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Mounting turning block to the base of the mast

Dec 1, 2020
93
CAL 27 Illahee / Brownsville WA
I would like to route my halyards to the cockpit for single hand sailing this summer. The cost to have a crane pull the mast simply to put a mast base with holes for the turning blocks was prohibitive when the boat was pulled for paint. I have read that mounting the blocks to the cabin top is a bad idea due to the constant loads and it's much better to let the mast carry those loads.

I have looked for some type of "strap mount" that would wrap around the mast and have some block attachment holes or connection points of some type that would help distribute the load and not found anything like this.

If nothing else is available are turning blocks/SS attachments screwed (or bolted?) to the mast base acceptable?

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and and might use one or two thru-bolts to tie the strap/blocks to the mast with fewer holes in the mast than
 

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May 29, 2018
300
Canel 25 foot Shiogama, japan
Hi Rick.
Me again,
If nothing else is available are turning blocks/SS attachments screwed (or bolted?) to the mast base acceptable?
From your good clear photos it seems that you have a keel stepped mast.
So you are talking about fixing something to the mast just above where it goes through the deck, aren't you.
Do you have internal halyards that exit the mast higher up and go to mast mounted winches?

You have a padeye mounted just behind the mast for the vang.
In theory you could fit one padeye to each side of the mast then shackle blocks to turn the line back to the cockpit.
Problem is that they would run right across the hatch, down the centerline of the boat.

So, you need a blocks at the mast base that lead to port and starboard and then deck mounted flush blocks (organizers) to turn the lines aft. Then winches and cam or jam cleats.
All of that deck gear needs to have decent mounting pads beneath them with proper waterproofing.

Check out what other boats around you have and come to a decision about whether it is viable.
People single handed before lines were led back to the cockpit.

gary
 
Dec 25, 2000
5,050
Hunter Passage 42 Shelter Bay, WA
Hi Rick, if it were my boat I would avoid drilling holes in the mast for the purpose in question. Rather, the deck around the mast appears to have sufficient build strength to attach turning blocks for what you want to do. The pad eye in your pic that is being used for your vang seems to support the strength you need. Spend some time figuring out how that pad eye is secured and consider doing the same for any turning blocks that you add. Is the pad eye through bolted or is there a plate embedded in the FRP where machine screws (not wood type) are being used to secured the pad? On our boat the builder embedded metal plates at stress points for mounting working hardware and used machine screws to secure the device to the plate using a quality sealant to keep moisture at bay.
 
Dec 1, 2020
93
CAL 27 Illahee / Brownsville WA
Thanks to all. The mast is deck stepped, external halyards.

Mermike, that Barton product is very interesting, thanks for sharing it.
 
Dec 25, 2000
5,050
Hunter Passage 42 Shelter Bay, WA
The mast on our boat is also deck stepped and sits on a cast aluminum plate that is through bolted. Inside the boat next to the compression post is a removable cover. Removing that cover gives access to the mast step through bolts, which might also show you where other attach points might work for your turning blocks.
 
Sep 22, 2018
1,869
Hunter 216 Kingston
I would like to route my halyards to the cockpit for single hand sailing this summer. The cost to have a crane pull the mast simply to put a mast base with holes for the turning blocks was prohibitive when the boat was pulled for paint. I have read that mounting the blocks to the cabin top is a bad idea due to the constant loads and it's much better to let the mast carry those loads.

I have looked for some type of "strap mount" that would wrap around the mast and have some block attachment holes or connection points of some type that would help distribute the load and not found anything like this.

If nothing else is available are turning blocks/SS attachments screwed (or bolted?) to the mast base acceptable?

View attachment 188187View attachment 188188View attachment 188189

and and might use one or two thru-bolts to tie the strap/blocks to the mast with fewer holes in the mast than
This is a link that speaks to the construction and mast stepping that others have pointed out.


I don’t know what your complete plan as you only mention the turning blocks but have you considered fabricating a two part “clamp” that would bolt together at the bottom of the mast where it enters the cabin top? No need to pull the mast, drill holes in the mast or in the FRP if those options concern you.
 
Dec 28, 2015
1,357
Laser, Hunter H30 Cherubini Tacoma
If I was challenged with this and didn’t want to mount individual blocks , I’d look at the possibility of taking a large mast base, cutting out the base part to slide around the mast like a horse collar. You would need to have some tabs fabbed up to secure to the mast ( I’d use large stainless rivets) and probably three through bolts through the cabin. One on each side of the mast opening and the third on the opposite end. That’s better than two through bolts per block. Done right it would be hard to tell that it didn’t go under the mast.
 

RoyS

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Jun 3, 2012
1,218
Hunter 33 Steamboat Wharf, Hull, MA
I would pay the riggers to remove the mast for installation of an organizer plate. While the mast is down you could inspect and repair as necessary mast mechanical and electrical components. Maybe paint it. As part of this project you will be replacing all of your halyards with longer ones and this could also be done while the mast is down. The organizer plates are inexpensive and place the halyard loads exactly where you want them onto the mast base. You should consider that someone may have to be raised up the mast using a halyard while designing your system. Please keep us informed of your progress. Good luck.
 
