Friday, September 28, 2007


This is what the decks looked like after yesterdays "candy bag method":

And the dorsomedial view:

A detail after sanding down the ridges. Unevenness not visible to the eye is revealed. The location dowels are removed for easier working access:

Then I started filling the gaps between the ridges. This turned out to be much more time consuming than expected as very small holes in the fairing compound tended to appear when trying to smooth it out. I expect plenty of low spots after first fairing, that is ok as I have to fill all those small holes anyway.

It will be hard to find much time to work on the boat the next 6 days due to my working schedule, we will see... And it sure takes a lot of concentration/focusing to get through this stage without spending too much time procrastinating. I must say I know of a few activities associated with more fun than fairing...

Thursday, September 27, 2007

Support rails and fairing compound

I cut out the support rails and glued the vertical supports in.

Making sure there was room for the deck hatch

And the shrouds.

Then I marked all the attachment points for the support rails and calculated an overlap for the tape at the attachment areas and then cut the peel ply around these areas. Then I de-peeled the decks and used the random orbital sander to remove some minor glue ridges at a few peel ply overlaps.

Then I lay down thin ridges of fairing compound, about every 10cm, method from Henny's site. Both decks and transoms are now covered with fairing compound ridges. When I start to sand down these I will get an idea on how well my building have been. I can't wait (but I have to in order to let the fairing compound cure properly) to get on with it!

Sunday, September 23, 2007

Heat cure completed

It all went uneventful. The six thermometers had readings in the range from 51°C to 64°C (124°F - 147°F), the hotter on deck level of course, the lover approximately 5 cm below keel. I kept the heat on for almost 20 hours which is more than required.

I am satisfied with the way this turned out. Now it is fairing, attaching wing net rails and deciding on which version of the F-22 to build. Ian Farrier sure makes this difficult as he provides plans for four different versions, all of them really great boats. Olivers newly published pictures of his main hull made me think maybe I should make as much inner space as possible after all, the cockpit seemed roomier than I had expected and I sure live a place where it can be a challenge being outdoor, all year through!

Heat curing floats

The final decision was a mix of all the inputs I have got. Thank you all! I set up a frame of wood, extending it using wires from wall to wall. Then covered with foam intended to use for the main hull in the ceiling and then covering it all with the big canvas/cover/presenning (sorry don't know the right word). Here the frame work:

Looking from the distal end of the "tent", the heater visible between the hulls:

The opposite view, the "power plant" in the foreground, looking into the slightly insulated tunnel. There are openings down by the floor, the idea is that the heater fills the space with hot air and the least hot air evacuates along the floor to make room for the new. After this shot was taken I made a modification, covering the lower 8" of the opening to prevent the air stream from the heater to drag cold air into the tunnel:

Two of the total six thermometer readings a few minutes after start up. After one hour the temperature seemed to be between 48°C and 54°c, depending on height above floor. I will run full power till tomorrow, then decide whether it is necessary to turn the floats around for another round to ensure full cure over all (based on thermometer readings):

Friday, September 21, 2007

Post curing the floats

I have to heat post cure the floats. A minimum temperature of 50° C for 16 hours is required to obtain maximum mechanical properties of the epoxy. I have a 40 kW heater delivering a significant amount of air, a 5m x 7m quite heavy canvas? (presenning). The temperatures in Levanger at the moment is between 0°C and 10°C, so that is what I have to fight... Any ideas on how to do this is appreciated.

I figure I will line up the floats parallel, cover them using some sort of frame to make a "tent", 7 m long and as narrow as possible. Then let the heater blow through this tent. I might have to reverse the floats in order to achieve the required temperature in both ends. I am really trying to figure out the best way to do this.

Thursday, September 20, 2007

Finished laminating floats

Today I finished the float exterior lamination. Uneventful really, except I found a bubble when I went back to the workshop a few hours later. I managed to squeeze all the air out and I expect a very good laminate taken into consideration no vacuum was applied. I start feeling so confident with my hand laminating technique now that I seriously consider not bothering to lay up the main hull foam air tight. Still considering that is. If I was to use thicker fabrics I would tend to use vacuum, also if the hull was larger, as this size is about the biggest I can manage in a wet lay up without any helping hand, I guess.

No pictures today, I guess you have seen it already. The only distinct difference is the placement of the chain plate being on port side of this one.

I am currently trying to figure out the best way to set up for post curing. 50 deg Celsius for 16 hour is the least recommended post cure scheme to obtain excellent properties of the epoxy.

