: Their website also lists the following: Marine-Grade Polyester: With a
: breathable acrylic coating, this woven fabric repels water and withstands
: extended outdoor exposure. Commonly used for truck and boat covers and
: tarps.

: Does anyone have experience using this material to skin a boat? How does it
: compare with PVC reinforced vinyl? (For example, is it just as
: water-repellant but more breathable?) And is there any difference between
: "vinyl coated" and "vinyl laminated" besides the
: thickness of the material?

I think what you are looking at is a eneric version of a very popular material called "Sunbrella". this is a tightly woven polyester fabric which has about the same weight as a 10 to 12 ounce cotton canvas. It is lightly coated with material that helps it shed water. The best comparison would be with cotton canvas products used for making tents and awnings. Rain water will run off of these fabrics, but if it is allowed to pool in areas where the fabric sags then you may get small leaks. This is the material which is used for most of the fabric covers for boats.

If you used the material as-is you would have a nice hull which would not have a very long life before developing small leaks. On the other hand, I bought some similar material at the local fabric store ( sold for awnings) with the intention of using it for a water resistant deck which i would not need to paint or color, as it was already a very bold blue. I think this should make a nice deck, but I haven't installed it yet.

If you coated this with a better waterproof coating it might make a very nice hull material. Problems here are cost (Sunbrella can be upwards of $10-$18 a yard vs. $7 to $8 for #10 duck, or less than $10 per yard for a heavy-weight nylon or polyester from Dyson) and finding a compatible waterproofing coating. The latter shouldn't be too hard to accomplish, but because of the initial cost I don't know of any experimenters, so you would be on your own.

This does not compare with ANY of the PVC reinforced vinyl fabrics, but it might compare slightly with a polyester reinforced pvc or polyester reinforced vinyl fabric.

Lets look at the materials you are considering:

Plain "vinyl" plastic can be extruded in very thin sheets, and in very long lengths and rolled up. Thinner varieties used to be used to make slip covers for sofas, and the thicker varieties are used for the clear, roll up windows on power boats, and even thicker material is used in strips for the drive-thru doors on loading docks. There are some good inflatable boats (I own two like this) which are made from plain vinyl. There are also a lot of cheap inflatable air mattresses and beach balls made from thinner vinyl.

Plain vinyl needs to be thick to be strong, so there are many ways to reinforce it. One is to use a fabric woven of PVC (another form of vinyl) and then coat that with vinyl. Basically you are talking vinyl on vinyl here, with two different varieties being combined to give the advantages of both.

Another idea is to take a common fabric and coat it with a layer of vinyl (or PVC). this can be amde in a great variet of weights and strengths. You see this material used for raincoats and tablecloths. for our needs we would like a vinyl/plastic coating on a fairly strong base fabric, and there are two basic ways that this can be manufactured.

In both cases you start with your base fabric. You can coat one or both sides of this fabric, and you would use a machine whch looks like newspaper printing press.

For PVC laminated material a pair of large, heated, rollers are adjusted so they are very close together, and a sandwich of three layers of materials is inserted between them. The top layer is a piece of vinyl of a predetermined thickness, the middle layer is the fabric used for reinforcing, and the bottom layer is another sheet of vinyl. The heat of the rollers, and their close spacing, causes the vinyl to soften and under the pressure of the rollers it is forced to bond with the fabric. Some fabrics only coat one side, and they do this the same way, but just use a single layer of vinyl.

So, with vinyl laminated materials you get a very even thickness of vinyl on the surface of the supporting material.

Vinyl coated materials are basically painted with a liquid vinyl. They can melt or dissolve an existing vinyl material and apply that, but more likely they'll use a liquid material which needs to be cured or polymerized before it becomes the stuff we think of as vinyl. Typically the reinforcing fabric goes over a big roller and the liquid vinyl materials are dumped on top. As the fabric comes off the roller a scraper, or "doctor blade" removes the excess liquid and controls the thickness of the coating. With two hoppers for delivering liquid vinyl to both sides of the fabric, and two doctor blades, both sides of the fabric can be coated at once. Once coated the fabric can pass through another set of heated rollers to polymerize the vinyl, or it might be exposed to Infra red heat, or UV light to do this.

With coated fabrics the vinyl soaks into the weave of the material and is trapped tightly all the way through.

You can find coated and laminated fabrics which are strong enough to serve for kayak hulls, or you can make your own coated nylon or polyester fabrics simply by painting an appropriate material over your fabric after you have applied that fabric to your kayak frame. vinyl coatings are probably a bit messy to work with at home, but you can find gallon cans of Plasti-dip. Otherwise, more common coatings are urethane varnishes, and synthetic rubbers such as hypalon, neoprene, and elastomeric roofing compounds. Dyson ( and others) sell the hypalon and neoprene, and you can find elastomeric roofing materials at most hardware stores, or buy it form online hardware dealers.

If you want to make your own laminated materials you can find a clear material which you can iron onto your base fabric. It is fairly expensive to do this for an entire boat.

Hope this helps.

PGJ