F85SR Concept Boat

Folks,
I have been back working on the boat for a couple weeks now after finishing the work required to make a storage space for them under my front verandah.
The chain plates are made and fitted and I'll take the folding mechanism to the anodisers later in the month when they come back from their christmas break.
Currently I'm in the process of fairing the floats.
I've made 5mmx5mm notches in 250mm long heavy duty plastic trowel with 30mm between each notch. The trowel is held at an angle when applying the filler to the hull which makes the beads of filler only 2mm high. It takes 0.95 litres of resin to bead one half of one hull. Once cured it then takes 1.5 hours to sand most of it off with a 4 ft longboard with 40 grit paper. That is working hard and sweating a lot it ends up being a full body workout but it gets good results.
It takes a similar amount of resin to fill the hollows marked by the beads remaining after the long boarding.
At this stage I'm really glad that I was so careful in placing the foam as the fairness of the hull is much better than it otherwise would be resulting in less work and less added weight in the form of fairing compound.
I'm pretty happy with the way the fairing is going.

I'd post some pics but I still cant upload pics to the catsailor.com photo albumn.

Hello everyone!

Bullit has been bit.

I'm a beginner in this boat building malarky so have a couple of questions:

What are the real world advantages of vac bagging the hulls, how much weight do you really save and what strength gain is there?

What about carbon... pro and cons, I guess you save a bunch of weight in using a lighter cloth(much more than vac bagging by my estimate). Whats the down side, I've seen something about poorer collision durability, a little bit more egg shell like, would this be fair? Would you use carbon for the hulls and not vac bag?

I've got a lot of reading to do!

So you purchased the plans? good show <img src="<>/grin.gif" alt="grin" title="grin" height="15" width="15" />

Hello Ed, I can't give you any figures and it depends probably on the laminating skills as well. It might save up to 25% in weight compared to a really wet layup.

As for Carbon fibre, you will not find consensus on it. Some people swear by carbon. Others say it's not worth the cost. It certainly is lighter. But the laminate is also thinner and more prone to dents. For a racer the first point is important. For a cruiser you might be concerned about the second. I know one F-32 builder who uses carbon without vacuumbagging. It is more difficult to see if you have the laminate saturated with epoxy though.

For my boat the hulls are in (E)glass. Rudder, daggerboard and beams will be in carbon. For the mast and the wingnet beams I am thinking about carbon iso aluminium.

Handlayup (glass) F-22 Menno
Vacuum bagging and infusion (glass) F-82R Martin
Vacuumbagging (carbon) F-22 Andrew
Vacuumbagging (carbon) F-22 Tor
Handlayup (glass) F-22 Jay
Handlayup (glass) F-44SC Allen
Infusion (glass) F-39 Henny

Ed,
It is very good news that you have taken the plunge.
I hope you enjoy the building as much as I am.

As to you questions re vacuum and carbon.

I will give you my persective on these points but yours may
finally vary depending on what your intended primary use.

First vacuum- the weight that you will save will depend on how
skilled you are at hand laminating.
An unskilled person will save more weight by vacuuming than a
skilled laminator. In my case I have given figures in previous
posts in this thread as to the amount of resin used to wet out the
laminate and then how much came out in the vacuum comsumeables.
From that you can work out the weight savings. With some calculations
you could probably break that down to an average per sq metre
saving and with info in the plans work out how much I would save
given my skill level.
You may save more or less but it will put you in the ballpark.

I will use my boat in coastal sailing so my primary reason for
vacuuming is strength. The bond between the foam and laminate under
vacuum is as good as can be achieved.

The other considerations when vacuuming is the added cost and the
added time. There is the cost of the vacuum consumeables vaccum film,
tacky tape, wadding and bleeder.

It may be as much as $1,000 say 1/15 the cost of the hull materials.
Then there is time.
Once you have a structure ready to laminate you can roughly treble
the time it takes. To get a good vacuum you have to prepare a surface
that the tacky tape can form a really good seal to, laminate, apply
the vacuum consumeables and film and chase any leaks. I've managed
to get a vacuum of around 25 inches of mercury on most of my sessions
which is quite a good vacuum but there is no such thing as a free lunch.

