Bayliner Element HDPE Seaboard Casting Deck
The new Bayliner Element 160 is turning out to be a fantastic boat. When we were looking around for a new boat it needed to fill a number of roles. It needed to be comfortable for cruising around on the harbour with friends, low maintenance and easy to launch/retrieve. But with all those cushions it didn’t look much like a dedicated fishing boat.
Before destroying the upholstery with my fishing adventures I decided to fabricate some hatches to turn the front and rear into spacious casting platforms. The hull was already perfectly designed with a lip around where each hatch was going. I just needed to fill the holes.
After searching around for a supplier I found some 19mm Seaboard HDPE at a local supplier.
I quickly found out there were a few serious shortfalls with HDPE
– It comes in really large sheets (2400m x 1200mm)
– It is extremely heavy (2 big guys had difficulty lifting the sheet)
– It is very expensive (approx $550 for the whole sheet)
Keeping in mind this was a long term investment I ended up biting the bullet and purchasing a sheet. Everything I’ve read about HDPE says you can use ordinary woodworking tools with it. Being a practical kind of guy with a bit of experience and a range of tools this should be fairly straightforward.
Here are the steps I went through to create my casting deck on the Bayliner Element.
Step 1 – Cardboard templates
First up I created a template of each hatch carefully traced and trimmed out of sheets of cardboard. I could then work out the layout of all my hatches on the HDPE sheet to minimise wastage when cutting the (expensive) HDPE. After working out the most efficient layout I carefully traced around the cardboard templates with a permanent marker (sharpie). An important step is to test a small section of HDPE to see if the marker can be wiped off. Methylated spirits worked very well removing the marker I was using.
Step 2 – Corner Templates
Next problem were the corners of the hatches. Thankfully there were only a handful of different curves but there was no way I could freehand with the router to cut perfect corners. A template for each corner needed to be fabricated out of plywood that I could follow with the router.
At the local office supply store (Officeworks) I purchased a flexible curve which I could push into the corners of the boat hatches to replicate the shape exactly. Once I had the right shape with the flexible curve I traced it onto my plywood.
I had a flexible router guide that I purchased for another job and found it to be really useful for making tidy curves with the router. I marked the apex of the curve we just traced onto the plywood with a 45 degree square. I used this reference to place the centre screw for the router guide. Once all the screws were in place there was a perfect curve that I could then run the router around creating a perfectly curved template. I repeated this process for ever unique curve required.
Step 3 – Breaking the board
They say measure twice, cut once. When dealing with a $550 board I ensured I measured many (many) times.
Using my cardboard templates combined with corner templates I laid out all the pieces on the HDPE board. I left more material around each of the pieces than necessary. Having never worked with HDPE previously I wanted to leave plenty of room in case I made a mistake cutting it out.
I carefully went around each of the shapes using a jigsaw. I found that using a wood blade on a slower setting helped the jigsaw move quite well through the board. Faster settings seemed to melt the board and didn’t necessarily improve cutting speed.
Step 4 – Shaping the Hatches
Now that i had all my shapes roughly cut it was time to start working back to the final dimensions. Firstly I attacked the straight edges. By clamping a straight edge to the board I could run the router along the edge with a straight bit to make tidy straight cut. It took several passes of the plunge router to cut the full depth of the 19mm board. The finish on the router cut edges was extremely clean compared to using a jigsaw or handsaw.
Attaching the router upside down to my homemade router table I could then work on the corners. I changed my straight bit to a flush trim bit with a bearing and adjusted the plunge on the router to the correct depth.
I attached my wood corner templates to the HDPE boards with mastic tape. Mastic tape was about the only thing I could find that would adequately stick to the board. After trimming off as much of the excess as possible I carefully followed each of my corner templates with the flush trim bit to create perfect reproductions of my template shapes.
To speed up the process I simply stuck a finished hatch on top of an unfinished one. Then using the flush trim bit I could quickly duplicate the exact shape.
IMPORTANT NOTE: Just like when working with wood, only remove small volumes of HDPE with the router in any one pass. If you try to remove too much material the router will bite into the material and become uncontrollable.
Step 5 – Tidy up
Although the router did a 95% accurate job there were still a few patches that were either a bit rough or needed additional material removed to fit into our hatch holes. This was a fairly simple affair using standard woodworking tools. I used a shaving plane to take off small amounts of material until the boards fit into the holes in the boat. Then I used various grades of sandpaper to tidy up the edges of the board. It’s worth noting that I didn’t go for an absolutely mirror finish edge but it is important to get the surface smooth for the next step.
IMPORTANT NOTE: At this stage the hatches fit really snugly into the hatch holes in the boat. Make sure you have a plan to get them out before you test them in the holes!
Step 6 – Rounding the edges
For a nice finish I wanted rounded edges on my hatches. Again using the plunge router I changed the bit over to a round over bit with a bearing. After testing a number of fixed cutting depths on some spare board I chose one that provided a nice little round on the edge of the board. I carefully worked around each of the boards. The results were awesome and I have to say that I was pleasantly surprised that they didn’t even need sanding after this stage.
Step 7 – Fixtures and fittings
The hatches required a catch which would hold them in place as well as provide a lifting point. I purchased some plastic slam catches from the local boating store.
I needed to cut some holes for the slam catches. By cutting down one of my wood corner templates I built a circle template for my router. I carefully marked out and then hammered a nail into the centre point of each catch location. This was then lined up with a hole in my router template and it was simply a matter of guiding the router around the nail centre-point in a circle. Again it was important to make several passes and not try and remove too much material in one go. With a little bit of filing the catches went straight in.
As we aren’t permanently installing the hatches, the fitting of hinges would not be possible. I needed to make some “hooks” out of HDPE that would work in conjunction with the slam catches to hold the hatch in place. These were screwed into the underside of the hatch on the opposite side of the slam catches preventing the hatch popping out in rough water. I fabricated these with the jigsaw and hand tools.
Step 8 – Finished
All the hatches and deck infills installed and looking great. After testing all the hatches I was surprised at how little the HDPE flexes under my weight. The texture is also quite grippy in the wet.
- Go slow and have a plan for your next step.
- Most woodworking tools work well on HDPE. You will need to go a bit slower so they don’t clog or jam.
- Measure, measure and measure. Then before you cut, measure again!
- Clean up regularly – HDPE shavings go everywhere and are very difficult to clean up.
- Consult Youtube woodworking videos. The processes can easily be adapted to HDPE.
- Give it a go, wear your protective gear and work safe!