I am still in the middle of refurbing my new to me 1981 16 and have a couple quick questions.
I need to temporarily remove the compression post. I removed the two through bolts near the base - I figured this would allow the post to drop down and be removed. Even with the bolts out, the post seems just as secure. Is there something holding it at the top as well - maybe a lag bolt under the mast step? I figured before I get in a wrestling match with it, It'd be best to post for answers here.
My other question is in regard to the area just forward of the compression post. It seems like it would be a good spot to add a bit of storage. The previous owner must have wanted to see what was there as well, as there is a 3/4 inch hole drilled in that forward area. I stuck a screwdriver down the hole and it didn't go very far before hitting what seems to be the same foam that is under the cockpit sole. Any idea what the foam is there for? Doesn't seem to be near enough to serve as flotation. Anyone converted this area to stowage?
Thanks for any help.
Fair winds,
Bill
Bill - although I have a 19, I believe the boats are similar in this area. On my 19 there is a single wood screw through the deck into the top of the compression post. It's too small to serve any structural purpose, so I assume it's there to keep the top of the compression post from sliding around when the mast is removed (believe me, when the mast is in place and the rigging is tensioned, that compression post isn't moving anywhere except possibly straight downward). To get to this screw you will probably have to temporarily remove your mast tabernacle. If your boat is a 1981, it's probably a good idea to remove and re-bed the tabernacle hardware anyway.
You are right about the foam - it is not intended to provide positive flotation. It's my understanding that the factory put it there for sound deadening reasons primarily - to reduce water/hull noise. On my boat, some previous owner cut a relatively big opening in the plywood just forward of the compression post (about 12" x 12" square) and then cut out a section of foam in order to reach the hull and drill a hole for a through-hull depth transducer. It's a good spot for that - maybe 12" forward of the keel and 12" off to the port side.
Wes
Bill asks, " Any idea what the foam is there for? "
Only to keep the hull quiet when pounding into the waves. And a bit of stiffening for slings.
I don't think on a CP-16 that there is enough space once the foam is removed to make it a viable storage area.
It's worth it on a CP-19 though. Can't help you on the 'other' end of the compression post. As the two lag bolt screws are out try a rubber hammer at the cabin top and see what happens...
skip.
Thanks for the replies wes and skip. Wes your probably right about my mast tabernacle being due (probably overdue) for a rebedding. I have to worry about rain today, but we have a good forecast for the next couple of days, so I'll give it a go then.
I remember reading on another thread that the tabernacle shouldn't be through bolted (although I have to tell you, it seems like it should be) - so I shouldn't be surprised to find it just screwed down?
Thanks for any further advice.
Fair winds,
Bill
I can confirm that on a 16 there is a long bolt underneath the tabernacle, through the mast step into the compression post. I had to rebuild my step area after significant water penetration into the small plywood core of the step, so I know the anatomy there a little better than I'd like. :)
Bill - if you attach your tabernacle to the deck with screws and (God forbid) you get dismasted someday, you will probably have four holes to fill with epoxy and re-drill. If your tabernacle is through-bolted nice and strong and you get dismasted, you will probably have a honking big hunk of your deck ripped out, which is a serious repair job. That's why the factory uses screws.
There is really no advantage to through-bolting, since there's very little stress on the attachment point when the mast is up. The rigging would probably hold it in place almost as well if you used double-sided sticky tape :)
Sometimes stronger is too strong.
Wes
Thanks again for the replies guys - a big help. :) Buckaroo - hopefully I won't need advice on rebuilding the step area after removing the tabernacle!
Fair winds,
Bill
I sure do wish that some people would keep there fingers off the key board when they relay don't know what there talking about.The foam is there to keep you afloat should you ever take on water. I wonder if my 1979 com pac 16 will have enough to keep me up if needed?The compression post is bolted on the bottom and has 4 1 1/2 inch screws coming from the top thur the tabernacle and cabin top into the top of the post,be very carefull when separating the post from the cabin top because some old boats are balsa cored and its not easy to repair and old sealant and glue gets between the post and cabin top sometimes is hard to remove . something to think about adding when the tabernacle is up is a deck plate under it before putting it all back together,its a nice way to run lines down and then aft. Just some to think about. Rob
See post "Foam in the boat" by MacGyver. Probably applies in this instance also.
QuoteI remember reading on another thread that the tabernacle shouldn't be through bolted (although I have to tell you, it seems like it should be) - so I shouldn't be surprised to find it just screwed down?
