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PostPosted: Mon Apr 14, 2014 10:50 am 
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I think that the 7 are so tight that the epoxy would stay in that center space. So I would have effectively made one fiberglass rod out of 8. However, there would still be flex between the rod and the PVC.

I'm not sure what is desirable. Do we want flex or rigidity for these toppers?


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PostPosted: Mon Apr 14, 2014 12:13 pm 
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DM06:
If it were me I would just put the PVC around the rods, stick the bolt into the bottom of the T, held on center with a cardboard cutout, tip that sucker so the bottom of the T points up, and just pour cheep fiberglass resin (polyester resin, is way cheaper than epoxy and is way more waterproof). The stuff pours like pancake syrup so it's not going venture up those rods more than a couple inches at most, besides it will help hold everything together. If you have giant openings try to fill with something just to fill some of the space.

That's the method I use on most everything. Here is some pics of my new motor mounts that I made over the weekend, it took me about 2 1/2 hrs to make. The 4 yr old single motor mount still worked fine but I had used plain steel 3/8" dia rods and they were all rusty and would have rusted thru eventually (plus it was all beat up).
In this pic you can see I just stuffed paper towels in about an inch or two below the lowest aluminum rod, then just poured away (the brown pancake syrup looking stuff is cheap polyester resin (completely waterproof)). It sets up very quickly (about 5 minutes) but gets fairly hot.

Image

Here is another view
Image

Here is the completed unit all ready to go.
Image

This is my setup for duel Honda BF2.3 engines for offshore high speed runs out to the coral reefs (I'm fully expecting 30 mph speeds with the hydrofoils mounted of course) so we can go scuba diving (current setup maxes out at around 20 mph in the trade winds). Fingers crossed

The wood is just pressure treated 2x4's, I mixed half west system epoxy, and half denatured alcohol, put the wood into our vacuum food bagging system, and sucked all the air out of the wood (impregnating the wood with epoxy), nobody tell Slaughter I used my vacuum bagging system for this ( He's is a big fan of those vacuum systems).

Hope this helps
Bob


Last edited by fusioneng on Mon Apr 14, 2014 2:01 pm, edited 1 time in total.

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PostPosted: Mon Apr 14, 2014 1:31 pm 
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Bob, I have to question your comment that polyester resin is more waterproof than epoxy.

West Systems epoxy treatment of boat hulls is legendary (and their reputation is built on it), and when my glassfibre yacht developed osmosis, I was told to grind off the gelcoat, and replace it with a slurry of epoxy resin and solid glass beads.

After several build-up coats of this supposedly impervious mix, I then switched to epoxy resin plus micro balloons (which being hollow, sanded more easily), and then multiple coats of filler etc.

Of course, I should add that in the context of a masthead fitting, the difference in resins is moot.

_________________
Tony Stott
2012 Tandem Island "SIC EM"
www.scenefromabove.com.au


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PostPosted: Mon Apr 14, 2014 1:59 pm 
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Tony:
Of course West systems epoxy is legendary stuff, but also very expensive (4x the cost of polyester resin), I use so much of the West epoxy I have a dispensing system in my garage. DM06 was talking about picking up something like Devcon 5 minute epoxy at home depot, which is not water proof at all (and states so on the can). If I have a choice between polyester resin and cheap epoxy in a marine environment (cheap epoxy turns white right away and disintegrates in water, if you look at any of the early Hobie TI masts the epoxy that held the furling drums on all mine was white as a ghost, and they all let loose) I'll always pick polyester resin for bulk stuff that I know is going to get wet, plus it's cheap ( I've built several wooden boats over the years using both epoxy and polyester). The only exception being when you are working with Styrofoam and some plastics in the same family ( ie... ABS), then you have to use epoxy only.
I only vacuum impregnate wood with epoxy (really common in boat building), never tried polyester, don't even know if it would work.

Bob


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PostPosted: Mon Apr 14, 2014 5:22 pm 
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KonaTI2 wrote:
This photo shows the jib as it is relative to the main sail.
Image
Today I have raised the jib 12" to see if there is any improvement in performance.
Having any luck with this mod? I was wondering if you went out in any of this "big wind" lately. (Last weekend it was running 20-30mph).

Certainly, 10-20mph is a decent (normal) day here on the windward sides. Any feedback to offer about how the Jib does on days like that?


