newbie epoxy question

[capt jake]

I suppose that would seal well, but wouldnt it leave a rough "clothish" look on the outside?

You have to fill the weave of the cloth. Adding fairing compounds to the epoxy makes it thicker and aid in this process (unless you want a bright finish, tehn straight epoxy multiple times). Takes time but it can be done. Oh, and lots of sanding.........

[BobSmalser]

wow! there is alot more to take in than I thought. One thing I am unsure of (actually there are many)' date=' do I understand that you can cover the exterior of a small craft with fiberglass cloth, and still get a nice paint job? I suppose that would seal well, but wouldnt it leave a rough "clothish" look on the outside?[/quote']

The thinner fiberglass cloths like this 4oz on solid H.Mahog, simply disappear....even in two layers.

The thicker ones just take more epoxy.

[Guest]

and everyone apparently seals their boats with epoxy resin

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First off, its nice to be able to logon here again. Missed you guys with the bum computer[still dealing with it] but at least I got a password to get here. 8)

Now where was I? Well, there are instances that this helps your boat with some form of finish work. If this is your first venture with this legal drug[boat building] I do recommend a quick down and dirty dinghy type hull to get your feet wet, and ti learn about woods and its bending and working properties, extremes of the products you intend on using right now.

Next I have used about every type of product for building and for finish work, high dollar paints to hardware paints. In enamel paints, in most instances, there are some very good hardware paints and some very good brand name paints that are always avaliable at your good commercial paint stores such as Sherwin Williams or Benjamin Moore that we use on some of these rigs and for some folks that are first starting out.

Plywoods purchased at the local big box stores can vary from okay to a disaster. One must begin, sometimes with some of these types to understand about frustration of using these types of wood from these stores to understand when folks suggest, for plywood, search for the best that you can find, keeping in mind there are huge differences in costs.

There is a good site called Wood finder that searches out outlets in your area for many species of plywoods and solid woods of all description

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http://www.woodfinder.com/

As far as building with solid woods, yes this can be done. But make sure the plans are set up for this types of construction, as you will need additional framing, in most cases, for these types of boat. And no it always important to seal with epoxy. Actually there are some very good pigmented epoxy coatings that we use for the interior coatings that are wonderful and gives you a one step coat and sealer for your hulls. Its important that you keep in mind that areas of bonding of parts are exempt in precoating of the woods if you go this avenue.

[capt jake]

Plywoods purchased at the local big box stores can vary from okay to a disaster.

And I have found the consistancy of quality rather fickle these days. I used to use a plywood product for all sorts of things, some boat related some not until I cut into one sheet and found that 1/2 of it was delaminating. Needless to say, I won't be using anything but marine grade in the future (luckily I caught this). Heck If I find a good deal on something, I try to by a bunch of it if the quality is there. ;) (3 slings of Honduran may last me a while).

[Kevinh]

This is not really an epoxy question, but something else I have been pondering. How do you figure out the waterline and the maximum hp engine that can be used? is there a (simple) formula for any of the two?

[Barry Pyeatt]

The waterline on a Weekender or any small dory type hull is at best a guesstimate. The hull with its rocker will sit slightly differently in the water for each bulder. The variables are the weight of the materials being used, the amount of additional weight added such as batteries, motor mounts, sails and rigging and of course crew and their gear. The boat will sit, in most cases with the front of the bottom of the hull and the stern just out of the water by about 1-3 inches or so and of course mostly even on either side. Put a cooler in the boat and it will change. Put a marine battery anywhere and it will change. Step onto the boat and set your crew down and it will have changed. And it this case significantly.

So check out a bunch of the on the water photos and see what I mean with the boats at rest without crew and loaded to what ever extent.

This is the reason that most small boats do not have defined waterlines painted on them.

The amount of power required to move a hull to rated speed is a function of a number of variables. To roughly figure hull speed take the square root of the waterline length and that will be close to hull speed. How much power to get you there is more complicated.

A 2 hp gas engine will move a Weekender in a lake quite well, 4 hp will come close to hull speed in a lake. Hull speed is calculated at roughly 5-6 knots on this hull. A lot depends again on loading.

A 40# thrust electric is plenty to get you out and home again on a Weekender. It will not get you to hull speed.

If you are working into a current, of course you need substantially more.

Anything larger than about 9 hp is pretty much wasted on one of these hulls and will handle a Vacationer quite well in most all conditions. Larger than about 5 on a Weekender is pretty much wasted as well.

In an electric you are only going to go as fast as the prop will allow and they are all trolling motors, not "get you there quick" power.

Much larger than a 55# thrust on a Weekender is pretty much wasted effort and investment, it just isn't going to go any faster. But it will help if you are in a current.