My PerfectPass system has been sitting in its box for nearly a month. Yesterday, I finally got up the courage to cut a hole in the bottom of the hull of my brand new boat. This answers the question of why the system was sitting in the box for nearly a month. Who wants to do this? Are they interested in self-torture? Yes and no. While this was painful to think about (and do), it was not nearly as painful as trying to wakeboard behind a boat being driven by an eager-to-learn but inexperienced driver. I promised to map this out when I started, so here goes. My apologies in advance for not charging the battery on my digital cam. As a result, I have no pics. I'll edit when I get a chance to show the flange installed, but I won't be able to produce pictures of cutting or the hole itself at any stage. I promise that the additional steps WILL include pics.
Installation: Step 1
The instructions with the unit are pretty straight-forward. There is a flange that goes into the hull where the speedo paddle wheel later is installed. The flange is threaded, is about 2" in diameter, and is approximately 6" tall with a lip at the bottom that is approximately 2 3/4" to 3" in diameter. It is pretty simple to see what you have to do. You have to use a 2" hole saw, and cut into the hull inside the engine compartment, just in front of the engine. Then you plug the flange into the hull from the bottom of the boat, and put a foam rubber washer plastic nut on it inside the bilge area and tighten it down. You use silicone sealer along the way to keep the water out, but this process is more complicated than it sounds. Read on, kids. Read on.
So how do you do this?
1. Locate a spot on the bottom of the hull with the boat on the trailer, where there is no bunk, about 5 inches from the keel. Make sure there is no chine, strake, or other interfering object on the bow side of this spot. If there is a depthfinder transducer, go to the opposite side of the keel. You want a perfectly smooth location.
2. From inside the bilge, measure approximately the same distance from the keel, and mark that spot in front of the the engine (toward the bow).
3. Drill a 1/8 pilot hole from the inside of the bilge area at the marked spot.
4. Lay on ground under trailer and locate pilot hole on bottom of hole. Use a reversible drill, attach a 2" hole saw, and begin cutting the outer skin of the hull's fiberglass IN REVERSE. This helps prevent spider cracking of the fiberglass around the hole. Take your time and stop every so often to examine the skin. Once you get all the way through the skin, STOP. DO NOT CUT THE HOLE ALL THE WAY THROUGH. Using a flathead screwdriver, pry/knock out the disk of fiberglass that you have created.
5. Get back in the boat, and repeat step 4 (but from inside the bilge area) using a 2 1/2" hole saw. DO NOT use the same 2" hole saw. The hole on the inside of the bilge area MUST be a little bigger. Do not go any bigger than 2 1/2", though. Make sure you STOP once you get through the skin of fiberglass inside the bilge. DO NOT CUT THE HOLE ALL THE WAY THROUGH. Again, use a flathead screwdriver and pry/knock out the disk of fiberglass that you have created on the inside of the bilge area.
6. You should now see a bunch of foam, which is the boat's foam core. Using the same flathead screwdriver, work from inside the bilge area and break up the foam all the way to the outside skin of the hull. When you get done, you should have a 2 1/2" round hole in the foam all the way down to the outer skin. The outer skin should have a very thin layer of wood that you can see, and should have a 2" hole (a little smaller than the hole in the foam) that is visible and clearly allows you to see the ground.
Questions to ponder: Why did you do this? What is wrong with just cutting the 2" hole all the way through, sealing the heck out of it with silicone, and tightening it down? The layer of wood is the major reason. If the hull's core were all foam, you might do that (I still wouldn't recommend it). But, a FW Horizon has wood. If you developed a leak at a later time at the flange, the wood would essentially suck the water into itself and then wick it around to the wood layer placed throughout the hull. Eventually, you have a hull full of water-NOT GOOD.
*edit* here is a site explaining the concept of an epoxy "sleeve" pretty well:
http://members.toast.net/boatguy/drill.htm Sorry, meant to include that originally but didn't. Steps 7-11 create the epoxy "sleeve" but in a way in which you do not have to wait 24 hours or drill the epoxy out at a later time. Also, Steps 5-6 create the alternate method shown on this page, which results in "superior protection" of the core.
On with the lesson.
7. Find something with which to construct a 2"cylinder that is approximately 6-7" tall. This can be tough to find. I used an empty paper towel roll wrapped around the outside of the flange. Since the diameter of a paper towel roll is smaller than 2", it takes some cutting and taping to get it done, but eventually you will come up with a cardboard cylinder that is just slightly bigger than 2". Voila.
8. Coat the cylinder with wax or vaseline, and insert the cylinder into the 2" hole and leave it there. Make sure some of they cylinder sticks out of the bottom of the boat when you look at it from outside.
9. When you look at the hole from the inside, you should be able to see a gap of approximately 1/4" all the way around between the edge of the hole you cut inside the bilge area (the 2 1/2" hole) and the cylinder. Make sure that this is the case, and that ALL foam is cleaned out to make a nice smooth wall all the way around the hole on the inside of the hull.
10. From inside the bilge area, fill the entire area between the cylinder and the foam core with epoxy. I recommend buying the type of epoxy tubes that have a nozzle which mixes the 2 parts into one tube so that all you have to do is push the plunger down and mixed epoxy comes out. I bought these at Lowe's-very easy to find and not all that expensive. I used approximately 4 tubes of 5-minute epoxy in this type of dispenser. It was easy to squirt the stuff exactly where I wanted it, and it set up quickly. Be careful not to overfill the 1/4" gap-you don't want the inside of the bilge area to have an uneven or "high" edge because eventually you'll be putting a sealing washer and plastic nut right over everything. Also be sure to check the outside of the hull to make sure no epoxy is visible. If it is remove it before it cures.
11. After the epoxy has cured, slide the cylinder out. The wax/vaseline should allow this to happen very easily. The result should be a nice 2" diameter hole all the way from the inside to the outside. Most of what you can see is a hole with a smooth epoxy wall reaching all the way down to the hole in the outer skin. You have just sealed the wood and foam core with epoxy so that it will not take on any water. Allow the epoxy some additional time to cure in the open air (10 minutes or so). This is (hopefully) the last time this epoxy will see open air.
12. Use silicone sealer and coat the flange, inside of your newly made epoxy-walled hole, and the threads of the flange.
13. Insert flange into the hole from under the boat. Make sure the arrow is pointing toward the bow and is parallel to the keel. Install foam rubber washer and plastic nut. Hand tighten. While tightening, verify that the notch on the top of the threaded portion is facing toward the bow. This notch is in the same location as the arrow on the bottom of the flange, and helps you know from the inside that it is still facing the correct direction. Hand tighten only. DO NOT TORQUE the plastic nut. Make sure there is some silicone sealer on the threads to "lock" the plastic nut in place.
The real key to cutting the hole is getting everything internal sealed/covered with epoxy to prevent water infiltration. If you screw that up, you have a lot of work ahead of you to re-do it. If you screw up just the bedding of the flange with the sealant, that is much easier to re-do.
Step 2 (installing electronic components) is coming soon.