Uni-directional carbon fiber in the rudder blade (updated)

There are a number of steps involved in getting the basic foam core re-inforced properly.  After the wrapped high density core is inserted,  some unidirectional carbon fiber tape has to be laid down on top of it.

Here are the pieces of tape cut to length and ready for application.  I used a 9 oz. weight carbon fiber  tape.  I can never get the tape trimmed as perfect as the plans show it.   You can also see the rebate around the high density core.  I tried to tailor the depth of the rebate down the length of the blade but I am sure some fairing putty will be required to get the profile shape back.  I'm always slightly phobic about making the rebate deep enough (is the high density core too thick?, is it mounted properly?), but I just stick to the dimensions indicated in the plans.

First I filled up the gaps around the rounded corners of the high density core with some high density putty.

And while still wet applied the layers of carbon tape.  The epoxy saturated  carbon uni-directional material really needs to be compressed and using a plastic sheet to squeeze out the excess resin really does minimize the overall thickness, which I think is what you really want.  

Everthing looks good and when it's cured I will apply the fairing putty to the trailing edge of the blade and recover the profile shape over all this carbon fiber.  Then turn the blade over and do the other side.

Updated December 23rd

Work has slowed a bit with Christmas and other projects but I have made a bit of progress in finishing off the one side of the rudder blade.

The above picture shows the trailing edge cut away to the centre and is ready for the lightweight putty fill.  The original layer of 6 oz fiberglass cloth really helps here to cut away one side of the blade at a time.

Here is the blade (port side) with the putty applied and sanded down close to a point that is almost ready for carbon fiber cloth sheathing.  I will now turn the blade over and finish the other side but  I have run low on carbon fiber and will have to visit Noah's or Canada Composites soon. ( A trip to the other side of Toronto).   I want to make sure I have enough material to finish the blade and rudder case.  This will be my last post of the year so merry Christmas and a happy new year to all.  2009 should be interesting. 

Inserting the final high density core into the rudder blade

The final high density insert has to be wrapped in carbon fiber (F-22R option) and helps to create the longitudinal rigidity required in a modern lightweight foam rudder.  The high density foam is tailored in thickness so that further uni-directional carbon can be added on top of each side without adding thickness to the rudder blade.

I wrapped the upper and lower halves seperately so that it could be held for wrapping.  You can see the plastic stretch wrap which really helps to hold the carbon cloth in place.  It also allows all the excess resin to be squeezed out to either end.  

For some reason I decided to shape the foam before glueing in this core.  It probably would have been easier to insert the tailored wrapped core into the original rectangular block of foam, and then do the shaping.  Inserting the core after shaping required the use of some simple jigs, spacers and clamps to make sure there was no twisting or mis-alignment in the blade while the epoxy glue was hardening.

The offcuts from the original blade block of foam were put to good use.  The operation was successful and I am now putting in the rebates for the uni-directional re-inforcements.

Rudder blade foam shaping

Fellow builder Menno had a idea that he shared on the builders group.  He wrote

"My idea is to draw lines on the blank lengthwise, combining all points where the rudder/centerboard has the same thickness. Then use a router to make grooves with the correct depth and use those grooves as a guide..."

Something about this idea stuck with me and the thought of again artistically shaping the blade through the use of the templates seemed like a lot of work.  I know,  I shaped the daggerboard that way last winter.  So I decided to give the router approach a try.

Above is the block of foam with the high density inserts in place.  The block is thicker than required but I wanted to glue the foam  so that the centre had a glue joint.  I also applied a light fiberglass cloth in this centre joint (as I did on the daggerboard)  so that this thin blade might hold together a bit better.  Using the full size plan I transferred the lines.  All the arrows are to remind me to keep the cutter to the outside. 

I've used this mini-router before to create rebates where needed.  This time it is being put to very good use.
Removing the extra block thickness.

I used the oribital sander to get the shape close and then finally some hand sanding. 

And viola, here it is,  close enough to start work on getting the high density foam core inserted down the middle.   I wish I had made the daggerboard this way, this approach is much easier for me.  

 

Two more F-22's launched

Ian Farrier has posted pictures of two more F-22's launched in Australia and the Philippines.  The pictures can be seen here.

I suspect we will see more Farrier trimarans coming out of Melvest Marine.  If you check the link to their web site you can download a pricing spreadsheet for your very own F-22, if you want. Anyway,  I am still waiting for good pictures of an F-22 sailing hard with the screacher flying from the bow pole.

Work on the rudder is going well and I should have an update very soon. 

Bobstay bow eye

My family finds the name of this part interesting.  Say it three times really fast.  

