Monday, November 11, 2019

Hardtop Project, Part 7

Lay Up Begins!

While the previous post the work happened over 4-5 days in this post the work was done in about 5-6 hours. Even with the extra slow hardener (West Systems) the team has to work very quickly.

The technique is referred to as "Wet Preg". All the cloth is precut, wetted in a bath then run between two rollers saturating the fabric and squeezing out the excess resin. The cloth is then layed out between 2 thin sheets of plastic, this allows the cloth to be handled, cut and trimmed as needed. To apply the cloth the plastic is removed from one side then the cloth is laid by hand and formed into place. Once in position the top layer of plastic is removed. Once the lay up including coring is completed the entire structure is vacuum bagged which squeezes all the layers together and pulls out any air and excess resin. The technique was first developed in New Zealand and is now a fairly common technique.

Below: Paul laying down a strip of  Wet Preg carbon cloth into one of the ribs. The plastic film has been removed from the underside of the cloth but not the topside......yet.

The center "beam". This channel is hollow for solar and light wiring.

 Wetting out the Corcell® coring.

Below: A layer of core mat which adds stiffness and prevents "bleed through" meaning the top structure when laminated on top will not show through to the underside.

Below: Bagging the entire structure.

Under vacuum!

Below: You can see the excess epoxy being pulled up into the bleed cloth. Pauls says the pressure is approximately 9 pounds per square inch, over a ton of pressure on this structure.

Saturday, November 9, 2019

Hardtop Project, Part 6

The support structure is mostly carbon/epoxy/foam core construction but the "flange" that will be bonded to the flybridge coaming is solid glass/epoxy. In the previous post you can see the planning and mock up of the design. This way Paul uses the boat as a  "pattern" to accurately transfer dimensions to the workshop.  I should mention, Sylken sea is on the hard, 5 meters from Paul's shop. Convenient and efficient.

Below: This is solid glass/epoxy and will become the flange that is bonded to the boat. I thought using the boat as the "mold" was a clever idea. Once the support is bonded to this flange the entire piece will be released from the "mold" and taken to the shop for finishing.

Below: The carbon/foam/epoxy support leg bonded to the flange.

Below: Supports and flange remove and "rough" finished in the shop. Each of these weigh only 11 kg!

Below: Detail of flange/support temporarily in position. As expected the fit is perfect.

It's starting to come together now!

The top will have an opening that these supports fit into, fairly snug fit, the openings are molded into the top.  The plan is to bond the top to the supports on the boat then remove the entire structure as one single piece for painting before the final installation.

Saturday, November 2, 2019

Hard Top Project, Part 5

The guys are waiting on some material to finish up the mold so they start on the support structure. Spent a whole day building a mock up, measuring and making patterns.

Above: Cutting out patterns.

Below: "OK it will go like this, right?" Discussing details and finalizing the design. The supports will not just be straight up and down nor will they be parallel to the boat centre line. They will be  angled to match the angles of the fly bridge coaming, tapered to look like part of the original boat.

Below: Mock up of the support in place, starboard side.

Happiness is a new Exhaust Elbow

Ten years, 4540 hours and four exhaust elbows, the genny is just fine!  Northern Lights has changed the design a bit, new part number. Still a casting so not sure if they have improved the life expectancy. I use a mirror and flashlight and inspect at least once a year, usually twice, 'cause if she drips nasty salty water guess where it goes? Yep, bye, bye Genny.

Friday, November 1, 2019

Hard Top Project, Part 4

Things are moving along nicely, I knew molds take time to build but I had no idea how much time. The sanding, faring, sealing is endless. Now we are in the late stages, Paul and his team are applying Teflon® release tape to the mold, almost ready to do the layup!

Below: The brown material you see is a very cool Teflon® release tape. It is called "tape" but actually comes in a large roll. Paul tells me "nothing sticks to it". I am very impressed with Paul Ammon and his team, Caribbean Carbon Works Ltd. Paul understands what we want, appreciates nice lines and understands functionality. So fun to work with someone who is passionate about their art.

Friday, October 25, 2019

Hardtop Project Part 3

So for most of the week Paul and his guys have been working full days building the mold for the bottom side of the hardtop, the side you will see. I think it is almost done. The mold is made up of multiple layers of 1/2" MDF. Very labour intensive. It has been apart numerous times before final lamination and gluing (West System Epoxy). Every panel is labeled, dowel pins ensue perfect alignment
The last day and a half have been spent fairing, sanding and sealing.

Sanding and sealing the mold. Everything has to be perfect. Not easy to see here but all edges are radiused, channels are tapered. If not done correctly the part will not release properly from the mold, will have tear outs and will require a lot of after mold repair not only time consuming but it would add weight.  If you are wondering why I am obsessed with weight, I like it down low, not up high. 

Below is the top of the hard top, (see part 2) just being "unbagged". This structure weighed in at 70lbs!
The beam of light across the panel is pure Trini 8am sunlight!

Tuesday, October 22, 2019

Hardtop Project Part 2

The lamination begins! Starting with a release layer wetted out with epoxy, then a layer of woven bidirectional carbon also wetted out, topped with 1/2 foam coring. On top of the foam coring both bidirectional and unidirectional carbon all wetted out with West System epoxy by rollers.

Mold is waxed then a release layer is laid and wetted out with epoxy

The bottom bidirectional carbon has been laid and wetted out. On top of that layer you can see the 1/2" foam coring. The unidirectional is laid in a strategic pattern to add stiffness. The first few pieces of bidirectional are being laid on top, all wetted out as the process moves forward.

Final few pieces of bidirectional carbon fiber being laid.

All the carbon is now laid down and wetted out with rollers.

Laying down a perforated release layer, This film has tiny pin holes to allow the vacuum to work effectively.

Perforated film in place. Laying down the bleed layer begins.

 Bleed layer laid down and being trimmed.

All bagged and under vacuum, the vacuum draws out any air, excess epoxy and compresses the carbon, Light and strong!