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Bob Perry's Carbon Cutters

184K views 1K replies 94 participants last post by  outbound 
#1 · (Edited by Moderator)
Re: Steel vs Fiberglass

Mod Note: I've copied all the photo posts on this project over from the Steel vs Fiberglass thread.. this way we can follow this project without the distractions of that thread, which, btw, remains intact.
Ron (Faster)

John:
I am a bit ahead of you on that. Right now we are building four, semi-traditional 43' cutters at Jim Betts yard in Anacortes,WA and they will be all carbon fiber and epoxy. They are all for one client. We will use some e glass down in the keel to build up some thickness. Theses will not be light boats but the structure will be very light. The light structure will allow us a B/D of at leat 43% and we should have some very stiff and fine sailing offshore boats. We are using carbon fiber because we believe it is the very best material for the job. We are also using titanium in many areas including the rudder pintels. To my knowledge there has never been a traditional type design like this built using carbon fiber before. Our hull laminate weighs 1.46 lbs. per sq. ft. and is far in excessive of what we need for strength. No fallard, these will not be cheap boats and my client could care a less about resale value. I am now working on a 32' version also to be built in CF for another client. There is plenty of room for all sorts of approaches.




 
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#2 ·
Re: Steel vs Fiberglass

I'm just back from the yard . Fun ****. I had a long chat with Jim Betts about repairing boats. Jim has built a ot of alu boats and he is very good at it but he thinks they can be the hardest to repair in remote areas. He says steel would be next because you need an electrical source. He thinks grp is easiest because you can quickly slap on a patch with no power on hand. Each carbon cutter will come with a WEST System repair kit.

As for titanium being so difficult to work with Jim says not so. Jim says it's easier to work with than 316 s.s..

Structural floors have eight layers of bi-axial and 0-90 carbon over 2" of foam rolling over the top to make an "L". This will be glasses in the hull and then uni direction carbon will be run across the top of each floor and taped up onto the inside of the hull. This will be then covered with more bi-axial carbon.

There will always be semi informed nay sayers. They have dogged me my entire career. But I'll tell you this, there has never been a cruising boat built to this standard before. Jim and I discuss details and at one point this morning we just looked at each other and smiled. I said, "We are going where no man has gone before." Jim said, " I know."

 
#3 ·
Re: Steel vs Fiberglass

Fun at the Betts yard yesterday. Each completed piece gets weighed and the weight is compared to what I have in the initial weight estimate and corrected if needed. So far my estimates are very close. No worries at this stage.
Completed floor.


Working the carbon fiber fabric into the L flange of the floor.


Floors being vacuum bagged with vacuum about half complete at this point.
 
#5 ·
Re: Steel vs Fiberglass

" The only good designer of steel cruising boats is one who understands the material,"
OK, then Brent show us some of your design work.

Here is some of mine as rendered by my buddy Jody as we finalize the cockpit details for the carbon cutters. I like to use every design tool available and having the 3d images allows far more refinement in the design process. I can post hundreds of photos of my boats and I can post as many drawings as time allows. Brent seems to not be able to do this.
 
#8 ·
Re: Steel vs Fiberglass

Fun day at the boat yard. Real people doing real things and me watching them. Here is a pic of the plug covered in Taconic film that is the barrier coat that prevents the hull lam rsin from bleeding back into the plug.



The trailing edge of the keel is now bonded on with carbon. The plastic you see is the beginnings of the vacuum bag that has to be ready and in place the moment the last carbon pass is on. This pic shows the last of the Taconic film being applied before the "peel ply" layer. The peel ply will make it easy (prayers) to get the hull off the plug and this layer will stay in the boat until it is removed later. Nothing sticks to it so you cannot leave it in the hull.

With Taconic film and, peel ply in place the first layer of carbon goes on, lapping over the bottom of the keel and up the other side 4". The total thickness of the laminate at the bottom of gthe keel will be 1.25" of solid carbon and e glass.

No BS, just high quality custom boat building. Maybe not Boeing level high tech but not bad for Anacortes. I was impressed by the teamwork and skill shown. I am very confident. I felt quite humble as I left today seeing those guys working that way and knowing that we are producing a fabulous boat. Without that crew I'd be lost.
 
