Rudder Rust

Comment

Comment by Clyde A. Phillips on August 5, 2013 at 10:44pm

Rudder Rust:  The rudder is two layers of 1" marine grade plywood.  The rudder stock is of bronze.  The plywood rudder blade is held to the rudder stock with long bronze rods with threads on the outboard end (for washers and nuts) and the inboard end (at the stock) is (as I remember) headed over into a countersink in the forward side of the stock.  The whole was then fiberglassed.  What I have no idea about is how the two halves of the rudder is held together.  Ack was in philosophy a belt and suspenders man (though in dress he wasn't).  He depended in many places in the ability of glue or mechanical fasteners (screws, nails, etc.) separately but most often he combined them, often using the mechanical fasteners to apply "clamping power" for the glue to set.  Chances are that the screws were galvanized.  It so, that would be the only thing in the rudder to rust.  The fiberglass around the bare bronze stock at the bottom of the rudder is a handy exit for rust laden water to escape and that, my friends, is my best guess.

I remember hearing Ack tell someone that he used galvanized boat nails for the planking and decking because they tightened up in time.  The process of tightening lay in the fact that the nails would rust to a certain extent and then stop rusting (because there is only so much oxygen in plywood) and therefore the nails would swell a little to hold the planking and decking tight against the deck beams and frames.  Keep in mind that glass over plywood was a new technology at the time and fiberglassing was thought to be a cure-all for waterproofing and a never failing end of maintenance.  After fifty years we are finding that these ideas leave a lot to be desired.  The new ideas of doing things right are now being used to give these boats another half century, and then some, of use.

Comment by bob mitchell on August 5, 2013 at 8:57pm

hi Britton - glad that you found that info -  I was so curious - because as far as we knew only 124, MNOONFLEET being the last, were built. Now the rust, in that area, is strange. I have featured a shot of the bronze rudder fitting, maybe the gudgeon, - and the rudder was originally bronze, so neither of those would "rust", but the deadwood rod, to the left, of which there are 6, three on each side, that go up through the apron and hold the deadwood stack of douglas fir beams together beyond the keel ( in the keel area they are held together by the keel bolts, 7/8 inch bronze), could be the source of rust. If I had to guess I might say the rudder had been replaced and instead of using bronze they used steel. Or possibly,

looking closely, the rudder socket wore and they put a steel bushing in it.