Kidding aside,  I take the function of this part very seriously.  This bow eye has to take a substantial part of the load that will be created when the screacher is flying from the bow pole.   The bobstay holds down the bow pole and is connected to this eye which is mounted fairly low in the bow of the boat.   Knowing that I will probably like to drive the boat pretty hard I want to do a good job on the part.  It's another one of those parts that reduce the amount of metal in the boat and requires the use of carbon fiber.

I was able to make the part entirely from cut-off and left over material.  Above is the initial foam core that I artistically created from one piece of foam cut out from the daggerboard core.

The actual bow eye is made from a simple mold, tape and two pieces of foam and some high density putty (Cabosil and epoxy resin).  

I found that cutting and applying  the narrow strips of carbon interesting.  The unidirectional is made by knitting together bundles of carbon fiber strands  in parallel.  It was impossible to keep the knitting together with a cut of the stitching every 5 bundles, so the wrapping consisted of gathering up 5 individual bundles and wrapping them around the bow eye.  The two plastic plates really helped to keep the bundles in place.  

Final covering with the s-glass cloth was also quite challenging.  I have to admit I finally resorted to using a stretch  plastic food wrap to keep the cloth down.  I saw this hint from a post to the buildersgroup by Andrew Cuthbert.

I used a small piece of G10 tube that was cut off in making the rudder mount to help make a solid bow eye opening.  I plan to lash the bobstay synthetic rope (no shackle) so I also tried to  'bell mouth' the opening as I do not think that synthetics like a tight radius.

Don't think I can put off working on the rudder any longer.

Rudder Mount

The rudder mount went together pretty smoothly although there are many steps involved.  Below are some pictures I took at various stages of the part fabrication.

The gudgeon mold worked out pretty well.  On the first part some of the thickened putty leaked around the G10 tube.  So on the second part I made sure some of the glass reinforcement was pushed up into this area.  This fixed that problem.  I used a little hot melt glue to keep the foam in place.

I removed the parts from the mold when they are not fully cured.  This is not just impatience.  I like to use a knife to clean up the part ,cut off the flashing, etc.  This is harder to do when its really hard.  

The molded gudgeons are wrapped in carbon fiber for strength.  I only have 9oz carbon unidirectional so I had to increase the number of pieces to get to the correct total weight.  Only issue I had was in keeping the many layers on top of each other.  But all is good in the end.

The finished gudgeons are then glued into the foam web.  I found that a tightly fitting wood dowel was sufficient to keep the two parts aligned and clamped into place.  

The part is then wrapped in fiberglass.  I used a number of pieces of the s-glass cloth.  It is pretty drapable and I did not have much of a struggle to get everthing covered.  I just prefer to make sure that the part and the cloth is wet with resin before performing my hand lay up.

When the covering is still green and tacky to touch I applied the remaining reinforcements as per the plans requirements.  I had no peel ply on hand so there is probably a bit more resin in this part than needs be...

The finished part weighs 1.27 lbs. It's  not really that pretty but most of it will be buried under the cockpit floor.  

Now it looks like I have to start thinking about the rudder fabrication.  This will be a bigger job.

Winter is for building smaller parts

Well, I did have to get the primer parts (the paint) warm using a pail of hot water, but I was able to finish off the port side float to the same point as the starboard float.  They will both need sanding, perhaps more primer - then the topcoat.  After that they will just need the hardware.

I've now covered them with a plastic sheet and tarps for winter.  Hopefully the winter will not be like last years - way too much snow!  But the good thing about storing hulls in your back yard is that you can watch them closely.  There will be no snow loading on these hulls allowed.

So now with the floats tucked away I can concentrate on winter work.   My overall plan is to have as much of the smaller parts done before the main hull is started in the spring.   Here is a quick list of work that I am starting to think about.

• Finish fairing and painting the daggerboard.
• Work on the rudder, rudder case and all the associated parts.
• Main 'pop up' cabin top.
• Finish laminating all the flat panels.

Hopefully the main hull will go together like a kit.

Hull preparation - my best techniques summary

This post is mean't to be a notes to myself for that time 'hopefully' in the not to distant future, when I am preparing the main hull.  It's also a post for others with the following label.  'Every amatuer builder is different and the best techniques for one builder will not be a good fit for another.'  

1) Lay up the foam as fair as possible.  Use the polyurethane construction glue (the stuff that does not expand that much) so that the outer hull can be immediately sanded without any hard spots.

2) Always wet out the foam before laying any laminate.  I have found that this is absolutely required with the fine weave aerospace cloth that I am using.   

