Backing Plate Testing

Breaking stuff in the name of science is always fun! Parts of this appeared in Practical Sailor in 2015, some not.

The test rig

The bolt is tightened and torque recorded until something gives.

  

I tested laminate samples to make sure the failures were appropriate (good bonding). As you can see, the core is failing in shear.1 layer 17-ounce biax on the bottom, one layer 17-ounce biax and one layer 6-ounce cloth on the top, 1/2-inch end grain balsa.

I replaced core with plugs--standard practice.

The Poor

Starboard showed micro cracks after 3 week. It also creeps a lot--I had to keep re-torquing for 48 hours.

 

Teak is a big failure. Note how the distorted washer became a wedge.

 

 The Best

Just 2 layers of 17 ounce biax were very impressive, holding 1.5 tons. 4 layers would be correct for 1/4-inch bolts.

1/8-inch FRP bonded  did better than 1/8 SS, particularly on rough surfaces. 1/4-inch FRP would be correct for 1/4-inch bolts.

 The Bottom Line

• 1/8" aluminum for light duty in dry locations. Thickness = 1/3 bolt diameter minimum.
• 1/4" FRP most places, bonded if there is high load. Thickness = 2/3 bolt diameter minimum.
• 4 layers of 17 ounce biaxial cloth for every 1/4-inch of bolt diameter, where there is high load and irregular surfaces.
• Diameter of plate = 5 bolt diameters minimum.

And never, ever use fender washers. They bend into cones and are LESS effective than standard bolting washers in actually distributing the load.  Buy extra thick (Bolt Depot).

 A little more if the skins are very thin. Less with solid glass.

In praise of WAG Bags

On my last boat I had a conventional holding tanks system, and properly maintained and designed, I believe it is the best answer for most cruisers. I've done lots of research, used composting heads, and have no reservations about this recomendation. But with my new boat, the right answer is WAG bags.

WAG (Waste Alleviation and Gel) bags are widely used by the military and FEMA in situations where conventional sanitation practices aren't practical. For example, I used antifreeze in the toilet of my PDQ in the winter, and that worked well, but carrying a portable toilet on an icy dock from my F-24 seemed pointlessly dangerous. So I investigated WAG bags as a winter alternative.

A heavy duty bag and a gel very similar to that used in diapers. Pretty simple. We have a portable toilet, but we don't put solution in it anymore. These are simpler.

Not pleasant, to our western sensibilities. But think of the plus sides:

• Light.
• No head to clean.
• No odor once off the boat. 
• No pump-out station, no lugging the portable head home to clean and refill.

I'm not saying they are for everyone. We hardly ever use the head on the boat. We hit the shore side toilets before heading out, and if we drink some beer, that goes over the side. I doubt we use more than one bag a year.

But even when cruising, I would have kept a box onboard for emergencies, had I known of them. They can be laid right in the head (drain and clean first, obviously) or used over a bucket, no mess.

Not pretty, but darn functional.

Why Not Webbing?

As I did more with low friction rings, it became evident that rope is not the best material for sliding. Double braid can get lumpy and is high friction. Single braids, like Amsteel flatten under load, leading us to the obvious conclusion that webbing is better for some things. 

By including loops at several points, it can adjust to various reefing heights. This boat uses roller reefing, so there is no jiffy-reefing tack line.

For example, webbing has been used for years in dinghy Cunninghams. The purchase is doubled by running it through the Cunningham eye, but it's just a regular grommet. Webbing runs more smoothly, with less friction.

Webbing is perhaps the most traditional method of attaching sail slugs to the mainsail. Wrap 2-3 times and sew.

So what about other applications?

• Lifeline lashings.
• Sewn to the jib or reacher sheets at the end, there is nothing to hang up on.
• Slab reefing outhaul tackles. Less friction through the clew ring.
• Furler line. I use webbing on the reacher--I can fit more on the drum that way. The webbing is spliced to a larger rope tail.
• Control lines that are underfoot on deck.

This is also similar to what we do when we strip cores, such as on furlers. I'm aware of that. You don't want to handle it under load and it does not play well with winches.

Ideas?

PDQ 32 and 36 Rudder Core

Posted just in case any PDQ owners were curious about what lies inside.

Anchor Lights Get Smaller

Once upon a time anchor lights took a huge bite out of your battery overnight. Some drew as much as 25 watts, costing you as much as 20 aH by morning, or nearly the entire usable capacity of a group 24 battery. The also burned out every 1000-2000 hours, requiring frequent trips up the mast to keep them burning. LEDs promised as much as 100 times less draw and lamp life up to 50,000 hours, but the the first generation didn't always deliver.

 On the left, the home-built masterpiece a PO installed. The engineering was pretty, but heavy and ultimately failed. On the right, the replacement Tecniq M10. It is tiny, draws less power, is USCG certified, and weighs less than 1/2 ounce. (both are 2.5-inch in diameter, both light through the same vertical angle)

They came from a cottage industry, some nearly works of art and others crude affairs. Some nav lights were the wrong colors. They didn't always shine through the correct angle. Some interfered with VHF, a particular problem with anchor lights, being located right next to the antenna. None were USCG approved.

I don't mind the heights, but the up and down trips for the stuff you forgot are annoying. In this case, I needed two odd size screws from the hardware store. I remembered everything else.

I'm keeping the old one on my bookshelf, like a little lighthouse. But I'm happier the Tecniq is at the masthead.

