| Author | Message | ||
     Mike Bergmann New member Username: Mike_bergmann Post Number: 15 Registered: 09-2005 Rating: N/A |
Hi Scott I am not very worried about this - I have owned the boat for 10 years and this situation has been pretty constant over that time. In my experience of boats, all hulls settle or shift slightly from the "land" support to the "water" support. In the case of our boats, the load on the keel stub is an upward force supporting the rest of the boat when on land, and it is a downward force supporting the weight of the keel (less buoyancy) when in the water. The "ring" shape of any hull will change slightly when a force on it changes from 4800 lbs. upward (the weight of the boat without keel) to 3000 lbs. downward (the weight of the keel less buoyancy). My measurements on the tie rod show that the deflection is in the range of 1/4". If I launched the boat with the partners already set up I would never even see this. My previous boat (a Cal 24) would deflect about 1/8" to 3/16" from the trailer to the water, and I have never seen a boat that does not. As a structural engineer, I can tell you that all structures will flex or deflect under load. If the deflection is excessive, you will observe damage or distress in the material. I have no stress cracks or other signs of distress. The shroud turnbuckles have not shifted since I have owned the boat. As I noted before, the lowers are closed up (about 3/4" remaining.) The uppers have about 1 1/2" left, and the intermediates are almost fully extended. If the step had settled, all turnbuckles would be closed up, not just 2 of 6. I think the people who cut these shrouds just had a slightly off day. Since the lengths are almost identical from port to starboard, I am guessing that they had a slightly defective set of measurements. My method of setting up the shrouds is simple and reliable - I learned it from my first racing skipper on a Lighting in the early 1970's. Once the boat is properly tuned (I follow the factory instructions), I leave it that way until the mast is to be unstepped. I release exactly 10 full turns on all turnbuckles on the boat before unstepping, and leave them that way (cotter pins inserted) through the winter. In the spring, after the mast partners are set up, I crank the same number of turns back on each turnbuckle. Since the boat has slightly settled over the winter, I can generally only get about 7 to 9 of the turns back on immediately. I wait about a week and then put the rest of the turns back on, and I generally do not have to retune for the rest of the season. If I do have to tune, it is never more than one turn on an upper. The fact that the tune stays almost constant for several months, and is repeatable over several seasons, tells me that the boat is very stiff, and tells me that there is no structural problem. I have checked the mast step area several times, and everything is extremely rigid there. If I find a problem, I can fix it easily. My previous boat had a deck-stepped mast supported by a laminated wood beam (no post) and the beam had been cracked by a collision before I owned the boat. I repaired it with a steel reinforcement, and that eventually settled. I finally laminated the wood beam with unidirectional carbon fiber as wll as carbon roving, and that ended up stronger than the original. I also had a broken boom on that boat, and I spliced it with carbon also. That boom is still on the boat 12 years later. My problems with the S2 are very small compared to the work I had to do on that old boat. Anyway, thanks a lot for the advice. Your recommendations on the mast stepping process are excellent. I had learned some of the same things "the hard way" so I'm glad you are passing on the experience to others. | ||
| Scott Corder Moderator Username: Scott_corder Post Number: 25 Registered: 01-2005 Rating: N/A |
Mike, A few things concern me about your note: First, the fact that you think your keel may be sinking a little when the boat goes in the water makes me worry that somewhere your hull is changing shape prior to stepping the mast. Even if your mast step itself seems solid since your re-build, something somewhere is deflecting. Check to be sure that the mast step is rigid in its attachment on up the food chain to the bulkheads, etc. Secondly, the fact that your lower shroud turnbuckles are cranked nearly all the way down reaffirms for me that some where your hull is flexing. Basically, as a keel drops, it is vertically elongating the oval-like cross-section shape created by the mast step, the bulkheads and the cabin top. My hunch is that you've got something soft somewhere in that cross-section I just mentioned above. Maybe Jeff can share more as well on this? | ||
| Mike Bergmann New member Username: Mike_bergmann Post Number: 14 Registered: 09-2005 Rating: N/A |
