You "simply" add enough two-part polyurethane foam to displace the weight of water about equal to the weight of the boat. Why 'about'?
The boat itself displaces a significant amount of water. We can help you determine the proper amount of foam.
For doing some simple calculations, consider that seawater weighs approximately 64 lbs. per cubic foot.
Installing foam flotation is not without risk. There are many, many, stories of boat repair shops removing great quantities of waterlogged foam. Be very careful in your foam selection. Do your homework.
Hotcoating is a slang term that means to coat a surface with epoxy resin with no fiberglass. This is done to ensure that all wood is fully encapsulated and protected.
The underside of the deck of a small boat, for example, if often hot-coated.
Hmmm. Although we get that question frequently, we have never figured out how to answer it. Other than: "It depends." Depends on what? Well, here goes.
Even a small boat is a significant project but one that rewards you at every milestone with incredible satisfaction. Talk to any our our current builders!
Let's start by emphasizing that there are tools you MUST have and tools that are nice to have. This is true for power tools and hand tools alike.
We will continue to develop these lists to provide you with a good understanding of the tools required.
As long as it is properly constructed and installed, either work fine. This is another one of those topics where experts will line up on both sides of the question. Additionally, we have had about an equal number of customers state that:
What it seems to depend on most is whether you personally have ever had a bad experience with one material or the other. The question is almost moot however when you get into big boats with big fuel tanks. In those situations, it is highly unlikely that you will find a plastic tank that will work. Typically, to get the substantial weight of a large tank full of fuel in the right place in the boat, it needs to be specifically designed for that boat.
There are three species of marine plywood that we commonly supply with our products. We typically supply Meranti or Douglas Fir for primary structural components and Okoumé for areas where flexibility is desired.
Our kits typically combine species in order to maximize value. In other words, we use the right wood for the job and that typically works out well from a cost standpoint.
Okoumé, as stated above, is more flexible than Meranti. Obviously, flexibility is very important when bending plywood to form the hull sides. The smaller the boat, the tighter the curve and the more important flexibility is as a characteristic. However, we have had customers successfully build our 17 with only Meranti. Our 16 and 17 Redfish Flats boats have even tighter curves though and we would be hesitant to recommend building those with Meranti. When thinking about the weight savings using Okoumé to form the sides of the boat, consider that a cold-molded boat is already considerably lighter than a similar boat constructed of solid fiberglass.
Douglas fir is the wood of choice for the laminated structures in a cold-mold boat. It has excellent properties of:
Certainly other woods of similar properties can be used. One of our builders is very successfully using cypress.
Make sure that any wood you use has been properly dried to its equalibrium level. You can Google™ to determine a wood's moisture equalibrium. We bring this up because cypress, for example, is often not sufficiently dried.