Hi Bill, well that made me shudder. Check out my post about what can happen:
http://cpyoa.geekworkshosting.com/forum/index.php?topic=5758.0
We just replaced our compression post and there is a screw under the tabernacle as well as a bolt at the base. I talked to Hutchins about the replacement and he said the new one could touch the keel, even though they were not built that way.
Hope this helps. Good luck with your repairs.
Pam
Pam, Thanks for the info. So sorry about your dismasting and subsequent damage to your boat. :-[ At least no one was hurt - things certainly could have been much worse. Your pics of the damage to your boat certainly puts an exclamation point on screwing down as opposed to through bolting the tabernacle.
I'm not sure if I should get involved with removing the tabernacle now or wait until spring. We're supposed to have highs in the 40's this weekend - not the best temps for most bedding compounds. At any rate, thanks again for the info and good luck with your repairs as well.
Fair winds,
Bill
Quote from: Wes on October 23, 2012, 06:24:53 PM
Bill - if you attach your tabernacle to the deck with screws and (God forbid) you get dismasted someday, you will probably have four holes to fill with epoxy and re-drill. If your tabernacle is through-bolted nice and strong and you get dismasted, you will probably have a honking big hunk of your deck ripped out, which is a serious repair job. That's why the factory uses screws.
There is really no advantage to through-bolting, since there's very little stress on the attachment point when the mast is up. The rigging would probably hold it in place almost as well if you used double-sided sticky tape :)
Sometimes stronger is too strong.
Wes
My 16 was dismasted during a bad wind storm while docked at its seasonal slip by the previous owner, and after seeing and repairing the damage firsthand, I see no reason not to thru bolt it! The weak point on my 16 was the flimsy tabernacle, which simply bent one of the ears over when the mast flopped to the side when the standing rigging failed. It did not pull out of the top of the cabin, the previous owner actually had to unscrew it to remove the tabernacle from its mount. I could see it ripping the fiberglass and block apart if the area was already rotten, but not if it is in good shape. Mine is now thru bolted with two long stainless bolts with giant washers and nuts in the cabin and two long stainless screws that actually go directly into the compression post. The mount is much stronger than the stainless sheet metal tabernacle Hutchins originally equipped our boats with. I have also seen it first hand while practicing raising and lowering the mast single handed, I lost control of the mast and it simply bent the tabernacle over, didn't even budge at the base. The original tabernacle on my 1980 is so flimsy you can bend it by hand, not sure if later models were different or received beefier tabernacles?
(http://i1231.photobucket.com/albums/ee514/scotimier/6C3607D3-9855-43A8-91A0-5FE3AE6882B0-1319-0000015C1BB4345C.jpg)
I "borrowed" Pamelina photo to try and show what I mean. When theirs was dismasted, by not being thru bolted into the compression post, it allowed the top of the cabin to flex until the point that the fiberglass couldn't give anymore and it tore... I will argue that if the tabernacle was thru bolted into the compression post, the tabernacle would have bent, but not tore off because it is now one with the compression post. On my CP16 only two of the 4 bolts are drilled thru and bolted with washers and nuts, the other two are thru bolted with long stainless lag screws into the compression post. My compression post also appears to be much larger than the one in hers pics, hers looks to be nothing more than a 2x4 that someone had replaced the original compression post with, I would use at least a 4x4 post if I were replacing mine.
The Tabernacle can do some serious damage if a shroud lets go and the mast comes down as the above photo shows.
If it is simply screwed in place it will just pull out the screws and bend the Tabernacle.
I removed the Tabernacle and replaced it with a rotating mast base like the ones on my catamarans and my Butterfly sailboat.
With my set up, if a shroud lets go it won't do any damage to my boat.
I can't seem to post photos but I could email some if another member could post them for me.
Quote from: Rob on October 23, 2012, 07:41:53 PM
The foam is there to keep you afloat should you ever take on water. I wonder if my 1979 com pac 16 will have enough to keep me up if needed?
A liter of foam will displace 2.2 pounds of water.
My boat weighs about 1,000 pounds.
I don't have any where close to 450 liters of foam in my C 16.
It would sink if full of water.
Rob said, " I sure do wish that some people would keep there fingers off the key board when they relay don't know what there talking about. The foam is there to keep you afloat should you ever take on water. "
I must respectfully disagree.
