Large enough radius to avoid hassles w/ cloth lifting?

[Tod Mills]

Hello,

This is my first post to these forums.

I have a 1972 Tartan 26 (Tom Norton design), hull #30, that I bought a while back with the idea of fixing up for coastal cruising. I'm still a ways from retirement, so my thought is to have a spot in the cabin where I can work at a computer, combining a bit of sailing with work, although at the rate I'm going on this boat I may well be retired before she's launched! I'm still removing fittings from the boat and haven't started with any repairs or modifications.

Anyway, my question today is: what would be a comfortable fillet radius for cloth to avoid having to fight with the cloth wanting to lift (and getting bubbles under it)?

Thanks,

Tod

[Tim]

Welcome to the forum, Tod!

Depending on the material, you can get away with as small a radius as 1/4", but only for lightweight cloth. 3/8" is better as a minimum, if possible, and of course larger is better in all cases.

Heavier material, such as biax, requires correspondingly larger radii. You can have success with as small as 3/8", but 1/2" to 3/4" is usually a better benchmark as a minimum. Again, the more rounded the better.

Trying to laminate over a too-tight radius can be frustrating and ineffective. I have managed to get 15 oz. biax to lay over a roughly 1/4" radius, but it wasn't fun or easy. So the general rule is to plan on as large a radius as possible within the practical limitations of the individual project.

[Tod Mills]

I can see I need to do some more research on materials. I'm not familiar with biaxial fiberglass. All I've ever known is mat, roving, and cloth and have only a small amount of experience with them, enough to know that I wouldn't want to try to make a living laying it up!. To get the boat where I want her to be, I'll have to do a little of it; no escaping it.

Of course, there are some soft spots in the deck to be repaired and some thru-hulls filled. I want no thru-hulls below or near the waterline. Right now there are two, a sink drain and an inboard engine intake. (cockpit drains are out the transom) I plan to convert to outboard power despite the loss of aesthetics and risk of prop lift-out in chop.

This boat's sheerline is a wee bit too flat to my eye, and worse, the "toerail" is very tiny. I've only had the boat out one time, a test sail to get a feel for her before bringing her home to the driveway, and during that test sail I decide a larger toerail would be a very good thing. While I'm at it, I figure I can give the boat a tad more sheer. I'd like to keep the exterior as low-maintenance as I can, so I'm thinking of a fiberglass-over-foam toerail. At this point I'm thinking of laminating some foam in place, sanding it to suit the height/shape/swoop that suits my eye, then glassing over it.

I am not fond of lifelines, despite their obvious practicality, so the large toerail plus good handholds are intended to replace them.

Thanks again for your input,

Tod

[dkall]

Vacuum bagging the laminate will result in a tighter higher quality radius. Depend on how much you have to do and where it is at.