Built by North Shore Composites (2015)
These carbon sinks were for an interesting yacht called FOGGY which builder Brooklin Boat Yard describes as “a 74′ German Frers-designed daysailer with styling by the world-renowned architect Frank Gehry.” It had five of these sinks set under titanium counter-tops. I never saw them installed except in a magazine. The boat is an incredible piece of work – totally worth looking up some pictures if you like wood or composites or craftsmanship at the peak of the boatbuilding game!
- More on tooling paste here: Building Big with Tooling Paste
- And more on pre-pregs and how to use them here: Laminating with Pre-pregs
Tooling
So I made these five sinks – actually six because one had a little fold in the first layer of carbon – oops! I wanted to have a really nice surface and so decided on a carbon mold made on a tooling paste plug. I could have used tooling board or even MDF for the plug but was doing another job with paste at the same time so it was easy to piggy-back this little one.
The paste was finished with Duratec primer. A carbon tool was infused (Proset 114LV with high Tg hardener) with 800g triaxial offcuts backing up a 200g woven surface layer – all up about 4-5mm thick. This tool got post-cured on the plug at around 65C, and then ramped up to 100C after demolding.
Machining 3lb urethane foam 
Foam glassed with two plies of 1oz mat (more would have been better!) 
Machining tooling putty (ATC T28) 
Fairing and sealing with Duratec polyester primer 
Infusing the mold 
Mold, post cured but not trimmed. 
Laying up the inside surface layer. I used teflon on the flange for easier release – not ideal! 
Curing in the autoclave 
Clearcoat!
The Parts
Layup
Cosmetics were the key issue here and after some testing and discussing the cosmetic needs of the project, I found that a single piece of 200g carbon pre-preg 2×2 twill would be heat-gunned and stretched over the mold. The little lines of “chevrons” or the 45 degree pattern that shows up in twill weave fabrics was the primary visible element here. The bulk of the laminate was sections of 400g biaxial pre-preg with another final layer of twill over the outside. Total thickness about 3mm.
Material
The pre-preg was Gurit SE84LV. Because the sinks were set under the counter, the seam where the rim ply of twill meets the continuous bowl layer was hidden.
Curing
They were cured in the autoclave at around 100C and 50psi. The bagging stack consisted of non-perforated release film right on the laminate, scrunched up so it wouldn’t bridge. This just got some breather over to vent the bagged surface. There was no resin bled off during the cure. Demolding was aided by a small area where the drain goes that wasn’t laminated. A couple of very shallow wedges around the rim and a wack with a mallet and they popped right off!
The finished sinks got trimmed and coated with a two part clear-coat.