When it comes to boating projects, sythetic building matrials sell themelves. Polymer lumber and related plastics – the best known is StarBoard – cost a bit more than wood, but they are waterproof, require no finish and eliminate problems like delamination and rot. What's not to like?

The truth, however, is that the devil is always in the details. While marine-grade lumber has a track record going back decades, experienced boaters and builders know that there can be surprises when working with new materials. Until you get the goods into the shop, you really don't have the whole story.

So in order to demonstrate the versatility of these products, we have outlined a selection of projects – a boarding ladder, a companionway hatch, an electrical panel, a grab rail and a propane locker – that successfully substituted synthetic materials for wood.

The goal is not to teach you how to build these particular items, though most would be at home on almost any boat. Rather, the idea is to demonstrate the wide range of uses, pass on some tips and tricks and get you thinking about projects of your own.

THE BOARDING STEP

Getting on and off a boat tied to a floating dock can be tricky. My friend, Vince Purcell, built a boarding step that fit securely over the toe rail of his 34–foot sailboat. The step made boarding a snap, even for those of us "experienced" sailors with less than perfect knees.Paul EsterleThe Boarding step in place on the boat (lanyard not shown). It is taken up while underway.

Unfortunately, his version was made from marine plywood. After several seasons of use, the plywood began to deteriorate and eventually broke while he was visiting us. After inspecting his step and evaluating the problem, I developed an alternative built from synthetics.

I used StarBoard, which can "cold flow" or deform under pressure. To offset this problem I added a support under the front of the step and a higher toe kick on top of the back of the step. The step itself was inset into a shallow rabbet or groove (see photo).

The other point of concern was the narrow part of the step where it fit over the toe rail. I made the top of the side plates higher to provide more material to resist the tendency for the step to crack at the top of the toe rail opening. All the fasteners were standard stainless steel self–tapping screws, installed in pre–drilled pilot holes.

I developed the pattern for the toe rail using artists foam board. This product is available in most craft stores and is comprised of a thin layer of foam bonded between to sheets of thin cardboard. The material is easily cut with a hobby knife but is rigid enough to hold its shape. It was a cut–and–try process until I had a final fit. The important thing was to develop a shape that would be secure when hooked over the toe rail yet could easily be lifted off.

Once I made the pattern, the rest was simple. Most of the cuts were straight. A table saw would have been ideal, but I made them using a battery-powered circular saw. I made the groove using my router and a guide bar clamped to the side plate.

After that, it was a simple job of pre–drilling holes and screwing the step together. One additional feature I added was to tie a lanyard to the step that could be secured to the boat. There's no sense in building a step that can be dropped overboard.

DROP BOARD

The drop board on my 20–foot project boat was made from plywood. I had laminated teak veneer to the outer surface to make it look better and preserve the plywood underneath. However, it still required an annual sanding and recoating with varnish to keep it looking good.

A friend happened to be marketing a foamed PVC material called Kleer. He offered me several samples in order to experiment, including enough 3/4–inch thick material for several projects, one of which would become this replacement drop board.

This material, which has a foamed interior, is lighter than StarBoard. I was a little concerned about the exposed edges of the material being weaker than the upper and lower surfaces. After inspecting the material, my fears were laid to rest; the surface of the exposed edges has a slight grain that is hardly noticeable.

The drop board in this boat is small enough that it can be made from a single piece of material. It would be a little on the heavy side if I were to make it from StarBoard but this foamed material was light enough to make a single piece practical.

All the cuts were straight. The only complication was that the top and bottom cuts were beveled slightly. Luckily, I already had the plywood original to set the angle on my circular saw. I used a guide bar clamped to the PVC to ensure straight and accurate cuts.

The PVC material has the same propensity to deform as StarBoard. There was a remote possibility that a breaking wave or a person falling against the drop board could deform it enough to push it into the cabin, so it would require reinforcement. Paul EsterleThe drop board in closed position.

