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Monday, August 10, 2015

Sailing Dinghy update.

I'm having lots of fun with my Lehman 12 sailing dinghy project as a creative outlet.   The goal is to replace our existing outboard powered inflatable dinghy with a highly versatile sailing and rowing dinghy.  Rowing will be a good form of exercise, sailing will be fun and having a zero emissions dinghy will compliment our minimalist low carbon lifestyle.

I selected the Lehman 12 largely on the advice of sailing friends Steve and Carol who have a Lehman 10 as auxilry tender to their outboard powered RIB inflatable, they use theirs plenty and often just for the joy of rowing or sailing around the harbor.

  I really like the classic lines of the Lehman with a traditional sheer and a very cool plumb bow as very few designs have such a traditional look.   

The Lehman was first built in the early 1950's and represents one of the very first commercial produced fiberglass boats.  Our particular Lehman 12 is hull number 258 and was built by WD Schock in 1972.  From what we know the most recent name was 'Cup Holder' and this Lehman was most recently sailed out of Newport Harbor Yacht Club. If you have more info on the history of this boat or old photo, please contact me.

To adapt our Lehman 12 for use as a yacht tender, the boat would need significant modifications to make it user friendly.   Rigging should be simple, making or striking sail should be simple, fast and easily accomplished by one person.  Standing rigging should be eliminated in favor of a free standing mast for simplicity and ease of boarding from a dinghy dock.  Oars should be stowable inboard and secured to prevent loss in event of capsize and from theft.  Sufficiency sized flotation tanks should allow self recovery in event of capsize. Rudder should kick up beach landings and be of modern design for optimal sailing performance.  Storage for anchor, life jackets and ancillary gear should be secure and protected from weather.  Transom should allow for fitting of small outboard engine. Seating should optimized for sailing longer distances without sitting in the bottom of the boat with a wet bum.  Seating should also be flexible enough to accommodate two rowing stations with movable athwart seat(s) to optimize trim while rowing.. Main sheeting should be mid-boom and vang controls should also be close at hand near main sheet.   Boom should stow easily and quickly aboard and out of the way while rowing.  The sails should be efficient and look good.   The boat should have integral drink holders and perhaps a secure location to strap in a cooler for picnics and longer beach outings.


Locating a affordable replacement mast proved to be a bit of a challenge, at first I thought we rig the boat with a Laser mast, boom and sail.  Surely, it would be easy to find a used Laser rig given the Laser is one of the most popular one design classes in the world.  As it turned out, Laser masts NEVER come up on Craigslist here in the Bay Area.  However, I got a tip from Kame Richards of Pineapple Sails that maybe I should be looking for a Banshee 13 sailboat and particularly one of the carbon versions.

Lucky me as I found a Banshee 13 on Craigslist just a few days later and it was a very rare variant called the Griffen and constructed primarily of carbon fiber.  The 'donor' boat was over 100 miles away in Cooperopolis on the far side of the Central Valley.  I made the drive and found the boat to be a diamond in the rough and struck a deal and loaded the boat on top of our roof racks for the drive back to the city.


 Back in Alameda I stripped off all the parts I wanted and then put the boat (hull only) back on Craigslist and it quickly sold for enough to cover my travel expenses and put a few $ in my pocket.  With the carbon mast on hand the project could really start moving forward.

The 2.0 version of the Lehman required lots of reconstruction, All the wood trim was removed, the mast partners trashed, stern seat was cut out and the entire boat was sanded to remove way too many layers of old paint.
In the beginning, this Lehman 12 was showing it's age with cracked oak rails and lots of ugly paint.
 Profile of new rub rails that will replace original white oak rails.

Bonding the new foam rails to hull in preparation to fiberglassing.

Closing in the open bow would make for a drier ride and ease boarding from a crowded dinghy dock.
 I was able to get some camber in the fore deck by installing the foam then lashing some ropes around the hull to bend the foredeck up into a nice curve.  With everything in place I filleted the foam in place with West Systems epoxy thickened with 407 filler.

Corcel boat building foam is not cheap at $230 for a 4x8 sheet, but it's super light weight and easy to cut with just a razor blade knife.  I'm using West Systems epoxy for the build for ultimate strength and carbon fiber at high load areas.

Plenty of clamps helped lock in some of the curved shapes while the expoy cured.
Side seats might look like this panel of 1/2" Corcel with 14oz biaxial carbon fiber laminated on both sides.
Mast base will be some sort of carbon tube.  The free standing mast will require lots of reinforcement.  I may or may not keep the original center board.  I'd like to replace it, but the board that came with the Banshee, is ruined from sun damage and unusable.