Miscellaneous Questions and Answers
This is an unorganized collection of questions and answers.
Golden Rule of PDRacer Building
Above all else, if there is a question or indecision about something, just take a guess and build it -- you can always tinker with it later, but can never go back in time and sail on a day that you missed.
Anything can be fixed or re-configured later, if you don't believe me, see the article on re-configuring BucketEars
I have learned 2 things about boating by Andrew Linn
1) You can't stay dry, so Waterproof is a lie. The trick is to not stay
wet. Buy quick dry garments and make sure you have access hatches to any
enclosed area of your boat.
2) Sailing is a 'wear and tear' operation. You drag your boat over small
rocks on the shoreline, you drop it from off your car, you catch the
kids using the leeboard as a launchpad for springing Barbie into
space.All that stuff. Light and dainty is the recipe for matienance pie.
Heavy and overbuilt is the mantra of people with strained testicles and
back problems. Find a happy medium.
The best advice I can offer is to make the words 'Cheap and Quick' be
your guide. This is a Puddle Duck Racer, not a yacht. Build, test, race,
crash, and at the end of summer, take a field trip somewhere and burn
it. Over the winter, build a new one, refining it with innovations from
your experiences.
Is "marine plywood" necessary?
No, most boats are made from either AC or BC plywood.
The most important factor is that the plywood be made with waterproof glue, otherwise after a while it will delaminate (the layers will come apart).
You can test a piece of plywood by boiling it for 1 hour, and seeing if it falls apart or gets soft.
This is just one test, there are others, but the real test will be over time.
If you can get marine plywood at a reasonable cost, then it would be a good idea to use it.
How thick of plywood should I use?
Most people use 1/4" for everything.
I used 3/8" for the bottom to make it take more abuse, because I plan on banging mine up a bit.
Skids and stringers make the plywood stiff, not the thickness of the plywood.
What glue should I use?
I prefer Titebond II, it is a very cheap and common construction glue that is waterproof and has passed the boil test.
Others use polyurathane type glues (like gorilla glue) because they expand in the joint to fill gaps.
If you want to use a glue, you should make a test joint and boil it for an hour.
If the joint falls apart or gets soft, you might want to consider another glue.
If the glue is advertised as waterproof, then it is probably a good one to use.
Many boats have been built with "weldwood", which fails the boil test. (but the boats are still around).
What should I use to fill gaps?
I mix Titebond II glue with sawdust to make a peanut butter like consistancy, and use that as a putty type filler.
It shrinks a lot, and requires multiple layers to cover big gaps, but it is cheap and it works.
Epoxy mixed with various fillers works great - but is toxic so you have to wear protective gear.
For really big gaps, take small pieces of wood and glue them in, and fill the rest.
Also - you can run a bead of PL Premium (concrete blend) on the inside of all your seams and / or fill gaps with it.
This will keep the water out of the cracks, which helps prevent rot.
You can also use bath tub caulk.
Should I completely cover the outside of the hull with resin?
Epoxy or polyester resin coating will help increase the life of a boat, but a boat that is just painted will last for atleast 10 years with the right care.
The most important factor is preventing standing water in the boat.
How should I store a boat outside?
If stored outside, do it upside down, so the water runs off it, and the underside stays dry, or dries quickly.
Also keep it off the ground !!!
Keeping it covered will also help extend it's life, the cover or tarp should be suspended above it so that air can flow between and it will be dry after it rains.
If you lay a tarp on it, the water will collect between the tarp and the boat and continue to be wet between them, and help develop rot.
Can't go to windward in heavy winds
What happens is that the sails produce a certain amount of lifting force.
That force increases with the wind speed in an uneven manner, so that they lift the best in a certain wind speed, and then the more wind you have, you only get a little bit more lift.
The hull freeboard (the hull part above the water) produces drag as the wind blows on it.
The drag seems to increase steadily as the wind speed increases.
So when the wind isn't blowing that hard, your lift can easily overcome the drag.
As the wind picks up, you get more and more drag, but not so much more lift, and eventually the lift power of your sails can not overcome the drag of the hull, and you loose your ability to sail to windward.