I considered using carbon instead of glass. From the plans you could
work out the weight savings.
Three things influenced my decision.
1) Cost, I did a rough calculation on he added cost of carbon and it nearly
doubled the cost of building the basic structure. If you are seriously
considering carbon get some prices and see how it comes out for you.

2) I don't like cutting and grinding carbon. I've found nothing as sharp
as fibres of cut cured carbon. Using carbon in the beams and boards
will be enough for me.

3) Resale value- I did not think if I sold the boat in years to come that
I would get the added cost of the carbon back.

This is just the way that i see it.

Regards,
Phill

Thanks for the opinions guys.

I've got a couple of months of building bulkheads and bits before I move house and can start on the main hulls proper so will give me chance to have a bit of an experiment with materials and techniques before have to get cloth and foam in large quantities.

I'm mostly going to be racing in and out of the harbour with maybe 5 or 6 coastal races a year, plus a bit of cruising when time permits.

In a few years time there may be some mileage in organising an unofficial world champs somewhere

Cheers

And then there were 8!

As you are only dealing with a single layer of glass for the lay-up, vacuum bagging doesn't seem worth the agro. You can still batch out your resin and make sure that the lay-up is the right ratio. Peel ply everything though.

Carbon saves about 10% in total weight and can make the hull more prone to impact damage. Not worth the money in my mind.

Paul,
I'm vacuuming not so much for weight saving (as a bit more effort with a squeegee can get similar weights) but more to get the best possible bond between the layup and the foam.
If I planned on only sailing in lakes and not up and down the coast I probably wouldn't bother.
I got my folding mechanism back from the anodiser a couple days back. I'm very happy with the way it has come up.
I'd post a pic only it's been over 3 months since I could upload any photo to the photo albumn on this site.

I'm still enjoying working on the F85. The fairing was much easier than I thought it would be having faired 32ft cedar strip hulls in the past. The hulls are all faired with just 6 hours of long boarding all up. Now I'm getting the beam jig CNC cut so I can get to work on the beams.

Phil, have you got a handle on what the all up weight of the boat is going to be yet?

The class rule for the 8.5 has a minimum weight of 900kg so I'm keen to try to get close.

Ed,
Its a bit early for me to know for sure but I do
expect if built with care 900kg would be achievable.
I expect my floats beamed and painted will be well under 100kg each and that leaves over 700kg for main hull rig and sailing gear.

Phill-

I would be interested on how your numbers compare to my F25c...

See info from Bill Adams Jr who built all 48 F25c below:

Thom,

If I remember right the main deck and hull were about 600#, the beams with hardware were about 100# each and the ama's were about 150# each. For a total of about 1300#. I remember that 2 guys could lift the hull and carry it around the shop before it had bulkheads etc!(The main deck was heavier than the hull). All of these weights were before paint and hardware and all the other add-ons.

The way we flipped them was to remove the ama's and then support the bow using the spinnaker pole in a cradle that allows it to turn. Support the pole close to the bow, not at the tip. Then pick up the back of the boat with as many friends as you can find and roll it over. We used to do it all the time with 6 guys. When it is upside down support it under the beam pads front and back. (Don't let it hang on the pole for a long time)

thommerrill
F25c 009
Charisma
Have a nice Thanksgiving
Bill

Thom,
I have been taking weights but not lately and currently held up working on it by a broken collar bone so I can't do much with the boat except give you estimates from what I've measured so far. Bear in mind that I'm building using the heavier glass laminate option and carbon beams built under vacuum.

The floats were around 130 each with the lifting foil cases installed but still some internals and fairing which has already been done but not weighed since. I expect it to be less than the 150. and the floats are much more bouyant , ie- larger, than the F82.

