Dan's Pelagic

[AlohaDan]

I haven't been up to par health wise. So haven't done much the last six months.

However I have tinkered with a rudder design.

Here's some background on some design criteria.

First source was Phil's foils. He lays out most of the construction methods and technology at:

http://www.philsfoils.com/TechInfo.html

Also sells a kayak rudder (Rather expensive and he tells why in the technology):

http://fastcomposites.ca/products/details.php?p=SK01R

Which is very similar to the WaterTribe design:

http://watertribe.com/Magazine/Y2006/M0 ... udder.aspx

With some left over plywood I decided to try and build one that might last long enough to test and see what adjustments might be required for a good performance. I based my size primarily on Steve's size and kind of used Phil's
info to trace out the foil.

So I cut out some pieces.



Then used some more scrap to build up the foil. In hindsight those piecs should have been wider to build up the foil thickness to where it should be fore and aft.



Then I continued to build the shape up using West Systems microlite fairing filler.



You can see here the foil is starting to take shape.



It's a matter of sanding between coats and building up using a cut out foil section for shaping.



Then per Phil's info I narrowed the foil a bit at the water line.



I've got it pretty smooth now. Debating whether to just glass it or go whole hog and try and make a strong enough piece using carbon fiber. When I finish, I'll make more pics.

[AlohaDan]

I had a pretty good day today, so resurrected some old shots. Some stuff is missing, so put on your thinking caps.

Here's the last check I did on hull alignment. If you look close you can see the lead weight.



Here are some dry fittings of the cockpit pieces. Second one shows the rod tunnels. Matt might want to take a look at the new Hobie Pro Angler (essentially a bass boat with yak characteristics). You tube of features is at: http://www.youtube.com/watch?v=wbr9Q36KAgc

Looking aft



Fwd showing rod tube holders.



The instructions called to assemble some of this outside the hull and then place.

It was too tight to do this IMHO. The dry fittings were difficult enough toget inside due the curved sides. Checking each time carefully I went ahead and glued by pieces inside.
the hull.

Shots aren't that great. I was already going down hill.

Looking aft you can just see the tops of the cockpit frames.



Here they are looking fwd. Scupper drain fitting in the center. Filled in some gaps with glue.



Matt's instruction called for the side wings of station 4 to be cut off. I left them on as you can see above and below to form a WT bulkhead to the after storage compartment.



There was a lot of dry testing with the drive holder, including a full assembly that had been tacked glued.





Here's the final assembly illustrating use o brass inserts for the cam cleat bolts.



It's too heavy. IMHO the pieces should be narrower by at least a third (reduce outside demension) and there would still be enough structural strength. The top piece was not needed.

Here's the cockpit shaping up.Note gin bottle were placed on the outside of the cockpit frames . I'm hoping to get at least two gallons of air storage inside.



Here's an inside pic of the mast receiver on a Hobie Adventure Island. Note the yoke.



You not only need access to it, you need access to the nut that holds it down on a machine screw if you ever have to replace the receiver (I have!). How to do this and prevent tearing the boat apart?

I put a hatch from the fwd storage compartment through bulhead #2. If the central compartment floods for any reason I should be able to drain it using this hatch and a pump. I've tried to make both bulkhead 1 & 2 WT.






Here's the center compartment:



I'm now stumbling through getting the mast receiver base just right. This entails mounting it on the upper deck (used a backup ply patch), dry fitting the front deck, and seeing how high the receiver is off the bottom of the hull. I have to drill a hole up through the bottom or from the inside so a 1/4 inch bolt comes up through the receiver and additional make sure the receiver shim is adjusted corrctly.

When I flip her back she will get the aluminun (for hardness) and graphite coats.

[Bemm 52]

When I flip her back she will get the aluminun (for hardness) and graphite coats.

Dan
I would like to know more about your Aluminium /Grahite bottom treatment
Your boat is comming along gee you've got a lot to nut out
Cheers Paul

[AlohaDan]

You can do a search on here and get quite a bit of info on graphite.

West System also makes an Aluminun additive that increases hardness and abrasion resistance.
I have a call into the tech staff to see about mixing it with graphite. Will post later on results.

[AlohaDan]

Still struggling a bit with health. Another month to go I think before doing more than minor stuff. The mast step, deck, and tunnel wall line up is becoming a deep puzzle. I may have it down though. Will take some pics as I do it.

Ok

I spoke with West Systems staff today on bottom coating.

