F85SR Concept Boat

I've glassed in the first Lifting foil case and added some pics to my album.

A couple of them shown below.

I've hoisted the second float half to the roof.
Backed off the screws holding the battens to the mould (after numbering them so I know where each one goes). Lifted the battens up and reversed all the frames and then screwed the battens back in the mirrored position. So now I can start cutting foam to make the other side of the two floats.
Leaving all the screws in and keeping the battens in the same relative position saved me a heap of work.

Richard,
I foam planked the third half Friday. If the rain stops I'll laminate the inside tomorrow and join them together Sunday. So if you are out and about drop in.

Hi Phill You are joking if it stops raining, I hope you can fit two of each animals in side the tri. I'm busy Sunday and going into nights next week, I'll PM you . Might catch up Tuesday
Richard

Richard,
There was a break in the rain for a while so the third float half got laminated. Again pulling a really good vacuum. (25" once again)

I used slow hardener and to save having to run the vacuum for 15 hours I brought the laminate temp from the teens up into the 30s with the simple setup using a fan heater in the transom. The setup is shown below.

BTW:- is Monday any better for you?

I pulled all the vacuum layers off the hull yesterday including the peel ply. The laminate looks perfect. I've been right over it and there are no pin holes in the weave and the fibres all look properly wet out.
When doing the laminating I have some friends that come around and help so I have the luxury of being able to keep accurate records when mixing the resin. The weight of the hardener and resin for each mix is recorded.

We used 5.7kg of resin mix to wet out approx 7 sq metres of 400gm E glass.When the absorption fabric was removed I weighed it and weighed samples to work out how heavy it was before it went in.
This allowed me to work out how much of that 5.7kg was absorbed and how much left in the laminate. So it looks like the laminate took up 3.2kg of resin to properly wet out both the laminate and foam.

Now the interesting fact is that people have been talking about 250 to 300gms of resin per sq metre being needed just to wet the foam. Assuming a 50/50 glass resin ratio,it seems that with a really good vacuum and a little heat at the right time it may be less than 100gms per square metre needed for the foam.
Only one more float half to go. I'll probably do the same measurements on that one to see if I get the same results.

Glued the starboard float sides together today.
I posted some pics in my albumn like below.

It's time to get started on the 4th and last float side.
I have suspended the joined stbd float from the ceiling and cut and rebated the foam. I've taken a pic of all the foam required to make one of the float sides. See below.

I managed to place all the foam in the float mould before lunch today
however due to other commitments I won't be able to apply the
inside laminate for nearly a week.
Hopefully I'll be able to get to it next Thursday.

I laminated the inside of the 4th float half a couple of days ago and glassed in the lifting foil case today. Over the weekend I hope to join the two halves of the second float together.
I'll post some more pics once that is done.

I joined the second float over the weekend.
I screwed a batten to the top of the mould along the keel and deck C/Ls which makes the top half captive when it is being glued. The ratchet straps apply pressure and the top half tries to spread but the extra battens limit the movement and this effectively aligns the two edges. Pick below of the sides strapped together.

Once the resin has cure the hull come out and I fill the rebates in the foam for the newest side. The reflection of the flash on the different surfaces fails to show how incredible fair the hull is given the construction method.
I will still take my time preparing the external surface as best I can before the outside laminate is vacuumed on.

When you look at the amount of buoyancy in these floats it is quite impressive.

Right now both the bow and transom look a bit funny because foam extends past what they have
to be so I have a surface to prepare for the vacuum seal when I laminate the outside.

The float will look really cool when the ends are trimmed and the solid foam bow goes on.

I forgot to mention that I now have a set of CNC machines F85SR float frames and bulkhead templates that are surplus to my requirements. Anyone interested in a kick start on this exciting project should let me know.

Hi Phil,

Your project looks very nice.
I have one question about your bowfloats. They are vert slim on top. Is this your own design or according to plan. I like the small topsite because this makes it less funerable to flip the boat when the bow is submerged.

Arno

I'm building to plan and intend to continue to build to plan.
BTW:- I also really like the shape Ian has for the floats.

are the SR bowfloats different from the normal one's on the topsite?

Arno,
I'm building the F85SR. The closest to this design is the F82R.
Towards the bow there appears to be a difference in deck shape as you have noticed in the photos of my F85SR floats.

Ian would be the best person to direct questions to about the design if you want more detail.

Regards,
Phill

I've not had much chance to work on the boat lately but I have taken some more pics of the stuff I have had a chance to do.

Suspending the floats with webbing straps on lines makes it easy to both rotate the floats and vary how high they are off the ground depending on the task at hand.

Below I'm preparing the area around where the foil case comes out of the deck to take a high density filler.
The plastic is taped to the foam to ensure the only place the filler goes is where it is needed.

After the deck I did the keel and in both cases removing the foam is much harder than I expected.
It has a pretty strong bond with the internal laminate.

Most of the foam has been removed but still more work to do. I'm glad it is so hard to separate the foam.
Bodes well for the integrity of the final structure.

I wanted to glass the first 1200mm or 4ft of the keel and deck joins from the openings still in the ends of the floats.
Being able to adjust the distance of the floats off the ground allowed me to stand in a comfortable position for the work. I made up a brush screwed and glued perpendicular to the axis of a 1/2 inch by 1/2inch 6ft long stick. I also made up a device to apply a small fillet on the join.
In the case of the bow I had to get 4 inch wide glass tape and peel ply trough a 2 inch wide slot. I expected this to be quite difficult but it wasn't that hard after all. Below is a pic of the final product after the peel ply has been removed.

When I went to glass the first 4 ft of the transom end joins I used the same method as the bow because it worked to well.

