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Mast Horn Cleat

IrishAyes

New Member
I see that many newer Sunfish have a horn cleat on the starboard side of the mast.

My older rig does not have one. Is that something I need to add?? If so, what is the best way for me to attach it to the mast? Aluminum Pop Rivets? Screws?
 

JohnCT

Active Member
I used screws for mine.

You don't "need" to add one, the advantage is it takes the halyard load off the deck and makes it easier to tie the tail end as a vang to keep the lower spar down going down wind.

Something from the race community
 

signal charlie

Well-Known Member
Staff member
Make sure the rig is still secured to the hull somehow, other wise the mast, spars and sail can fall our during a capsize.
 

L&VW

Well-Known Member
I see that many newer Sunfish have a horn cleat on the starboard side of the mast. My older rig does not have one. Is that something I need to add?? If so, what is the best way for me to attach it to the mast? Aluminum Pop Rivets? Screws?
Having had a mast snap at 14" above the deck, I hesitate to drill holes in the mast. Has anyone used 3M 5200 adhesive for this purpose?

Some find it difficult to work with. :p

 

JohnCT

Active Member
I used 5200 and screws, I also put it as high off the deck as the rules allow to avoid the high stress area near the base.
 

tag

my2fish
I used screws, and like JohnCT, put it as high up off the deck as possible. I used the 3M 4200 sealant behind the cleat, and fastened it on with #10 stainless steel sheet metal screws – I had to pre-drill the mast with small pilot holes.

this picture is a good diagram of where to put it, as well as other rigging information.
 

mixmkr

Well-Known Member
If you put the cleat too high, you won't be able to reach it in waist deep water. You might consider that too. Lastly I think two properly drilled holes with screws will not be the weak area in a Sunfish mast.
 

ayoungcms

New Member
a lot of breeze and probably just old. However, it did snap at the exact place where the horn cleat was. I agree with someone above that said it should be at least 4 feet off the deck...
 

beldar boathead

Well-Known Member
a lot of breeze and probably just old. However, it did snap at the exact place where the horn cleat was. I agree with someone above that said it should be at least 4 feet off the deck...
If you are going to race check the Sunfish rules. There is some type of rule about where the mast cleat can go.
 

Sailflow

Active Member
As beldar says

One cleat of any type may be installed on the mast not more than four (4‟) feet from the base, for cleating the line used to tie the „Jens Rig‟ (Ref. Rule 3.7.3). It may also be used to cleat the halyard. If utilized, there must be some means to securely attach the rig to the hull using the end of the halyard.
 

L&VW

Well-Known Member
a lot of breeze and probably just old. However, it did snap at the exact place where the horn cleat was. I agree with someone above that said it should be at least 4 feet off the deck...
Any "insult" to the mast can be expected to cause trouble.

My mast broke in a very strong wind; however, I couldn't find any significant corrosion at the break site. (No different there, than the rest of the mast). I suspect that an overloaded mast can break at roughly the same location on any Sunfish. If an "insult" (corrosion- or drilled-hole) is added, expect that hole to be the site of a break. Higher cleats would be safer for the mast.

Later Sunfish were equipped with an internal sleeve, which can be retrofitted.
P6100039.JPG
(This mast had no cleat).

.
 

L&VW

Well-Known Member
'Wuz wondering about using an adhesive to bond the cleat to the mast. Is 3M's 5200 up to the job? Went here and found a lot of choices available: :oops:
Joining metal with adhesives

Aluminum forms a protective oxide finish within seconds of "roughing-up" the surface. You'd have to put the adhesive on immediately after preparation—then slap the cleat on the mast and clamp it. Just remember to align the cleat with the mast cap. :confused:

The idea being, to eliminate drilling holes altogether. Though I'd be tempted to wait 'til it's set, then drill one hole for a pop-rivet. The innovative "aDP" pop-rivet might have a future here. ADP Rivets - Colored Blind Rivets Made in the USA (Makes its own backing-plate!) :)

It wouldn't hurt to wrap a piece of coarse sandpaper around the mast, and hand-form the cleat base into a matching concave shape. I have some 24-grit sandpaper. :eek: (Need gloves to handle it!)

I'll be back at my three Sunfish "haven" in two weeks and might give an adhesive a try.

.
 

tag

my2fish
[puts on my day job structural engineer hat]
drilling a small pilot hole should not significantly weaken the mast cross section. traditional checks on the member's gross, or full, cross section are against the material yield strength, and net section checks are against the material rupture strength (often 15% higher, or more, than yield strength) - so while the pilot hole does cause a small loss of net section, the higher rupture strength compensates for it.

if failures are occurring at that location, I'd hazard to guess it is primarily due to years of corrosion, not the small loss of net section from the pilot hole. the bending and shear stresses on the mast will be highest down near the deck, so that would mean the higher you mount the mast cleat, the better. granted, the 48" limit makes it difficult to reach the cleat to de-rig if you're standing in the water.
 

Alan S. Glos

Active Member
Other advantages of the mast cleat: The mast cleat reduces the down-thrust of the mast and, I believe, makes the boat easier to tack in light air. It also reduces the tendency of the the base of the mast to grind through the bottom of the mast hole and cause leaks or even structural problems, a problem made worse if you get beach sand inside the mast hole. I have seen some Sunfish that have been sailed without a plastic base cap on the bottom of the mast, and the raw metal edge of the mast acts like a cookie cutter as it rotates from tack to tack over time. That said, if you use a mast cleat for the halyard, be sure to run the slack end of the line through the deck eye and cleat it off loosely to avoid having the entire rig fall out of the mast hole in a capsize.

For the last few years, I have used a small, open ended clam cleat rather than a horn cleat and this rig works fine even when I use the slack end of the halyard to make a boom vang.

Alan Glos
Cazenovia NY
 

Dickhogg

Active Member
Any "insult" to the mast can be expected to cause trouble.

My mast broke in a very strong wind; however, I couldn't find any significant corrosion at the break site. (No different there, than the rest of the mast). I suspect that an overloaded mast can break at roughly the same location on any Sunfish. If an "insult" (corrosion- or drilled-hole) is added, expect that hole to be the site of a break. Higher cleats would be safer for the mast.

Later Sunfish were equipped with an internal sleeve, which can be retrofitted.
View attachment 30436
(This mast had no cleat).

.
This is about where my mast snapped last year. I had no cleat installed or drilled holes.
 
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