Scott & Jeff Thanks for the input. My mast step is Ok - I check that every year with the mast down. As Jeff says, the rod has to be tensioned before setting up the shrouds, and I do that. I fully assemble the "gland" and the rod before tightening any shrouds. My boat is on jack stands and keel blocking every winter. The weight mainly rests on the keel - sometimes the stands are actually a little loose in the spring. In this position, everything is OK. My marina likes to step and unstep the mast with the boat in the water. They can handle the boat on land with the mast up, but they prefer not to. I think what happens is that the keel slightly settles with the boat in the water and the mast not yet stepped, and this slightly changes the shape of the hull. If I could talk them into stepping with the boat on land I would not have this problem. I had the same issue before I rebuilt the partners. I maintained the same dimensions when I did that, and all of the fittings fit exactly the same. My shroud turnbuckles vary in the "set up" position - the intermediates tend to be extended, while the lowers tend to be closed up. The uppers and the backstay splits are in the middle. Since the rod is actually threaded into the mast step itself, I could probably adjust its length by shimming the step up a little bit. I just launched last weekend and stepped the mast, so I will do that next off season. | ||
| Scott Corder Moderator Username: Scott_corder Post Number: 23 Registered: 01-2005 Rating: N/A |
Mike, I would agree completely with Jeff that you should be concerned about the rod not seeming long enough. Something somewhere is deflecting to make this happen - and it is happenng in an area you don't want going soft. If the job is more difficult when on the hard, you should look at how your boat is resting in its cradle. It strikes me that you are probably resting too much on the pads - and not enough on the keel. As Jeff wrote, if the boat is truly resting on its keel, the job should actually get easier - not more difficult. Also, if you are actually able to "pull the cabin top down", you clearly have some stiffness issues somewhere. I would do a very thorough inspection of both the mast step and the collar areas. My hunch is that you need to re-build or stiffen the mast step area itself. Unless this has been done in a truly structural manner, there just wasn't enough structure there to begin with for it to withstand years of stress. Another thing to look at for a hint of trouble: are your shroud tunbuckles about mid-way in the threads when the rig is up and tuned? If not, this is another sign that your boat is deflecting somewhere. Finally, is it possible that the repairs you made around the collar resulted in the cabin top now being higher than before? I know it seems a silly question, but I had to ask - as it could also be a factor. Nonetheless, I'd get the mast step checked out by a structural proffesional. | ||
| Jeff Roy New member Username: Jeffr Post Number: 110 Registered: 03-2001 Rating: N/A |
Mike, if that is the case I would look carefully at your mast step. I suspect it is compressed/compressing, pulling the tie rod lower. Also, you want to tight the tie rod before you put a lot of tension on the shrouds. If anything, the boat settling while on the hard should push the area under the mast up because most of the weight is on the keel. | ||
| Mike Bergmann New member Username: Mike_bergmann Post Number: 13 Registered: 09-2005 Rating: N/A |
I remove my mast every year, and I generally follow the same procedure Scott has explained. All of Scott's "warnings" about wires, etc. are very important. I rebuilt my partners about 5 years ago. The seating surface for the gasket is just a little tighter than before, so I need to put more force on the bolts to compress the gasket. One problem I have, and I don't know if others have had this happen too: the stainless steel rod from the mast step to the partners is just a little short. When I am restepping the mast I cannot get the acorn nut back onto the rod. I think this is caused by the boat settling slightly when it is on land. I now rig a steel clamp that I fabricated to grip the rod, and I "pull" the cabin top down enough (with long temporary bolts) to get the nut started. I also took the aft partner plate off the boat a few years ago and ground a "pocket" where the acorn nut sits, so I could grip the threads more easily. | ||
| Scott Corder Moderator Username: Scott_corder Post Number: 22 Registered: 01-2005 Rating: N/A |
John: In its original application, the stainless plate that installs around the mast collar was intended to be installed AFTER the mast is inserted. The idea being that the stainless plate then compressed the rubber gasket and formed the final seal. Since your boat has had repairs done in this area, I cannot advise on your plans. I can say this: it is typically difficult enough to insert the mast into the fiberglass hole, let alone through the stainless plate. For what it is worth, I've done some repairs to my hole and still use the rubber gasket and plate with great success. | ||
| John Stefancik New member Username: Jstef Post Number: 28 Registered: 01-2001 Rating: N/A |
Well I may or may not use the rubber gasket replacement I purchased from S2 part dept. It is looking like it may not fit the hole (repairs have been) at the partners. Too bad. But as I am re-reading all of this info in this thread, I am wondering, does it make a difference if I install the deck plate before dropping the mast in the boat? I am thinking I should install the plate first, then stick the mast in the hole, which will be nice and rigid from the deck plate being there. Not sure if I can fit the gasket in the space, and if not I will try Spartite or some other gasket materials + some silcone sealant. Please let me know what you think. Thanks for your insights. John Stefancik Hurricane Kelley (hull #5) Annapolis, MD | ||
| WilliamShirley``` Unregistered guest Rating: N/A |
