| Hobie Forums http://www.hobie.com/forums/ |
|
| Mast base cast creaks loudly moving slightly front/back. http://www.hobie.com/forums/viewtopic.php?f=13&t=70037 |
Page 1 of 1 |
| Author: | canstey [ Tue Jul 12, 2022 4:55 pm ] |
| Post subject: | Mast base cast creaks loudly moving slightly front/back. |
My Hobie 18 is now making loud creaking and cracking sounds when under high wind load (>15 mph). I have traced it down to the mast base casting moving slightly up and down front to back (1-2 mm) when pulling on the dolphin striker front and back. Zero movement side to side. Is this amount of movement okay? The creaking and cracking sounds loud and a bit scary that the mast might come crashing down. |
|
| Author: | mmiller [ Wed Jul 13, 2022 8:16 am ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
Movement is never good. Re-rivet the casting or add rivets. |
|
| Author: | srm [ Wed Jul 13, 2022 6:33 pm ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
The mast step should not have any noticeable movement. As Matt suggested, re-rivet it. That can sometimes be a little challenging since you will need to first loosen the dolphin striker rod, and they have a tendency to seize in the corner castings. Many years ago, I posted a thread explaining how to bed the mast step in epoxy before re-riveting to give it an even more secure attachment to the crossbar - you may be able to find that thread with some searching. A loose mast step will not cause the mast to come crashing down, but it can accelerate wear on the front crossbar, which will eventually crack around the mast step holes. So the looseness needs to be corrected. sm |
|
| Author: | mmiller [ Thu Jul 14, 2022 8:39 am ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
Use the scissor jack or clamp trick to get the casting down tight for riveting. This is about H16, but the same idea. https://s3-us-west-1.amazonaws.com/media.hobie.com/2010_archive/support/pdfs/h16-step-replace.pdf |
|
| Author: | Hobie1983 [ Tue Aug 02, 2022 7:59 am ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
I just had the same issue with my 1983 18 this weekend Dropped the mast and drilled out rivets. Front and Rear rivet holes in crossbar badly worn and likely won't hold even a larger 1/4 rivet. Left and Right rivets and holes were fine. Great info, as I was questioning if adding new holes and rivets was the proper method. Canstey, what year is your boat? Have you made the repairs yet? |
|
| Author: | srm [ Tue Aug 02, 2022 9:33 am ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
I would avoid adding more holes to the mast step. There is already a lot of material missing from the crossbar in that area due to the existing holes. I would start by trying 1/4” rivets. You can also add washers to the rivets inside the crossbar or add a backing plate, but both of those options are a little tricky and a bit more involved since you need to disassemble the crossbar. sm |
|
| Author: | John Forbes [ Thu Aug 11, 2022 6:48 pm ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
Before drilling out the existing rivets holding the mast step casting on the front beam it is important to release the tension on the dolphin striker. To do this, remove the small covers on the front beam end castings (assuming your boat still has them, many are lost over the years). Undo the 3/8” UNF nyloc nut a few turns each side with a socket. If the dolphin striker rod is ceased into the front beam end castings due to 30-40 years of salt water allowing the stainless steel dolphin striker rod fuse into the aluminium beam end casting, then the McGyver alternative is to put the nyloc nuts back on to their original position. With the boat in its normal position on the trailer, tie a medium sized (5mm) line around the centre of the dolphin striker rod and then down around the centre bar of the trailer and back up and down a few times and pull very tight. This will in turn pull the upward load off the mast base casting because the dolphin striker rod (the vertical rod) is pushing up hard against the lower face of the mast base casting. You don’t want any vertical force or load going up whilst drilling out the rivets. Once the load is off, drill out the rivets, release the rope tension and inspect the main beam area. If the holes are very elongated, see if a 1/4” drill bit will fit in them. If it doesn’t then you can utilise 1/4” rivets in place of the current 3/16” rivets. If the hole is larger than 1/4” then the best option is to use a 5mm stainless steel riv-nut (also known as a thread insert). Most commonly available riv-nuts are either aluminium or mild steel so you may need to buy some stainless steel ones on ebay. Easy to purchase. The riv-nuts should only be used for the two side rivets. The front and rear holes are at an awkward angle to use a riv-nut so try and use a 3/16” or 1/4” rivet in that application. Once the riv-nuts are in place, use a 5mm bolt with an Allen key dome head approx 20mm long. This is then strong enough to take the vertical load once the beam is re-assembled. Please try and use an anti-corrosive compound such as Duralac or TefGel when re-assembling. Enjoy. |
|
| Author: | martinjt [ Sat Jan 20, 2024 2:54 pm ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
Hi Guys, this is a problem that I have also on my 1982 Hobie 18. The fore and aft rivets in the mastfoot are loose and I can move it by pushing the dolphin striker forward and backward. Also I notice that the top of the beam where the mast step rests, is slightly (2mm or so) depressed. I'm wondering if this is why I have a bit of loose sidestay tension? I can't see any cracks in the beam and can't imagine the cause of the depression because there has been no excessive downwards pressure (apart from the mast weight and sidestay tension). If I can re-rivet the mast step and perhaps get some epoxy underneath as was suggested to bed the mast step and as the boat is on a freshwater lake, do you guys think I'll have a problem with the beam? Also, is there a teflon or plastic "Bearing" in the mast foot assembly? I can't seem to find anything in the parts list. Thanks. Cheers, Marty. |
|
| Author: | srm [ Mon Jan 22, 2024 5:08 am ] |
| Post subject: | Re: Mast base cast creaks loudly moving slightly front/back. |
As long as the beam isn’t cracked, it should be fine once you re-rivet the step. You can inspect it once you remove the rivets. If you can get the striker rod to loosen up, it will make re-riveting the step much easier. I’m not sure when Hobie changed from the 2-rivet to the 4-rivet mast step, but it would have been sometime in the early 1980’s. If your boat has a 2-rivet step, you should look into swapping it out for a 4-rivet step, which is more secure. After you remove the rivets, lift the mast step out and closely inspect the top of the beam for cracks. Typically I have seen the cracks going between the rivet holes and the dolphin striker post hole. The crack will then start to extend around the circumfrence of the beam. It’s important to make sure the mast step is firmly connected to the crossbar and that the striker assembly is kept tight. For your shroud tension, the mast step won’t impact that. No matter how tight you make your shrouds when rigging the boat, you will pretty much always notice that the leeward shroud goes slack when sailing upwind. This is because the mast is flexible and when you sheet in the mainsail, the mast bends. When it bends, the distance between the mast tang and the mast step shortens and the leeward shroud goes slack. This is totally normal. There should be a bearing in the mast step between the casting and the plastic hemispherical top of the step. You may have to purchase a mast step rebuild kit which includes the bearing and the hemisphere. Or I believe you can use a Hobie 16 mast chip and just drill a hole in the center to use as a bearing. sm |
|
| Page 1 of 1 | All times are UTC - 8 hours [ DST ] |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|