the deck on my Pearson Ensign

Discussion in 'Sailboats' started by LeRi222, Apr 2, 2010.

  1. seasailor55
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    seasailor55 Senior Member

    Very nice boat! How does it sail with that long boom? My guess is that the jib on the bowsprit compensates for that. I"m asking because the boom on my 16' daysailer will overhang the stern also, and I'm considering adding a bowsprit for the jib.

    I'm having a hard time finding clear fir in my area. It seems that it's as pricey as teak as just as hard to get. On the other hand, spruce is fairly inexpensive and very available. I've mentioned spruce several times as a possible boatbuilding material, but no one seems to favor it. Is there something wrong with spruce? I know it's been used for years in aircraft, and I'm told that it's very light, but stringy.
     
  2. PAR
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    PAR Yacht Designer/Builder

    Spruce is a large species, can you refine the type (white, black, eastern, etc.). Most of the stuff available is quite light weight, which is good for spars, thin planking and light framing. This stuff also tends to crush easily, doesn't hold fasteners very well, etc., which are typical of most very light woods.

    Long leaf pine may be available to you. It's difficult to say, especially after Katrina. What are you able to find? What does Lowe's/Depot offer in tongue and groove, non-pressure treated decking material?
     
  3. seasailor55
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    seasailor55 Senior Member

    If you mean tongue and groove plywood, yes. It's sold as underlayment for flooring. I've seen it mostly in 1/2" to 3/4". A little heavy for decking on the Ensign. Long leaf yellow pine is still available, mostly in dimensional lumber. If you mean untreated tongue and groove decking planks, I haven't noticed any.

    As far as the species of spruce available locally, I don't know but I'm a very good friend of a local lumber expert, who works at a building supply and has probably 40 years experience in the lumber industry. I bought some 10' spruce studs from him for a house I had built years ago, and the builder loved them (light, straight, and not prone to splitting or warping).

    Does most spruce take epoxy and gluing well? I had considered using it for the longitudinal deck stringers on the Ensign, but if it doesn't takes fastener well, then maybe I shouldn't. I've seen it on classic yacht masts and booms and it's beautiful, although I understand that for large spars it gets very pricey.

    I was planning on laminating some routed out spruce 2X4s, then eight siding and rounding them to create a hollow 3" diameter spruce mast stepped through the foredeck with side shrouds and a forestay. The boom and gaff would be either 2X4s with radiused edges, or laminations. This is a for a 700 lb. 16' centerboarder with 7' beam. The mast would be about 18', the gaff about 10', and the boom about 13'. This is another project that I'm planning on tackling after the Ensign. Any comments or guidance would be appreciated.
     
  4. PAR
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    PAR Yacht Designer/Builder

    Lowe's/Depot, sell a 1x6 tongue and groove for decking or siding. It's found in the same isle as the "fancy woods" like #1 pine, #2 pine, oak, poplar, etc. It's available in long lengths, usually is straight grained and knot free too.

    Most spruces take to glue and epoxy very well, but again there are a lot of spruces. I'll assume the stuff you're seeing is eastern white spruce, which if isn't very knot filled, is good stuff for spars.

    Consider a birdsmouth mast, instead of plowing out a solid stick. It orients the grain properly and makes it more uniform in strength and stiffness. Also a solid boom on a gaffer is acceptable, but weight isn't a friend of any small craft, so I usually forgo tradition and make things light, especially the gaff. An aluminum tube for the gaff, painted medium brown, is very difficult to tell from a broom stick and a whole lot lighter and stronger.

    If you can get some long leaf pine, then grab up a few 16' 2x10's and/or 2x12's. I mentioned earlier that this board have to be milled from older, larger trees, so finding them with straight grain and knot free is easy. Just flip through a stack of 2x12's and you'll see what I mean. Of course you have to re-mill them to the sizes you need.
     
  5. alan white
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    alan white Senior Member