Jun 8, 2004
8,893
-na -NA Anywhere USA
@ricksoth
Can you specify the specific sailboat mfg and model.
Better pictures of deck towards mast from both suggestions.
Interior picture of cabin ceiling where mast comes thru deck

@Hunter216
Pulling a deck thru mast should be handled to those who have experience. Could be dicey when mast is stuck inside the boat when pulling up with crane. Did that as a dealer as well as safety is a big issue
 
Dec 1, 2020
93
CAL 27 Illahee / Brownsville WA
1977 Cal Boats 2-27 model.

Roy, I agree the best solution would be to pull the mast but at $750 just to add a $100 base plate, it was not in the budget at this time which got me considering alternatives.
 
Dec 1, 2020
93
CAL 27 Illahee / Brownsville WA
Here are some more photos from the cabin top and inside. It's interesting what you see when you pay attention, the Vang bolts don't even have backing plates. The Cal has plywood/resin deck core according to what I have read and for 1977 my deck and inside seem pretty uniform and solid ( Thank goodness ).

Looking at this I'm thinking backing plates on bolts through the cabin top seem like a reasonable approach. If I do the Schafer Snap Furler 700 this Spring, leave that halyard on the mast and just have main, spinnaker on the cabin top since these are "occasional" loads.

I need to figure out how the electrical and radio co-ax is getting into the mast. Some of that wood must have screws which open up the channels where the wire is running.
 

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Dec 25, 2000
5,050
Hunter Passage 42 Shelter Bay, WA
Some of that wood must have screws which open up the channels where the wire is running.
Agree, Rick. No experience with that kind of compression post, whether it is solid wood with a dado cut to create a wire chase, or just wood facia over a steel post. Please let us know what you find out.

Our boat has a steel pipe as a compression post. All the mast wiring comes through the coach roof and through the head liner to various points of connection.
 
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Oct 26, 2008
5,021
Catalina 320 Barnegat, NJ
You can easily attach blocks to the mast or the deck. From a practical standpoint you can do anything you want as long as you do it right and make it secure. The only question I would have is that it appears that you have a very nice, clean layout already. Think carefully about whether or not you want to disturb the aesthetic that Cal put into the boat. If it doesn't matter to you, then lead your lines back to the cockpit. What make is your mast?
IMG_0897.JPG

This is my Starwind 27 with a Kenyon MORC mast (please pay no attention to the birdshit). The boat originally had 2 Kenyon halyard blocks mounted at the base of the mast for the main halyard and the genoa halyard (both internal with exits above the boom). In this case, the boat has a pad for the deck organizers and the original had just a pair of 2-sheave organizers (Schaefer). The only control line that came back was the vang. The reefing lines and outhaul were clutched at the gooseneck.

I said, "F-that", I need everything and more going back to the cockpit. I added 2 Kenyon blocks (from Rig Rite - very expensive), and 3 Schaefer blocks to the mast. They are all attached with tapped holes and SS machine screws (as done originally - no pointy ended screws). I also added 2 Schaefer deck blocks. To lead it all back to the cockpit, I drilled another hole for the deck organizer on both sides and mounted a pair of double-decked triples. So the boat now has 2 genoa halyards, 1 spinnaker halyard, main halyard, 2 topping lifts, 2 reefing lines, double-ended vang control, and the outhaul all coming back to the cockpit. There is one slot in the organizer on one side that is open for something else.

None of this compromises the mast or the deck in any way. But I will admit that if I were to do it over, I would use that part that @mermike references. :plus: If you don't want an excessive number of lines cluttering your cockpit, you don't need to go to that extreme.

I found that the machine screws are fine in the wall of the mast, as long as the holes are carefully tapped. The SS steel screws WILL fuse to the aluminum, I had to drill one out of the original installation. If the thread doesn't tap properly, the blocks are at the base and you can easily use a washer and a locking nut for any screw that strips the aluminum at the thread. But you have to wait until the mast is down. I didn't have any problem waiting a few years to fix one of those. Three out of four screws firmly secured did just fine at one block!

The parts are still expensive, any way you go about it. If you want the base plate instead of all the penetrations, I wouldn't hesitate to install the base plate. $750 to take the mast down isn't that much in the grand scheme of it all. Find other reasons to have the mast down if the cost still sticks in your craw!

If you are running lines back to the cockpit, you will have to plan the location of the organizers. My Catalina runs the lines direct from the mast base to the cockpit on a diagonal. It has a mast plate that holds blocks and also a few deck-mounted blocks.

Nobody says that you can't adapt your boat the way you want it. Some may object that it isn't "original", but it's your boat, your choice.
 

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Oct 22, 2014
16,150
CAL 35 Cruiser moored EVERETT WA
Rick
We likely have the same post design. I frustrated when I removed my mast that the wires were not accessible. So I modified the wire structure to meet my needs.

After refitting the mast with new wires. I made a connection block for easy removal in the future, on the compression post. I installed a new wire chase

Through the Deck Step
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Enter the Cabin
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Down the compression post and turn at the sole
62B345C9-B4BD-41EB-8CA2-15E2C99B35D7.jpeg
Along the sole to connect to the Instruments
D1E281B7-A7B9-4907-9F3F-82C627593104.jpeg
Covered with a wood chase
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Nov 21, 2012
283
Yamaha 33 Port Ludlow, WA
Any time you use dissimilar metals, you run the risk of corrosion. A generous coating of Tef-Gel or similar on stainless screws in aluminum works wonders. I also use a 3M film product (can't remember the name) to isolate things like stainless steel brackets and bases from aluminum mounting points.