Thursday, February 5, 2009

Building the Amas

This is the first entry for 2009 and it corresponds with another feat in my building process. Yesterday, I popped another ama (float) half out of the form frames, so I now have two port halves.

It is now time for me to rotate each of the 11 stations 180 degrees to build the starboard halves. Once each starboard half is ready, I can take one of the port sides and join the two. I can't wait for this moment because it will be the first time I get a feel for the size of the amas (volume, flotation, weight, etc).

For other Farrier builders out there: I have been making a somewhat high density putty for the bulkhead fillets. In this putty, I am mixing epoxy resin with milled glass fibers (40%), colloidal silica (40%)and microspheres (20%). I originally used chopped glass fibers (1/4"), but I would advise against the chopped glass because it is very difficult (if not impossible) to get them to a smooth texture.

Other hints I've discovered:

1) The Fein multimaster tool does an incredible job of trimming the keel foam to the same height as the keel batten. I don't think there is a better tool out there for this job.

2) Use packing tape instead of mold release wax whenever possible. Wax on a fiberglass surface is just about the worst contamination imaginable and it is very difficult to remove thoroughly.

3) If you extend the foam at the bow past the bow bulkhead (at least to the length of the bow template), you will not have to fair this foam when the two halves are joined. You just have to fill the gap with pieces of foam, which in my opinion, is much easier.

Finally the pictures:

This is an image of the stiffeners underneath the ama deck. Ian's plans call for 3/4" thick stiffeners, but mine are 1" thick because I am using 1/2" foam, rather than 3/8". Thicker is stiffer in this case.



My vacuum bagging setup: One pump drives a manifold with 10 different ports. As the director of METC says "it could suck the chrome off a trailer hitch" :)



The second port half under vacuum bag.



Bulkheads filleted and taped - bow view



Stern view of the ama with raked transom. You can also see that the access hole in the aft beam bulkhead has been dug out and putty filled to a depth of 1/2".

The first float half I built is displayed in the top-right portion of this picture. It is resting on the air conditioning ducts.