Bon Tardi,
A whole bunch of cruisers requested to have some postings in English so that they could read it instead of just looking at the photo's . . . so here you have it! I will favour English when I think a posting is interresting for many cruisers. Also, check out some free services on the Internet that can translate a webpage for you if you want to read a Dutch posting. I think Google can do that.
This posting is about cleats being mounted on deck. The cleats are not very interresting; it's the "mounting on deck" which gets interresting if you have a cored fiberglas lay-up for your deck, like we have. You must replace the core with solid fiberglas where you attach deck hardware for two reasons:
- Water ingress. When water finds a way to get into the core, it can do a lot of damage. Some cores tend to hold water like a sponge and it might spread along whole lengths of deck. Apart from carying the weight, the core will start to rot with expensive repairs as a result.
- Compression force. When you bolt a piece of hardware on the deck, those bolts need to be tight. The core can't handle that force and will compress with loosening of the bolt as a result. Also, the outer layers of the lay-up will deflect/indent which will break the water-seal on deck so that water will get in and that's where you get back to the first reason again.
There are many ways for replacing a core with solid fiberglas and we did this many times both above and below waterline and think we came up with a good, fast and easy method. In the first photo (click on photo's to see them bigger in a pop-up window) you see the result of the first step.
The first side-note should go here; it's better to do this from the inside of the boat so that the outside (wet side) stays intact. I know that, but this method will be just as good when done right and is way easier than working upside down!
Our cleats use four 10mm holes which we marked on deck. We then took a 1 inch or so holesaw and used it to cut until the center pilot-drill touched the lower layer of fiberglass. Don't drill through the lower layer yet! After drilling/cutting you still have to get the upper layer and core out. We use a flat blade screwdriver for that. Be careful not to damage the fiberglass around the hole, put something under the screwdriver when you need to use the deck for leverage. Use screwdriver and sandpaper to clean the hole of all core material.
For the next step you need a special tool which every cruiser should have aboard: the Dremel tool or look-alike. You need the little drum-sander to sand away the core under the upper layer. I can't show this on a photo because the camera wouldn't fit in the hole but you basically stick the drum-sander in the hole and work to the side into the core, as high up as possible, until the shaft touches the edge of the hole in the upper layer of fiberglas. Then work your way around the perimeter. Feel if you took all core, all the way up to the underside, off the top layer. This step compensates for not working from the inside of the boat, because you make a large surface area for the epoxy to adhere to the upper layer, forming a very strong and waterproof seal.
Next step is masking the holes and filling them up again. We use West System epoxy with slow hardener and high density filler (ketchup consistency). You have to layer with a maximum layer thickness of 10mm because otherwise the epoxy will overheat and boil. If this happens you have to remove it because it's very weak as there's lots of airbubbles in it. If you are not in the tropics you might want to use the regular hardener. Also, you have to pour additional layers while the previous one is still sticky: wet on wet. The last layer needs to touch/adhere to the top layer of fiberglas. When you're not sure if there's air trapped in there use a match stick to poke around a bit. Also, the deck isn't level I hope so stop filling before it overflows and close the higher part with some thicker mixture and match stick / toothpick. This stuff is very hard to sand so make sure not to overfill. We're gonna put more on top in the next step anyway.
Next step is shown on the third and fourth photos. We mask an area where the hardware will touch deck but just a hair smaller than that (stay just within the outline). The deck will probably have some anti-slip pattern which might crush under the compresssion forces so we will build the epoxy up until above the level of anti-slip. We did this by stacking 3-4 layers of masking tape. If the epoxy in the holes is already cured, you need to sand it until dull before continuing. Because we might need to sand the layer we're gonna put on now, we use only a little high density filler plus the colloidal silica filler to make it a peanut butter consistancy (still hard to sand). Use a plastic spreader (cut to size) and keep it as parallel to the deck as possible and let it cure. Sand it flat before removing the masking tape. As you can see on the photo's, I dropped and spilled epoxy on deck even with double width masking tape, so you might want to protect your deck even better. If you spill like I did and only notice this after it's cured, like I did, just let the sun work on it for a while and use the Dremel to take it off the anti-slip. With this step, we made kind of pedestals for the hardware, bonded to both upside and underside of the top layer of fiberglass, so water won't get in and it will not compress.
Next step is drilling the holes for the bolts which isn't very easy. You have to make a template with the hole-pattern or use the hardware itself as a template. Carefully position it and drill the first hole at right angles to the deck, with the final size drill-bit, 10mm in this case. Next, put a bolt through there and see if the head of the bolt fits nicely against the hardware. If not, you drilled at the wrong angle. With a good sharp drillbit you can correct this. This will probably void the warrenty on you drill but stick the bit in there and bring the drill to the right angle on medium speed. Leave everything in place while drilling the 2nd hole diagonally at the other side. Bolt that second hole too. Now drill the rest and fit/correct until you're satisfied.
Next step is the backing plate, see the last photo. We made it out of King Starboard instead of traditional stainless steel or thick aluminium. There's always a weak point and I selected this to be it, so that only the cleat and a small part of the deck gets ripped of when something has to give. I rather have that than half my stern ripped off! Whatever you use, it's easiest to take a two step approach; first, attach the plate to the underside of the deck and next, drill the holes for the bolts through it and mount the hardware. We fabricated the plates and drilled six small holes in each for attaching it to the deck. We cleaned the deck with aceton and used LifeCaulk from BoatLife as bedding compound (3M's 101 is good too). We also closed the countersank holes/screws with some caulking to protect them from corrosion. We used 6 screws because we used Starboard; with a metal plate 2 or 3 will do.
Last step is mounting the hardware. Use masking tape and bedding compound above and below and also put some bedding compound on the bolts, just under their heads. Really try to get 316 type (A4 in Europe) stainless steel bolts, nuts and washers. Gradually tighten the bolts. The bedding compound is easy to clean up after curing.
Only question we're left with is why our boat came without stern cleats? Or really the last one would be why all other cleats have no backing plates...
Good luck,
Nick.
Bon Dia!
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