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PostPosted: Mon Apr 14, 2014 10:28 pm 
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Nohuhu,

I did some sailing with the sail raised and didn't notice any difference in light or moderate winds. I didn't like where I had to relocate the jib lines and trying to furrl the jib didn't work as the furrler was 12" higher and just wanted to bow the fore stay line. I like having the jam cleats in a row on the front haka bar. It keeps things simple clean and easy.
Image

I have had the jib out in the stiff winds........what I find is that I'm wanting to furrl the jib after about 18kts. As the wind increases and the mast bends the jib starts to lay more to the horizontal and I'm not seeing an increase in the speed so it seems like unnecessary stress on the mast for minimal gain if any. All the while my partner is out on the haka platform to balance the boat. It seems best to have her hike out about half way to keep the windward ama just out of the water so it creates no additional drag yet provides balance.

Here is a video showing what I feel is optimum wind for the jib sail. It is a you tube video but I can't find how to post the link directly ...sorry. Hobie Tandem Island sailing on the Jib!


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PostPosted: Tue Apr 15, 2014 4:01 am 
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Kona:
I used to have my old jib control lines rigged the same way as yours, I found they didn't want to pull out as easily if I wrapped them around them around the aka bar first, then thru the harken cleat. I had much lighter line on mine and would run the line from the sail back around the little round cleat above the mesh pocket, then up to the cleat. This saved me from having to adjust the cleats all the time from left tack to right tack. I would just grab the line and pull it over the post on the tack I needed at the moment.
With my current jib since it has a boom I only need one light control line that I cleat into the rudder up cleat by the left mesh pocket. On a right tack the jib halyard line prevents the jib control line from getting tangled in my main and foot pedals. Since it's a rigid symmetric wing I only need to release it and let it weather vane when not using it.
I had the same results as you in higher winds with my old jib ( we don't get those kind of winds around here except one month a year at best). With the jib there is so much healing moment on a reach it helped me a lot to only show about half the jib (partially furled) in winds over 12mph, I was still able to point closer to the wind. Actually because of the shape of the inter coast 90 percent of the time we are either upwind or downwind sailing (seldom on a reach). I found our best point of sail to be almost upwind, gives me the best vmg). What I do is point upwind pull both the sails full out and pull them as tight as possible. I the start pedaling like mad and slowly turn off the wind until the sails catch. You end up sailing upwind at a very good pace about 15 or 20 degrees off the wind ( the best point of sail on my boat anyway ( reach is the worst). This is an un-natural mode and you have to keep pedaling lightly and keep tight rudder control to maintain, I found if I stop pedaling the boat just rounds into the wind and stops. You have to be very careful though in 15 to 20 mph winds doing this though because if you turn off the wind too far you go over so fast it's crazy. Actually there is very little strain on the mast. Fortunately with my boat anyway if I'm not paying attention my boat naturally just points straight into the wind and stops rather than going broadside to the wind, where if that happens you have to release and furl the sails very quickly. In higher winds (over 10-12 mph) I find furling the main in a couple turns gives me better performance. With a jib the TI is a different animal ( in my experience anyway)
Hope this helps
Bob


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PostPosted: Sat Apr 19, 2014 8:30 pm 
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Whered yall get your stainless attaching hardware? My boats only seen freshwater so there is like zero corrosion on any metal part thus far.


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PostPosted: Sun Apr 20, 2014 1:26 am 
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The ability to furl some on both sails should be a huge help in big wind. Bob seems to confirm this.

I believe a smaller jib is what's called for on our AIs and TIs, anyway. There's too much mast deflection and not enough rig strength.

Keep trying Kona, this is getting interesting. (Winds are predicted to gust up to 50mph on Easter Day).


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PostPosted: Mon Apr 21, 2014 6:45 am 
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DM06 wrote:
Whered yall get your stainless attaching hardware? My boats only seen freshwater so there is like zero corrosion on any metal part thus far.


Dense foam too. Thought I could pilfer some from an old PFD but they appear to be made of a bunch of thin sheets of foam.


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PostPosted: Mon Apr 21, 2014 12:35 pm 
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NOHUHU,

I have been using this jib now for around four months now. It is 5' at the foot and 15' 3' on the luff. I really like this size...a lucky guess. I feel it gives excellent performance in the light to moderate winds it was planned for and provides a good benefit on down wind runs in the bat wing configuration.

In higher winds even the main sail alone needs some reefing. We are working within the design limits of the TI displacement hull to optimize performance within it's range. The jib modification is very useful even though the speed advantage is modest. Typically in most light to moderate winds 4-6.5kts boat speed is all I can expect 14-18kts will produce 6-8.5kts bursts to 9.5. Usually in the higher wind range you are dealing with rougher water conditions which goes smoothly but demands a bit more attention and of coarse my partner hiking out.