    The boat's manners are impeccable; regarding the long boom---- about 13 ft, a boom like that is capable of swinging the boat quickly, such is the huge leverage. It's a snap to round up when the wind heads just by hauling in the sheet. I think you can steer much better with the sheet when the boom is that long.
    The boom is just long enough that I have to reach a bit when gasketing the sail.
    The bowsprit I added and the balance seems ideal. I did some calculations when designing the rig and I ended up moving the mast aft 14" when I added the jib. The main is 155 sq ft and the jib 30 sq ft. This amounts to 185 total though I'm not counting the whole fore triangle (Probably 190 is closer to accurate). This is a lot for a fifteen foot boat but she's probably 1200-1400 lbs and I'm pretty used to that big sailplan by now. One thing for sure, she's amazing in light air.
    Regarding the fir, if you're doing a hollow mast, I'd do as PAR says and do a birdsmouth joint mast. Fir is often only available in 2 x 4s and 4 x 4s in the box stores, spruce everywhere in every dimension. So if fir is difficult to source, rip pieces of spruce from wide stock to get clear wood (knots are more avoidable in big planks). If the diameter is max 3", which sounds about right, the staves will be quite small and easy to find clear.
    Spruce is the lightest and strongest per pound of the spar woods and I know eastern spruce is a good choice. Around here in Maine, it's easy to find good Eastern spruce in any lumber yard.
    Whoever told you that spruce isn't a good spar wood doesn't know boats. Rot isn't an issue since it won't develop easily in sunlight and where there's breeze and lack of constant moisture.
     
  6. seasailor55
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    seasailor55 Senior Member

    Well,

    I've listened to the feedback and the pros and cons of this method or that method, assessed what I've got and what I'm trying to do, and took a long look at how much work there is to do vs. potential return, thanks to all the excellent input from all of you. I've decided to do the flush deck with a 9" crown sweeping slightly toward the bow to compliment the boat's sheer line, and wooden hatches for access and ventilation. I'll retain the v-berth with the rear cabin bulkhead, (accessed by a companionway with hatch boards and a deck hatch, probably hinged forward) and a ring frame at the forward end of the v-berth, with beams and longitudinal stringers to support the foredeck. Headroom (from the cabin sole to the deck at the companionway hatch) will be about 45". I've also retained the Ensign's fore and aft lower shrouds, mainly to keep from having to modify chainplates, although I'm seriously considering terminating the cap shroud and a single lower stay on a larger single chainplate per side.

    The open cockpit (which makes up 40% of the boat) will have varnished wood coamings and cockpit sole, slightly curving cockpit seats, and a rear bulkhead at the rudder head, followed by an aft deck with a hatch and mainsheet traveler. The reverse transom will be plywood reinforced fiberglass with a varnished wood veneer. All wood will of course be sealed with epoxy and, where applicable, fiberglass cloth.

    I have attached some sketches of what I envision it to look like. The first thumbnail is a hull profile with sailplan. The second thumbnail includes cross-sections of the hull showing locations of the bulkheads, v-berth, ring frame, cabin sole, cockpit sole and seats, etc. Please give them a look-over and let me know if the proportions appear right and balanced. Thanks.
     

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  7. PAR
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    PAR Yacht Designer/Builder

    Making a new chain plate knee isn't going to be especially difficult and you can really clean up the rig with a slightly swept back spreader and cap shroud. It'll also make tuning the rig a lot easier.

    I like the proportions and still think you can get away with more deck crown if desired. The aft end of the cockpit, where the seat is fully athwart, will there be a bulkhead in the lower portion of this seat box? I ask as it looks as if the rudder shaft will have to pass through this to get to the exit point in the seat top. If this is the case, don't use a bulkhead and make this portion of the seat top removable by having it sit on some cleats.

    Lastly, there's no accommodation for an engine. A bracket mounted outboard will clutter up the dainty stern and dribble oil and fuel onto your varnished veneers too. With the amount of aft deck you have and the amount of aft over hang, you might consider an outboard in a well. With the rudder tucked way under, it could mount on the centerline, possibly on a reinforced aft bulkhead itself. The hole can be plugged for sailing with a well trimmed piece of 'glass covered foam or if you feel really adventurous a trap door that closes when the engine is raised. Also make the forward hatch with a plexi glass (polycarbonate, acrylic, what ever) top so you can have light below.
     
  8. seasailor55
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    seasailor55 Senior Member

    I agree. The speaders on my rig are already slightly swept back, so that shoud be a good fit with a single lower stay, slightly aft of the mast's centerline. Looking at the sketch, it did appear to me that more crown could be added without spoiling the profile, but I wanted some else's opinion.

    The rear cockpit bulkhead is aft of the rudder post. The rear seat does not fully enclose the rudder post tube, but sits on top of it and ties into the side seats, just as in the Ensign. This seat could be removable, as there is a stainless collar which bolts to the seat and slides over the rudder post, but since this seat provides support for the top of the rudder post, I was going to attach it to the front of the bulkhead and the side seats for rigidity.

