So, I figured it's time to payback the online community by providing info on making hatch panels for the interior of the boat.
I have a 1989 MacGregor 26D, so these panels are designed for it. Other models may have different size panels.
My story actually begins a year ago when I made panels out of some sort of ply, not sure if it was oak on the outside with cheaper wood for the interior layers. Regardless, it was cheaper than real oak ply, but more than regular building grad plywood. Without proper tools - I only had a table saw and electric sanders - I spent hours cutting, rounding the corners of the panels, and sanding the edges to round. I then spent even more time, not knowing any better, and used Thomspon's Water Seal to seal the boards. Well, that turned out to be a disaster. The water seal caused the boards to warp in the sun when I coated just one side of a panel. Then to top if off, the water seal isn't actually water repellent, and water drops on it cause weird stains. But the worst part is that in just 6 weeks through this past winter half of them went mouldy. So the water seal not only wasn't a waterproofer, it offered absolutely no protection from mould, and offered no means of easily removing the mould.
After reading this forum I heard about using what most of you call "starboard" also known as HDPE aka cutting board material. Well, actually, according to the supplier (a very big plastics warehouse) HDPE and cutting board material aren't exactly the same thing; though they didn't exactly clarify what the differences are.
So, my first step was to figure out the optimum layout of the panels. They offered both 8' and 10' lengths of 4' wide sheet. I was able not only to get all the panels onto one 8' sheet, but I was also able to accomplish it in such a way that they could cut it into more manageable pieces on their "wall saw". Well, in fact they ended up cutting most of the panels, but as you can see from my layout, it can all be done with their wall saw. The diagram illustrates all the sizes that you need as well. Though, it does seem that a couple panels MAY be 1/4" or so oversize.
The 4 panels for the rear berth are actually less than 34.5". I can't remember exactly at the moment, but I'm thinking 34.25" is more accurate. I'll measure them again and post later. Using the wall saw you can see that I've labelled the first 3 cuts in the order they should be done. Hopefully logic will dictate the order of the subsequent cuts. If there are still questions about it, I'll post a more detailed diagram.
After cutting the panels to size, I used a 1" spade bit on a drill press to make "finger holes". (Photos to come at a later time) I located them 2.25" in from each side.
The panel corners had to be rounded. It took MUCH trial and error to determine that a diameter of 5.75" appeared to be the ideal size. However, the panels for the rear bunk use a much smaller diameter. I'll post that later. I first used a table saw to 45 the corners, and then cut those corners off a bit. After that I used a metal cutting disc on the table saw to actually circumference the corners. It turned out VERY well, looked professional, and blended well to the straight sides.
After that, all that was left to do was router the edges. The edges are VERY sharp, and really must be smoothed out. I'd never owned a router, but realized I really needed one if I was going to do these panels properly. Mounted on a table, it was enjoyable work, but took a lot of trial and error to do just right. I routered both the outer edges, and the finger holes. I did this on both sides of the panels.
The HDPE I got was not UV stabilized, but I felt, being on the interior, that would not be an issue. I am curious if I would have preferred black panels, but they did not have it in stock.
A few more notes:
1) I did not round the one edge of the rear berth panels where they meet. I felt that if they were rounded, there was a greater chance of one panel slipping and riding up on the other.
2) The panels are very slippery. I am currently experimenting with Dynaflex 230 around the perimeter on one side of the panels to see if they will provide a prudent level of grip. However this product seems to take nearly a week to fully cure. Someone else had mentioned on here what they used, and it was my inspiration for trying this product, but I can't remember what it was.
3) The panels, particularly the berth ones, are quite heavy. So you've got slippery and heavy to deal with when you're trying to move them around. They are 1/2" thick, but I wouldn't go too much thinner for fear of them not supporting the weight of someone kneeling on them. A sixteenth of an inch thinner, maybe, but not sure if 3/8" thick would be too thin.
4) While this write up is relatively succinct. For a first timer this is a fairly lengthy project. Requiring many hours, and many tools. If you have the money, pay someone else to do this!
5) It appears that HDPE actually floats!
Here's a pic of the finger hole:
The next two pictures depict the fact that where the two panels butt to each other, I have left a flat edge:
I did not put a finger hole in the panel covering the food storage bin:
On the aft berth panels, I located a hole at each of the front corners of each panel:
Here is a picture of the saw blades I used. The toothed blade has the 80 teeth, and has the words "professional" and "mirror finish" on it. The teeth alternating angling off to each side of the blade. I don't know what the other blade is called, but it's for cutting metal, is abrasive over the entire disk. This is what I used to radius the corners after first cutting off the major chunks of the corners:
I have a 1989 MacGregor 26D, so these panels are designed for it. Other models may have different size panels.
