Trimaran - Especially Searunner - Owners

[Boatguy30]

Here is a pic of the Yanmar 3YM30 I fitted into the Searunner 34 Serenity earlier this year. There is just clearance to remove the air cleaner and access for a medium build person to the front of the engine and water pump is pretty good. Top view pic was take prior to rebuilding that area of the cockpit.

Note the engine beds and entire centerboard trunk were also replaced.

[PhantomBoatwork]

Thanks, that is a great help, and thanks for the nice comments about the table.
John designed the epoxy/polyproplene bushings around a 1" stainless steel shaft bonded in place. I asked John about that, and he said that he wanted to avoid any holes below the water line. The trim tab I want probably won't be for a wind vane, just a tillermaster in the sterncastle.
I just now ripped my wood "cheeks" for the skeg and rudder and laid out the lines for both parts on my 1/2 plywood. I've got several rolls of bi-axial cloth in various width and intend to use it a lot. If you have a little patience, that stuff will contour around some amazingly tight corners. Bi-axial is the only way to go, IMHO.As for the number of layers of cloth, well let's just say that I have never seen a Searunner that didn't have some issues with cracked glass below the water line on either the rudder or center board.

[sassarassa]

Originally Posted by Boatguy30

that looks to be a 2QM15 made from 1978-81

Cheers,
Jeff

Definitely a 2gm20 - just cleaned off the model plate to check - it had every water gallery in the block clogged with salt except one, which let water into the cylinder when the head gasket blew.

Really looking forward to seeing the performance of the new engine.

[sassarassa]

Roy

Thanks, my shaft is shorter (he he I have never said that before) in the 37'. So I would be over the moon if I can get similar performance.

My shaft had not been removed in years. The one support bearing had to be cut off. The gearbox coupling broke 2 pullers before coming loose. Also there was no cutlass bearing in the stern tube. The new bearing only slid in 3" before binding so I just cut it off. I slid it in from the inside because from outside it wouldn't fit. Weird?

[sassarassa]

Mark,

Have you got any more details on the metal-less rudder design? My lintel pins all have huge amounts of play. All but the bottom one look easy to fix with a larger hole and bigger pin. The bottom one looks like some kind of pin that slides ip inside the rudder setup - I haven't pulled if off yet to see properly.

Cheers

Jon

[Boatguy30]

Possibly a 2QM20 higher rpm version of the 15.
That engine in the pics is not a GM series engine.

anyhow, of little matter now. good luck with the new engine!

[Mark Johnson]

Good job Jeff. I bet it was a beast, but obviously, even a total CB trunk replacement can be done...

The "Drive Saver" is a good idea, and the advantage of the longer shaft here is that the shaking of it further back, (with the engine), is a bit less at that point.

Before setting out cruising, Vincent would be well advised to do a dry run, or at least choreograph, the first replacements and maintenance basics, to be sure it can be done without removing the engine.

Paramount... he needs to be able to bleed the fuel lines, for when he runs out of fuel someday... (happened twice in 17 years, for us).

Obviously he needs to be able to adjust and change belts, and if his alternator is like ours, re-align it each time.

The impeller will need replacements, and the first two failures are likely to be the mechanical fuel pump, and then the raw water pump itself.

If necessary, he may want to saw a large round access hole in the frame at the front of the engine, (avoiding the timber at the edges), so he can perform what he needs to, from the front cabin.

Might also be good to have stringers on the hull and CB trunk walls so a temporary piece of padded ply or composite floor, can be layed across them. This would allow crawling on the top of the engine, without actually crawling on the engine itself.

For all of us... I suggest a dusty dry bilge, ALWAYS! This has maintenance advantages, and lets one know it there is an engine leak or something. (The engine is the #1 source for flooding the hull).

If there is a conventional shaft seal, a 1 gallon or so sump under and around it, with a small bilge pump inside, will leave that dusty dry bilge, even under the engine, in spite of the normal occasional dripping of the seal. An engine diaper takes care of engine oil drips.

Keeping the well glassed and epoxied engine bilge area a light color, 100% sealed, bone dry, and pristine, as well as regular engine wipedowns, is how we find minor engine problems long before they become major ones.

M.

[PhantomBoatwork]

Originally Posted by sassarassa

Mark,

Have you got any more details on the metal-less rudder design? My lintel pins all have huge amounts of play. All but the bottom one look easy to fix with a larger hole and bigger pin. The bottom one looks like some kind of pin that slides ip inside the rudder setup - I haven't pulled if off yet to see properly.