The beams and hardware should come out quite a bit lighter. Maybe as low as half. The folding mech only weighs around 5kg 11pounds plus bolts per beam.
I don't know about the main hull as I have not started it yet.

I will be able to provide more info when I am a little more mobile and can do some more work.

Regards,
Phill

Sorry to hear about your injury.

I wanted to ask you if you had seen Tor Rabe's mast for his F22R? Its a custom shape and similar to some CST shapes.

Take care of yourself,

thommerrill
F25c 009
Charisma

I have been following this thread for a while now and finally took the plunge yesterday to get a F-85SR built. I wish I had the time and patience to build one of these trimarans myself, but I don't.

Instead, I have commissioned Michael Mallory of Multihullsdirect in the Philippines to build the boat. I have been assigned Sail No. 10 and I hope to launch the boat around the 1st October this year.

I have decided to get a standard F-85 built, with following modifications:
- centreboard option (so that it will kick back if I hit a rock)
- reinforcement for the lifting foil cases, so that I can fit them in the future
- all the necessary attachments so that I can race in Category 3 passage races.
- It is an epoxy foam boat with carbon reinforcement only as specified in the plans

Initially I will be racing in the Philippines, but will probably take it back to Perth once my current assignment is over, maybe in 2015.

I am very excited to see how this trimaran performs and will keep you updated with photos. According to Michael, by the end of April, the hull should be well and truly taking shape.

Michael is looking for more customers, so if you want his contact details, please PM me. I think it is a pretty competitive build price, compared to what second Farriers are currently priced at in Australia.

Have just received the first F-85SR main hull photo, which is hopefully attached?

Edit - Seems it is attached, but how do I make it display in the message itself?

Ian Farrier
Farrier Marine

BTW:- this is not my boat however this F85SR builder only lives a few kms from me.
Always handy to have someone to compare notes. Especially when it is someone who has built a Farrier Tri before.

Regards,
Phill

Hello Ian-

I am always amazed to see these photos from builders around the globe.. The surfaces appear to have come from a mold.

Have you heard from Fiat about his F32SRX?

How is the new factory coming along? When do you think the manufacturing of the F22s will start??

thommerrill
F25c 0009
Charisma

I managed to put my folding mechanism together and pinned it up on the back wall for storage.
Mark Hastings machined the mechanism for me on his CNC and then offered to put a 10mm drill
through the centre of the pins so I could use a tool to remove them easily should I ever need to once
the boat is finished. Interestingly that hole through the pins reduced the weight of all the pins by 1kg.

Small savings add up.

I have just finished the internal laminate of all 4 beams.
My broken collar bone really slowed me down for around 3 months but that is finally coming good so it is all ahead full again.

On the last beam ,which was a front beam, I took some notes.
I noted the quantity of resin in each mix, the time of the mix and the temp in the workshop at the time of the mix.

The reason I noted down the temp & time was because the day was supposed to get quite hot but at the time I started it was quite cool. I just wanted to make sure that I stayed inside the vacuum window prescribed for the resin I was using.

I found that the combined weight of glass and uni carbon was 1.17kg. All up I mixed 1.45kg of resin. 80gms of this was used to mix up a bog for fillets along the beam side/bottom join, leaving 1.37kg of resin to wet out the 1.17kg of laminate.
Following wetting out the laminate I pulled a good vacuum of 25 inches. Upon cure I weighed the peel ply and absorption fabric as it was removed to work out how much resin came out in the fabrics. I found that around 200 gms of resin came out leaving 1.17kg of resin in the laminate.
I was very happy with these results.

I must say it is a relief to get this work done, it is fiddly working inside the beams because of the flanges.
Since then most of the internal beam B/Hs have been fitted so after a bit of work to install the UFS recess and some reinforcing around the inner beam end I will be able to start laminating the outside of the beams which should be much easier work.

Folks,

I've just made up a prototype of my wing net rails.

