# Clapper in the mast ! **URL:** \ **Category:** Newsgroups Archive Prior to 2025\ **Created:** [July 9, 2022, 7:38pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549 "2022-07-09T19:38:06Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Graham\_Kent](https://avatars.discourse-cdn.com/v4/letter/g/3d9bf3/32.png) [@Graham\_Kent](https://nonsuch.discourse.group/u/Graham_Kent)\ **Post date:** [July 9, 2022, 7:38pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/1 "2022-07-09T19:38:06Z")
Last week I heard an intermittent banging noise coming from the bow. I was sailing on a broad reach in 3-5’ seas in light winds. The boom was slapping around and I thought that was cause of the noise. But when I went forward to the mast it seemed the noise was coming from some metal object that was banging on the inside of the mast(???). Like a clapper on a bell. It didn’t happen frequently and it was not a thwacking noise you might expect from a cable running on the inside of the mast. After I dropped the sail and motored the last 2 miles to harbor the sound went away, even though the boat motion was basically the same. Any thoughts or ideas on the cause of the noise? How worried should I be? Thanks for any help or advice. Graham Kent “Blue Heron” 30U #411 East Greenwich, RI ---
**Author:** ![Michael\_Howard](https://avatars.discourse-cdn.com/v4/letter/m/bbce88/32.png) [@Michael\_Howard](https://nonsuch.discourse.group/u/Michael_Howard)\ **Post date:** [July 9, 2022, 7:50pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/2 "2022-07-09T19:50:11Z")
Your mast might be loose. Try tightening the 4 bolts at the base of the mast. Cheers Mike Howard Intuition N36 Ft Pierce, Fl. ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 9, 2022, 8:34pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/3 "2022-07-09T20:34:21Z")
Hi Graham, Mike’s right. It’s likely that the bolts at the base of the mast have backed off a bit. This can happen over time and even more so when your mast wedges have worked loose. Ron Ron & Diane Schryver “Alpha Waves” '87 NS30U #393 Georgian Bay Midland ON ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 9, 2022, 8:49pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/4 "2022-07-09T20:49:34Z")
Check that it was not your anchor. It can seem to “cast” noise elsewhere. Don Ringsmuth Selkie 30U 425 East Hampton, NY Hi Graham, Mike’s right. It’s likely that the bolts at the base of the mast have backed off a bit. This can happen over time and even more so when your mast wedges have worked loose. Ron Ron & Diane Schryver “Alpha Waves” '87 NS30U #393 Georgian Bay Midland ON ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 9, 2022, 9:19pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/5 "2022-07-09T21:19:12Z")
Graham First thing I would check are the bolts in the mast shoe. Mine got loose one time and created a metallic bang. Good luck Pete DePascale Branford, CT Irish Mist 006 33’ ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 10, 2022, 10:58am UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/6 "2022-07-10T10:58:48Z")
I had the same symptom a few years back. It was the mast bolts. Especially noticeable when going down wind. Bill Evans Companionship 20U 465 West River MD ---
**Author:** ![BOB\_JENKINS](https://avatars.discourse-cdn.com/v4/letter/b/898d66/32.png) [@BOB\_JENKINS](https://nonsuch.discourse.group/u/BOB_JENKINS)\ **Post date:** [July 10, 2022, 11:34am UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/7 "2022-07-10T11:34:51Z")
Graham just to add this idea re mast bolts tightening. While sailing on a tack go down and tighten the loose bolt . Then change tack and address the other bolt remembering that this cast aluminum and not to overtighten . Bob Jenkins Previous owner 30U Aurora on ---
**Author:** ![Eric\_Hakanson](https://avatars.discourse-cdn.com/v4/letter/e/7bcc69/32.png) [@Eric\_Hakanson](https://nonsuch.discourse.group/u/Eric_Hakanson)\ **Post date:** [July 10, 2022, 12:57pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/8 "2022-07-10T12:57:41Z")
The overwhelming recommendation is to check the mast step bolts. Secondary suggestion is to check the anchor chain. Rhythmic boat motion and a clapper noise, could be chain whacking inside of anchor locker. Please let us know how you correct the problem. Good luck! Eric Hakanson Former owner NS 30U #484 Eric C. Hakanson 207.350.5235 (m) Boothbay, ME ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 10, 2022, 1:11pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/9 "2022-07-10T13:11:51Z")
Check the bolts in the mast shoe by loosening the lock nuts first. Also, of importance, check the shims at the mast partners. If they’re wood, get the newer composite versions. Joe Valinoti S/V iL Gatto NS30U #221 Sea Harbour YC Oriental, NC USA ```auto ``` ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/n26_115_233/original/1X/39e3f8ffb93f4278d654ae38d831066e407d616b.jpeg) [@system](https://nonsuch.discourse.group/u/system)\ **Post date:** [July 11, 2022, 1:35am UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/10 "2022-07-11T01:35:55Z")
Hi Graham, I just finished dinner with a friend of mine that recently owned a Nonsuch 26. He had a problem that sounded exactly like yours. It was as if you were describing, in detail, his problem. I may have the detail not exactly correct but it should give you enough information to run with. The mast was an original. Where the upper portion is married to the lower portion there is some kind of a sleeve. Separation took place between the sleeve and the mast causing the clapper sound. I witnessed it myself and the problem appeared to be many of the things previously suggested to you, but it wasn’t. The fix, done by a local marina was some kind of a specialty epoxy for aluminum. It solved the problem but was not cheap. Here is my suggestion: Contact me directly and I will provide you with Al’s contact information. Discuss the issue with him to see if this could be the same problem. Al spent a lot of time researching the issue as did the marina. Possibly Al’s info could save you a bunch of bucks if it happens to be the same problem. He’s a great guy and I am sure he would be glad to discuss the subject with you. I wish you the best of luck. Cheers, Butch Butch Garren Nonsuch 30 #196 “Whiskers II” SIYC Slip 12 Solomons, MD ![](https://cdck-file-uploads-canada1.s3.dualstack.ca-central-1.amazonaws.com/flex011/uploads/n26_115_233/original/1X/a0a903473275953e8096de8178e9c1eaedc79591.png) ---
**Author:** ![Graham\_Kent](https://avatars.discourse-cdn.com/v4/letter/g/3d9bf3/32.png) [@Graham\_Kent](https://nonsuch.discourse.group/u/Graham_Kent)\ **Post date:** [July 11, 2022, 12:34pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/11 "2022-07-11T12:34:05Z")
Thanks Joe for the tip. You always give great advice, Graham Kent ---
**Author:** ![Graham\_Kent](https://avatars.discourse-cdn.com/v4/letter/g/3d9bf3/32.png) [@Graham\_Kent](https://nonsuch.discourse.group/u/Graham_Kent)\ **Post date:** [July 11, 2022, 12:43pm UTC](https://nonsuch.discourse.group/t/clapper-in-the-mast/8549/12 "2022-07-11T12:43:11Z")
Sincerely grateful for all the help and advice. Later this week I’ll be back at the boat and will check the mast bolts and other sources that were suggested. Best wishes,