Infusing the board on Geoff’s KHSD 49 cat. That is carbon. That is one of the halves. The core is bagged in next.
Simo on his amazing 24′ tri has another brush with fame.
Between rush deadlines and supporting some 50 ongoing projects, the blog has fallen behind. As soon as I can surface for air, some of the topics will be:
Revisiting Post-Apocalyptic Boat Building.
Always new projects submitted.
Latest on sealing the vacuum bag.
Looking into PET foam.
The greater Seattle area has about a dozen relatively exotic KHSD multis building and sailing- lets look.
The cat projects in Africa and Estonia are ongoing.
I should catch up soon.
I’m off to Fish Expo today. Fortified myself with sardine lunch. They have upscaled the name to Pacific Marine Expo, http://www.pacificmarineexpo.com/10/public/enter.aspx but we still know it as Fish Expo. Its a serious boat show, especially for Alaska fishermen. I ran into Steve Sheidler there once and he put it perfectly. He said “If these guys have equipment failure, people die.”
How strong is glass compared to plywood? Here is a table comparing strengths with out of plane loads (like water pressure).
Plywood/Glass Thickness Conversion comparing bending strength. (Assumed 60,000 psi bending strength for glass and 10,000 for plywood)
Assumed that triaxial amount is on both sides of a core
Ply thickness Triaxial thickness Core
3mm ply equals (12 oz) 400 gsm w/12 mm core
4mm ply equals (17 oz) 600 gsm w/12 mm core
6mm ply equals (22 oz ) 750 gsm w/12 mm core
9mm ply equals (34 oz) 1150 gsm w/19 mm core
12mm ply equals (2) (22 oz ) 1500 gsm w/19 mm core
I just got this link from Craig Riley of Composites West in Incline, NV.
This plywood/epoxy CM catamaran has been carrying passengers for more than 20 years there on Lake Tahoe. It was always one of my favorites. And its a demountable boat.
I understand that the USCG stability rules are catching up with the increasing girth of Americans. The official passenger weight for COI boats is to go up from 160 lbs to 180 lbs as I understand it. For monohulls, that can be a crisis. For catamarans, it will not actually change the stability at all. I expect that everybody will need to revise their stabilty calculations and stability letters. I have spreadsheets ready and can do that for everyone who needs it.
Related, I can’t believe that with all the budget cuts, a plans submittal and inspections for a COI vessel is still free. Where else can you get a building permit for free? I can’t imagine it will be free for long. Submit those COI plans soon.