Securing Cheek block mounts

[Willie G]

Well let’s See if I can get this correct. I have a Hunter 29.5. with three winches above the salon. I have decided to add two winches back on the cockpit either side of the helm. There are specific pre-destinded places for these winchs when the boat was built. So the winches have already been mounted and there were no issue. What I am concerned with is a cheek block that needs to be positioned so that the jibsheet comes from the bottom of the winch. I have not, nor will I change the position of the lead block or the track so the jib sheet will travel from the job to the lead to the cheek to the Winch. To gain the correct angle of the cheek block I have cut a wedge shaped block out of white UHMW that I will mount the cheek block too. I need to attach the block to the outside the cockpit on a vertical surface, there is a slight curve but I have matched it exact on the back side of the spacer block. My question is this. Is Dow 5200 tough enough to hold the spacer block in place without any screws or bolts going through the hull? I do have the ability to support the spacer blocks to keep them in place while the 5200 is curing and will be able to put 4 pound of pressure horizontially pushing the block against the hull.

Somewhat long winded but would appreciate your thoughts.

 

[Ted]

Is Dow 5200 tough enough to hold the spacer block in place without any screws or bolts going through the hull? I do have the ability to support the spacer blocks to keep them in place while the 5200 is curing and will be able to put 4 pound of pressure horizontially pushing the block against the hull.

The short answer is NO. Your proposed attachment method using 5200 is solely dependent on bonding your angled block to the gelcoat. There is a very good possibility that the bond between the gelcoat and fiberglass substrate will fail. The cheek block should be through bolted.

 

[dlochner]

The short answer is NO. Your proposed attachment method using 5200 is solely dependent on bonding your angled block to the gelcoat. There is a very good possibility that the bond between the gelcoat and fiberglass substrate will fail. The cheek block should be through bolted.

What @Ted said. One characteristic of UHMW plastics is that not much will stick to them. Including 3M 5200. The turning blocks will be subject to a lot of shear pressure, through bolting is the best solution.

 

[Willie G]

I thank you both for your input. So I’ll use through bolts with a backing plate. To assure no leaks as the port side is inside above the back berth I’ll need to assure I have the best caulking rather than strength. 5200 seamed a bit runny the only time I’ve used it. Do you have a different suggestion, A 25 year silicone caulk?????

 

[Gunni]

Butyl tape.

 

[dlochner]

A 25 year silicone caulk?????

No Silicone! Terrible stuff. Gets into the gelcoat and nothing sticks to it. It is just as bad as 5200 in the other direction. The uses for either silicone or 5200 are very limited.

I"m with @Gunni on this butyl tape from this source https://shop.marinehowto.com/products/bed-it-tape

 

[Charlie Jones s/v Tehani]

Remember- 5200 is NOT a caulk! It's an adhesive. Best used for things like hull/deck joins, etc.

And silicone is NOT allowed on my boats anywhere.

 

[jssailem]

@Willie G final answer and best answer
Butyl Tape. Best product, purchased from MaineSail.
Follow directions provided on MaineSail’s web site for install.
Then no leaks and happy sailing.

 

[jibes138]

Re: your original question. Think in terms of failure modes and effects. If the bond joint failed what might it result in for consequences to the crew or the boat. In this case a highly loaded block will be flying through the air at very high velocity with the potential to kill if it hit someone in the head or neck, and likely serious injury if it hit elsewhere. If it happened right when you were trying to maneuver to avoid hitting another vessel (like perhaps a large container ship) it could prove catastrophic. There is always a challenge in designing such things on boats to minimize weight while ensuring adequate strength, without good information regarding stresses on the objects you really can't make an informed decision on the required strength of the installation. Best to err on the side of safety with a very robust installation.

 

[rgranger]

Butyl tape.

I bought mine from @Maine Sail

 

[Willie G]

Thanks for all of the advice. We had a 60 degree day and I got them mounted and they are everything I had hoped for. The Butyl Tape was the trick. I’ll need to tighten the bolts a bit once we get some 90 degree days but that can be gaged by the amount of Butyl being compressed out the side. Thanks again great solution.

