When the summer sun is beating down on you, shade over your cockpit can be a desirable addition on any boat, and a bimini usually fills that bill. But on a small boat, like my Potter 15, a bimini always appeared to be in the way. It makes it hard to see the sail; and it can make it difficult to get into and out of the boat. If heavy wind is heading toward my small boat, I’ve found that the best place for any extra canvas is stowed down in the cabin, not up on deck -- or attached to a bimini frame. And for a trailer-sailer that gets towed long distances, at highway speeds, a bimini is not only extra drag, but gets exposed to lots of road wear and tear. I need a better solution...
In addition to all the problems mentioned, I found that many lower-cost bimini tops are fabricated without zipper attachment flaps and must actually be de-mounted from the boat to remove the canvas from the bows. Therefore I felt it would be a good challenge to fabricate a sunshade that I could rig and unrig in just a couple of minutes. In addition, I wanted a sunshade that could be easily moved out of the way if I need to get a better look at sail trim, or whenever I’m maneuvering around the dock or setting the anchor. I had no requirement or need for a professional-looking rig. My guiding rules were function, simplicity, and flexibility. And since I didn’t have a bimini on my Potter, I was starting from scratch. If you’ve already got a bimini on your small boat, you still might want to keep reading. You can add an easily-removable sunshade to your existing bimini frame -- maybe when you decide to replace the worn-out bimini top.
Starting with the frame, you can “bend your own” with electrical conduit, aluminum or stainless steel tubing, or buy pre-bent components from Sailrite (www.sailrite.com). Low-cost plastic and stainless steel fittings are available from Duckworks (www.duckworksbbs.com). I recycled aluminum frame parts from a four-bow bimini that had been used on a bigger boat. For my Potter 15, a two-bow rig is big enough to cover the cockpit, so I had plenty of material to work with. Each bow consisted of two bent legs and a slightly curved middle section that locked together. I measured the width across the cockpit and shortened the middle section to an appropriate length. A plumbing pipe cutter and a small file was all it took to cut the aluminum tubing. The frame ended up a bit wider than the cockpit rails, which is fine because the aluminum bows have plenty of “bend” in them.
The only challenge was attaching the frame’s legs to the cockpit railing (to avoid drilling holes in the coaming or the railing). The tubing around the Potter cockpit and the bimini bows are both one inch in diameter, but I could not find low-cost plastic bimini hardware, so I only had what came with the original bimini. Apparently it’s much more common to use ⅞-inch diameter tubing for biminis, and that is what I would choose if I had to buy and bend tubing. I could find stainless steel fittings for 1-inch tubing, but they are expensive. So instead I used a couple of small stainless steel hose clamps around the Potter railing to attach the primary (front) hinge points to the cockpit railing (see photo below).
Two-bow sunshade frame. The front hinge is about a foot aft of the cabin bulkhead
On many biminis the frame is constrained by adjustable straps -- fore and aft. Instead of these I added two diagonal brace tubes to support the primary bow using some ⅞-inch aluminum tubing from my scrap bin. Then I fabricated mounting blocks on the cockpit rails using polyvinyl chloride (PVC) lumber scraps and a couple of U-bolts from the hardware store, and attached the plastic hinge points to the blocks with stainless steel hardware. This arrangement worked well enough that I’m going to replicate it for the front pivots, instead of the hose clamps. These diagonal braces really stiffen up the frame when they are tightened up, in contrast to straps that don’t.
Detail of rear brace attachment to the cockpit rail
When I’m towing Blue Knot for short distances and driving at low speed, the frame is strong enough that it can stay up. With the front bow folded back, it’s even strong enough to double as a boom gallows. As shown in the photo above, the rear diagonal braces have wing nuts so that I can easily adjust the fore-and-aft position of the blocks on the rail to change the height of the frame. When disconnected from the rear blocks, the frame folds aft, resting ahead of the transom, which keeps it out of the cockpit working areas, and it rests on top of my storage cuddies at the aft end of the cockpit (see photo below). This is also the mode that I use when I’m towing Blue Knot on the highway. The frame is down and secured to reduce drag and potential damage; and the sunshade is safely stowed below, out of the sun and weather.
Collapsed frame for stowage and long-distance towing modes
If I fold the shade frame to its forward position, it will clear the companionway hatch and rest just aft of the mast step. I can then easily access the lazarette storage compartments. When I’m out on the water I rarely leave the cockpit to go forward, so folding the frame up forward when not in use is perfect. I need to lift the boom to swing the frame under it, but that has not been a problem. And I’m still trying to figure out how to configure it as a dodger...
Frame in forward position clears the hatch and the cockpit. Ideas for a dodger in the future?
Now on to the sunshade…Sailrite has several excellent on-line videos on fabricating dodgers, bimini tops, and sails. If you are considering building one of their professional-quality kits, or if you want to take a crack at building your own from scratch, make sure that you see what you’re getting yourself into. For my sunshade I wanted something simpler than a “fitted” bimini top that is designed for a more permanent installation like on the big boats. All that I really needed or wanted was a flat sheet that would block the sun and not blow away. Something that would attach to the frame using grommets and bungee cord, both cheap and readily available, was good enough for my prototype. Sailrite has lots of good options for sunshade fabric, Sunbrella being the big boat favorite. But it is not the only option. I had been gifted a couple of yards of crisp Dacron sailcloth (an end-of-roll remnant, I’m guessing), and that was what I decided to experiment with. And since I’m interested in learning something about sailmaking (my copy of Emiliano Marino’s “Sailmaker’s Apprentice” is well-thumbed), I figured that making a flat sunshade would be an excellent project to practice broadseaming and edge treatments.
