|From: STEVE CHAPIN [mailto:firstname.lastname@example.org] |
Sent: Tuesday, March 23, 2010
To: email@example.com; 'Stuart Jenkins'
Subject: Re: Hoh refinishing
Dianne's description of the deck replacement is correct. I'll try to elaborate.
The dacron I obtain from www.aircraftspruce.com. I use their lightest-weight material, intended for ultralight aircraft. Recently I started using their recommended fabric cement, Poly-Tak, in place of contact cement which I buy at the local hardware store. In the past, the dacron was simply fastened to the deck edge with staples. Cement works better because it is a more effective water barrier and produces a smoother, lower-profile fabric edge, but takes a bit more effort and skill. I was getting marginal success with the contact cement, which is easy to use. I find Poly-Tak is more secure but I'm still on a learning curve.
The completed dacron deck, after being heat-shrunk and infused with three coats of varnish, is transformed to a translucent, waterproof material. It has the tautness and sound of a drum, but not its toughness. You have to be careful not to deform it much, lest it take a permanent impression.Also, you should be forewarned that the completed material cannot be reused, as the heat-shrinking is a one-time process.
The deck edge surface needs to be very smooth, both on the side of the hull and on the top of the gunwale. The cement is applied only to the hull, where the fabric edge will be covered by bede or tape; the cement fills the weave and looks really ugly, so don't get any up on the gunwale. Two coats of cement are applied. The first is brushed on and let to dry, followed soon after by the second, which takes longer to dry. Before it does so, the dacron is lightly stretched in place and the fabric is pressed into the wet cement with a seam rubber, filling the weave. If the cement has begun to dry, lift the fabric away just enough to rewet the interface with more cement applied with a brush.
After the cement has dried sufficiently, maybe a couple hours, the dacron can be heat-shrunk with an iron. The manufacturer's instructions are to use a three-step process with increasing temperature each step.
Then varnish is applied. I use Epifanes Hi-gloss, but any good spar varnish should do. Care must be taken to apply a uniform thickness of material with the goal of filling the weave, but not too much so that drips form on the underside of the dacron. These will be visible forever. I use a good bristle brush for the first coat, then a roller followed by tipping with a brush for the 2nd and 3rd coats. A sprayer might be the best way to go. There is no way to sand the dacron between coats, so be careful.
There are probably more tricks I could relate, but this should give you a good idea of what's involved in installing a dacron deck. I hope this is helpful to you.
Wishing You Well,
From: Stuart Jenkins [mailto:firstname.lastname@example.org]
I was reading your webpages on the restoration of the Hoh and was wondering if you could help me out with some information on the finer points please.
I'm particularly interested in the part about replacing the decks - we have a few wooden shells and few wood-framed fibreglass shells (all Sykes) that require rebuilding to incorporate sealed buoyancy compartments. This requires replacing the canvases and I'd like to use something nicer (and hopefully stronger) than the nasty 1980's vinyl they currently have!
I'd be grateful if you could pass on any tips and advice you may have about replacing the decks and also give some advice on which exact materials to use.
Here in Australia many of the smaller clubs have a few wooden shells in their boathouse - we have a 2x, 4x+ and 8+ for example - but the availibility of cheap Chinese boats has led to the replacement of many recently. I fear the impending tightening of buoyancy regulations will see the end of a few more.
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