3) Always use peel ply when doing any hand lamination.  Using plastic sheet over the peel ply is a good way to ensure a good result.  When squeegeed the plastic creates a local vacuum (for good adhesion) and allows you to remove the excess resin.  I may be at the point of not bothering with vacuum bagging as I fail to see any major benefit for all the extra trouble and cost.

4) Apply fairing compound sparingly and sand most of it off.  Good results were obtained with Quickfair.  Sand, sand and sand with the long board (60 grit) until there are no low spots left.  Where possible make sure the bare laminate serves as the local high spot for the long board.  

5) Apply skim coats of epoxy resin to seal up the fairing compond and fill the pinholes.  Sand with the orbital sander (no more hand sanding, except for the hard to get at places), with 120 grit until the hull is smooth.  Smooth is when the surface is all smooth and dull with no shiny spots.  It's okay to apply more fairing compond at this point, this is the last chance.  The thin first primer coat will seal it.

6) Apply the bottom paint.  Thinking ahead, do a good job with a manometer or laser to get the designed waterline right on the main hull.  VC Performance Epoxy can be rolled on.   At least 3 coats.  The  surface can be wet sanded as smooth as required.

7) Apply the topcoat finishing primer with a foam roller.  With Endura EP-2C primer sealer thinned 15% air bubbles are not a huge problem.   I have been waiting till it is fully cured then sand with the orbital sander with 220 grit until the hull is smooth. 

8) Unless an excellent method for applying the topcoat is found, take the hull to a paint shop for topcoat spraying.  

No topcoat painting for now

The weather was recently quite nice, low humidity and pushing 20+ degrees C,  so I decided to apply a coat of Endura topcoat on the outer half of the starboard float.  I used a foam roller and tipped out the air bubbles with a brush.  Making a long story over a few days - well short, I was not happy with the result,  so I sanded this coat down to 220 grit.  It is now very smooth but dull.  So ...I have decided to leave the floats for the time being with the finishing primer on the hulls.   Maybe I will have a professional paint shop apply the final topcoat when I have all 3 hulls ready.  

Winter is fast approaching and I hope there is  time get the port float all sealed and primed as well. 

Update: We weighed the starboard float today, it looks to be ~ 125lbs as is.

Finishing primer on the starboard float hull

The skim coats of epoxy seemed to work really well at providing a very fair smooth surface after sanding.  Fair enough, and I decided to hang the hull once again and apply the finishing primer to the whole hull (excluding of course the bottom paint which I masked off).  I applied the two coats of  Endura EP-FD primer with the foam roller and found that with the doors open I was able to get by with the half face respirator.  I think flowing on the paint is far less dangerous than atomizing it with a spray gun.  Quality wise I think rolling on the paint when the hull is hung like this is not optimal, I do have some paint runs here and there.  However since I will be sanding this primer down to 320 grit, I thought that getting it all painted was more important.  However, when I get to the topside paint I think I will be painting the hull in sections (roll and tip) , ie on one side, the other side and then the deck.   If anyone is interested I found a very good tutorial (for Sterling paint) here.

Below are a few pics of the now white primer coloured float hull.

Bottom paint

I turned the hull over to get better access for sanding and applying the small amount of bottom paint on the float.  I used the Interlux VC Performance Epoxy product.  It has no anti-fouling properties but does give you a hard surface that is easily wet sanded smooth.

The below the waterline area on the float is so small that I did not need to use any kind of laserline or manometer to mark out the area.  I simply used a chaulk line.  The area looks reasonable.

I used a foam roller to apply the paint, and put on 4 coats.  After each coat I lightly sanded with 220 grit dry sandpaper.  I am sure that wet sanding now with 400 grit or higher will result in a very slick smooth surface.

Now to finish sanding and get the Endura topside paint primer on.

Float painting strategy

As it seems with every new activity/task associated with this build, I am finding that my painting strategy is changing day to day as I take my little steps forward.   

Here is what I have done so far.

1) Purchased enough Endura EP-FD primer and EX-2C topcoat to paint the floats.  It is the toxic stinky stuff, and my intention is to roll and tip at this point.  I have purchased no high build primer.  I want to acheive that optically smooth surface without the use of a high build primer.

2) I am currently applying a series of skim coats of epoxy resin to the hulls. My intention  here is to fill the pin holes and smooth out the scratches from the 60 grit sanding.  Interestingly, I had no luck coating the resin with roll and tip techniques.  My laminating resin simply flowed/turned into an orange peel texture.  I found that applying the resin with the roller and then squeeging the excess resin off works very well. 

Here is the starboard float with 2 skim coats applied.  Next step (already started) is to sand with 120-150 grit sandpaper and recoat.  Then sand with 220 grit.  Then apply the endura primer.  At this point I am blessing my random orbital sander which is very useful on the relatively flat sections of the float hull.

