The prop on our '95 C36 MkII was "dinged" when we bought the boat last year. It wasn't causing a vibration problem, and we had other "new boat" expenses to deal with so we just decided to run through last summer with the old dinged prop. Now that I'm getting ready to haul out for bottom paint, it seems like the right time to deal with the prop too. I could just have it repaired, but where's the fun in that? I'm thinking about upgrading the (probably original) 2 blade to a 3 blade Campbell Sailer. I'm wondering if anyone has feedback on this choice.
I briefly thought about upgrading to a folding or feathering prop, but we're cruisers, not racers. The reduced drag while sailing didn't seem like enough of a tradeoff for the added initial cost, maintenance, and vulnerability in our sometimes trashy water (something dinged the prop I have - it could happen again).
I like the idea of moving to a 3 blade prop for better performance, and the Campbell Sailer seems to have the lowest drag of any 3 blade fixed I've seen. Kelsey at CS just suggested their RH 14x7 as the best match for my configuration (M35a 30 HP@3200 w/ ZF-15 trans at 1.875 ratio). Previous posts on this and other forums talk about the CS RH14x8 being good, but maybe a little overpropped. So maybe the 14x7 is about right.??? I look forward to words of wisdom from those who have traveled this path before me.
Steve Bogert / Bonnie Sprague
"Wild Spirit"
1995 Catalina 36 Mk II, Tall Rig, Fin Keel, Hull #1412
Bellingham, WA
Les & Trish Troyer
Mahalo
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor.
Commodore
A search on this site will give you a lot of reading on prop selection and Campbell Sailor as well. I also went the CS route many years ago and my experience is documented here: https://www.catalina36.org/forum/technical-discussion/campbell-sailer-prop
If you scroll down there is detail on my change to the new prop with RPM and performance info.
Overall I am happy with the prop but I would not repeat the effort. My next prop (not likely) will be the original two blade - reworked and balanced.
The prop walk with my CS is really not that much less and performance gains aren't significant in my view.
Either way - good luck!
_____________
Harold Baker
S/V Lucky Duck
Duncan Bay Boat Club
Cheboygan Michigan - Lake Huron
1989 C-36 mkI TR/WK M25XP
Les and Harold,
Thanks for your feedback. I especially appreciate Harold's 2011 writeup that compared the performance of 2 props. I used it to build a spreadsheet and play some "what If" games. I'm not claiming that my spreadsheets are super precise, but they were enough to convince me that the CS14x7 is in the right ballpark for my 30 Hp configuration.
Today I had a nice chat with Kelsey at North by Northwest. He explained his process and philosopy in specifying props, and why the recommendations are a little more conservative now than they were 10 years ago (Experience counts!). Based on our conversation and my spreadsheet work, I decided to order the CS14x7 prop. I'll let you all know how it works after I install it during my next haul-out.
Steve
Steve Bogert / Bonnie Sprague
"Wild Spirit"
1995 Catalina 36 Mk II, Tall Rig, Fin Keel, Hull #1412
Bellingham, WA
This is just a follow up after using the Campbel Sailor prop for a couple of summers. I love it! My old 2 blade was under-propped for my 30 HP engine. At full throttle, the RPMs would spin up to well over the rated 3200. At a cruising speed of 2500 rpm, the engine wasn't working very hard, and I never got the speed I thought I should. After installing the CS 14x7 prop and applying a fresh coat of bottom paint, I took her out for a test run. I could immediately feel that the engine was working more efficiently. Full throttle took the engine to almost exactly its rated 3200 RPM. At 2500 RPM, it was over a knot faster than before (though I have to attribute some of that to the clean bottom). Now, 2 summers later, I'm still delighted with the CS. It is well matched to my engine and always feels like I'm getting optimum "traction" with the water (no slipping, no lugging). I haven't noticed any more drag when sailing with the CS than I had with my old 2 blade prop. Bottom Line: If you are looking for an upgraded prop but want to avoid a folding/variable prop's cost and complexity, I can highly recommend the Campbel Sailor.
Steve Bogert / Bonnie Sprague
"Wild Spirit"
1995 Catalina 36 Mk II, Tall Rig, Fin Keel, Hull #1412
Bellingham, WA