I decided to add two reinforcing bars to the back side of the drop board. These would be made from metal and screwed in place. My first idea was to use stainless steel bar stock, and I actually made one of these bars. However, it was an absolute hassle to cut and drill with hand tools, and it was overkill as far as strength goes.

So I switched to aluminum bar stock for the second piece. This was much easier to both cut and drill, and was more than stiff enough.

I wanted the bars as smooth and seamless as possible. Using a 3/4–inch bit in my router and a guide bar clamped to the drop board, I milled two grooves in the back of the board. I drilled four fastener holes in each bar. I didn't want an exposed nut on either side of the board, so I turned to an old favorite: barrel nuts.

Barrel nuts are somewhat like bolts, with a head and a stem. The difference is that the threads are on the inside of the hollow stem instead of on the outside of a solid stem. These require a slightly bigger mounting hole but the benefit was a smooth head on both sides of the board.

I wanted some sort of a handle to make using the board easier. A quick trip to my local marine store resulted in a molded white plastic handle that was a good color match and complimented the style of the drop board.

I built this drop board from the PVC material as a long–term test of its durability. After three years of use, it is still in excellent shape. The color hasn't yellowed and the edges haven't experienced any deterioration. It's a keeper.

ELECTRICAL PANEL

I decided to completely rewire my 26–foot project boat. That included changing the location of the electrical panel as well as building a new electrical panel. The new panel would have the panels and switches mounted on the front and terminal blocks and bus bars mounted on the back. I decided to use non–conductive StarBoard for the pane.

My first thought was to make the panel from 1/4 inch stock, but considering the things I planned to screw to both the front and the back, I ultimately decided on 3/4–inch stock.

I used my computer's CAD program to layout the placement of the various items on the panel. After several tries, I was able to print off a dimensioned drawing for the panel layout. King Plastics, the maker of StarBoard, recommends using a china or grease pen to write on StarBoard as other markers may stain the surface or may be hard to remove.

I chose to cover the entire front surface of the panel with blue masking tape. That made layout easier to read and follow. Once all the cutout locations were marked, I drilled an access hole in each opening for the jig saw blade.

The accurate layout and careful cutting of the openings required very little follow up work on my part, the components fit where they needed to be and resulted in a neat looking panel.Paul EsterleThe electrical panel during a trial fit.

FLARE CANISTER MOUNT

Your flare gun is one of those things that you need to have aboard but never want to use. That being said, should the time come when it's needed, you'll want to find it quickly. That means having it accessible, not buried deep in some locker.

I decided to mount my orange flare canister inside the cabin, just under the companionway opening. My first mount was made from several pieces of mahogany. This unit performed well but, being made from wood, required periodic refinishing. In my quest to reduce varnishing to an absolute minimum I decided to replace it from one made from StarBoard.

As luck would have it, I had enough scrap material left over from past projects that I didn't have to buy any new material. The lesson: don't throw away your scraps. You never know when they'll come in handy.

The backboard is a simple rectangle made from 1/2–inch stock, while the cradles are cut from 3/4–inch stock. A couple of stainless steel self–tapping screws hold the cradles on the back board. A small hole in the bottom edge of each cradle accommodates a short length of bungee cord. The top of the bungee loop is held by a hammock hook, a commonly available part in most marines stores used to hold hammock style gear nets.

The flare canister is placed in the cradle and the bungee is looped over the top and hooked into the hammock. Adjust the length of the bungee hook to keep the canister firmly in place, but loose enough so that it can be quickly released. I can reach inside the companionway and pop the canister out of its mount with one hand.

HANDRAILS

The wooden handrails on my 20–foot project boat required regular sanding and revarnishing. Years of doing this whittled them down to the point they were thin enough to be unsafe. Having been given some samples of Kleer, I decided to see if I could use it for replacement handrails.

