Some Thoughts on Building Low Weight Structures

From the always active mind of Dan Newland …..

Hey guys.

I was using this table when it occurred to me that perhaps you could also use these figures.

Attached are some real, measured weights I’ve kept for when I need to do calculations, (the exception are the foam cores that are calculated).  Many came from laminate samples or real wood pieces that I have and commonly use around the shop.  It occurred to me that maybe you could use this but if not, I will assume the delete button works well and it can go into the Ether.  Anyway, I try and keep the samples and do honest weights when I can since I always am a bit suspicious of some assumed weights.  So these are for the most part real world weights based on parts that I have weighed but of course the wood can go up or down.  Still, it is valuable to have, sorry if it is hard to read.
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By |2010-10-04T07:31:40+00:00October 4th, 2010|Boat Maintenance|0 Comments

Cleaning the brush: A Chemical Engineer’s perspective

Take a look around the docks and it’s clear that the Wooden Boat Festival is around the corner. There’s lots of last minute work going on to get already well tended boats even better tended. In that spirit, here’s a short item on cleaning your varnish brush from the blog Windborne in Puget Sound.

Clean thoroughly and store in the freezer.

Good varnishing brushes are definitely not cheap! The quickest way to ruin one is to let varnish dry in the brush – not something any of us wants to do.

But cleaning a brush is not an easy task. You may think that after triple-rinsing it in fresh paint thinner, the brush is clean. But put it away for a couple of days, and when you go to use it next, the bristles are  disappointingly stiff.

As a Chemical Engineer, I learned several things that have made brush cleaning a lot easier.  (What?  Practical knowledge?  Who knew?):

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By |2010-09-02T08:20:29+00:00September 2nd, 2010|Boat Maintenance|0 Comments

Projects

We pulled into the waiting line at the Kingston ferry and through the fog I saw an unexpected sight – an old flat bed truck with what appeared to be a Jensen Healey struggling to stay on board. A Jensen Healey? On a flat bed truck? So I wandered over. I didn’t get the whole story but the gist of it was that for $300 cash money this historic pile of rust, whitworth (or maybe just metric) bolts, dreams and unlimited potential, fresh from being excavated from the salal could be mine. One voice in my head raised from a youth spent reading Road & Track started telling me “this is an unbelievable deal, buy it.” The other voice whispered in my other ear that this will be the easiest of the $300’s you’ll spend on this one. Look at the rust on the axles and bottom trunk panel. Why do you think it was parked in the first place? So feeling good I could still identify a Jensen Healey in the fog, walked away.

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By |2010-09-02T14:16:19+00:00August 31st, 2010|Boat Maintenance|0 Comments

Missing Miss Annie

Since this spring’s Round-the-County, Annie Too has been sitting at the dock with her stick out. According to Ted Pike, the mast cracked in the high winds of the race and he’s been working hard to put it back together. You got to love a town where folks take a classic, race the hell out of it, and if it breaks, know how (or know someone here who knows how) to put it back together again.

Hopefully, she’ll be back out on the Bay soon. But until then, a gallery of pictures to remind us what great lines Bill Lapworth drew for the Lapworth 45.

By |2010-07-25T16:27:04+00:00July 25th, 2010|Boat Maintenance, Wood boats|0 Comments

Single Braid Line and the Brummel Splice

12 strand line, super strong and easy to work with

12 strand line, super strong and easy to work with

In a simplistic view of the history of marine lines, there’s been a progression from single braid manilla three strand, to double braid with the load being carried by the inner core, to today’s return to single braid but using high-tech materials, most frequently with 12 or more strands.

The new single braid lines can be super strong, small in diameter, and relatively easy to work with. They aren’t for use everywhere on your boat, some flatten out and don’t like to work in a clutch, some need UV protection, and some need the wear resistance of a cover. But for things like a cascade to turn a 4-to-1 vang into 8-to-1, they seem hard to beat. In more complex applications these lines are being used as sheets, halyards, and in control line applications.

There are more of these lines available all the time from a number of manufacturers.  Some of the lines available today include Dyneema and Vectran lines like Amsteel Blue by Samson or Vectrus 12 by Yale, AS-90 made of Dyneema SK-90 by Samson, and Dynex Dux 75 by Hampidjan. While tensile strength is not the same thing as working strength, this stuff is pretty amazing. Comparing the tensile strength of 1/4″ lines:

Sta-set double braid      2,500
7×19 rigging wire           6,400
Amsteel                           8,600
Vectrus                            8,000
AS-90                              9,700
Dynex Dux                    16,411

These lines are easy to splice using a Brummel splice.

By |2011-07-18T10:38:51+00:00April 4th, 2010|Boat Maintenance|0 Comments

Boatyard Stormwater Regulations Forum

From a flyer sent over by the Port Townsend Yacht Club ….

New regulations seek to tighten the allowable heavy metal content in the stormwater outflows of ports and boatyard across Washington.

The Port of Port Townsend may not be able to meet these new standards resulting in huge fines and possible closures. Get educated. let your opinions be heard. Tuesday, March 22, 5:15 PM, Port Townsend Yacht Club.

More information on this issue can be found on Three Sheets Northwest here, here, here, and here.

What are your thoughts on this issue? Use the comments below to make your voice heard.

By |2011-11-21T10:21:30+00:00March 22nd, 2010|Boat Maintenance|0 Comments

A Reminder about Bottom Work and Wind

big wind and not enough pads can work out badly

big wind and not enough pads can work out badly

Many of us will no doubt be doing bottom work this coming spring and this picture is a reminder that although it is tempting to move the stand yourself, it might be better to ask the yard guys for a hand.

The story behind this shot from Sailing Anarchy is that a stand was moved to paint an area of the bottom that had been covered by a stand pad, the wind came up, the boat came down.  The Sydney 32 and the Alden in the picture took a beating, too.

By |2011-07-18T10:29:49+00:00December 9th, 2009|Boat Maintenance|0 Comments