals.
What I've been seeing for figures for compression and flexural strength for pre-made cored panels seem to indicate that even 1/2" core should produce a rigid structure suitable for a top. Enough to support a 300lb person falling on it...and fortunately I don't weigh that much. Since we won't be holding any dance competitions up there, I think having a reinforced center section and thinner (1/2" core) sides will produce a decent trade off of functionality for weight.
The stringers will likely be incorporated in order to provide wire chases anyway, and have been used on most of the examples I've seen, so I'm thinking they are a good idea. I call them stringers because it is the most appropriate description, but they won't be formed like strings you see in a timber framed roof.
One of my decision points right now is if I should try to embed the solar panels in the top. Solar panels hate heat, so having cool air flowing under them would be a big advantage in efficiency over mounting them on the surface of the bimini, but would make the top more complex...not to mention the top would then be tied to a specific size solar panel. Of course embedded leaves one less thing for a line to get hung up on up there. Decisions...decisions.
Guess I'd better make the decision fast...time is quickly running out.
Hi,
DeleteAlternative is Corecell product. low cost supplier is noahsmarine.com in NY 19mm 4'x8' is $250 while 25mm is $300. Carry both West System and East epoxy along with fiberglas cloth. Corecell supposedly has better adhesion between fiberglas/resin and panel, smaller closed cells than divinycell.
Note Divinycell regional office for maker DIAM co is in NJ and should be able to tell you nearest supplier
Doug