    As to the outboard, which is the bane of any sailboat's looks, I was planning on using a removable bracket, with the tripod mounting system as used on racing Ensigns (quick and easy to remove and store below). I've considered installing a well, as I've seen them on similar overhanging hulls (Cape Dory, Bristol, Sea Sprite, etc.) but wasn't sure how involved it would be, or whether it would turn out to be a major project. There will be a substantial bulkhead there, that will be tied into the cockpit side decks and carlins, the aft deck, the cockpit seats, and the hull itself. What's the best way to go about creating a well?

    I'm going to use lexan in the front hatch and possibly the main hatch for light access, since there are no portlights. I do have two Beckson opening ports which came with the boat that I considered installing in the bulkhead, looking out on the cockpit, but I've never seen that type of installation and wasn't sure how that would look. What do you think?

    When all is said and done, I'd like it to be a boat that is reasonably good looking, fun to sail and teach others to sail, and doesn't cost a fortune to maintain and operate.
     
  9. PAR
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    PAR Yacht Designer/Builder

    Yep, put the ports in the cockpit bulkhead, many boats are done this way, if for no other reason then to check other people's knee caps.
     
  10. seasailor55
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    seasailor55 Senior Member

    On another note, I raised the foredeck crown to 12", to see what it would look like. It still looks okay to me, and gives the coamings a higher forward termination point, which is good. It also creates more headroom (actually more headroom than the Ensign cuddy cabin, because the entire deck is raised, not just the cuddy cabin) above the v-berth.
    I played around with the angle of the coamings, and I think I can terminate them perpendicular to the crown of the deck, which will give me a nice angle (about 15 degrees) for a backrest.

    I have a question. In the photo of my foredeck that you so kindly overlaid with the proposed beams and longitudinal deck stringers, I noted that the stringers are oriented vertically, obviously for strength. I assume that this would require that they be beveled to match the crown of the deck. If they were oriented radially, that is, the top of the stringers would be notched into the beams and bulkheads at an angle that matches the deck crown, (which, if I used a 12" crown, would have quite a bit more arc than the photo shows) would this significantly decrease the rigidity of the framing, and therefore the deck? It would save a lot of beveling, although I'm not sure how that would affect the sheer clamp/stringer joint.

    Would you install a 1X2 oriented horizontally under and glued/screwed to the vertical sheer clamp to give the beams/stringers something to rest upon, or would beams and stringers butted to the sheer clamp be sufficient? I considered notching the beam/stringer/clamp joints, but this would also require a lot of tricky beveling. I apologize for fretting over things that may seem obvious, but I haven't had much experience with structural wood/epoxy joints, (being historically a Carpenter's Wood Glue adherent) and I always seem to want to overbuild things.

    By the way, I got a call yesterday from a gentleman who is considering donating two Pearson Electras to our sailing program. From what I was told, one boat has sails, rig, and trailer. The other boat has a rig, but no sails or trailer. He is supposed to let me know in a few days if I can come and pick them up. If this comes through, hopefully we'll eventually have 3 vintage Pearsons to sail and maybe do some match racing.
     

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  11. Boat Design Net Moderator
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    Boat Design Net Moderator Moderator

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  12. PAR
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    PAR Yacht Designer/Builder

    Deck beams are usually "let" into the sheer clamp and notched to receive stringers (if they're deep enough).

    Yep, longitudinal stringers are beveled to match the crown of the deck. This might seem difficult, but generally it's not and usually it's the same angle the full length, so you can do it on a table saw. If they were oriented radially, they wouldn't be working as the upper flange of the "beam" and will likely tend to deflect under load, because they're being pressed down at an angle to their vertical orientation. Picture a 2x4 on edge, straight up and down, holding up a weight. In column this isn't an issue, but once you introduce the radial orientation, the load in now is trying to twist the stringer out of it's orientation, rather then just bear the load as a straight one will.

    The additional crown wouldn't decrease the beam/stringer strength, it would likely improve it. Curved surfaces are inherently stronger then flatter panels. If the crown is 12" you'll probably need to have some bent or laminated longitudinal stringers. Maybe take the crown as tall as the old cabin and call it good.

    Yep, as you and I have discussed previously, glue a perimeter "sheer clamp" all around the hull shell edge. It'll reinforce any exterior rub rail you install, offer some beef to the chain plates, makes a good nailer for the edge of the decking, provides a place for the deck beams to land, etc.

    About the angled beam pockets. This is a traditional method and it has a lot to recommend it. When the beam is cut to the right length, it fits perfectly, if not it's too tall or too low. If it's too tall, you just shave it until it drops down where it needs to be. If it's too short, then you can shim it up with a sliver of wood and get it right. The slope also provides a natural path for moisture to drain out of the joint, if it happens to get in there, so it's less likely to rot. In real life, you'll glue and screw the beams into the clamp, so not as big a deal for rot and shedding water.

