Flexofold Problem Query

[Sailor Vee]

I am currently sailing with my wife, the lovely Kay Syrah here in the Abacos but have encountered an unexpected problem with my starboard flexofold prop.

Apparently, I wrapped a line in a dirty little harbor, it must have slipped aft over the folded prop and locked them in the folded position.

If the noise and chatter had happened during a normal start up I would not have not tried to push through the odd sounds when in gear but of course our anchor had apparently perfectly caught a discarded alternator (did I mention it was a dirty little harbor?) causing us to drag in the night back toward a lee shore.
at 2 am, a lee shore approaching, it seemed a good time to force the prop to respond.

Now it doesn't want to engage - either in forward or reverse. I suspect stripped gears, but can't seem to find any one else who has ever reported such a problem.

If you have experienced such a phenomenon (or know some one who has) please let me know and how they resolved the problem. I have a spare set of blades but must reuse the old bolts and install it underwater. Any idea on what to use since locktite apparently is not recommended by FlexoFold? I was thinking a thin epoxy since it sets up well underwater, but your suggestions are appreciated.

Sailor Vee

[Marinheiro]

You mention "noise and chatter during normal start up" - was this with the gearbox in neutral? If yes, much more likely to be your flywheel dampner plate.
If not, suggest next step is anchor in some clear water (should not be hard to find) and hop over the side with a mask for a look to see what the problem migh be. Good Luck

[Sailor Vee]

Well that post was before dawn. Indeed I am going in the water when the sun gets a bit higher. Pretty sure what I will find though.

No, the chatter was while in gear, not neutral and coming from the prop.

Ordinarily I would have gone under water to try to figure it out but the lee shore was threatening...

Sailor Vee

[fstbttms]

Originally Posted by Sailor Vee

I suspect stripped gears, but can't seem to find any one else who has ever reported such a problem.

This seems pretty unlikely to me. Flex-O-Fold props are very robust and a simple rope entanglement would probably not break any teeth off the gears, unless they had been been previously weakened by corrosion.

Originally Posted by Sailor Vee

I have a spare set of blades but must reuse the old bolts and install it underwater. Any idea on what to use since locktite apparently is not recommended by FlexoFold? I was thinking a thin epoxy since it sets up well underwater, but your suggestions are appreciated.

If disassembly and reinstallation of the prop is necessary, Flex-O-Fold does, in fact, recommend the use of Loctite 243, which is the blue stuff. DO NOT epoxy any of the mounting hardware. Unless you want to use a hacksaw as the main tool to remove your prop next time.

[Sailor Vee]

An update. Since I frequently refer to Cruisers Forum for answers to the myriad problems I encounter along the way before posting a question in a new thread, I am updating my post regarding the Flexofold issues that I had. It may be helpful to readers a decade down the road to get the complete story after the problems are finally solved. I am a bit chagrined because after removing the prop from the hub and inspecting I realized that the problem had nothing to do with the Flexofold prop, but rather was traced to an improper installation (by a multihull "yard" in VA) of a new drive shaft. They had reused the old fasteners and failed to employ loctite on any of the bolts connecting the new drive shaft to the engine and what I thought was a prop issue turned out to be caused by four bolts having come out of my drive shaft to engine connection.

It is all good now but I learned a few things along the way which I would like to share....First off...Loctite 243 as suggested by fastbottoms above is great for use on the hard, but it IS NOT RECOMMENDED FOR USE UNDERWATER. My diver /prop installer had used some and it was gooey and failing.

Flexofold recommends replacing the bolts with new pre taped bolts every time you take one out.

This seemed absurd to me due to the high cost not only of the bolts, but also of getting them to me in the Bahamas. I agree with Fastbottom that even sparing use of epoxy would be a poor choice but after some research, I decided to use Loctite 249 Tape which arrived yesterday with a guest to the boat. This is an "anaerobic set tape" that can be pre applied to the bolt and when it is installed sets up due to the absence of oxygen. They seem to be a great solution for this application. If I were in a remote part of the world, and did not have any Loctite 249 tape and wanted to secure the bolts underwater, I would probably be comfortable employing a moisture activated urethane adhesive (Gorilla Glue is the most common form available) I suspect that would be a good long term solution that would be fairly easy to remove a few years later.

Anyway, Keld Willberg from Flexofold was extremely helpful, the props are about as bombproof as can be internally, and I must comment that the new props are MUCH quieter when shifting into reverse and forward than the old hub design due to the addition of a polyurethane impact plate in the design.

These are truly works of art and I recommend the product and the company highly.

[fstbttms]

Originally Posted by Sailor Vee

It is all good now but I learned a few things along the way which I would like to share....First off...Loctite 243 as suggested by fastbottoms above is great for use on the hard, but it IS NOT RECOMMENDED FOR USE UNDERWATER. My diver /prop installer had used some and it was gooey and failing.