My story actually begins a year ago when I made panels out of some sort of ply, not sure if it was oak on the outside with cheaper wood for the interior layers. Regardless, it was cheaper than real oak ply, but more than regular building grad plywood. Without proper tools - I only had a table saw and electric sanders - I spent hours cutting, rounding the corners of the panels, and sanding the edges to round. I then spent even more time, not knowing any better, and used Thomspon's Water Seal to seal the boards. Well, that turned out to be a disaster. The water seal caused the boards to warp in the sun when I coated just one side of a panel. Then to top if off, the water seal isn't actually water repellent, and water drops on it cause weird stains. But the worst part is that in just 6 weeks through this past winter half of them went mouldy. So the water seal not only wasn't a waterproofer, it offered absolutely no protection from mould, and offered no means of easily removing the mould.
After reading this forum I heard about using what most of you call "starboard" also known as HDPE aka cutting board material. Well, actually, according to the supplier (a very big plastics warehouse) HDPE and cutting board material aren't exactly the same thing; though they didn't exactly clarify what the differences are.
So, my first step was to figure out the optimum layout of the panels. They offered both 8' and 10' lengths of 4' wide sheet. I was able not only to get all the panels onto one 8' sheet, but I was also able to accomplish it in such a way that they could cut it into more manageable pieces on their "wall saw". Well, in fact they ended up cutting most of the panels, but as you can see from my layout, it can all be done with their wall saw. The diagram illustrates all the sizes that you need as well. Though, it does seem that a couple panels MAY be 1/4" or so oversize.
The 4 panels for the rear berth are actually less than 34.5". I can't remember exactly at the moment, but I'm thinking 34.25" is more accurate. I'll measure them again and post later. Using the wall saw you can see that I've labelled the first 3 cuts in the order they should be done. Hopefully logic will dictate the order of the subsequent cuts. If there are still questions about it, I'll post a more detailed diagram.
After cutting the panels to size, I used a 1" spade bit on a drill press to make "finger holes". (Photos to come at a later time) I located them 2.25" in from each side.
The panel corners had to be rounded. It took MUCH trial and error to determine that a diameter of 5.75" appeared to be the ideal size. However, the panels for the rear bunk use a much smaller diameter. I'll post that later. I first used a table saw to 45 the corners, and then cut those corners off a bit. After that I used a metal cutting disc on the table saw to actually circumference the corners. It turned out VERY well, looked professional, and blended well to the straight sides.
After that, all that was left to do was router the edges. The edges are VERY sharp, and really must be smoothed out. I'd never owned a router, but realized I really needed one if I was going to do these panels properly. Mounted on a table, it was enjoyable work, but took a lot of trial and error to do just right. I routered both the outer edges, and the finger holes. I did this on both sides of the panels.
The HDPE I got was not UV stabilized, but I felt, being on the interior, that would not be an issue. I am curious if I would have preferred black panels, but they did not have it in stock.
A few more notes:
1) I did not round the one edge of the rear berth panels where they meet. I felt that if they were rounded, there was a greater chance of one panel slipping and riding up on the other.
2) The panels are very slippery. I am currently experimenting with Dynaflex 230 around the perimeter on one side of the panels to see if they will provide a prudent level of grip. However this product seems to take nearly a week to fully cure. Someone else had mentioned on here what they used, and it was my inspiration for trying this product, but I can't remember what it was.
3) The panels, particularly the berth ones, are quite heavy. So you've got slippery and heavy to deal with when you're trying to move them around. They are 1/2" thick, but I wouldn't go too much thinner for fear of them not supporting the weight of someone kneeling on them. A sixteenth of an inch thinner, maybe, but not sure if 3/8" thick would be too thin.
4) While this write up is relatively succinct. For a first timer this is a fairly lengthy project. Requiring many hours, and many tools. If you have the money, pay someone else to do this!
5) It appears that HDPE actually floats!
Here's a pic of the finger hole:
The next two pictures depict the fact that where the two panels butt to each other, I have left a flat edge:
I did not put a finger hole in the panel covering the food storage bin:
On the aft berth panels, I located a hole at each of the front corners of each panel:
Here is a picture of the saw blades I used. The toothed blade has the 80 teeth, and has the words "professional" and "mirror finish" on it. The teeth alternating angling off to each side of the blade. I don't know what the other blade is called, but it's for cutting metal, is abrasive over the entire disk. This is what I used to radius the corners after first cutting off the major chunks of the corners:
.