The moderate winds 8-12kts are the most fun. Usually calm rolling water things trim up nicely. Reference the You Tube video in my last post....ideal conditions. I plan on running things just as they are. This is what works for me others will find what works for their situation. It is so great to have this forum to see all the Ideas people share.
Image

Live Aloha!


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PostPosted: Mon Apr 21, 2014 1:31 pm 
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Trying to put the mast topper together today was pure comedy gold.

Had everything sized right, cut to the right lengths, plan set, ready for the resin. First batch, use the resin: hardener ratio stated on the back of the can. Stirrrr stirrr stirrrr, waiting for it to start to get to a sirup consistency to start pouring. All of a sudden, wham, I'm stirring jello. And ouch, the jello is hot. Zero to unworkable in literally 5 seconds.

OK. Batch 2. Pour around 8 oz in a red solo cup (my other cup now ruined) and instead of 10 drops of hardener per 1 oz. I just put in 20 drops. I'll have plenty of time, I say.

Stirrr stirrr stirrr....fast forward 15-20 minutes later, stirr stirrr st--it's eating the cup. Crap. Pour it into another cup, I think it's starting to set. Here we go, pour it into the T. Dissipating through the tubing between the rods, Pour a little more. Cool, looks like-- hey why is there an exrta rod sitting over there? CRAP! Grab the rod and try to push it in. Normally the middle rod slides in with no effort but the bundle had collapsed on one end. Crap! Hammer, hammer hammer till the rod starts to splinter. Crap! Saw the rest of the rod off and shove it into the other end of the PVC. Hammer hammer hammer. Epoxy flying all over the place. My rubber gloves tore to pieces. Crap, my last garage pair. Go inside to get a new box. Crap! They're size small! Run back outside with gloves half on. Epoxy running out of both ends of the topper. Crap! Saw saw saw the 8 rods from the 2nd end and cap both ends.

Breather. OK bleeding is stopped. Epoxy in cup....still not setting. Stirrr stirr stirr. Fast forward 10 minutes and considerable cleaning.... stirr... Screw it. Add 10 more drops of hardener. Go time! Pour! Get that bolt set! Pou--ran out... Bolt set, bolt set!

After action review:
PVC topper with 7 in-tact fiberglass rods running the entire length of topper (8th cut and hammered into each side).
Epoxy with very little hardener in all but the T of the topper. Will it ever cure/harden? Or forever stay a sticky liquid? Beats me.
Enough legitimately hardened (warm to touch) epoxy on the top half of the T, half way up the bolt.
Empty space the rest of the way up the bolt.
Itchy fiberglass embedded in hands and arms
Sticky epoxy everywhere.



I don't know if I can trust this thing or if I should start over again. What a mess.


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PostPosted: Mon Apr 21, 2014 2:43 pm 
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:lol: Priceless!


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PostPosted: Sat Apr 26, 2014 8:22 pm 
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Well I did it, I ordered my second honda 2.3 engine an a pair of ten inch pitch props. Currently with the 7 inch prop running alone without sails just above engine idle (just enough power to engage the centrifugal clutch) propels the boat between 4 and 5 mph. I'm expecting with the higher pitch props that number will be just over 8 mph at just above idle. If the wing sail does it's job instead of sailing at my current 7-10 mph at 1/4 throttle, I expect the boat to sail between 10-12 mph in very light winds running engines at 1/4 throttle. At this point I think I will be hitting the famous brick wall speed wise because of the stock semi displacement hull design.
I have already prototyped out the new back of the boat converting the hull into a semi planing hull (actually shaped just like the hull rear on the weta tri) and it seems to do the trick. As speed increases with a wider behind the rear of the boat no longer squats as you approach displacement speed which will hopefully get the hull up on a semi plane. Once I overcome the brick wall (max displacement speed).
It will likely take me a month or two to get everything dialed in.
My near term phase 1 goal is to average 15 mph plus sailing speeds while still maintaining more than 50-75 mpg using my current setup with the stock Hobie mainsail. I'm still a year away from replacing the Hobies stock sail with a true wing main sail.
Hope all this stuff works.
Bob


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PostPosted: Sat Apr 26, 2014 9:55 pm 
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Hi Bob,

How did you attach the 2x4's to the metal rods? Also, do the rod holders handle the torque of the motors pretty well without stressing the plastic?

I am currently trying to get mine set up with an old Johnson 6hp but I have it mounted on a 2x6 bolted to 2 metal pipes that I put into the scupper holes. The 2x6 rests on the sides of the kayak. It works ok but I think your setup might be better. I tried a test run the other day but the motor kept slipping out of forward gear. I am in the process of rebuilding the gearbox and will try again. Running as bad as it did though it looked like it was very close to planning with the old 6hp 2 stroke.


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