Making Bearing Replacements for the Dogs
Naturally, it wasn't just the hatch that was broken. After years of UV exposure, the plastic surrounds of almost all hatch "dogs" broke. Since we've gotten pretty crafty and independent from Prout Catamarans by now, we elected to create our own surrounds using the old ones as molds. As with everything we replace on our Prout Escale, we strive for higher quality and durability. Hence our choice to go to fiberglass reinforced epoxy that has UV inhibitors (Aluminum, graphite).
Could Prout Catamarans have chosen a better way to keep the hatches closed and dry? Yes, but that would have required them to spend more money. This hatch locking design looks home-made to me and while generally effective, is quite flimsy. Bedding the surrounds in epoxy should make them stronger and less prone to falling out (along with the whole "locking" mechanism). Trouble is that most hatches are merely 3-4 layers of fiberglass - thus there is little with which hatch locking mechanism can be held in place.
Our epoxy replacements for the broken hatch sockets. The socket screws fit inside these brittle plastic pieces that are supposed to act as low friction bearing surfaces but (unfortunately) also double as water conduits. Now that we had replacements parts, the only remaining issue was to repair the hatches themselves.
Since all the wood around the bearing surfaces had rotted to mush, we had to remove as much as we could reach. A paint-can opener works great. We then let the remaining wood dry for a while before we filled the holes with reinforced epoxy. There are two benefits:
- Epoxy doesn't care if it gets wet
- Epoxy is much stronger than wood (if it has been reinforced with glass fibers).
The holes through the hatch were then re-drilled and the surface was prepared for the addition of the new plugs.
The new plugs are virtually indistinguashable from the old ones, except that they should be much more UV resistant and that they no longer allow the surrounding structure to rot.
Along the way to replacing all the dogs, we'll reinforce all the other hatches on our Escale to have thicker sections around the dogs. Most of these locking mechanisms are woefully unsupported and exit from the hatch easily. The amount of water that leaks into the hatches via the bolts is pretty minimal and as long as the surrounding core is waterproof, little damage will occur. We'll further inhibit corrosion by removing the bolts every two years or so and re-coating them with heavy grease.
Compared to the complexity of some of the other projects on our Prout Escale, this one is easy!
Best Estimate of Time Required:
|Construct mold to mimic shape of existing "dogs"||4 hours|
|Creation of new "dogs" made of reinforced epoxy w/UV block (12 total)||8 hours|
|Repair of rotten furnace hatch areas around dogs||4 hours|
|Reinforcement of other hatches on board||16 hours|