I'd just put a coat of resin on the area the tape is about to be placed and apply the fillet. Wet the tape and peel ply out together on a bench and then place the combination on 2 lengths of dowel with a 3rd length on top over the centerline.
Sandwiching the tape like this holds it in place with the center stick showing where the center line is to help positioning.
Put the lot inside the hull and roll the two underneath lengths out from under the tape. The rolling action ensures the glass tape lays flat on the work area. Then just go over it all with my brush on a stick to remove any air bubbles and bed it all down.
I could have just rolled the tape and peel ply onto a roller and unrolled it for the transom but the openning in the bow was too narrow for the roller method.
Anyway I'm pretty happy with the result.

looks great phill!

Thanks for the compliment.

Its great how when building your own boat you can get enjoyment from the smallest of achievements.

I made a glass tube yesterday which I needed for a part of a fitting that I'm making.
I wanted a tube with an internal dia of 35mm and around a 4mm wall thickness. I only need two sections of around 75mm so I made one 220mm section that I will cut up.
I used some 33mm al tube as a male mandrel, coated it in candle wax and then black plastic to keep the candlewax away from the end product. I wound 1250mm of 400gm BD cloth (220mm wide) onto the mandrel and spun it with a power drill while gripping it to compress the laminate. Then I wound 60mm strips of peel ply to form two layers which helped to further compress the layup and then two layer of PVC tape.
When cured I used my heat gun to warm it all up. The wax melted and the mandrel is released. Before I had a heat gun I would just pour boiling water down the tube.
Now the good bit is the final product contained 60/40 glass/resin ratio with a 4.5mm wall.
I've made lots of tubes this way before but never bothered to weigh and measure the components to work out the glass/resin ratio.
Half the fun in a project like this is taking pleasure from small achievements.

Folks,
When setting up a vacuum session it is always a challenge to find all the leaks to get good vacuum pressure.
I understand that you can buy untrasonic leak detectors but that are a bit pricey for the home builder.
Well a friend who was helping me suggested that I buy a stethescope as they were on sale at a local store for $10 ea.

Well I tried it and if you are looking at vacuuming and can get a stethescope to help find leaks give it a go - it works great.

Regards,
Phill

Hi Phill,

photos looks great and thanks for all the tips included!

Are you able to move the floats around by yourself?

Rolf,
I can spin the floats around and move them back and forth in the workshop easily by myself. Having them suspended on slings from the ceiling makes this very quick and easy.
It's not the weight but their girth, it is too big to get a good enough grip to carry one outside alone. With another person each picking up an end where it is easy to grip carrying them around is no problem. The F85SR has enough volume in the floats to fly 2 of the 3 hulls.
Given the size and volume of the floats they are surprising light.

Flying two out of three hulls sounds good. If you get all three hulls airborne, you need bigger foils and a license <img src="<>/wink.gif" alt="wink" title="wink" height="15" width="15" />

Rolf,
A few days back I dropped the glass tube that I made on the concrete floor of my workshop. It sounded just like the ringing chink of a glass bottle , the sound they make when they bounce rather than break. The tube has been cut up and part of the hulls now.
One step at a time. <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />
Regards,
Phill

I have added a few more picks of the work I have been doing.

The nose has been added to the floats and the glass tube included which is part of the fitting to take the brace for the spinnaker pole.

A 6mm long shank shackle is glued into the glass tube.

A 10mm silicon tube is used to ensure a path is maintained for the brace once the shackle is embedded into the resin.

A clamp is used to ensure the shackle finishes at or below the hull exterior surface. Giving a very clean look with just a couple of small holes. So there is an added benefit that the fitting does not interfere with fairing, painting or later on polishing.

<img src="http://www.catsailor.com/gallery/albums/userpics/10302/normal_Bow%20work29.JPG" alt="" />

The silicon tube pulled out quite easily after and I could double up a 5mm line and slide it through the smooth path left around the shackle. Therefore I can now pass a line with an eye splice through making it very easy to attach and detach the brace line.

Gee Phill That's a bit shackle, Aren't you worried about the boat nose diving with that amount of weight on the bow??? LOL

Richard,
What do you think the lifting foils are for?

The shackle weighs 31 grams. The whole fitting including glass tube and resin to bog the shackle into the tube weighed 151 grams.

Damn good thing I have those foils. <img src="<>/crazy.gif" alt="crazy" title="crazy" height="15" width="15" />

More pics in the photo albumn as per below.
I prepared a surface to bond the vacuum film to in order to ensure a good seal. Layer of filler on the foam followed by coat of resin. (I later found two coats of resin, allowing cure between coats, appear to do the same job.)

Float laminated with peel ply on.

Managed to again pull a vacuum of 25 inches. (Around 12 pounds of pressure per sq inch.)
My $10 stethescope was very handy at finding the small leaks. The big leaks don't make a noise but you can usually see them.
Also I found out that the tacky tape does not stick well to resin with amine blush on it. Had to clean the amine blush off with acetone. In the past I had used a resin for the seal that does not blush. In future I'll stick with the blush free epoxy that I have when making sealing surfaces on the foam.

Using plastic and fan heaters to bring the temp up to 25 degC as the day cools.

Weighing everything that goes in and comes out I determined that 6.4 kgs of resin went in before vacuum and after pulled around 1 kg out in the wadding and peel ply.
I was pretty happy leaving only 5.5kg of resin in the hull side given the heavier weight of the external laminate. The resin content of the laminate looks just right.

An interesting point in the process was the need to get the glass to wrap around the keel by 50mm and stay up against the foam while we prepared for the vacuum. Gravity would be trying to work against this so I applied a layer of resin with fast hardener on the foam and did not try to wrap the glass around until it went tacky. The tacky resin easily did the job of holding the glass up against the foam while I wet out the glass with slow resin and prepared the vacuum.