Cheers

Jon

Sure. The skeg and rudder have epoxy/polypropylene cloth bushings made by wrapping saturated poly cloth around a stainless steel shaft. The shaft is waxed with four coats of paste wax, or wrapped with waxed paper and the cloth wrapped around it. Then short sections, usually 3-6 inches are cut off and bonded in a trough in the skeg or the rudder. The stainless shaft is used to align everything perfectly on both pieces. Lots of bearing surface no metal to metal contact. Am just now starting the whole process, so I'm no expert my any means. A fellow multihuller who lives near here made a bushing like this, but the tolerances were so close that he couldn't remove the bushing from the shaft. I'm guessing that the thickness of a couple layers of waxed paper will be more than close enough.

[Boatguy30]

Mark

He will have a difficult time getting to the engine. access thru the forward cut outs is even tighter with no space to really make them much bigger meaning the forward port would not help. you or I could work on this engine really easy.

Jeff

[Mark Johnson]

Originally Posted by PhantomBoatwork

Thanks, that is a great help, and thanks for the nice comments about the table.
John designed the epoxy/polyproplene bushings around a 1" stainless steel shaft bonded in place. I asked John about that, and he said that he wanted to avoid any holes below the water line. The trim tab I want probably won't be for a wind vane, just a tillermaster in the sterncastle.
I just now ripped my wood "cheeks" for the skeg and rudder and laid out the lines for both parts on my 1/2 plywood. I've got several rolls of bi-axial cloth in various width and intend to use it a lot. If you have a little patience, that stuff will contour around some amazingly tight corners. Bi-axial is the only way to go, IMHO.As for the number of layers of cloth, well let's just say that I have never seen a Searunner that didn't have some issues with cracked glass below the water line on either the rudder or center board.

Sounds like you have it all sussed out, (as my British friends say).

GREAT that you have a version of the minimal metal / no bolts, rudder attachment. Its brilliant in my book...

You are right that most Searunners eventually developed problems with the rudder/skeg, and or the CB and its trunk. 99% are vastly under glassed here. By using the schedule I suggested, and thick spots where needed, including double glassing the trunk's interior, as well as filleting and glassing in those pin receptor through hulls... we have never had a bit of trouble with these areas. Like I said, we need to keep the boat light, but this is NO place to save weight!

I also used 3 descending width layers of bias cut tapes, on every single radius on the boat, above and below the rub rail. The hard "corners" on the hull and cabin got twice this! I have never gotten a "zipper" in these failure prone areas either. The overall additional weight is minor, because it is only 1% of the surface of the boat that gets this glass schedule.

Your bi-axial sounds great for this. It must be a loose weave to compound bend. The Bi-axial I have used was too stiff for tight compound radii, but I know it comes in all forms these days. With regular 10 oz fabric, cut on the bias with no selvedged edges, I can actually glass a golf ball! For really tricky spots, patches of this might still be better, but otherwise, your bi-axial is probably stronger.

Sounds like you're set on using the trim tab. Just a thought... Since the load is so very small, why not make it of glass/epoxy composite, to avoid the "issues" with under water metals. Metals are hard to keep paint on, even with 2 part primers, and once bare, really attract barnacles! (Due to the small current they create, barnacles attach at twice the rate of even "bare" fiberglass).

Post some photos of your project! I love that design...

BTW... Where I REALLY wanted a "tank", was the keel. I glassed it and its fillets about 1/4" thick, with the rubber flap held on by a glass worm shoe, that's 3/8" thick! Having gone up on an oyster rake at speed once, leaving DEEP groves, it was worth the effort. Once wood gets wet, it swells, and things start to "change". Prevention here, was easier than the cure.

M.

[Mark Johnson]

Originally Posted by PhantomBoatwork

Sure. The skeg and rudder have epoxy/polypropylene cloth bushings made by wrapping saturated poly cloth around a stainless steel shaft. The shaft is waxed with four coats of paste wax, or wrapped with waxed paper and the cloth wrapped around it. Then short sections, usually 3-6 inches are cut off and bonded in a trough in the skeg or the rudder. The stainless shaft is used to align everything perfectly on both pieces. Lots of bearing surface no metal to metal contact. Am just now starting the whole process, so I'm no expert my any means. A fellow multihuller who lives near here made a bushing like this, but the tolerances were so close that he couldn't remove the bushing from the shaft. I'm guessing that the thickness of a couple layers of waxed paper will be more than close enough.

Phantom answered your question...

I might add, wrap the rod with it warm, and let the fabric run wild, (past the end). After set up, applying mild heat to the bearing wrap, while the other end of the SS rod is in a bucket of ice water, will aid removal. Having some of the new cylinder hanging off the rod, gives something to grab with needle nosed vice grips. It also helps to make short sections of these bearings at a time. I had no problem, and ended up with a "0" tolerance, rattle free fit.

I would then glass the **** out of these, (after making the complete bearing), especially the ends and wraps.

Properly done, it is a brilliant improvement over nuts and bolts, and SO much easier to live with!


