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Tamanu cat ideas

Page history last edited by dstgean@... 12 years, 4 months ago

7/20/11  We managed to drag the hulls out of the garage, get the beams fit, and actually paint a bit on the hulls.  However, I didn't reprime after fairing a bit and the red I chose would never cover.  So...three coats into the red I decided to make a tactical retreat and reprime.  I had the paint lady at HD add some red to the primer to maybe speed things up a tad and I ended up with pepto pink.  Not one to be easily deterred, I rolled it on anyhow and it kinda remended me of my daughter's little stuffed animal so creatively named "pink pink".  I had to drag it over to get a photo for her which I now share here.

After an afternoon's embarrassment over my pink boat, not warranted really as I feel I could rock a pink boat if necessary, I rolled and tipped out a coat of RED, retina burning red from the Glidden porch and floor oil based paint.  Not exactly Interlux Perfection, but neither is my fairing job.  It works for me and isn't silly glossy.  I still have several more coats to go at this stage, but the plan is to have white decks and red topsides and footwells.


6/2/11  Well it's been a crazy three months where not much got done.  However, school is winding down and I'll have a bit of time to work on the boat.





3/21/11  First day of Spring!  The weather cooperated as well, so I dragged the hulls out to the driveway to align them.  Here's a look at rhe boat side of the garage.  Hi, My name is Dan and I'm a multihull 'ohaulic.

Here's some detail shots of the beams sitting on the new beefed up spots.

Although the hatch looks buried, it is actually accessable if needed.

Here's the other side showing the deck crown.

Here's a shot of the boat from the side looking at the beam landing on both hulls.

This is the stern view with the stack laminated rear beam and the box beam forward of that.

Starboard hull with both beams.  I'll probably scribe the aft beam to the deck contour.


I was perusing the L7 list that Mike Leneman runs and he suggested I add some glass tow to bond the beams to the hulls as a really bomber way to go.  Should I go with carbon or glass to do that?




Brian and I got the hulls dragged over to the high school which is nice as their shop is a toasty 68 degrees.  Not to mention having lots of tools...  So, the plan was to add structure to the hulls which will allow  the hulls to bolt up to the beams we've built.  On to pictures!










I've got the hulls dragged into the driveway to do some mockup work and decide on how to attach the beams to the hulls.  I have a couple different ideas on how to do that.  Here's a couple different ideas on how to bolt the

beams in place.  Thoughts?



Well it's Valentine's Day and my sweetie and kids are in San Diego visiting my folks.  I guess I'll have to work on the boat....  I've got the main beam done and have the aft beam stack laminated.  I'll be changing the method I'm attaching the beams a bit after a note frim Gary.  Instead of a bulkhead extension only, I'll be making a Wae or crossmember the width of the footwell.  This will span the footwell and be braced to the sides of the footwell as well as the bulkhead.  the bolts holding the beam to the boat will be placed vertically down through the beam and into the Wae.  I could lash this beam, but I'd lose some beam from the overall hull.  Additionally, I will be gluing a wae under the aft deck and bolting the back beam in place as well.  The deck will at least for this summer be cedar supported by some 1x4's running across the hulls.  A lighter ply and foam deck may be in the offing later.  Anyhow, the 50 degree temps are letting me mock some of this stuff up on the driveway.  I still have to fashion something for the Hobie 18 mast step to sit on & decide if the SS post should go through the beam or just get epoxied to the beam itself.  Thoughts?


Here's a shot of the beam with the last lamination on top.  This is why you hear the phrase, "You can never have too many clamps."



Brian and I got into the shop to continue building the beams for the cat.  We had stack laminated some OLD doug. fir reclaimed out of some beams in my house.  However the stock wasn't perfect and the resultant stack was heavy!  Gary describes building some box beams, and we decided to pursue that approach.  Cutting the sections away was a challenge as my saw did not cut all the way through & drilling was tedious.  I finally got it done and we were able to get the 6mm sides out of a single sheet of ply by cutting on the diagonal.  Pictures forthcoming.  I'll have to laminate one more layer on topto get the desired strength, but I'm impressed enough to be thinking of doing the same thing with the aft beam.  I'm also not totally sure if I should go with a laminated ply/foam/ply approach for the deck panels or go with lateral stringers and fore n' aft cedar decking.  Pics forthcoming.

Clamps! This shot is laminating the ply to the sides of the box beam.

This started life as beams in my 1950's addition to my house.  I had them removed while remodeling and resawed them into 1x4" material.  Althought the stock was douglas fir and of good quality, there were still some knots.  I decided to stack laminate the pieces to make sure no one knot would jeopardize the structure of the beam.  The stacked beam is pretty but HEAVY!  I decided to cut it into a frame of a box beam and removed the middle of the stack leaving solid material where the beam crosses the gunwale and at the mast as well.  What a pain--I'll make box beams again, but not starting from a stack lam.  A waste of material too.  We were able to get the beam skinned in 6mm ply by using the sheet on the diagonal to cover the 8'6" width.  The result is light enough I might go through the hassle of doing it to the rear stack laminated beam as well.


I'm also figuring out what to do with the deck.  The easiest thing is to run some 1x4 material across both canoes and deck it with cedar.  It might be lighter to go with a foam and ply hard deck though...still deliberating on that one though.



