Flexofold 2 or 3 blade folding on oversized 50hp FP Lavezzi

[Greatest Lakes]

I recently went 2 blade, but I'm a good deal smaller on both length and horsepower, given your situation, I do think I would do the 3 blade, despite the costs. The increased efficiency when you do have to motor may help make up for the difference in cost over time. Mine is an 18/12.

[David B]

Originally Posted by CaptainRivet

What Antifouling do you use on the saildrive and props, you cannot use Coopercoat there?

Thank you, i have the new Volvo 130S saildrives with split anodes and can service them from on top. allready exchanged anodes in water.

Cat is on the dry dock for the next 3 month now to repair the damage from a 8m rogue wave, so assembly of whatever I will finally buy is easy.

Sorry to hear about the rogue wave - what was the damage?

While you can use Coppercoat on aluminium without any issues, the problem with a sail drive is it is in sections, and the joints have potential for exposing bare aluminium. I have therefore yet to be tempted to go that way.

All I do is several coats of two-pack epoxy primer/undercoat, then several coats of hard antifouling paint. Seems to work for 5 years or so. By that, I mean the coatings stay there for that period.

As far as fouling is concerned, it is lower than I would expect, and I put that down to the mass of Coppercoated hull around it. We actually don't bother anymore with the prop - stays fairly clean.

We have been in a lot of different areas - some notorious for fouling, and other than a bit of furring, the hull stays clean. As you have no doubt also found, the Coppercoat has saved a lot of hassle and a lot of expense. Nine years so far, and still going strong .

[thegui]

Hi
I have a FF 3 blade on my Hunter 37. Motoring in forward is no problem. However I have virtually NO Reverse. The blades do not open or open very slightly in reverse. If you do not plan to back up then you are fine, but I'd check out videos on line about the sketchy reverse or ask Flexofold. I'm thinking about switching to a feathering prop.

[dbraymer]

Autoprops are generally in the resale cost range between folding and feathering.

They are self deploying feathering props.
https://ab-marine.com/feathering/auto-prop/

They have a significant down side in that they continuously change pitch until an equilibrium is established between boat speed, drag, and RPM. Also your propeller blades will dangle down when you are on the hard, getting a few sophomoric comments about the rigidity of your propeller(s)

In tight quarters and when changing RPMs, you will not get a linear response to the throttle. You must adjust the throttle and wait a bit to see the final effect.

But open ocean they are the nuts. With no engine RPMs, they are folded by the water flow. You fire up and pick the best RPMs for charging the battery, and the prop adjusts itself to the best pitch. The wind picks up, and a couple of seconds later, the pitch changes! I rebuilt mine (1 on a CT47), and found the service pack to be still available, complete, and only created a few head scratches.

If you are losing a couple of knots on your Cat, there are graphs all over on the various loss of speed per prop drag, and the autoprop is above 90 percent reduction (in drag). The real expensive jobs are a touch better.

The auto prop is very similar to generations older folding prop designs, the resulting "hub" is just a bit bigger (a touch more drag), but you have three blades. Three blades are much less likely to set up any kind of a vibration, as opposing to an unfolding two blade. The pivot point on an autoprop is a lubed bearing, something like three inches, so this is greatly improved in precision from a two blade flop open thing, which immediately will develop "where does it stop" self mal-adjustments

Unfortunately, this is not an easy, completely better in all ways suggestion.

The upsides are: open ocean advantage, minimal adjustment or maintenance. The down sides are: in the harbor throttle response. The median considerations are medium cost and slightly more drag than a true folding prop

You will find these for sale here and there often by racers, who want 99.99% reduction of drag or guys who are in and out of the harbor every weekend, and do not understand the throttle response delay...

If you do a lot of distance sailing, these units are worth considering.

[Fbfisher]

Talk to the very informed folks at Flex-o-Fold. They will collect all of the data about your boat and engines and tell you exactly which prop you need, they will also tell you the consequences of choosing two or three blades. As a result, your decision will be based on their expert knowledge.

I did this and am very happy with the result.

[Fbfisher]

Originally Posted by thegui

Hi
I have a FF 3 blade on my Hunter 37. Motoring in forward is no problem. However I have virtually NO Reverse. The blades do not open or open very slightly in reverse. If you do not plan to back up then you are fine, but I'd check out videos on line about the sketchy reverse or ask Flexofold. I'm thinking about switching to a feathering prop.

