Mailport: September 2021

MULTIHULL MADNESS

Regarding your report on the rising popularity of multihulls (see PS March 2017, “Multihull Madness”), when the wind speed doubles, the force and heeling moment on the sails quadruples. It does not go up by a factor of 100. Anyone with a knowledge of aerodynamics could confirm this. Secondly, while some multis do capsize by tipping sideways, they mostly go over because they dug a leeward bow into a wave, causing the bow to dig in and the boat to capsize diagonally. By design, this is really difficult to do with a modern cruising cat – especially on boats with a solid bridge deck between the bows. Finally, unless there is a really strong and sudden squall (e.g. a downdraft from a thunderstorm), there is lots of warning that a cruising multi is starting to get overpowered. While I would not say that you could not capsize a modern cruising cat, barring an unforseen thunderstorm squall, I think that you would have to work at it.

Rob Davidge

Endeavour Catamaran 30

Kingston, Ontario

Good point. We have made similar observations in a report on catamaran stability that explores in greater detail the impact that elements like hull shape and bridge-deck clearance have on performance and safety (see PS February 2021,“Multihull Capsize Risk Check).

UNDERWATER KINETICS LED FLASHLIGHT

With regards to your discussion on reports on LED flashlights (see PS December 2007, “Practical Sailor Sheds Some Light on LED Flashlights.”

I am an avid diver and instructor. I have had good experiences with Underwater Kinetics (UK) underwater lights. And I do a lot of night diving, often in excess of a hundred feet. I still have a few that work fine after 30 years of use. I just keep the o-rings lubed occasionally with silicon grease.

Fred Read

Tartan 37, Merry Dolphin

Oriental, North Carolina

EATING WEEVILS

Regarding your recent blog post “The Pesky Problem of Boat Pests,” I know that this may seem revolting to some people, but cooking and eating pasta and rice which contains weevils will (from my own experience—I’m not a doctor) do you no harm at all. You may not even notice them, other than as tiny dark specks. When living in an old 9 meter steel sloop in Brazil, we frequently found weevils in our pasta and rice supplies. My girlfriend/crew, whose father was a medical doctor, pointed out that they are only reformed proteins from the starches.

Before cooking, we picked out as many as we could bother to pick (not many), and ignored the rest. There were no discernible effects. So cook and crunch away happily! By the way, when we bought the boat in Brazil it was quite literally crawling with cockroaches, some as long as 5 cm. Sprays had no effect. Then we scattered piles of Boric acid powder in every dark corner. Magic ; after just one week, we never saw another cockroach.

You should be able to buy boric acid powder in any chemist/pharmacy, anywhere in the world.

Rob Neal

MGC-27

Norwich, England

We’re longtime fan of boric acid and borate-based cleaners such as Formula B (Homemade Mildew Preventers That Really Work, PS Blog May, 2018), in part because they are effective biocides, but also because bugs hate them. Thus a little boric acid in the pantry makes sense to us. The roaches do not eat it directly, but it does get on their legs, and when they clean themselves they die (see “PS August 2019, Giving Bugs the Big Goodbye”).

ROSEMARY OIL VS. SPIDERS

Regarding your “Pesky Pests” post, a solution of rosemary oil and vinegar can be applied to dock lines and other surfaces to discourage spiders. The herb does not harm them, but can keep them off. In the alternative, just teach the larger ones to roll tack.

C&C 41

National Yacht Club

Toronto, Canada

WATERPROOF EPOXY

I read with interest your report on hull damage and holes under water and waterproof epoxy. I wonder if a solution to an underwater hole could be found with NASCAR?

The idea came to me while watching the dreadful movie All Is Lost.

Routinely NASCAR has wrecks. Many times the sheet metal alone is damaged, but the car can still compete. Pit crews use a product called ISC X-Flex Racers Tape which comes as a roll and as a sheet 11” X 15” made of butyl rubber adhesive. The manufacturer claims it is waterproof, but I found no mention of it being able to be applied to a wet surface. It is slapped on by a pit crew member inside a 15 second pit stop.

Perhaps a test of available emergency repair pads such as this along with say Gorilla Tape which claims to be waterproof as well? Something like this might save a boat.

Norm Marshal

via PS Online

Sounds like a good project for us. Although we’ve not tested ISC Race Tape for this use, it did well in tests for chafe protection (see PS December 2020, “Chafe Tape Plan”).

STUCK BOLTS

Regarding your Inside PS blog post “More Boat Tips: Unsticking Stuck Nuts and Bolts,” Another trick for drilling out a fastener seized in a threaded bore , if it is broken above flush to the female threads, is to file or grind a perpendicular flat on the fastener and then carefully center punch the flat so the drill does not wander off-center and enlarge the bore. Starting with a smaller diameter pilot drill and then using a bigger drill, works well, too.

Drive-in style ‘easy-outs work well when the suggested ‘stud remover’ does not have enough fastener height to grip.

I noted that heat was not mentioned as another form of persuasion. Heating with a torch may damage or discolor anodizing, and will definitely destroy paint, as will a heat gun. To avoid harming surrounding surfaces, try heating the tip of a tightly fitting screwdriver, just shy of glowing red, and then insert it into the fastener’s slot or socket to transfer the heat. If a snapped fastener has been ground flat, press a heated flat faced punch against it. A few tries may be required, but this method has often saved the day and saved the paint.

Bruce Pfund

BP Special Projects

STUCK BOLTS II

Threadlocker (Loctite) not only keeps bolts from coming loose but also fills the space on the back side of the threads to prevent rust. An NCT bolt only has about 15 percent thread engagement leaving lots of space for moisture (rust). I use blue thread locker on everything I put together. For frozen nuts I have had lots of luck heating the nut red hot with an acetylene torch and immediately pouring cold water on the nut.

The thermal shock breaks the nut loose from the bolt and usually comes off easily. For small bolts that break off, drill completely through the bolt with a drill size that allows a bolt extractor to work. Heat the bolt and melt beeswax (from a sewing or craft store) against the hot bolt. The beeswax has a very low viscosity and works its way into the seized threads allowing easy removal of the broken bolt. I learned these tricks from working as a diesel mechanic for 45 years.

Robert Jacobs

Harrison Township, MI