Just stepped the mast after a deck rebuild...I am the new owner and haven't done it before. Quick note to make things easier. I had a hard time getting the bolts to line up with the bottom plate after driving them thru the top plate and the deck. The new deck holes were precise, but with all those holes, it took some playing around with that bottom plate to get them all thru. Then I remembered an old trick my Dad taught me. Push a spare bolt from the bottom plate up. Then, (using the bolt you are trying to install) drive it back out from the top. Turns a 2 hour knuckle beating and swear fest into a 15 minute operation. | ||
| Deborah Davenport (Ddavenport) Rating: N/A |
Scott has provided an excellent approach. Here's an alternative that we have used successfully: Place the red rubber gasket in before the mast. Align the base of the mast into the gasket; apply silicon spray to the mast as it is being lowered through the gasket. Use leather work gloves to grab the mast butt inside the cabin - they seem to sop up the silicon spray so that you have good control of the mast as you are oh-so-carefully aligning it with the step plate. | ||
| Phil Walters Rating: N/A |
In the past removing and reinstalling the mast has been troublesome due to the tight fit of the gasket at the partners. This year I dissasembled the aluminium partner plates but the red rubber gasket has remained caulked in place. Should the plates be left off when the mast is placed through and the gasket left in place? | ||
| Scott Corder (Commodore) Rating: N/A |
Here's what I have found to be successful (having pulled my mast five of the past six winters): 1. Obviously, the chrome plates must be removed in order to pull the mast. These plates compress the red rubber gasket in order to achieve a waterproof seal. Remember to number and diagram the bolts as you pull them because they are likely to be of differing lengths. You will save yourself alot of headaches when it is time to re-step the mast. 2. My experience is that the red rubber gasket usually comes out of the deck opening with the mast as it is pulled upward. 3. With the rubber gasket removed, the mast is very easy to lower back through the hole. The red gasket is then re-installed around the mast prior to re-installing the plates. 4. Also, it is advisable to re-seal the red gasket into place each time you remove the mast. This would include a thorough cleaning of the mast, the deck opening and the gasket before applying new silicon caulk and re-installing the mast. 5. Be careful not to use a sealant like 3M 5200. This is an ADHESIVE that makes it VERY difficult to separate items adhered together. Silicon is merely a sealant, equally effective, can be separated easily and cleans up nicely. 6. Here's the order of events when I re-install my mast: 1) clean all areas to be sealed. 2) Drop the mast into position (read my note regarding wiring below). 3) place a little silicon in the deck opening where the gasket will be placed. 4) install the rubber gasket. 5) place silicon around the top surface of the gasket where it will contact the plate and at each bolt hole for the deck plate. 6) re-install the deck plate. 7) Once the plate bolts are tightened, run a bead of silicon around the top of the red gasket that is exposed around the mast above the plate. 8) wrap some rigging tape around the top of the gasket/mast line of contact. 7. NOTE: one of the plate bolts does not have a nut on the underside. It threads directly into the lavatory bulkhead. Be careful not to strip the threads on this permanently embedded nut! 8. Another note: I usually tape a strip of carpeting, foam pad or moving blanket on the lavatory bulkhead prior to lowering the mast into place. This helps prevent any potential damage to the bulkhead if the mast butt gets a little out of control as you lower it down into the cabin. 9. Yet another note: When pulling the mast, all the wiring to/from the mast needs to be stuffed back into its exit hole in the mast BEFORE it is lifted through the deck opening because the wiring can interfere with the butt of the mast fitting through the deck opening. This process should be also reversed when re-installing the mast. Stuff the wiring inside the mast BEFORE the mast is lowered through the hole. Then, once the mast butt is through the deck opening, pull the wiring back out through its exit hole BEFORE the mast bottom is settled onto the mast step plate. 10. All this should take place before tightening any of the shrouds. | ||
| Russ Fender (Admin) Rating: N/A |
Scott, great job on your overview of stepping the mast. Your step number 1. mapping the location of each bolt would have saved me over a half of a day of frustration if I'd known that prior to my first mast stepping. It's great information you offer should and be a big help to Phil and other class members as well. | ||
| Phil Walters Rating: N/A |
Thankyou Scott for the detailed directions for the mast partners. I suspect the red gasket on my boat is bonded in place with 5200 as it is beginning to tear upon removal. I'll try writing to the factory now while I still have some time to see if I can locate another. By the way with the partners fully asembled and the gasket bonded in place the boatyard and I managed to get the rig in last year, but it took a generous amount of superlube and the cunningham fastened to the gooseneck to crank it down. Admitedly not the best tecknique. Thanks! |