I have a Beneteau 423 with a FoF 3 blade prop. It works great in both forward and reverse, way better than my OEM fixed 3 blade. No loss in forward thrust, way less prop walk in reverse.

[skipmac]

Originally Posted by thegui

Hi
I have a FF 3 blade on my Hunter 37. Motoring in forward is no problem. However I have virtually NO Reverse. The blades do not open or open very slightly in reverse. If you do not plan to back up then you are fine, but I'd check out videos on line about the sketchy reverse or ask Flexofold. I'm thinking about switching to a feathering prop.

You must have a problem with your FoF prop. My experience after a year with the FoF is the same as Fbfisher.

Forward is as good if not better than my previous fixed 3-blade. This could be because the fixed prop was a little too much for the boat.

Reverse comparable to the old fixed prop, maybe just a little more rpm to stop but nothing significant.

[Jef & Marin, Netherlands]

Maybe a suggestion you will reject immediately..... but on the off chance you like it I write it anyhow.

D2-50's is 2 times 95 kilo heavier than the D1-30. This weight is not centered at all. It makes your boat slower. The fuel consumption is probably 1.5 liters higher than the D1-30 per engine. Check the leaflets. The oil change is 5 liters instead of 2-3.

You write that you engines are pretty new. Maybe you can find somebody who is prepared to swap engines on maybe a 44' cat?
Maybe with closed wallet, depending on your and the other's technical competence and who does the job? Maybe you can get some money back since your engine is pretty new and was more expensive? Maybe you can do a good deal with a shop?

It is a route I would at least try, because I value sailing performance and reduction of fuel consumption much more than engine speed. For me an engine is auxiliary, to get in and out of port.
And you might get folding propellors from the other owner?


And if you can not find an opportunity for a swap after half a year of trying..... Wel there is always the propellor option.

[Primipile13]

i recently delivered à Bali 5.4 equipped with Kiwiprops. worked great. far cheaper than maxprop and flexofold...

[CaptainRivet]

Originally Posted by Jef & Marin, Netherlands

Maybe a suggestion you will reject immediately..... but on the off chance you like it I write it anyhow.

D2-50's is 2 times 95 kilo heavier than the D1-30. This weight is not centered at all. It makes your boat slower. The fuel consumption is probably 1.5 liters higher than the D1-30 per engine. Check the leaflets. The oil change is 5 liters instead of 2-3.

You write that you engines are pretty new. Maybe you can find somebody who is prepared to swap engines on maybe a 44' cat?
Maybe with closed wallet, depending on your and the other's technical competence and who does the job? Maybe you can get some money back since your engine is pretty new and was more expensive? Maybe you can do a good deal with a shop?

It is a route I would at least try, because I value sailing performance and reduction of fuel consumption much more than engine speed. For me an engine is auxiliary, to get in and out of port.
And you might get folding propellors from the other owner?


And if you can not find an opportunity for a swap after half a year of trying..... Wel there is always the propellor option.

Thank you for the suggestions and still writing them.
I bought it like this and if I had to repower and carry the cost you are right I would have chosen 30hp betas, no green hell.
But overall package was great (price hardly took a simple repower with similar engines into account) and install even supported by FP who delivered the drawings for the new engine positions and engine mounts plus advise to move water boiler and batteries to account for weight gain.

Engines+saildrives were 27k Euro, install 40k as nothing fitted anymore from engine mounts till seacock, electric, pipes, exhaust ….the whole engine rooms are basically new. So going back to D1-30 not possible and don‘t want to as able to motor 13kn is quite cool too and motorsailing 7kn is around 1,5l diesel an hour…plus engines are far more quieter. Fuel consumption is lower as the engine runs on lower rpm compared before plus one instead of 2.

2nd: I know that they are 95kilo heavier but they where not dumb and took measures which I continued.
BB hull the hot water heater moved from engine room under the bed near the centre. The 3 lead starter batteries was replaced with one AGM which I change to LTO battery. 80kg of the 95kg neutralized the 15kg don‘t matter anymore.
STB hull: house/starter 500AH lead in the engine room replaced by LifePo4 840AH under the bed more centered egalized the whole 95kg STB.

3rd : new 130S saildrives can be maintained from on top, the corresponding d1-30 saildrive not.