Recommendation was to mix Al and Graphite 50-50 before adding to epoxy. Provides a slippery(graphite) hardness(Al)

How much of this mix to add to epoxy . Roughly max would be 1/3 volume, probably less. Mix your epoxy first, then slowly stir in your Al/Graphite mix.

Start with a set aside volume of 1/5 Al/graphite of the epoxy as you slowly stir in. Feel any increase in shearing on the mix stick. Add some more until you can feel this. If 1/5 isn't enough, incease slightly, keep stirring. Don't go beyound 1/3. You might not get there BTW. Test. It should still roll out OK.

Roll on a small area at a time (3 sq feet or so). Brush out with a "snow shovel" . That's a piece of roller foam attached to a stick that's been notched in one end. Work your way down the hull.

If you do more than one coat, their staff stated increase the proportion of graphite to Al. I'd estimate 3-1, then 4 or 5-1 last coat. That's the graphite to Al mix.

Here's what another builder did, but used colodial silica versus Al.(note 2002 date) I'd suspect the Al will be better. It also provides some UV protection. Note his comments on sponge rollers, however. Also recommended by West Systems. Also it looks like he had a higher ratio of the graphite mix to epoxy on all coats. On the first coat, anticipate the AL/graphite will prove as effective a thickner as the his graphite/silica mix. A reason to test your first batch for roll out.

http://tomangelakis.tripod.com/graphite_bottom.htm

[jem]

Been a heck of journey for you and this boat. I hope you get back to feeling well and are satisfied with your boat.

[AlohaDan]

OK for those interested in adopting the AI sail rig.

I was able to make this fitting for the Hobie mast receiver. For their poly pro Advenure Islands models it's molded into the hull. You fit the receiver through the hull ontop of this fixture then tighten it down using a bolt that's also molded in.






The bottom of my three piece duplication will have to be epoxied to the hull at the correct height. I first mounted the receiver to the upper deck and did a hell of a lot of dry measurements. Drilling the bolt hole through the fixture precisely vertical required a drill press with lazer beam spot, mounting the fixture in the receiver, then getting a mark on the hull so I could drill out the hole for the bolt to come through the hull up through the fixture, then the receiver itself. If this doesn't make sense, it will if youever study the mast receiver before purchasing the AI system.

I'm almost over my last treatment so should be able to get back to heavy duty glass work next week. I keep rereading the graphite threads. Do I overlap each layer like the top sketch or underlap them?

[jem]

I'd say the top one would finish cleaner.

[AlohaDan]

Ok I'm using Matt's method.

The first coat used an additive that was 50% Al and 50% graphite.

The graphite can for graphite alone said to add 10% by volume to the epoxy. This would have been a tablespoon to 5 oz of epoxy. I was probably closer to 15-20% as I was also looking for the stiffness in the mixture as described by the West System rep (see previous post)

I di not sand before the second coat, but applied it approximately 3-4 hours later when the hull was still slightly tacky. That provides a good chemical bond for the second coat usine a 2-1 graphite mix over Al.

I let her dry over night, and sanded down this AM with 120 to knock down bumbs, followed by 240 grit.



The smoothing out using a sponge shovel worked well although some small sponge rollers I picked up did a pretty good job.

One word of caution on the Aluminum. It evidently absorbs moisture and cakes hard on it's own. I had to litterally scrape it with a screwdriver to get enough powder out. There were some lumps I thought I had beat to death pounding in the bottom of a cup, but no they showed yp in the botoom of the epoxy mix even though I kept stirring as I applied the epoxy.

Be sure to war a mask when handling the Al or graphite.

I'll put the 3rd coat on later today. Pics maybe tomorrow.

[AlohaDan]

Here's a shot of the final coat. Turned out OK except for the bow. Better than the pic shows, that line is straighter.



I had laid a 6" strip of cloth down the CL. As much as I nipped and tucked I could (edit:) NOT get it to lay flat on the bow's edge. Sanded it alll off and the repair looks worse. It's only a small 5-6" patch so I am determined, but will probably do it later.

Now staring at a cutout hole for the transducer. Not sure what I'm going to do there. I have taped a piece of West systems release cloth over the outside of the hole.

Thus I'm in a position to use Mick's solution of filling in the hole with resin.

Or someone else's. Can't find the post. Pour in some glass and set the transducer right in the mix.

Or Jim Day's solution that CraigLewis recently posted. Hey Craig any report yet on the comparison test?

While I'm thinking about it, going to flip her and do some work up front.