Originally Posted by BruceK
So, no need for Propspeed?
No. We've never put anything on our props. The yard will do whatever one wants-- Propspeed, the spray-on zinc stuff, etc.-- but the yard owner told us years ago that what he's observed is that if one hauls every two to three years, as we do, no matter what is put on the props they end up coming out with barnacles and stuff on them just like the props that have nothing on them. The yard has observed that prop treatments are good for about a year after which they offer no significant benefit. The dive service that works our harbor says the same thing.
We use our boat regularly and if we go for four weeks without actually going out we run the engines in gear at about 1300-1400 rpm for 30 minutes once they get up to temperature. This keeps the props pretty clean.
This summer has been a bad one for barnacles as there has been almost no cloud cover. Everybody's
boat is getting lots of barnacles on the running gear and rudders including, the yard owner said, boats on which they did prop treatments two years ago. His advice regarding prop treatments is save your money unless the boat just sits and is rarely used.