[CaptainRivet]

Originally Posted by Primipile13

i recently delivered à Bali 5.4 equipped with Kiwiprops. worked great. far cheaper than maxprop and flexofold...

I was very interested in them too and besides price the composite blades can be eg coopercoated.
BUT the reviews on them are very mixed, test show bad performance compared to others and main complaint reliability which is my top 1 requirement.
What is the best propeller worth if it’s not working when I need it…so I crossed it off my list.

That’s how I ended with FFOF, price middle field but reliability and performance top and I couldn’t find one who complains after he got it. To everyone you talk, great working and if there was a problem quickly fixed.

[CaptainRivet]

Originally Posted by David B

Sorry to hear about the rogue wave - what was the damage?

While you can use Coppercoat on aluminium without any issues, the problem with a sail drive is it is in sections, and the joints have potential for exposing bare aluminium. I have therefore yet to be tempted to go that way.

All I do is several coats of two-pack epoxy primer/undercoat, then several coats of hard antifouling paint. Seems to work for 5 years or so. By that, I mean the coatings stay there for that period.

As far as fouling is concerned, it is lower than I would expect, and I put that down to the mass of Coppercoated hull around it. We actually don't bother anymore with the prop - stays fairly clean.

We have been in a lot of different areas - some notorious for fouling, and other than a bit of furring, the hull stays clean. As you have no doubt also found, the Coppercoat has saved a lot of hassle and a lot of expense. Nine years so far, and still going strong .

The rogue wave got me with around 30 degrees to the wave and broke on top of the BB bow which was in the air on half of its length.
Rogue wave cracked 4, 2 got completely deattached of the 7 bulkheads in BB hull and 3 of 6 bulkheads cracked in STB hull plus 2 supporting bulkheads in the salon and 1 in the anchor locker. Outside no damage, was lucky and could turn the cat due to the power of the oversized engines to minimize damage.
Damage mostly because lovely FP just glued them in with tons of Perspex (technical drawing states max 5mm, mine had 3cm Perspex) that is hard like porcelain and glued in serveral places on top of the topcoat
the burner was the BB bulkhead at the stairs, 5kg of Perspex that didn’t hold anywhere because the hull had still the separation wax of the mold onwhen they glued it in….
the Lavezzi is light and starts to flex to handle the forces. But the Perspex cannot flex with so it cracks or where not sticky because glue on top coat it completely deattached. STB hull had a small damage before and professionally repaired and the repairer glued and fibreglassed 3 bulkheads in the area he repaired in and they did hold well, only the 3 with Perspex cracked. Well all mass production cats and boats produced like this today my surveyor said but it still took an 8m wave to crack them.
So solution is take all bulkheads out, sand down glue area to fiberglass so it properly sticks, reglue with a glue that stays flexible and is mixed with fibers plus laminate them in from both sides with 3 different webbings and 6 layers. Afterwards the cat is better then new and 300% stronger then new from factory.
What’s the real effort is to get to the damaged bulkheads…BB the whole head needs to be out to reach them…kinda 3k to actually repair them like before, 7k to properly reenforce by laminating them additionally in but 40k to get to and make it optically new again.

[Jim Cate]

^^^^^

"Perspex" is a brand name for acrylic plastic. I suspect that you meant Plexus, a high tech bonding adhesive used to glue some plastic boats together (for a while).

And man! your poor boat really took a hit there. Must have been a bit traumatic for you as well!

Jim

[CaptainRivet]

Originally Posted by Jim Cate

^^^^^

"Perspex" is a brand name for acrylic plastic. I suspect that you meant Plexus, a high tech bonding adhesive used to glue some plastic boats together (for a while).

And man! your poor boat really took a hit there. Must have been a bit traumatic for you as well!

Jim

True Plexus, mixed it up.

Traumatic not, I know ocean is a bitch…. but that bang….I thought the cat is smashed to pieces.as it turned out I was kinda lucky. the 55ft mono in sight got there deck completely wiped and demasted as they got the wave fully in the main sail.

[Tupaia]

Originally Posted by dbraymer

You will find these for sale here and there often by racers, who want 99.99% reduction of drag or guys who are in and out of the harbor every weekend, and do not understand the throttle response delay...

In my investigations these do not perform well at sailing speeds in excess of about 8 knots.