#10 ·
Re: Steel vs Fiberglass

Denda:
The first layer is 0-90.
Did not ask how much time they had but all the panels were cut and stacked and the bag was all ready to go. I think the plan was to have the inner skin layer on the keel fin complete today.
They had the big door open and fans running. I'd guess it was maybe 75 degs in the shop. Maybe a bit less. I was not hot. I was not cold.

I'll guess the width of the roll is between 44" and 48" I did not measure.
No, they are not doing the entire layup in one shot. They do half the hull on Tuesday and the other half on Thursday.

We should meet at the yard some day.
 
#11 ·
Re: Steel vs Fiberglass

Given the loads on a spade rudder stock, bending and twisting, properly designed spade rudders can be very expensive compared to the small diameter titanium pintels we are using on the carbon cutters, 1/25" dia.. The choice of a spade has nothing to do with cost when I am designing.

Out:
"Winglets" have been tried on rudders for years and now we are seeing even foils on rudder tips. "Fences" have also been tried up and down the rudder blade. The old Chance 52'er WARRIOR, had a fence just below the DWL. But anything attached to the foil that will divert the water will cause drag. It's an automatic and much of the time you are not using enough rudder angle to make the fences needed. They come into play only near stall angle. I thought long and hard about putting some fences on the carbon cutters rudder. I just don't like that forward raked stock. I talked to a guy who is a foil expert and he was unsure as to the value. So, I bagged the idea and stuck with what I know. The rudder on the cutter is very big and the blade is well balanced so I am not anticipating any problems.
 
#12 ·
Re: Steel vs Fiberglass

Now we have the beginnings of half a boat! The other side is not laminated yet. This is the first layer of 0-90 carbon It has been applied over "peel ply" to let it release from the plug. All together there will be four layers of CF plus the Corecell core on the hull and all this will be done, on one side, today and vacuum bagged.


Here is the vacuum bag, attached o the other side of the hull waiting to be draped over the hull to vacuum bag down the fisnished laminate. The coating you see over the keel fin is to protect the vacuum bag from being punctured during the process. If all goes well this one bag will be used for the entire hull laminating sequence. The CF laminate will be covered in two different "breather " layers top allow the epoxy resin to bleed all the way through the laminate then covered by a layer of "fuzz mat" that will absorb the excess resin. These three layers will be discarded after each vacuum bagging process, i.e. inner skin as seen here, core and outer skin.

Look caerefully and you can see a box shaped thing on the hull side. This is a "plant" where the CF chainplates will go. Using the plant we will laminate solid there with extra reinforcing then strap the CF chainplates to that area. No core where the chainplates are. The plant will come off the plug with the hull, then peel off the hull.
 
#13 ·
Re: Steel vs Fiberglass

Agent: You have to break away from everything you know about construction when you are working with carbon and epoxy. The chainplates will be bonded into the hull with many wraps of unidirectional fibers that splay out to spread out the load. Then uni layers will wrap across the entire boat gunwhale to gunbwhale. It's a really strong way to do a chainplate that will never leak. I really hate to say this, but inn some ways it's a bit like working in steel.

Now I will go and wash my own mouth out with soap.
 
#14 ·
Re: Steel vs Fiberglass

Denda: Apparently carbon and s.s. have some social issues as well. That's why the carbon bearing area is wrapped in e glass before the s.s. goes on.

Here is a shot of the carbon cutter getting the first of it's 1" core epoxied on. The core is vacuum bagged on in patches so that it is easier to control.


The epoxy resin is thickened to ooze through the entire core and can be seen coming out the outside of the core in white splotches and white lines where the cuts in the core are. This is athe recess for the chainplate "plant" where there will be no core. That milky white stuff you see around the edges of the recess are epoxy oozing or being pulled by the vacuum pump, through the core.
 
#15 ·
Re: Steel vs Fiberglass

Here's a shot of the hull showing the dull black of the naked carbon fiber and the shiny black where the CF is still covered in peel ply.

