Saturday, October 23, 2010

Autobailers- Part Two

Removal and replacement with a watertight plate

For a very long time, leaking autobailers had been my nemesis as I battled to keep all 12 of our high school sailing team’s well used 420’s fully functional. This year, it was time to abandon our duct tape solution (actually better tape than duct tape, but just tape nonetheless) and move on to a real solution. Several ideas occurred to us, but each seemed both expensive and flawed in one way or another.

  • Replacing the autobailers would be expensive ($62 each x 12), and they would quickly fail again with the boats exposed to our very sandy environment and the care left in the hands of multiple, careless, high school students.
  • Fiberglass work to plug the holes after removing the autobailers would be tricky and time consuming, especially given the very thin hulls on 420’s. A quality fiberglass repair of a 3” by 5” hole also takes expertise I don’t have.
  • A friend offered to weld the old autobailers shut, but after discovering the gaskets inside, he determined they would melt into a gooey mess that was not compatible with welding.
  • A stainless steel plate bolted to the hull with the same bolts used by the removed autobailer would seem to work nicely. I couldn’t find anything like this sold commercially, and I worried that having them made would get almost as expensive as buying new autobailers. When I examined an old bailer I had removed, discovering that the bottom of the bailer was not flat, but a pan shape, I became totally discouraged about the cost of having such a piece custom made.
What we (mostly a former sailing team member, now a college graduate) finally came up with was a way to reuse pieces of the old autobailer to make a waterproof plate. The 420 autobailers are constructed from three separate pieces of stainless steel and a couple of gaskets. The chute that drops to let out water is sandwiched between two frames. Our solution was to replace the chute and its gaskets with a solid piece of hardened West System epoxy resin that would span the hole and bond to both frames of stainless steel with a water-tight seal. We tried it out on our boats during the summer, and we have been sailing for six weeks this fall with no leaks.

Here is what the process looks like:

First, we remove the autobailers and separate the three pieces, the two frames and the chute. They are fastened together with six copper rivets that need to be drilled out.

Drilling Out the Autobailer Rivits

Autobailer with Rivits and Lever Removed

After the pieces are separated, the chute and its gaskets are discarded.

Next, the top and bottom frames are tightly bolted together. Then, they are temporarily bolted to a piece of wood that will serve as the bottom form when we pour in the resin later. Wax paper must be inserted between the wood and the frames to prevent adhesion of resin to the wood.

Frames Ready to Receive Fluid Resin

The resin is two part West System epoxy with High Density 404 Adhesive Filler mixed to a thick, but pour-able, consistency. It is just poured into the frames, making sure all the corners are filled. (We waited 24 hours before removing the assembly, but the resin sets up in about an hour.)

Pouring Resin into Metal Frames

The final step is removing the new pieces from the temporary molding board and inserting them into the boats to plug the holes where the autobailers were removed.

Finished Autobailer Replacement Plate

All the old silicone or 5200 needs to be removed from the fiberglass on the boat before installing the new piece, and this is the most time consuming and tedious part of the process. When installing the new piece, all the old nuts and bolts are used. Working simultaneously from both the top and the bottom of the boat takes two people and is a little awkward. Careful attention needs to be paid to craftsmanship when the new sealant is installed. (We screwed this up on a couple of boats and had to reseal them.) We used marine silicone sealant which lasts for a long time, but had we been 100% sure this whole approach was going to work, we might have used 5200 for a permanent bond.

View of 420 Hull with Autobailer Plug Installed

Has anyone else come up with another way to eliminate autobailers that they would like to share? Other comments on autobailers?

Yarg

3 comments:

  1. "Duct tape, Dude!" Is wot I always said.....

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  2. Impressive! Somebody is going to look at one of these boats in about 20 years time and wonder how on earth this "autobailer" is supposed to work.

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  3. Looks great. Very elegant solution.

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