Attaching the wingnet rails

It seemed a bit odd to be setting up for actual assembly work after all that sanding.  Once again, all the time is spent in set up, preparing the float hull and verifying the rail position.  Here I am in preparation using straps and 2x4's  to help hold the wingnet rails in place.  It seems like a long time ago that I molded these parts in the basement. The rails were constructed in a fine weave 8.9 oz s-glass cloth.  They turned out very smooth a did not require any pre-fairing to get rid of laminate texture.

First I attached the rails to the deck and left the gunwale attachment points free.  I used 2 layers of the 8.9 oz s-glass cloth as tape.  I also added some cabosil to the epoxy resin where the rails are attached to the float.

Then with clamps the inner supports are attached to the gunwales.   The clamps did a very nice job lifting the rail up to the required height.

Finally,  the two hulls are swapped in position.  The starboard float is now in the garage.

Here is the port side float ready for final finishing and prep for the paint primer.

Video of F22 sailing and updated boat logo for Raven.

Ian Farrier has posted a video of Oliver Doms F22 at sail in Germany.  The link is near the top of the F22 page here.  It looks like they are cruising (in a close reach) at 8.7-8.9 knots with no trouble at all.  

My boat logo concept is now extending down the full side of the float.  I've updated the small picture in the side bar but here is  a better view (already updated).  

As I originally intended, there is a bit of the Canadian west coast tradition in this design.  But simple enough I hope for us to mask it off and paint it ourselves.

I've finished the float fairing and I am now setting up to attach the wingnet rails.  After that it is time for painting.  

Update Sept. 10th

Tom McCaw of Vancouver Island has cleverly put my logo on Oliver Doms F22 float hull in the water.  Tom reminds me that it is not his best effort, but I think it is brilliant.   I only hope Raven will look as good as this when complete.

I thought for a while Raven would have to be painted black.  But white ravens have been spotted on the island.

Jim Shula launches his F22

Jim Shula of Portland Maine has launched his F22 trimaran he has built for Sam Ballard.  Pictures can be seen here.  It's great to see another F22 in the water.  

Still fairing the floats

.... but I am getting close enough to think about attaching the wingnet rails and applying a paint system primer to the hulls. Here are the current set of questions in my mind.

1. What topside paint system should I use? I am tending toward using the two-part, water-borne linear polyurethane enamel from SystemThree. Environmental, thinning and cleanup attributes are very attractive.
   
2. Should I use a HVLP paint sprayer or roll and tip? Can I use my air compressor to drive a HVLP spray gun or is an air turbine required? The SystemThree LPU paint may work well with an air compressor driven HVLP spray gun as moisture in the compressed air could not possibly affect the finish.
   
3. Is there a designed below waterline region for a float? Some of Ian's drawings do indicate a small region, but I can see no dimension(s) explicitly called out. Is a topside 2 part LPU paint suitable for covering the complete float hull? I have been thinking about using Interlux performance epoxy for everywhere below the waterline, main hull and floats.
   

The fairing work goes much easier, in my height challenged garage, with the second hull sitting outside. I will be very glad indeed, when I am on to building a single main hull structure!

Visit with Jim, Carlene and Doug MacKenzie

A long overdue 2 1/2 hour drive to London, Ontario to visit with Jim, Carlene and Doug finally happened this past weekend. They have been making good progress and as I am finally planning my own main hull build I wanted to see a F22 main hull in person.

We helped Jim move a float from storage into the garage for, I suspect, some work on putting in the access and storage hatch features.

They have room to swing the main hull into any position in their very roomy build shed. Jim shows how easy it is to push the hull around. Height is no issue for this team. My first impression is that the F22 main hull has a great deal of beam that pictures published around the internet do not really indicate. Obviously, I like what I see.

Here is a picture taken from the stern into the main hatch companionway. You can clearly see how the newer beam designs has opened up the forward v berth area. They have opted for the centre board version which opens up the living area even more. The MacKenzie's have a great deal of experience cruising on their trailer tri and this experience is stimulating discussions about how best to utilize this space. It will be interesting to see their finished layout.

How can this space below the cockpit floor (no aft cabin) be best used? For example, I had not thought about where the outboard gas tank will be stored? In fact, talking to Jim and Doug has made me realize I will have lots to think about.



Doug and Jim showed me how the cockpit panels fit up. I joked that a F22 kit would go together very fast. After a quick lunch and a cold beer with Carlene it was off for a sail on Lake Fanshaw.

So .... I finally have had a chance to helm a Farrier trimaran. She handles wonderfully with the shifty breeze this sunny day.

My son Cameron discovers a comfortable place on the wingnet.