The plans have the nets terminating on a 50mm round al section between the beams out near the float. Thinking this would not be that comfortable to sit on when sailing from the nets I had some M80 corcell foam machined into a wing shape. Then I made a glass tube with a 16mm intenal dia and 2mm wall thickness. Routed out the foam to take the tube. If I cut a slot the length of the tube I'd have a luff grove but I will cut slots 90 deg to this at intervals that I will work out once I get the netting.
My aim is to use an open weave netting that will be laced in place to avoid the need of stitching as the stitching is always the first thing to fail.
I wrapped the foam and glass tube in a layer of 200gm plain weave glass , 2 layers of 300gm Uni carbon running lengthways and another layer of 200gm glass and cured it under a vacuum.
This will give me a nice comfortable wing shape to sit on when sailing from the nets.
So far I've only made a 1200mm section to test out the concept and test for both strength and weight. This section seems very robust and only weighs 1.2kg per metre. I'll leave it a few days for the resin to get to full strength and then do some deflection tests. Even so I'm so happy with how it has turned out so I've just given the rest of the foam to Mark to get CNC cut so I can make up 2 wing net rails 3600mm long. I only need 3300mm and the off cuts will be used as supports between the wing net rail and the float.
I think I'll use the prototype as the bow foil.
There is a lot more work in this than getting a bit of al tube but I enjoy the work so it is just good fun.

Regards,
Phill

sounds great. One of these I days I am going to do some stuff like this, though I don't know if I have the attention to detail to get it all right

Ian Farrier will not be selling plans anymore after September 25 2012.
If you think that there is any chance that you may want to build a Farrier design in the near future you are better off buying the plans now while you still can.

I would think that if you change your mind there will probably be people out there that decide after the end date and desperate to source plans.

BTW:- I still love working on this project. I just vacuumed the laminate on the underside of all 4 beams. I'm very happy with how it worked out. I'm taking plenty of photos of all the work.
Damn shame Ian has decided to stop selling plans I think I'd like to build another one when this one is finished.

Regards,
Phill

Cool down Phill,

if you want to build another one, Ian will sell you the plans for it. You are a good boat builder. With all your knowledge you have now and will learn during your built, you don't need the full support.

I think the real reason is that Ian is bored and frustrated by answering the same questions on the telephone over and over again.

And if not??? Ian Farrier is not the Messias of Boatdesign. There are other good Designers drwawing wonderful boats.

Best Regards, Michel

Hi Phill, do you have a larger break in your build or did you decide to stop just reporting here? I would like to read about the next steps of your project.

Best Regards, Michel

Michel,
I'm still working away. All 4 beams are ready for painting.
I've built nearly all aspects of the beams under a good vacuum of between 25 and 27 inches or mercury.

Building the beams is a very long process and doing it under vacuum has made the job much much longer than I expected.

This has also probably made more work in one beam than both floats. I'm happy that I've done it this way but would not recommend it just because of the amount of work involved.

Also I got side tracked organising and helping a group of 6 friends build some kayaks.

My next step is to paint the beams and floats including top coat prior to building the main hull. I figure that it will be easier to touch up the area where the beams and floats join than do the full paint job once they are joined. Just because they will be more difficult to move around once joined.

Regards,
Phill

Just downloading a few pics, with a forecast of 42 deg C, its too hot to do much else.

IN the first pic I applied the glue with a caulking gun. Just went to hardware store and bought a water solluble gap filler cartridge for $1.98. Squeezed the gap filler out and washed it out. Put glue in, insert cartridge in gun and away you go.It is also a great way of applying bog for fillets and was a great help when joining the float halves together.

Clamping the tops on with flat sections of wood rather than screwing gave me a very fair top on the beams. Only downside is it took 40 clamps to do it.

A couple more

Finally some paint. Well hi build primer.

Mark Hasting has done an excellent job of machining a plug to make a mould for my F85 rudder.
Hand shaping doesn't hold a candle to the accuracy of his CNC machine.
I'm in the process of putting a finish on the plug.
After spraying with two pack the foil section has been cut back.
Once I've done the same to the back board I'll start waxing it to make sure we get a good release.