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Reply to: Prindle Rudders

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[quote=klozhald][quote=briantroberts][quote=klozhald]
Making new rudders is really difficult to do well.[/quote]

Just curious, but what would be difficult about it? I've got 2 to use as templates, seems like it would be pretty easy given the right tools.[/quote]
Getting the shaping correct. You must shape your core material correctly to allow the protective outer coat to finish the profile needed and be the right size to fit the casting. The shape of a rudder is not a simple as it looks, and the wrong profile will create cavitation [i]and [/i]be difficult to trim for proper helm.

There are entire web sites dedicated to correctly shaping rudders, and the math involved.
[url]https://www.researchgate.net/figure/The-profiles-used-for-the-investigated-rudders_fig1_259579387[/url]
[url]https://www.sciencedirect.com/science/article/pii/S0029801816303134[/url]

Your nearly 40 year old "neglected" rudders are probably not prime templates. The original bottom edges had [b]square [/b]corners fore and aft. Do they still? This is not the issue, though.

My point is if you spend the time, effort and money to build rudders from a worn, 40 year old template, you end up with a new copy of a worn 40 year old rudder. Look for a pristine rudder to copy. I admire your courage and energy. I'm just trying to help you spend it wisely.[/quote]

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