Good day,
I was rigging up my new to me Supercat 17. Had actively engaged and pinned the mast to the mast ball while I reran the standing rigging. While I was doing that the mast ball popped off it's post.
It appeared to be glued on with a white glue. There is a pin, but as near as I can tell it just stops the mast from rotating at is just sits in a depression.
Does anyone know what glue is used to attach the mast ball to the post upon which it sits?
Do I have the correct understanding of the pin.
Thanks,
Don
Supercat 17 mast ball came off
- Rank: Lubber
- Registered: Jun 06, 2018
- Last visit: Aug 16, 2025
- Posts: 1
Posted: Aug 16, 2025 - 07:48 PM
- Rank: Mate
- Registered: Jul 29, 2015
- Last visit: Aug 17, 2025
- Posts: 611
Posted: Aug 17, 2025 - 06:03 PM
Forgot to login. Here is my previous post:
The mast ball is usually made of nylon or Delrin and threaded to fit the threaded mast support that goes through the crossbeam as the dolphin striker. On a Nacra, this is a 1-1/2" ball threaded to an 9/16" diameter by 18 pitch. The mast ball for Nacra is still sold by Murrays: [url]https://murrays.com/products/nacra-mast-ball-1-5-new-nylon[/ur l] I think the mast ball on the SC 17 and 19 is 2-inches in diameter and I don't know the thread size or pitch. You should plan on taking measurements of your current mast ball, and threaded mast support. The mast ball is intended to be threaded, so it is not glued, but with the part being difficult to find, it may be one way to get back on the water.
I just devised a mast-raising system for my Nacra that keeps the mast step in compression as the mast is raised. Lifting the mast from the trampoline imposts a lot of lifting stress on the mast ball that may cause the failure you experienced. I use a bracket that keeps the mast on its side and uses a gin pole to pull the forestay and that is powered by a winch on the trailer, so there is no lifting force on the mast, just leverage. If you repair your mast ball, you might want to consider a gin-pole mast raising system that minimizes stress on the mast step. Most importantly, the mast must be supported off the back of the boat when pinned to the mast ball or it will leverage the ball right off if balanced on the aft crossbar.
Edited by tominpa on Aug 17, 2025 - 07:11 PM.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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The mast ball is usually made of nylon or Delrin and threaded to fit the threaded mast support that goes through the crossbeam as the dolphin striker. On a Nacra, this is a 1-1/2" ball threaded to an 9/16" diameter by 18 pitch. The mast ball for Nacra is still sold by Murrays: [url]https://murrays.com/products/nacra-mast-ball-1-5-new-nylon[/ur l] I think the mast ball on the SC 17 and 19 is 2-inches in diameter and I don't know the thread size or pitch. You should plan on taking measurements of your current mast ball, and threaded mast support. The mast ball is intended to be threaded, so it is not glued, but with the part being difficult to find, it may be one way to get back on the water.
I just devised a mast-raising system for my Nacra that keeps the mast step in compression as the mast is raised. Lifting the mast from the trampoline imposts a lot of lifting stress on the mast ball that may cause the failure you experienced. I use a bracket that keeps the mast on its side and uses a gin pole to pull the forestay and that is powered by a winch on the trailer, so there is no lifting force on the mast, just leverage. If you repair your mast ball, you might want to consider a gin-pole mast raising system that minimizes stress on the mast step. Most importantly, the mast must be supported off the back of the boat when pinned to the mast ball or it will leverage the ball right off if balanced on the aft crossbar.
Edited by tominpa on Aug 17, 2025 - 07:11 PM.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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