Aegir-Ran is fitted with a Max-Prop V.P. feathering prop. It seems that the pitch was set wrong because hull speed (about 7.5 knots) could not be achieved at maximum engine speed. The prop is 16 inches in diameter and was set at an angle of 14 degrees (a pitch of 7.6). In principle, it is easy to change the pitch, even while the boat is in the water, by removing a screw, pulling back on a collar, and setting the new angle.
Unfortunately, the collar was frozen by calcification and dirty-packed grease. Also, the prop was fouled by barnacles after only being in the water a few weeks. Taking advantage of being on the hard, the prop was disassembled and cleaned with muriatic acid to remove the calcification. Even after cleaning, the collar on the hub would still not budge. After alternately soaking the hub in muriatic acid a gasoline, the collar could be forced partially back by taping with a wooden block, but it could not be completely pulled back to allow the collar to be turned. Using a gear puller, I was finally able to force the collar back only to learn the collar would only rotate a couple of degrees. By soaking the collar in gasoline and working it back and forth I was eventually (after a couple of hours) able to force out the calcified/hardened grease such that The collar could be rotated up to 20 degrees. The prop angle was set to 18 degrees ( a pitch of 9.8).
To deal with the fouling problem I decided to treat the prop with Propspeed. The product is expensive, but has a good reputation. The components of the prop was prepared according to the directions (finishing with sanding with 80 grit sandpaper to provide a surface for physical bonding).
There are four steps to treating the prop with Propspeed: 1) wipe with Propclean, 2) wipe with Propprep, 3) paint with two coats of an etching primer, and 4) apparition of a clear coat. The entire process is time sensitive, so it is important to read the instruction and have all the materials. It is also useful to watch the video.