I cut my sailcloth remnant in half and joined it side-to-side with a constant width broadseam. Now I had a piece of fabric wide enough and long enough to cover the cockpit. I rolled the rear edge and added three grommets along the length. Then I folded the front edge to form a “batten” pocket, with an extra hemmed edge for three more grommets. Short bungee cords through the grommets attach the canopy to the aft frame, and several more to the front. I inserted a full-length batten across the front edge that stiffens the canopy’s leading edge and makes it easy to roll it up when I want to stow it. The finished canopy length was about six inches longer than the distance between the bows, and I used a length of 2-inch diameter PVC pipe to stretch the fabric across the bows. Tension comes from two ⅛-inch bungee cords that run from the ends of the pipe, through an O-ring at the rear brace point, and forward to cleats on the gunwales. If the wind is light or moderate in strength, the front bow will stay down without extra help -- the weight of the batten and friction in the bow joint keeps it down and the canopy taut. If it’s windy, I add two more bungee cords to the front grommets to keep the front bow down.
Sunshade stretched between the bows, and tensioned by the bungie-roller setup
As I mentioned above, I can adjust the canopy height by moving the rear support attachment points and diagonal braces -- I can easily lower the frame to clear the boom while sailing, and I can increase headroom when at anchor. I can “rack” the canopy forward -- or aft -- by adjusting the width between the bows using the white strap that you can see around the middle of the bows. The roller-bungie tensioner keeps the sunshade taut no matter how far apart the bows are, or how tilted the shade is.
Sunshade in “air dam” mode (that is, tilted forward)
If I need to check the sail trim or just want the canopy out of the way, I simply lift the front bow and flip it back (the hinge points have knobs so the resistance adjustment is simple). The bungie tensioner pulls the PVC “roller” neatly down along the rear diagonal braces (see photo below). This arrangement might also be good for downwind sailing (!). A light pull on the front bow returns the canopy back to shade mode. Easy peesy.
Sunshade flipped back. Note roller tensioner action
When I’m done sailing for the day it takes about a minute to pop the front bungee cords and roll up the sunshade. The rest of the rig, including the PVC roller, can stay right where it is, ready to go, and everything is out of the way. And I’ve got great access over the forward gunwales for getting into and out of the cockpit. Removing and stowing the PVC roller results in a very compact bundle that I can bungee neatly to the bows (photo below). When I get ready to trailer the boat, I pop the bungee cords used to secure the sunshade to the aft bow and then stow the rolled up sunshade inside the cabin. Since the sunshade frame is aluminum tubing, it is not strong enough to use as a handhold. If I had used stainless steel, maybe.
Sunshade rolled up and bungied to the frame
I made the sunshade purposely wider than the frame figuring that I can always make it narrower. But the stiffness of the sailcloth fabric and the rolled edges help keep the sides lifted; and the uncurved shape made the sewing much, much easier. All the seams were flat, straight, and easy to feed into the sewing machine. Adding a batten across the front really helps keep the sunshade flat, and I’ve considered adding one or two more battens to stiffen it even more. Since I roll the sunshade up using the front batten, they would not present any impediment.
I realize that sailcloth is an unconventional choice. Dacron is sensitive to UV and wouldn’t last long if used to fabricate a traditional bimini that gets daily exposure to the sun. However, on Blue Knot the sunshade will spend most of its life inside the cabin, until I’m actually out on the boat and need it -- just like my sails. And my sails are as old as the boat (I know, I know...it’s probably time to invest in a new set). As a reference point, my sunshade used about two linear yards of 36-inch wide sailcloth. When I last checked 36-inch wide 4-oz Dacron sailcloth from Sailrite was running around $10/yard. Wider (54-58 inch) Supercruise Dacrons were about $12/yard for 4-oz sailcloth and $17/yard for 6-oz. Duckworks lists 36-inch wide 4-oz Challenger Dacon for $9.50/yard. Fabricating another sunshade using tougher, UV resistant fabric would be a snap because it’s easy to sew a flat sheet of fabric, there are no zippers to contend with, and there are only a few grommets that need to be set. In addition to the already-mentioned Sunbrella, which runs about $23/yard for the marine grade, I would also consider TopGun ($15/yard) and Odyssey ($12/yard). I still have the original top that came with my donor bimini; and it’s in good shape. Therefore another option would be to repurpose that fabric for an improved sunshade.
Once I got the sunshade frame and sunshade figured out, the “idea spigot” opened up. When the boat is sitting in the driveway between outings, the canopy frame supports a simple boat cover instead of the sunshade. The cover (still under development…) keeps rainwater, leaves and other debris off the cabin top and out of the cockpit, which greatly simplifies my cleaning tasks and keeps the cabin much drier (read, less mildew) between outings. I used fabric that is typically used for car covers, Evolution, which costs about $12/yard from Sailrite. And, based on the advantages that I got with a simple cover, I can see a future project to design and sew a cockpit tent -- with mosquito netting -- that will help extend my cruising season.
Evolution cockpit cover draped over the frame
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