Riding Sails

Some boats hunt all over the place in a breeze. Yawing through 90 degrees can double the force on the anchor and quadruple the forces working to twist it out. First, there are solutions related to the anchor and rode:

• All chain. Helps right up until the chain lifts off the bottom.
• Hammer lock mooring. A second anchor, just touching the bottom. Very effective in moderate wind, but can fail if strong enough.
• Two anchors. A whole nuther' topic, but can work very well. Also complicated, particularly if there are other boats anchored nearby (you will swing differently).
• Drogue on the chain. Didn't do much for me. You've got to be yawing fast for it to matter.

You can change your windage. After all, that is the source of the problem. Anything forward is like a riding sail at the wrong end.

• Take the dinghy off the bow. Big difference.
• Lower you reacher. Big difference.
• Add a  riding sail aft. We'll come back to this.

And you can change your under water profile.

• Lift the rudder. A HUGE help. But most people can't do this.

 I've been playing with riding sails. Single luff sails function by pushing the stern to one side, which creates a crude V. The problem is, it is very sensitive to how the boats windage changes with aspect change. Some it works, most not so much:

• Push the boom to one side. Didn't do much for me. Yawed through the same angle, just to one side.
• Riding sail. Same problem, plus it flaps when it reaches the extreme travel. Annoying.

I've also tried V-riding sails, with two luffs:

• This is a Fin-Delta, from Banner Bay Marine. I've heard goo things and need to get my hands on one.

• A less conventional approach is the V-Delta, conceived by Paratech but not marketed. Even this crude tarp was stable up to 25 knots. The grommets were set in a corner reinforced with only duct tape, and yet they didn't pull. The force is just not that great. It also reduce the yawing more than half, and the higher you set it, the better it works.

This was made from a tarp, and it worked up to 30 knots without even straining. 

 

 A full awning is possible, but a larger version of the riding sail makes a far more stable awning.

 The orange line is the riding sail. The Blue line is a larger version that serves as both awning and riding sail.

If  I didn't have  bridle, I'd be sewing one of these right now. So simple. Yes, it does increase the rode tension a few percent, but this is FAR less than the wind hitting the boat from the side and swinging it about.

 

I is an evolution on a Paratech design. 

 

 

Please share your riding sail experiences. I need to figure out what to test!

Weird Boat Award

Good Weird, I think. The boat is for sale in Italy, but I met them on the Chesapeake a about 7 or 8 years ago... I think.

It's really the paint job that sells it. I've always thought Americans, and indeed, most westerners are too shy about color. I'm a coward when it comes to choosing paint. But this is fun.











I know nothing of the boat's condition now. It was solid when I saw it. What I remember is that the colors and the crew were alive. If it had not been for the color scheme, I would never have photographed it, met the crew, or remembered it.

Birds

[First posted summer 2016]

On reasons to visit the boat regularly, at least in the spring...

"What in the hell was she thinking?"

Of course, the "she" was the bird that laid the egg, I was upset because a rotten one broke on my shirt just below the collar, and by the time my wife emerged I had changed my shirt, cleaned up, and half forgotten about the whole thing. Certainly I couldn't relate any of the mornings events to my wife's concern that I was upset.

Needless to the say the end of the boom has been sealed. Now I just have to figure out how to dispel the constant spring bombardment from the birds roosting in the rigging.

As soon as I sealed the end of the boom, they started building nests under the sail cover, pooping all over the sail. Arrg! Seal your covers up TIGHT in the spring.

 This hasn't been a problem on the F-24. The boom is sealed and the mainsail rolls tightly around the boom. But I'm going to revise the cover this spring to better protect the bolt rope. You can bet it will seal tightly.

Gybe Tamer

The English company making this devise folded, from what I understand.

Basically, it is like one of the gas struts that lifts your hatchback, but in reverse. It pulls open at a specific load. The idea was that in a hard jibe, it would ease the stress on the rig. They made them in three sizes.

The problem is that by the time the spring is stiff enough to hold the windward sailing load at near the reefing point, even the most monstrous accidental jibe will not extended it. It messes with mainsail trimming, without protecting the boat. I tested it on both my F-24 (video below) and the PDQ 32 (it had to be placed inside the tackle on the PDQ to reduce the load).

The best answers remain:

• Control the jibe through careful sheeting. Keep the vang on and bring the sheet in either before the turn or during.
• Keep some stretch in the mainsheet and vang systems. Dyneema does NOT stretch and transmits much larger shock loads. Leave it to the racers who enjoy replacing broken stuff. Use polyester double braid (nylon is too stretchy).
• Keep some stretch in the traveler as well. Polyester is good and nylon is even better (it only gives a few inches, which does not ruin trim--some racers have gone to nylon travelers for smoother crash jibes). Dyneema is a resounding NO.

How Long Does Synthetic Rigging Last?

I'm starting to use Dyneema more and more. I like the ease of use, economy, and the light weight.

But just because it is corrosion resistant and fatigue resistant does not mean it lasts forever. 6-8 years is safe in the tropic and probably 10 years here in Maryland (less sun), but I've seen older Dyneema break, and the remnants tested at only 25% of new strength (probably quite old, but not known). Same with lifelines; nice for 6-8 years, but after that it depends on how over-strength you went.

Just make sure you put it on a schedule, and like any rigging... inspect it!