Monday, September 17, 2007

Finally some progress again

This last week has been busy with work, sailing Frimann (we were planning on attending a regatta in Trondheim on Wednesday evening. The regatta was canceled, supposedly because of the very nice westerly breeze, so we went sailing anyway. It was a very nice sail which ended with the centerboard (33 years old piece of plywood) broke in a 25+ gust and we never saw it again.) and evacuating uninvited water. When I finally found time for building, my workshop was flooded again. I removed all the water and that was it for the day. The next day it was flooded again (I really have to do something, and it will not be easy to change the weather up here!) so I emptied it again. And that was all for that day.

This morning, however, the water was quite shallow and I managed to empty it all, then being home with the family for a few hours when everything dried up and tonight I was able to laminate the inner side of the starboard float. The fabric and peel ply to be used was already cut:

And the float was impatiently waiting to receive it's outer skin:

Then 3 1/2 hour of working with gloves and gas mask, no pictures obviously. I first wet out the foam with a short hair roller. Then the bow cap (reinforcements in the bow section) before I applied the first layer, 200g carbon fiber, making sure to drape it well and then cut it in the right length along the keel line. Then wetting out again before the final layer of hybrid fabric for better abrasive wear resistance. Finally the peel ply was applied and then, working from the center of the fabric, squeezing all excess resin out with a rubber squeegee. Resin consume approx 4,4 kg, significantly less than the other float. The result looked good:

Another view:

And a detail shot along the deck to side radius:

I am quite thorough to make sure the overlaps and fabric ends lay smooth to avoid excessive filler work. The peel ply is to great help in this aspect, it also makes it very easy to squeegee out excess resin and to make sure the fabric is tight. On the last inspection, 6 hours after the first wet out, there were no signs of bubbles.

Sunday, September 09, 2007

Epoxy and Frimann picked up, laminating continues

I got back from Oslo last night, bringing more Ampreg 20 hand laminating epoxy (and some carbon, peel ply, release film, foam etc) and as a bonus, Frimann.

(To you guys on the F-boat forum complaining of low mileage and short wheel base: This vehicle has a wheelbase of 3320 mm (130,7 inches), goes 34 mpg (diesel) without a trailer and more than 25 mpg with Frimann (Trailer and boat approx 2000 kg or 4410 pounds, United States Customary units of mass) on Norwegian roads, steady as a train. Great family car, up to ten seats and room for all your gear. Get a German car!)

Today I continued the process of hand laminating the exterior of the floats. I recessed the reinforcement areas of the deck with the electrical planer, then laminated the deck. On the port float I used approx 3 kg of epoxy on this part so I started out with 2 kg. This turned out to be almost sufficient, I ended up using approx 2,3 kg. I do not know the reason for this, but possible explanations are:

1. This float is made up entirely of the new formula Divinycell. The port float was some old formula, some new formula. The improvement consists of smaller cells in the foam, hence a smoother surface (more like Core Cell) and one would expect less resin to be caught in the surface.
2. I used slow hardener in stead of standard. The slow hardener has a lower viscosity (which also applies to the mixed epoxy) and this may lead to easier wet out of the fabric (aramid is very hard to wet out and vacuum techniques are of great help when using these fibers) hence less epoxy applied until I was satisfied regarding the change of color as a sign of proper wet out.
3. My technique may have improved.
4. A combination of the factors above

I did not weigh the fabric, but rough calculations suggest it is 1,15 kg on the deck. This gives a fiber to resin ratio of 1:2 (actually a bit better, the peel ply is soaked with resin that will be removed) which is not very good but I did not get a very good ratio with this thin fabric and vacuum either. I think the amount of bubbles and a bit more calculations and speculations will decide what I am doing when it comes to the main hull. I really love the the feel and the finish and the certainty of quality that a vacuum treat provides.....

Here is today's status of the starboard float:

Tuesday, September 04, 2007

Second support rail out of mold and table fixed

The second wingnet support rail was laminated without any problems with the vacuum and came out perfect. Really compact and nice, weighing 1.6 kg with the peel ply on. It is stored along with the other one, waiting for the final cure. Here it is prior to demoulding:

Then I had to rip off all the rests of the old vinyl flooring on the vacuum table. Then getting off the rests of the flooring and most of the glue. Here is a shot after it was covered again with new glue, pre curing prior to application of the new cover. It will be ready for more laminations tomorrow.