    More Electras? You're lucky to have them, though some might suggest you're into pain, maybe both. Think light and strong on this one, so you can stomp on the others.

    When plywood is epoxied to things like 1x2's and sheer clamps, it becomes incredibly strong. A piece of 1/4" plywood epoxied to a few 1x2's and a few 1x2 topped bulkheads, is more then strong enough to jump up and down on after winning your first match race. There's no place for 2x4's or 2 x anything on this boat. With the exception of the aft cabin bulkhead, which also could be just 1/4", all the plywood you'll need can be 1/4" stuff. The ring frame and the cabin bulkhead need to be pretty good plywood, so error on the thicker side if it's Lowe's/Depot stock, but the cockpit furniture can be cheaper, it's just got to hold your butt up.

    Hey, a sanitary thread again. We can get back to being reasonable and talking in a normal tone of voice again. Thanks Mr. Moderator, it's not something I would of thought of, a good idea though.
     

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  13. seasailor55
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    seasailor55 Senior Member

    Excellent explanation on the deck beam joints and longitudinal stringers. I suspected that radially oriented stringers would not be as strong, and you have confirmed that. I'll do the bevels on a table saw as suggested. The angled notches in the sheer clamp/deck beam joints were something I hadn't considered, but they make perfect sense, locking the beams into the sheer clamp to keep them from shifting fore or aft, and also providing an angled shelf for the beams to rest upon. I have also read that thickened expoxy makes incredibly strong joints, especially when fillets are used.

    As far as the decking plywood, I'm probably going to need to use the single layer of 1/4", as I still can't locate 1/8" in any kind of exterior fir, and I don't want to use thin interior lauan because of the glue. If I put some sweep in the deck line, as you suggested, opposed to a straight deck line fore and aft, assuming a 12" crown at the cabin bulkhead tapering down to a nearly flush deck at the bow, would 1/4" be pliable enough to take these bends?

    I haven't yet heard back from the prospective donor on the Electras, but I do plan to make the Ensign as light as possible, just in case!

    I have attached a rendering of the boat under sail, as I foresee it, with 12" of deck crown at the cabin bulkhead, natural finished wood coamings, hatches, hatch boards, cockpit sole, and transom veneer, and a single lower stay and cap shroud terminating at a common chainplate per side. Please look it over and let me know if it appears practical and balanced, from construction and aesthetic perspectives. Thanks!
     

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  14. PAR
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    A wonderful drawing and surprisingly lovely lines, don't you think? The cockpit sole and seat riser (vertical seat box face) looks to be very short. This is possible, but for best comfort the seat top width must be wide to match. The normal desk chair seating arrangement is a 16" rise with a 16" deep seat. For each inch you remove of rise you'll need to add this to the seat width, so a 12" rise requires a 20" seat width. Once you go shorter then 12" you need to add 2" for each inch you steal from the riser. So, a 10" riser will require a 24" seat and so on.

    You can use epoxy and fillets on the deck beam/sheer clamp interface. Technically, you can skip the sloped joint and all, just butt the beam to the clamp and lather it up with thickened goo. In reality, the clamp will have some cant to it as it follows the hull shell shapes, so it'll need a slightly sloped joint (on the beams) any way, just to fit. Personally, on the highly loaded partner beams I'd do both the sloped notch and heavy fillets. On all the others, you can just butt them up and use thickened goo.

    Are you sure the drawing shows a full 12" crown, looks more like 9" to me, but sure does look great in any case. If that is 12", then go for it, as it looks just fine.

    I'm not sure if the 1/4" plywood will tolerate bending over the compound curves of a crowned and "sheered" foredeck. My instincts say yes, if you "talk" to it, especially if you use Okoume plywood. Meranti plywood will bend better, but the Okoume is lighter and weaker, so it will protest less to the torture.

    Since this thread has been returned to normal, Paul B is now over there on the separated thread, arguing with the the moderator! Some things remain the same while others move along, I summit. Great drawing Seasailor, oh and one last thing, you don't need three deck hatches on this boat. Lose the aft hatch and make the area under it open to the cockpit, with a ring frame.
     

  15. sean9c
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    sean9c Senior Member

    10 pages of posts that I haven't read. Did read the last few posts. I've done cambered decked boats with 1/4" ply and in my opinion it's the bare minimum in strength unless you do a lot of frames and stringers. Especially if you're going to walk on it much.
    If it were my boat and I wanted it durable I'd do 3/8" ply or maybe find something metric 8 or 9mm
    Just an opinion
     
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