If you look very closely at this pic of the transom you can see there are white dots on 4" centers through the rigid foam core. This helps tell the workers when they have a complete bond. They want to see all those white dots,
 
#16 ·
Re: Steel vs Fiberglass

Just words BS. Your credibility is shot. Can't find that quote? No, because you made it up. I'll give you this: you can type. But that's it. Blah, blah, blah,,,,,

I'll post some actual design work. I'll let my work do the talking.



 
#17 ·
Re: Steel vs Fiberglass

Seems a good overview to me Jeff. Well done.

I'd suggest a look for another opinion on Kevlar in boat laminates. It was recently called a "disastrous experiment" by a group of powerboat designers at a design symposium. The builder of my carbon cutters won't touch Kevlar.

Rat:
"A better question might be what is the difference in cost between custom build and higher end production boats? Broadly speaking."
That is one complicated question. It depends.

Broadly speaking it would have to depend on the exact same boat being bid on by a custom builder and a production builder and exactly how many boats the production builder intended to sell. Very hard question to answer. There is a lot of cost i tooling for production boats that has to be passed along to the buyer. In most one offs there is minimal tooling cost. In my carbon cutter project we are on the line there, i.e. not exactly custom and not exactly production. I'd call it a "very limited production run". We are building four identical boats so some tooling is desirable.

A good example of this is the chastity strut. We need four of them so a female mold was made. Here is the finished two part product. It is .25" solid Carbon fiber. It will be filled almost solid with e glass and then foam will be added to fill the voids. Then it will be bonded together on the outside with carbon tape. If you look very closely you can see the rebate around the seam so the taping can be plush with the outer skins. One strut could have been built over a male CNC cut plug. Due to the high tolerances for the fit of this piece it was decided that a female mold would give us consistency but not save us money. The two skins weigh about 28 lbs.

 
#18 ·
Re: Steel vs Fiberglass

I went to the yard this morning to meet with the Hood Yacht Systems rep to go over final specs for the hatches, portlights and the custom made SS hatches that will go on the butterfly hatch. Not much excitement in that but it is necessary If I want to be part of the decision making process. While I was there I took some pics of the crew getting ready to lay down the next course of foam core. One again I was amazed at the skills needed and the small technique "tricks" required to make this process work well.

A lot of work was going into cleaniong up the upper edge of the first course of foam. The epoxy leaks through the edges when the vacuum is applied and while they try to prevent it from leaking out the edges some does escape and must be meticulously cleaned up so the next course of foam will bond. Due to the dramatic change in girth as you go foward the foam panels have to be "spiled" like planks on a wooden boat. OK, it's not the same thing but "spiled" was the word that came to mind as each panel has to be shaped. It's basic boatbuilding.


You can see in this pic the garboard course of foam where the foam is tapered into the inner skin where the hull will transition from all Carbon to carbon and e glass for a solid keel shell.

This shows the new foam being dry fit prior to being bonded and bagged. I asked Anthony who was cutting the panels to fit what the tolerance was and he said, "zero".
 
#19 ·
Re: Steel vs Fiberglass

Let me know if this is boring you. I find it fascinating myself.



If you have been following this build you will know that we have two stems: An inner or "false" stem where the entire hull lam will wrap around and an outer or "true" stem that will go on forward of the false stem and again be wrapped and lapped top the outer skin with 4 layers of CF. The CF bobstay fitting is captured within all of this and bonded to both skin layers. The foam core for the true stem was CNC cut and is now ready to go on the plug once the outer skin has been completed. The bobstay fitting will pierce this foam stem. In effect we will have a "crash box" at the stem.
But the real reason for the false stem is that iut is cut at the precise angle we need to let the hull slide up and back so it will clear the tumblehome aft when the hull is taken off the plug, the beauty of 3D modelling.

They were kind enough to give me my own "office" at the yard. Wish they'd give me a chair.