Rich Hutchin's talking at the All Sail Boat Show at Navy Pier in Chicago stated, " No amount of foam will keep a keeled Com-Pac afloat. Not with 600 lb of concrete in their keels." We were talking about Com-Pac 19's.
I believe in Bob Burgess's book 'Handbook of Trailer Sailing' about the same thing was said. And embellished to include foam is for stiffening and quite running when beating into the seas.
I don't know what model of Com-Pac we are talking about here. What ever it is let's tie it to a dock and fill it up till it sinks or floats.
skip.
I like this discussion. I'm sure there's a scientific way to determine how much foam is needed to float your boat. But, as Mr. Miyagi so eloquently stated in "Karate Kid": "the best way to avoid a punch is to not be there".
Keep the water out of your boats and you won't need any foam! When it's rough, put the drop boards in. Keep the foam for the pfd's. In my ever so humble opinion!
bob23
Man! I would need a s--tload of foam to overcome the 1350 lb. keel in my 23! There wouldn't be any room for me!
Hi Guys,
Rob23 mentioned that there must be a way to calculate the amount of foam neede to provide positive buoyancy for a boat. Yes there is, and here it is.
This formula is metric, sorry. Australia changed to the metric madness system about fourth years ago, and it took me nearly that long to get used to it, but now I'm so indoctrinated I can't mentally convert back to feet and pounds etc.
The buoyancy needed to float a boat: = 1.2x (MxK+F)/1000-D
where M=hull and deck mass in kilograms
K=constant for hull material, Fibre glass=0.37
Aluminum=0.62
Steel=0.8
F= mass of machinery, fittings, rudder,centre board and
ballast etc.
D= density of buoyancy material in kilograms per cubic
metre ( 35 kg. for foam approx)
For example for a Legacy, the design mass is about 500kg, but 200kg of that is ballast, so we have about 300kg of fibre glass so
M = 300, F = 200(ballast)+ 100kg for anchors, rudder, centre board etc. and 30kg for the outboard
Which allows us to calculate the buoyancy needed as:
1.2x(300x 0.37 + 330)/1000 - 35 = 0.55 cubic metros, say 0.6 for safety. This will float the boat but not necessarily upright, that depends on positioning.
Regards
Pete H
Bob23 says, " Keep the water out of your boats and you won't need any foam! When it's rough, put the drop boards in. Keep the foam for the pfd's. In my ever so humble opinion! "
Precisely. Corks don't sink. Button her up and stay in the cockpit with a PFD on.
skip.
I cant believe that a manufacturer will come out and say my boat sinks ,I haven't been in the coast guard regs lately but Iam sure theres something in there about floation that even dates back to the early Com Pacs .There is alot of good information and shared experience on this site its truly a shame that some posters dont know there limits. Rob
Rob, I think an apology is in order. The posts about floatation are correct as they relate to compacs.
Read the regulations. Sail and other certain crafts are excluded from floatation regulations.
http://www.uscgboating.org/regulations/boatbuilder_s_handbook/flotation_part1_a.aspx
Most power boats? Sure, they float.
Enough foam can be installed to keep it afloat! But what's there is for stiffening and quieting reasons from a design perspective.
Pete:
Thanks for the equation. Finally, math I can use! If I get ambitious, I may search for a non-metric equivilent but this will do!
Rob:
Now, now...let's remember that we are all flawed human beings here. This has (and is) an interesting discussion. Frankly, I never thought about how much foam would be needed to float my boat. But it is something I'll use sometime during some future boat building. As an aside, my 1985 Compac 23/2 has no, I repeat, no foam whatsoever. Dang, there's not enough room in there to begin with...I don't plan on giving any real estate to foam.
No worries, mate!
bob23
I remember reading an article by Dave Martin who, along with his wife Jaja and 3 kids, went on very long sailing adventures, somewhere close to the Arctic circle. As he was preparing his sailboat, he sealed off any cockpit lockers and made them watertight. He may have just glassed over them, don't remember. But he did shrink the size of the cockpit to very small by adding blocks of foam and glassed over them. And he enlarged the drains. His thinking made good sense: He knew he'd eventually take green water into the cockpit. The idea is to drain it before the second wave sinks the boat. He may have had watertight doors to the cabin. The article is somewhere in an old Good Old Boat magazine...lurking somewhere in my office.
