BobV

I've tested four coatings that I had in my paint cabinet from various projects. Ace polyurethane, Minwax polyurethane, Minwax spar urethane (which I think is another term for polyurethane), and Man O' War marine spar varnish. All the coatings worked with the 9 oz material. I'm going to go with the Man O' War varnish, my paint store mentioned that the spar varnish will be more flexible than a interior/exterior polyurethane. So it could be that Zar and Coelan are maybe the only two coatings not compatible with the 9 oz material.

I didn't wait a week to apply some heat. It did shrink but didn't last long. Do you know of any other polyurethane that will work?

I just coated the 9 oz fabric with Zar ultra exterior oil-based polyurethane and discovered that the two are not compatible. I'm guessing that the material expanded by 5% or so, lots of wrinkles. I should have tested it but used Zar many times on the 8 oz material with no problems. I'd like to use a polyurethane rather than a paint. What other brands of oil-based polyurethane have been used on the 9 oz fabric? I like the 9 oz material, no pull holes in sewing it up. I used the same method as with the 8 oz material that I learned from watching Jeff's videos, which are great by the way. It shrank as good as the 8 oz, and will appear to not need as many coats to fill the weave to a smooth finish.

Ekapi, I've tried the Target Coatings EM 9300, PPG's Break-Through, General Finishes 450, plus a couple other water based finishes. I had the best results with the General Finishes 450. After a couple hours in the water the finish softens and can be scraped off with a finger nail. The kayak with the Break-Through has grass embedded in the finish after placing it on some grass after two hours in the water. I had wanted to use a water based product to spray. I'm going be using Zar oil based poly on the next boat. I did a water soak test and after 5 days in the water the Zar did not soften. I'll apply the Zar with a foam brush. It's not recommened to spray the Zar because of bubbles, though I wouldn't spray it if it was. I did a test on some scrap material with a foam brush and was able to get a fairly smooth finish. I can always use some wet / dry 600 grit followed by a polishing compound. Bob

Here is another option, sewing the skin to the gunwale. Attached are two pictures of a mock up to see if this method would work before trying it on a kayak. The bottom was sewn on first. The fabric was wrapped around the cording, which is weed trimmer line and sewn to the gunwale, very similar to sewing the the fabric to a coaming. Then the top was wrapped around another cording and sewn to the bottom cording. This method took 18 hours to sew a 17' Yost Sea Rider, not counting sewing the coaming. If I were to use this method again I'd sew on the laminated coaming before sewing the top to the bottom. As it was there was just enough material to sew to the coaming. Also, the last few stiches at the ends were hard.

I built a lashed steam bent rib and stringer canoe, I have a lot a bumps. Which looks fine, in fact the lashing really stands out because the wax from the sinew penetrated the polyester and since I used a clear poly finish the brown wax shows through. On my current project, a Tom Yost Sea Rider, I slightly over sized the the chines and gunwales and filed grooves for all the lashings. The skin is on but not finished yet, working on the laminated coaming. I think I'll also like like the looks of the no bumps.