 
#20 ·
Re: Steel vs Fiberglass

Jeff:
You are correct. There is no short cut to getting the highest quality. Today the best materials are expensive and they are a fraction of the skilled labor cost. I have been very lucky to have had a long string of clients who are very easy to please. They want the best. It's as simple as that. I remember a client looking at me with a stern look and saying "Why didn't you tell me Rechtman made furlers?" I had not told him because the Rechtman furler was twice the cost of the next one. But this client flew his own commuter jet plane and that cost difference was insignificant to him. The cost/quality relationship can be infectious. Once the client sees how high the quality can go they tend to want every aspect of the boat to achieve the same level of quality. So the price of the boat increases and the time it takes to build it increases. One reason I work by the hour.

But in the end you get a boat that makes everyone involved proud.
 
#21 ·
Re: Steel vs Fiberglass

Aloof:
Thanks. It sure impresses me.

Here they are dry fitting the foam panels. Note the slight difference in the colors of the upper and lower foam. The topsiudes foam is heat tolerant meaning it has already been baked to make it more heat stable. This would be critical if the hull were to be a dark color. Below the DWL the foam is the same density but not the heat treated foam. We npw plan on having white boats but the heat tolerant foam was already ordered so we went with it anyway, It's a bit more expensive than the normal Corecell.
 
#22 ·
Re: Steel vs Fiberglass

Had some fun at the boatyard today. They are cleaning up the core foam and getting it ready for some serious fairing before the outer skin goes on. Everyone was either sanding, grinding, sweeping or vacuuming today. Except for Rick. Rick was dry fitting the foam stem piece. This will go on over the final out skin layer is on. Then it will be covered with another layer of outer skin lam and bonded to the hull. I was appreciative of the effort the yard put into dressing up the decor of my office by giving me a Herman Miller drafting stool. It swivels.



 
#24 ·
Re: Steel vs Fiberglass

BS:
You are repeating yourself. Alzheimer's?
It's s stout fitting that has worked well on 350 boats. That is several times all the BS boats ever built.

But you are very correct, it is a beautiful, full scale drawing. I'm a designer. I design.

Here is something beautiful straight off my drawing board/computer. I do love my work. I bet Frank Sinatra liked his own voice.
 
#25 ·
Re: Steel vs Fiberglass

Streamer:
I am jammed right now with work. Waiting right now for my BC pal Tim O. to show up so we can decipher the three bids for the carbon fiber rigs of the four cutters. Tim has kind of an accountant's approach to details. I ask him to help me frequently. He went back to NC with me last week.

I was expecting my own new boat a month ago but as usual it is behind schedule. Maybe in time I'll work up a CF version of the pea pod. I'm very keen on CF now having been immersed in it for the last three months.
Just got back from the yard. Nothing spectacular to show but I'll post a few pics to keep the "reality theme" going.

The true stem is now on and bonded to the primary laminate.


E glass skins are applied to build thickness in the keel fin area.

Outboard rudder female mold getting the first side laminated with carbon fiber. By the time I left today this side was being vacuum bagged and they were laminating the second side. Those "lumps" on the left near the worker's hands are where the pintels go.
 
#26 ·
Re: Steel vs Fiberglass

More BS from BS. Just words.

How about some boat reality: Nothing spectacular happening at the yard today. Just getting the vacuum bag ready to lay the outer carbon skin over the e glass keel shell. The inner CF skin is under all that e glass. We will have 1.25" of total CF and E glass build up on centerline. Try duplicating that in steel at that weight. Ain't gonna happen.

BS will like this part. Jim Betts welding up the strongback for the deck plug. Jim is an artist with a welder, a sculpture, as I saw when he built WILD HORSES.

Now the rudder blade ( you can go now Brent. You know nothing about this kind of construction. It is out of your experience range.) The carbon skins of the rudder blade are bonded together with a strong rebate in the outer shell so that the blade remains fair and true to my foil selection. Inside the blade there is a vertical "spar" of carbon running from top to bottom. This will be duplicated in both halves of the blade and bonded together when the skin halves are joined. This is a bit overkill but Jim Antrim, our engineer, wanted it so we do it. What Jim wants,,,,we do. We do engineer. We do not use the BS method of guessing. In a project like this there is far too much money involved to go with some wanker's guess. Each half of the rudder will have a "spar". When the two halves are bonded the spar halves will also be bonded. It's kind of close tolerance work and mighty fun to watch.
 
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