I'd like to think if I had sealed cockpit lockers in my 23, that she'd float with the cockpit full of water. But I don't plan on filling it to find out.
Bob23
I still cant believe a manufacturer would say his boat sinks ,The Lawyers will eat that up.Thanks for the link to the regs Ill have do some research its been years since I worked in my Dads boat yard and I do remember theres alot different regs .And as I said before there is alot of good information on this site its truly a shame that some posters don't know there limits. Rob
Rob:
Let me lay it on you staight: This is not a place for personal attacks, whether direct or subtle. You've made 3 references to someone who "should keep thier fingers off the keyboard" and "don't know thier limits." Hell, that could be all of us! I suggest that if you have a problem with anyone posting here, you work it out via personal message. If someone has offended you, let them know and work it out. In the distant past, we've been down this road before and I have been as guilty as anyone else for shooting my mouth off, probably more so. Some exchanges in the past got heated and alienated some wonderful people. When I was at fault, I sent a pm or email and apologized. In the interest of keeping this a great place to hang out, I suggest you might do the same if someone has offended you.
We are trying to keep this a place for the exchange of info, experiences as well some good old ribbing, of which I have been the well deserved recipient many times!
I've appreciated your posts. You are right about this being a source of " alot of good information and shared experiences". We're just trying to keep it that way. Personally, I'm wondering if I'm the "someone". I guess I'll recieve a pm soon if I am!
bob23
Bob 23 Yes this is a good site There is alot of good information that passes thur here and just like the rest of the internet its not all ture ,And I do belive that there are some regular posters that realy should keep there fingers off the keyboard because there in over there head from the start .I would like to think that this site is a sharing Of experiance ,not someplace to babble on the keyboard.If your posting just to see your slef post take it to facebook . Rob
Good idea with the rotating mast for both sailing purposes and possible dismasting without damaging the boat. I am familiar with the rotating mast from years of Hobie sailing and one dismasting (with no damage to me or the boat). Could you tell us where you found the parts to do this modification and if it was an exact fit in the mast? Thanks.
Quote from: Rob on November 08, 2012, 10:01:24 AM
,And I do belive that there are some regular posters that realy should keep there fingers off the keyboard because there in over there head from the start .
Considering that your initial point in this thread was incorrect, are we to infer that you might consider yourself one of them? ;)
Let's be men here gentlemen (apologize the ladies).
Indeed Rob is right, everyone should think before they post just like we should think before speaking. Myself included, and like Bob23 I'm sure I can recall a time or two when one of my posts perhaps a post was a bit offending-maybe not to all but certainly to some (notice the -2 Karma). Yep, we're not perfect--thank god.
If anyone believes represented facts to be untrue, we should absolutely discuss it as the community we are. If you don't feel comfortable piping up in a post or sending a private message for fear of retaliation, feel free to PM (Personal Message) one of the Administrators confidentially to work through it. Let us be the bad guy who challenges an opinion vs. fact. This isn't our first rodeo..let us help make this place as factual and fun as it can be.
by the way, welcome Pete! Exciting to see these boats in Oz. I bet they are perfect for the coastal areas down there.
Quote from: mandolinut on November 08, 2012, 06:12:36 PM
Good idea with the rotating mast for both sailing purposes and possible dismasting without damaging the boat. I am familiar with the rotating mast from years of Hobie sailing and one dismasting (with no damage to me or the boat). Could you tell us where you found the parts to do this modification and if it was an exact fit in the mast? Thanks.
The conversion was easy and cost almost nothing.
I used a piece of Ipe wood for the Tabernacle. The dimensions are 1" thick, 4.5" wide, and 6" long.
The original Tabernacle was used as a template so I could drill holes in the Ipe wood that could use the original mounting holes in the cabin top to fasten it to the boat.
I used screws that were the same size and type as the original screws but were 1" longer so they would fit into the original holes.
The pivot pin was made from a 1/2" stainless bolt that was threaded into a tapped hole in the Ipe wood with a nut and some fender washers to support the mast base.
The head was cut off the bolt leaving a short peg to serve as the pivot.
Then I made the mast base in the form of a wooden plug that has a tapered hole in it to center the mast. The plug is supported by the original mast bolt that was used on the stock set up.
I could send pictures that would make it clear how this works but I can't seem to post them here so, if you could send me an e-mail address I could send them to you and maybe you could post them. (Luddite here)
The whole thing is simple and works great.
Hope this helps.