Those of you who frequent marine stores probably have noticed StarBoard handrails for sale. I spent some time evaluating them and saw two major problems. First, the bases are only 3/4–inch wide, the thickness of the stock. This doesn't provide, in my opinion, enough side–to–side stability for something as important as a handrail. Secondly, they aren't available in the proper lengths, with the correct loop spacing, to fit my boat. So I went back to the drawing board with the Kleer product in mind.Paul EsterleAn overhead view of the port handrail, showing the curve.

I already knew that simply cutting the handrail profile from 3/4–inch stock wouldn't give me the stability I wanted. I also had to contend with the fact that the handrails had a pronounced curve to them. I decided to make the upper portion of the handrail 2 inches wide. To get the rail high enough off the cabin top to be able to get my fingers underneath, I spaced the rail 11/2 inches off the cabin top by using two layers of 3/4–inch stock.

After removing the old rail, I taped together a length of card stock long enough for the pattern and wider than needed. I cut 2–inch diameter circles from the same cardboard and temporarily screwed them in place, using the existing handrail mounting holes. This located the mounting holes on the cardboard pattern and the circle defined the outside edge of the 2-inch-wide handrail.

I used a flexible batten, placed against the cardboard circles, to outline the edges of the handrail. I then cut the pattern to the outlines and transferred it to the PVC. I cut the handrails out with my jig saw and drilled the mounting holes.

The next step was to make the spaces. I cut a series of rectangular blocks and center drilled them. I mounted them on a length of threaded rod and sanded all the edges even. A quick pass with a round over bit in my router gave the blocks smooth corners.

The nice thing about PVC is that it can be glued with standard plumbing PVC cement. I used the clear style to avoid staining the PVC and glued each support from two of the 3/4–inch blocks. I glued to longer blocks to each end of the handrail and then sanded them to a smooth, tapered shape with my belt sander.

To mount the handrails, I thru–bolted them using stainless steel oval headed machine screws and finishing washers on the top side. Inside the cabin, I use large stainless steel fender washers and acorn nuts. The acorn nuts provided a smooth, non–snagging and finished look to the project.

I left the handrails unfinished and can say, after three years in place, they look as good as new.

PROPANE LOCKER

My daughter's 34–foot sailboat had no propane locker and no convenient place to install one. After some experimentation with cardboard prototype, I found that I could build a propane locker to hold two 10-pound cylinders that would fit up against the aft end of the transom. Paul EsterleStarBoard project photos.

Before making any kind of propane locker, be sure to check the specs recommended by the American Boat & Yacht Council, which sets construction standards. You will find that the locker should be separate from any other compartments, sealed and have a drain to eliminate any leaking propane.

Making such a box using fiberglass would mean a complicated mold that requires a lot of finishing work. Neither of those options appealed to me. I decided to make the locker out of 1/2–inch StarBoard instead. The box would have a front and back, two sides and a bottom, as well as a hinged top that could be sealed. The box would angle to match the slope of the inside of the transom, and the bottom would be raised several inches off the deck. I did this for two reasons. It would give me room to install the fittings for the overboard drain and it would allow access to the top of the rudder shaft so the emergency tiller could be fitted.

The locker is required to be sealed so no propane can leak out. I accomplished this by using aluminum angles in all the corners and thru–bolting the StarBoard in place. I use 3M5300 sealant under the aluminum angles to provide a gas-tight seal. The product will not stick to the StarBoard but once in place and compressed by the aluminum angle, it forms a good gasket.

To add a little more function to the locker, I added teak fiddles to the top so it could be used as a small cockpit table. The finished unit, while a little expensive, was still cheaper and quicker than a custom-built fiberglass locker.

I hope these projects give you a better feel for marine polymer lumber and some of its many uses. Unless you like varnishing a whole lot more than I do, it's often a better way to go.

Paul Esterle is Technical Editor for Small Craft Advisor Magazine, and his freelance work has appeared in Sail, BoatWorks, Voyaging and Good Old Boat magazines. He has produced a series of boating videos and lectures widely. He also works at West Marine and has written product reviews for the company.