Monday, September 03, 2007

One more wingnet rail, and notes on how to destroy a vacuum table

This is how the wingnet support rail that I made yesterday looks like. I think it is very much like I hoped and expected. Very stiff on the long side, quite sloppy on torsion:

Here is the underside. Sorry, not a very good picture. It looks cool in real life, though.

It is now resting on top of the float, waiting for the heat cure in the "tent". I am looking forward to see how I will make that one, and whether it is going to work....

The mold is hollow as you can see on earlier posted pictures. Yesterday, I put it on the table and secured the vacuum bag to the table. As I was infusing yesterday I suddenly heard a loud bang and the vacuum dropped to about 1/2 atm. The resin was already distributed evenly, thanks for that. I could not find the reason for the bang nor the source of leak until this morning. It turns out that the vacuum inside the mold had lifted the Vinyl cover glued to the table until it tore apart, quite impressing forces in this vacuum, consisting of nothing, actually. Tomorrow I have to fix my table before I can start infusing all the flat panels for the main hull. Close up of the leak:

I had to obtain vacuum in another way today. What I did was putting the mold on top of the old deck flange molds from the float half production setup and wrap it all in a bag. With all layers and tubes in place, just starting to evacuate the air it looked like this:

Here is the complete infusion set up. Resin in the bucket down right is being sucked in to the bag and distributed along the mold trough the spiral tube in front. Resin then being distributed trough the resin distribution media (RDM), blue color, and trough the tiny holes of the release film being the next layer from top. Then all the tiny spaces between the fibers of the peel ply and the different layers of carbon and aramid formerly filled with air, at this point nothing, are filled with resin.

The vacuum pump is connected to the resin trap in the background which in turn is connected to the collecting spiral tube running along the back side of the mold. This means that all the resin not being trapped in the tiny spaces of nothing (above) leaves the story and have to be brought to the dump on a given day. This leaves a part totally free of bubbles and with a fiber to resin ratio of up to 70% providing the best possible strength to weight ratio:

The part will be left under vacuum for at least 10 hours. Slooooow hardener.

Wingnet rails

As stated earlier, I do not have any more of an appropriate resin/hardener to keep on hand laminating, thus the starboard float has to wait until this is brought in my custody. The port float is stored out of the way until both floats are laminated and ready for a treat in what will be some kind of a tent with the diesel heater connected to it in order to achieve around 70 deg C for 20 hours.

Instead I have been working on miscellaneous parts where infusion is the manufacturing method of choice. Here is a profile of the wing net rail mold:

Here I am vacuum bagging the wing net rail inner support, this will be cut into four parts:

Out of the bag:

And here I am infusing the first wing net rail. This part is 280 cm long and consists of carbon 200g + 450g + 450g + hybrid 240g. Carbon for the other rail seen in the background.

I have thought a lot on how it is best to proceed on fairing, mounting the rail, painting etc. I have come to a final answer. I will fair the floats as soon as they have undergone the post heat cure. I will also cut the holes for the hatches and fill the ends. The rails will be mounted and the final spray-coat of epoxy will be done after the beams are mounted. Then I will paint the floats with rails and beams.

Sunday, September 02, 2007

OJ's photo report on life in the workshop

I finished the outside laminate of the float on august 26. It went almost well, I ran out of standard hardener and had to use fast hardener for the last part which has left me with some challenging sanding work near the keel. I will not know how challenging until I unwrap the float from the peel ply. There are almost no bubbles, I have found three or four though, they are small (1 cm diameter) I think I will fix them with the use of two syringes with subcutaneous needles; one to suck the air out and one to inject epoxy. And I will have to accept a 0.5 mm thicker layer of fairing compound in those areas.

I will have to buy some more hand laminating resin (SP system Ampreg 20) and slow or standard hardener for the other float. As it is an 8 hour drive each way to the shop I haven't been able to pick it up yet, I will in the end of this week. I will then also bring Frimann to it's new home port Trondheim. Frimann was sold the other day and we are now three owners, the other two being Sigmund and Eivind. Eivind is starting the building of his Slinn these days and we will have Frimann for recreation as we build our new boats.

I made an album with a few of OJ's pictures (OJ being OJ Ramfjord, my brother in law, a former hard core windsurfer, now mostly addicted to catching salmon using his home made flies), showing me lurking around looking for bubbles and trying to figure out how to make the wingnet rail mold.

Photo report from the workshop on August 28.