 

[dlochner]

Willie, can you post a photo showing the cheek blocks in relation to the winches?

 

[jssailem]

Funny how a 60 degree day, after winter snows, can warm the heart.

Congrats on the install.

 

[Jackdaw]

Are those optional winches designed for Spinnaker work? That would seem to make the most sense to me. The placement makes for an awkward jib sheet run.

 

[Willie G]

In answer to the comments above, it was, for the first time this spring an incredible weekend in Arkansas when compared to the the weather so far this year.
No the winches are for the Jib sheets. My Hunter 29.5 came with three winches on the cabin roof, two to starboard and one on port. When the boat was laid up there is a winch mounting position back by the helm, just no winch. based on the lead block being on the top of the cabin as well as the winches I would say that the boat top half may have been used for several versions of Hunters, but in any case I needed the turning Cheek block to keep the line free from any rubbing or impingement.
I think there would have been multiple ways to run the line from the lead block, but this while not perfect, was the simplest and still effective. I will post a couple more pictures showing all later this week.

 

[dlochner]

Is this the model you have? https://www.marlow-hunter.com/wp-content/export/Brochures/29.5_1993_1997.pdf

 

[Willie G]

Yes this is it. I have a 1996. I snipped a picture from the brochure that shows the jib sheets tracking to the top of the cabin. I installed Lewmar CST 30 two speed winches back by the helm. the cheek blocks are located where I circled in the picture on the vertical surface. That is why I had to cant them a little bit to center the line in the pulley portion of the block.

 

[dlochner]

I think @Jackdaw is correct in saying that these winches are secondaries for a spinnaker. If you look a little to the left of your circle you'll see a black thing under the woman, it looks like a turning block for the spin sheets. Spin sheets run to the far aft of the boat and then back to the winch.

Not to throw a monkey wrench into your plans, however, the jib sheet will pose a tripping hazard if you are going forward.

 

[Willie G]

Looking at it I would have to say you are correct. Like so many things in life we end up trying to make lemonade out of lemons. For us spending time on the boat is about letting all of the stress of daily life evaporate. We are on a lake in Arkansas, and really are just about being out on the water. The closest we come to racing is a whisker poll once in a while. I did look at the tripping hazard potential before the installation and placed the blocks in a manner that has the line as low to the horizontal plain of the lowest kick surface. while it will reduce the trip hazard it does not alleviate it completely. Because we are on a lake, with the exception of a down wind run when the wind is just right, we do not have a point of sail longer than maybe 10 minutes. The trade off of having my wife and I together back at the helm vs a tripping hazard, potential leaks if the mounting of the winches and blocks are incorrect and all of the other potential issues was deemed worth it. Don't get me wrong I do appreciate this being pointed out. While I have spent my life in and on the water I am a neophyte with Sailing and will listen to any and all advice.

 

[Jackdaw]

Looking at it I would have to say you are correct. Like so many things in life we end up trying to make lemonade out of lemons. For us spending time on the boat is about letting all of the stress of daily life evaporate. We are on a lake in Arkansas, and really are just about being out on the water. The closest we come to racing is a whisker poll once in a while. I did look at the tripping hazard potential before the installation and placed the blocks in a manner that has the line as low to the horizontal plain of the lowest kick surface. while it will reduce the trip hazard it does not alleviate it completely. Because we are on a lake, with the exception of a down wind run when the wind is just right, we do not have a point of sail longer than maybe 10 minutes. The trade off of having my wife and I together back at the helm vs a tripping hazard, potential leaks if the mounting of the winches and blocks are incorrect and all of the other potential issues was deemed worth it. Don't get me wrong I do appreciate this being pointed out. While I have spent my life in and on the water I am a neophyte with Sailing and will listen to any and all advice.

For sure, my intent in pointing that out was not to dissuade you, but simply note the original intent of the aft winches, and that the jibsheet run aft might might not be clean because it was not designed to. I'm all for making a boat more safe, fun, and easy to sail.

My boat is laid out very similarly, and we love the cabintop headsail winches. But that is probably due to it being a tiller boat and not a wheel. Enjoy!