Well after digging out of 2' of snow and the joy of -1 degree F following that, I'm ready to think about warm weather pursuits!  I've decided to go with the above the deck beam setup.  Here's a MS Paint sketch which seem to get compressed here, but it get the idea across.  I have yet to decide if I'm going to use Dierking saddles or the bolting option mentioned below, but the generall look is now defined.  It's easy to mess around with it on the computer and not get any motivation to do anything in the shop sometimes...but Brian and I will be in there this Saturday fairing the hulls and building the beams.

Here's the updated look.  Any comments?


Well, after drawing up several variations, I thought the two most promising variation are a flush deck design at the expense of underwing clearance or a raised deck that will help hide the beams a bit and give a bit more footwell depth.  Thoughts?  My other decision is on whether to lash the beams to Dierking saddles or to bolt the beams to bulkhead extensions.  I'd get a couple inches of extra beam that way...


About to get going with my double Tamanu/H18 mashup.  My plan view is kind of like this:

I havn't decided on whether to lash, bolt, or bond the beams and deck to the hulls yet.  What you see in the drawing, beginning at the bows, is a mast section 2' back from the bows to hold a tramp, the main beam is 7' aft of that (a seriously overkill main beam after cracking the h18 beam in the T200), a 7' hard deck flush with the deck, and a strong aft beam as well.



Here's a profile view.  I need to decide on whether or not to have the beams flush with the deci or recessed a bit into the deck.  Advantage of the deck version is it gets the beam up higher and therfore the boom too.  Additionally it will help eliminate beam/underwing slap.



Well after consulting a bunch of people, I've come to a decision.  I'm going with the 8'6" beam version despite it's more limited stability and smaller camping area on deck.  What steered me towards this solution is that I already have some 8'6" beams mostly laminated up, the boat will be rightable like a standard Hobie 18, the deck area will be enough to set up a standard tent, and I can focus on getting a set of reef points sewn into the Hobie main.  If I were a bit more cash flush, I might have a set of sails made up with slugs in tanbark with two reef point already in.  However, that will have to wait for another day...  In the meantime, I'm going to get busy gettign this boat finished up and looking sharp.



Well the boats sat for a full year... that stinks.  After a full blitz of getting them done for the Texas 200, we coasted this year with other priorities.  I had a boy in April and that eliminated me from doing a trip in the summer.  Brian was crazy with work...


Now, however, I'm thinking of finishing the boat in a manner that will allow a nice camp cruisable catamaran.  I have not decided among the three iterations rolling around in my head though.


They are:

1.  A narrow beam cat with a small rig pirated off of the Ulua viewable here on wikiproa.  It would be narrow enough to fit in the garage--so 7'10"?

2.  A narrow beam cat that is 8'6" wide and uses the larger rig of the Hobie 18.  It would need wings and the rig would need two reef points to make for a safe cruiser.  Alternately, I could use the Ulua rig, but it is a bit underpowered.

3.  A folding version along the lines of Woods Wizard without the pod.  It would be about 11' extended and 7'6" or so folded.  Unlike Woods version, this one would ride on its trailer on the hull sides which are flat panels.  It would also use the Hobie 18 rig.



4.  A couple of other folder ideas like the Shark catamaran or TF Jones' cats, a folder along the lines of the Seaclipper 20, or a sliding beam version like the L7.


Thoughts?  Comments?



Comments (2)

dave.pont@... said

at 3:51 pm on Feb 14, 2011

Hi Dan. Not making the aft beam hollow? Presumably the hollow front beam is solid where the bolts will pass through? I made an outboard bracket like Gary's Fiji Tamanu, a 2x4 which passes clean through the hull to project out both sides. This is immensely strong construction and I now wish I had done my wae like this. You might consider this for your wae, they dont have to project out far in your case as not lashing, say 1/2", but this would really lock them in to the hull.
Hobie mast step and SS post - is this the dolphin striker, like a long bolt? Can you avoid weakening the main beam and fabricate a tube on the front face of the beam for this to pass through, ie add material rather than remove material at this high stress point. Whether through the beam or outside it a PVC or metal tube epoxied in?
I'm enjoying following your progress, cheers Dave (with the S&G Ulua).

dstgean@... said

at 11:38 am on Feb 15, 2011

Thanks for the comment Dave. Good ideas! I'm of two minds about projecting a 2x4 through the hull sides as I have a 1/4 turn port I don't want to cover up. I suppose I could remove it and glass the cutout back in...but I don't think so. I think instead I'll space out the wae from the bulkhead enough to get the plate off and on and bond a wae that sits flush with the gunwales and is notched to go under the stringer. I'd like to move the whole mess forwards a bit to the front edge of the footwell, but that would mess up the jib spacing and potentially shorten my fron tramp.

As for the box beam, I left a bunch of material in the gunwale location as well as in the center for the mast. I do agree that I'll NOT take all that material for the mast--although as I understand it, it wouldn't make the slightest bit of difference in strength other than removing a few fibers that are under tension or compression. I think I'd rather build up the curved section out of a chunk of Doug fir and only use a portion of the dolphin strikerto locate the mast step and use screws to secure it.

I'm wondering if I did move the mast up a bit to the front of the footwell if the loss of foot dimension wouldalter the set of the jib too much.


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