FOR THOSE OF US STUCK WITH NUTS & BOLTS RUDDERS...

If your rudder "rattles" when turning, or while motoring, and it bothers you, there is a way to improve this... The plans call for hardware with 1/2" holes in the gudgeons, and using 1/2" bolts for pintle pins. I started out with this.

I found that 1/2" bolts are not really 1/2" dia! They are a bit less, for easy insertion into a true 1/2" hole.

This is not true for 1/2" unthreaded rod, which really is 1/2" dia. The problem becomes getting it into the holes, with a "0" tolerance fit. Your alignments have to be perfect!

I cut sections of the rod, that were 2" longer than the bolts that they'd replace, then drilled small holes, (upper & lower), in the rod, (easing their edges at the ends). These are for cotter pins. These would hold the pin in place.

I then tapered the last 1" of the pin, and gently rounded and polished the bitter end.

Before installation, I put in homemade sheet Teflon washers, on the gudgeons bearing surfaces, after greasing them and the holes in the metal with TefGel.

Then I wiggle the rudder into place, and start the first (upper), pre greased and tapered end pin. It has to be carefully driven in with a small hammer, while moving the rudder side to side. It takes effort and time.

Then I do the same to the bottom, (WL) pin.

Much earlier, I had removed the very bottom skeg gudgeon, and had a nut welded on the bottom of the hole, which I later drilled out to match the existing hole. This increased the lower pin's bearing surface by 300%. Then I slightly tapered the rudder's pin, so it would go into the hole.

On assembly, this also gets greased with TefGel, and I have removed the rudder about 4 times now.

The underwater metal that started out polished and zinc protected, is now unprotected, primed, and bottom painted. When bare, it attracted barnacles like bait, and now, other than little spots, corrosion hasn't been a problem... at least so far.

This has made a 15 minute job to install the rudder, into a 2 hour one, but the boat steers literally, like I had power steering!

M.

[sassarassa]

Originally Posted by PhantomBoatwork

Sure. The skeg and rudder have epoxy/polypropylene cloth bushings made by wrapping saturated poly cloth around a stainless steel shaft. The shaft is waxed with four coats of paste wax, or wrapped with waxed paper and the cloth wrapped around it. Then short sections, usually 3-6 inches are cut off and bonded in a trough in the skeg or the rudder. The stainless shaft is used to align everything perfectly on both pieces. Lots of bearing surface no metal to metal contact. Am just now starting the whole process, so I'm no expert my any means. A fellow multihuller who lives near here made a bushing like this, but the tolerances were so close that he couldn't remove the bushing from the shaft. I'm guessing that the thickness of a couple layers of waxed paper will be more than close enough.

Thanks Phantom and Mark,

Could I do this just for the bottom lintel - it needs a redesign/rebuild anyway? The others should be fine with just oversizing the hole and pin.

Am I correct in thinking that there will be many, many wraps of saturated cloth to build up the desired thickness in the bushing (maybe 20 or more)?

Sorry for the questions but my small brain is trying to picture the process properly

[PhantomBoatwork]

Not really sure about the number of wraps. The construction manual just said to saturate the cloth on a piece of polyethyele film and roll it up on the shaft to the right thickness. Doesn't take an awful lot of cloth to get the desired thickness, just roll it up. John Marples did suggest that you roll the end up on a wooden dowel of the same diameter, and use that to pull off the bushing. Sounds good to me, I'll let you know in a few days how it works out.
BTW, the trim tab idea is just a holdover from some of the old ideas in the original Searunner construction manual. I'm not going to put in a wind vane, and having a wheel self steering would be a WHOLE lot easier. With the trim tab, I would have to put the tillermaster clear back in the sterncaste, and the controls in the cockpit. Not the best configuration, upon reflection. I'm going to do a re-think on the trim tab, and maybe eliminate it entirely. Most of Jim Brown's ideas were and are great, but that doesn't mean that some newer ideas aren't just as valid. I mean, would anyone go back to AC fir plywood and polyester resin to build a trimaran? Not me. And thanks for all of the input from everyone.

[PhantomBoatwork]

Since it is difficult to explain exactly what is shown in the drawings, I decided to copy and post a portion of the plans. My sincere apologies to John Marples if this violates his plan copyrights, but since this is the Searunner/CC trimaran owners, I thought this would be very helpful, and it certainly details what he specifies for the "no metal" pintle and gudgeons on the design. Brilliant stuff, and very practical. John knows very well whereof he speaks (and designs)

[Roy M]

Mark, just wanted to make sure you got the message I sent regarding Coppercoat. My neighbors just hauled out after six months, and their bottom was a disaster area. You were absolutely correct. Search the forum for the pics, I sent it to several discussions on bottom paint.