The lunar lander deck panel got a can of Kiwi Grip spread on it, then rolled out. I predicted it would take an hour. It took about 5 minutes and looks pretty good.  Thicker gives a bigger pattern; thinner gives a more mild pattern.

I got the epoxy primer on all the furniture in the lunar lander dwelling. I used a Matson 2 part epoxy product that seems to be just like 545 but at about half the price. With Awlgrip T00031 reducer it rolls and tips wonderfully. I buy at Farwest Paints here in Seattle. They sell a lot to Boeing.

Wood Boatbuilding Fusion
Some time ago I was invited to give a lecture to the Seattle Central Community College school of wooden boat building.
I advisd them that their futures were not in steamed knees and nuances of refastening a hull. I told them that the future of wood boatbuilding was in fusing wood/epoxy technology with composite technology. Together they offered advantages that neither can separately
I don’t know if they were impressed, but some of my fusion samples never made it back to me. I guess that is good.
Wood and plywood have many advantages that many composites don’t have. Woods, for example, have a fatigue strength that is only matched by carbon fiber and is more than double that of E glass. After some 10 million use cycles, plywood and carbon have about 50% of the strength they started with. E-glass has about 22% of the strength that it had initially.
Plywood has an industrial smooth surface finish that composites can only achieve after hours of finsh work or a large bagging table. It comes that way right out of the factory. One should try to use those advantages given by the economy of mass production wherever possible.
A fusion composite part probably will not need a mold. The plywood appearance face can form the part. When I built the composite lunar lander, if I would have had a big budget, I might have infused the parts with triaxial roving and pvc or sen core. I would have needed molds or at least a bagging table. I did not have the budget so I vacuum bagged my own SIP panels by vacuum bagging ply faces onto foam core.
By itself wood or plywood is too heavy to be efficient against out of plane loads or to be restrained against global loads. Composite cores like pvc, sen, or balsa can make a very strong panel by bagging the core to the plywood and in turn, bagging more plywood or composite fabric onto the opposite face. The result can resist out of plane loads and or, restrain a structure against global loads at much much less weight than a solid plywood or even plywood and stringers can do.

All wood used as an engineering material must be encapsulated in epoxy. That not only improves the wood’s mechanical properties, but it protects it against moisture and rot. The epoxy also becomes the bond with the core and or fabric that is used. Epoxy is also much easier to get right, especially if the temperature of the workspace changes during the day. Polyester or vinylester initiators and catylists must be mixed accurately to often fractions of a per cent. And that measure must change as a function of temperature. I always say that you can be almost brain dead and still get epoxy right.
Plywood has extra benefit from combining with carbon fiber. Plywood and carbon fiber both have a stretch to failure of about 1%. They work very well together. In comparison, E-glass has a stretch to failure of about 5% to 6%. So if the combined part of plywood and E-glass is loaded to failure, the plywood will fail while the glass is onIy contributing about 20% of its strength. I have seen plans of catamarans by famous multi designers, who charge much more than I do, who design beams with plywood and E-glass combined. With enough glass, it works, but is very inefficient. And I remember one set of plans I saw with something like 20 layers of e-glass uni was called for. The schedule not only had no cross laminates, but the contact surface with the plywood was minimal. Those each are a failure waiting to happen. Combined? Wow.
E-glass does have a place with fusion products, but not against global loads. Glass cloth is great at providing damage protection and a vapor barrier for plywood. Glass cloth or biaxial roving are ideal for joining parts where global loads are not involved. The extra give that glass has can do very well to prevent the energy of crack initiation on a plywood free edge. Like a ripstop.
Ideally the carbon fiber is vacuum bagged to the plywood with the warp in the same direction as the plywood 0 degree. In general you can replace about 10 thicknesses of plywood by one thickness of carbon fiber, for bending strength. Note that many other factors enter in, but in general that’s true.
Plywood, lumber and composites combined can create products that are synergistically better than the different parts that were combined. Fusion.

So I’m off to the Port Townsend Wooden Boat Show again. The list of topics is mostly traditional stuff. I see fellow designer Richard Woods will be presenting.
I should have offered my program on plywood/composite fusion that I presented at Seattle Central Community College School of Boatbuilding.  I thought it was at the website but I see not. I will post it in next post.

I did print up a splashy T shirt for the show.  Will be on a black shirt.

This sad project took a turn for the worse and remains another example of the need to sort out your mission statement before you build the hulls. And I spent dozens of hours hand-holding these guys.  They bought plans to the 32 ferry and wanted it stretched to 38.  But would only pay for the hull lines revision.

Years later they started again, demanding that it now carry 44 pasengers and cargo.   The hulls were already built, about the size of a 40′ trimaran amas, but weighed 1500 lbs each (3.5 lbs/sqft) so it was already in a huge payload deficit.  I talked them down to 40 seats and no cargo.

I 3D modeled the new design, sent ortho drawings of the new design, did new weight study,  designed  added laminates for impacts, structural updates and all the hand holding to try to save the project.  I gave them a minimal fee.

I just got word that if I didn’t agree to more design work at no cost to them, they would find a  new designer.  Corrosive when they got so much.  Remind me not to do more work than is paid for, in the future.

The freeboard on the KHSD 65 catamaran ferry for Uganda does look a bit low. It is lower than my other 65 ferrys. One of the lessons that I learned from Amani, also a 65, was that it must travel in containers. Bluebird is lower as it escapes a full length set of horizontal scarphs by being lower. I’m always in favor of a faster build if it can be just as safe.

My go-to guy at USCG MSC in Washington DC, Mark Ganulin retired. It seems that he didn’t train anyone nor leave any notes for the new staff on his way out the door.

This came into sharp focus last spring when I was submitting a tiny 27′ shore shuttle catamaran through MSC.  There is a thing in the CFR 46 called 170.173.  It states that no vessel may have its maximum transverse righting moment occurring at less than 15 degrees of heel.

A typical catamaran like I do or like Gold Coast does has that maximum righting occur at some 5 to 9 degrees, not 15.  It was irrelevant to catamarans and Mark ignored it.  It’s probably very important to single hulls, but not us.  One could design a catamaran what would get it’s maximum righting at 15 degrees, but it would have to have deep V hulls right beside each other.  No!

The new guys were adamant about it.  We spent months wrangling.  They stated that the only way forward was to show a hypothetical vessel that would comply, but they could not say what that vessel would be.  Kevin, the builder, finally filled barrels with water on one side and got it that way.

The take-away lesson is that any of the settled USCG requirements that we thought we could depend on could be gone.  They were like a terrier on a pantleg, even on something as ridiculous as 170.173.  They are polite but seem to have no experience with boats whatsoever, and the force of law behind them.

In the past I could state that I would include compliance with published regulations in the CFR 46 with purchase of a plans set.  I can no longer do that.  They could latch onto anything and demand something never done before.

I will also have to sharply raise the cost of the plans of USCG certified designs.

In the past I have always sprayed Awlgrip Hi-Build. I was in an interior situation in my lunar lander where I could not spray. I had tried brushing once with T0006 reducer years ago and it was a mess, so I was skeptical.
I have to say that the T0003 is wonderful. I strongly recommend it.  I was able to coat the furniture below very nicely.