Tag Archives: ama

Ama repair job

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A month ago my port ama suffered some cracks while on a practice sail for the NCC. I was able to do a temporary jury rig to finish the trip but needed a permanent repair before the ama could be used again.

To repair, I first ground out the cracks and filled with an epoxy colloidal silica mixture to provide a smooth surface for the subsequent steps. I then sanded off a large area of the gel-coat in preparation to lay down some extra fiberglass layers. I did this to both amas since whatever I did to the broken ama, I also did to the other one as well. I didn’t quite sand all the way down the fiberglass, but I did remove the shiny outer layer of the gel coat.

I next added and wetted down a small piece of fiberglass with an opening cut out for the wing connection to each ama. The line around the piece is from the felt-tip marker used to indicate where to cut the fiberglass. Hopefully a later painting step will cover this up.

Then I added a large piece of fiberglass over the entire area.

And proceeded to start to wet it out. I made some cuts at the center of the wing connection so it wraps down inside the connection.

After finishing wetting out, I added a piece of pealPly over the entire area. Using PealPly gives a better finish without using as much total epoxy.

Since pealPly won’t conform to strange curves, I had to make a number of slits up around the wing connection area.

After the epoxy started to gel-up, I cut off some of the excess and then temporarily made the connection with the wing to ensure that there was a good fit. I had pre-treated the wing with mold-release. I just kept the connection in place for a couple of minutes.

Then I finished removing the excess material and after it firmed up a bit more, the pealPly.

The last step after the epoxy cures will be to sand out any imperfections and coat with yellow-tinted gel-coat. I’ll post an edit to this post after I paint it.

Water in Amas

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I’ve been getting some water in my amas. Not a lot, but enough to worry about it if I go on en extended expedition. The prime suspect was water entering in through the bolt hole where the ama is attached to the wing. I had been putting silicon sealant there to minimize seepage. I should have that fairly well closed off.

I just did the experiment, though, of unscrewing the cap for the drainage hole and blowing in the ama with my lips sealed around the drainage hole. To my surprise, lots of air escaped from below the base of the drainage plug that is screwed on the ama. This might have been the main problem all along.

(Note this picture taken with a wide-angle lens which makes the ama look shorter and fatter than it really is).

When I unscrewed the drainage cap, I verified that there is no gasket providing a seal between the cap and the ama. This should be easy to fix. Fifteen cents worth of silicon sealant applied to the right place.

When I blew in the drainage hole after unscrewing the drainage plug (as shown above) the ama was air tight except for a tiny bit under considerable pressure being forced out through the bolt-hole.

I think the ama was acting like a lung and while sailing various forces where causing the ama to expand and contract causing an inhalation and exhalation around the base of the drainage plug. On some of the inhalations water sucked in. Over time a lot of water can suck in especially if you are burying the ama or if waves are crashing over it.

In conclusion, I need to add a bit of silicon under the drainage plug insert.

[Edit: It was pointed out to me that the amas need to be able to vent some to handle hot air expansion while sailing. Be sure not to seal things up too tight. Let it breathe a little and tolerate a little water getting inside. Otherwise, any built-up air pressure could cause other unwanted failures.]

[Edit: Be sure not to block the small hole at the base of the plug.  This is actually where the water will drain out.  If the hole is blocked, water will only be able to drain out through the end of the shaft that inserts into the ama and you will never be able to get it all out.  It might be a good idea to drill some extra holes at the base of the shaft.]

[Edit: I drilled a 2nd hole on the other side of the plug to allow the water to drain out twice as fast. I only put silicon on the plug away from the holes to not cover up the holes and also to allow a little air to vent at that location on the plug. The idea is to add some silicon to prevent some water from entering but not so much that it also prevents any necessary venting to avoid air pressure issues within the ama.]