Other manufacturers supply Loctite 243 with their props (Gori, for instance) and no mention of not using this product on parts that will be assembled underwater. Further, I have to wonder what magical, proprietary, blue-colored thread locker Flex-O-Fold puts on their parts that can be assembled underwater, as indicated in their prop installation instructions.

"There is an underwater proof thread locker pre-applied on all screws in the installation. These screws can be installed out of or under the water."

http://www.flexofold.com/upload_dir/...lade_shaft.pdf


In any event, I have contacted the manufactuer of Loctitie 243 to get the straight dope on whether or not it can be used on parts that will be assembled underwater and will post their response here.

[Sailor Vee]

FastBottoms, I will defer to your much broader experience base. As to what the magic tape contains, It is an anaerobic activated adhesive. It was about $19 US on Amazon for 24 feet of tape. It applies much like teflon tape and is of a similar thickness. I find it highly unlikely that thoughtful individuals could not clean the old bolts and apply the thread locking tape themselves. Incidentally Fastbottoms...I was terrified about dropping a bolt since I am a loooong way from a flexofold bolt store. I did the work without a net and did not have the possibility of building a catch tarp you described elsewhere. I came up with what I hope is a helpful solution for individuals concerned about dropping a bolt. I tied a 10" thread on to each bolt with a slip knot. When dropped into the muck under my boat in the marina where I did the install, the tied on threads were easy to spot as a guide to recovering the item. The strings were easy to remove once the bolt threads began to catch.

[delmarrey]

Loctite now makes a stik'n seal type dispenser that I'm sure would work pretty good underwater. It's oil based contaminates that will not allow loctite to stick.

Loctite 230461 water proof adhesive. Then there are the stick applicators too.


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[Sailor Vee]

With all respect, I must disagree DelMarrey. (you have been so helpful to me on past problems)

CAUTION: Do not install a $3,000 Flexofold Prop and hub with any product that is not designed for specific use as a threadlocker. I can't comment on all of the types you sent in the second photo but the first one you mention (230461) is NOT an underwater setting threadlocker. Also, although grease on the bolts would indeed be problematic, it is not the issue when you use an air cure adhesive under water.

[ggray]

My FOF props with the factory threadlock treated bolts were installed prior to the maiden launch. Bolts worked loose maybe 16 months later, and lost one blade. I now do the props myself during haul every other year, and have had no problem since. It had caused enough trouble that i take this very seriously.

I got a long ss bolt of proper thread, and with a hack saw cut longitudinal slots along threads to make a sort of "chase tap" that I use to clean out the threads with acetone. I then use red locktite on the bolts, and plenty of it. I decided I'd rather have a problem getting it loose when I wanted to than have it work loose when I didn't, but while it is tight 2 years later, I've never had a problem removing it. Obviously, this means you can't do it underwater.

The center bolt (saildrive) ,I use blue locktite.

[delmarrey]

Originally Posted by Sailor Vee

With all respect, I must disagree DelMarrey. (you have been so helpful to me on past problems)

CAUTION: Do not install a $3,000 Flexofold Prop and hub with any product that is not designed for specific use as a threadlocker. I can't comment on all of the types you sent in the second photo but the first one you mention (230461) is NOT an underwater setting threadlocker. Also, although grease on the bolts would indeed be problematic, it is not the issue when you use an air cure adhesive under water.

The Stik'n Seal does say "Not affected by water or moisture" but maybe that's after the cure, it doesn't say and neither does the MSDS. One will not know for sure w/o actually trying or seeing tests done.

Anyway, fstbttms is contacting loctite. We'll see what he comes back with. He relies on the info for his work.

[fstbttms]

My conversation with Richard Avery of Henkle Corp., makers of the Loctite products:

FastBottoms- In the case of pleasure boat folding propeller assembly; can Loctite 243 be applied to parts out of the water, allowed to cure and then be used in the underwater assembly of a propeller?

RA- Yes, Loctite anaerobics, including Loctite 243, have excellent water resistance when cured, and can be submerged in water.

FastBottoms- Thanks for the quick response. Just to make sure I’m understanding correctly, let me run this scenario past you; I coat the screws needed to assemble a folding sailboat propeller out of the water with Loctite 243 and allow them to cure. Then I do the assembly of the prop underwater. Loctite 243 will perform in this situation, yes?

RA- If I am understanding you correctly, then this will not work. Loctite 243 will not cure unless it is between two pieces of metal and restricted of air, hence the name anaerobic. It will remain a liquid if you coat the bolt and just let it sit in open air. If you need a threadlocker that can be applied underwater, you will need to use Loctite 248 Quickstix or Loctite 249 Quicktape.

So the answer is that Loctite 243 is not suitable for underwater assembly of folding props. I am going to begin using the 248 Quickstix for all future installations.

This has been an extremely informative thread.

[delmarrey]

Originally Posted by fstbttms

So the answer is that Loctite 243 is not suitable for underwater assembly of folding props. I am going to begin using the 248 Quickstix for all future installations. [/FONT][/FONT]
This has been an extremely informative thread.

So, there we go the 248 Quickstix will cure underwater.


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