PS Advisor: 04/06
The original insulation on my 1994 Com Pac 35 refrigeration is fiberglass duct board. During the summers, it absorbs moisture and becomes nearly useless. I plan to remove and replace the insulation through access holes I will cut in “hidden” areas, like under the galley sink. It appears my best option is to fill the insulation cavity with expanding foam, but there is very little information about its use. I’ve received advice from several self-described marine refrigeration experts, but the foam manufacturers disagreed on how to use the available products. Any advice?
On production boats, the insulation on iceboxes, refrigerators, and freezers frequently is poorly done, so you’re right to have a go at improving yours. Making access holes to remove what’s there shouldn’t be difficult because you’re just cutting into non-critical space between the box and its container.
The only experience PS has had with expanding foam came when we rebuilt the rudder of a test boat. The rudder is a hollow fiberglass shell containing the rudder stock and some metal reinforcement with everything encapsulated in foam.
It might be helpful for you to take a look at the Jan. 15, 2000 issue to see how the rudder job was done.
For your purposes, the foam pouring we did is what’s important. You’ll be doing your “pours” in layers, because the foam creates considerable pressure when it expands.
Working with foam is extremely tricky. First of all, it comes in various consistencies. What you want is the 2-pound version used for insulation and small boat flotation. (We used 8-pound foam for the rudder; the heavier foams become structural.)
Use calibrated glass or metal containers (they’ll be ruined) to see how fast the stuff goes off, how hot it gets, and how quickly it expands. Practice, practice, practice.
We obtained expert advice and foam from Composites One in Bristol, R.I. (401/253-4800)
Vangs and Topping Lifts
On seeing the beautiful Tartan 34 at the Mentor Harbor Yacht Club in mid October, I asked Tim Jackett why he had both a mechanical boom vang and a topping lift. He said it was to reduce the wear of the internal spring of the topping lift. Your article makes no mention of using a topping lift along with a mechanical vang, and while I extremely dislike a topping lift, and don’t currently use one, I’m open to expert opinion. Any comments?
Designer Tim Jackett’s suggestion to use a boat’s topping lift to relieve the wear on a rigid vang’s internal spring is sound advice. In fact, several manufacturers of spring-based vangs—including two whose products we tested in the February issue—recommend a similar practice.
The final instructions for assembling Forespar’s Yacht Rod read: “To prevent damage to your Yacht Rod, use your main halyard to support the outboard end of your boom when at the dock or at anchor.”
Hall Spars’ operating instructions for its Quik Vang say: “It is always good practice to attach the main halyard to the end of the boom after furling the sail. This procedure allows the tightening of the mainsheet and removes the risk of damage to the Quik Vang.” They also suggest tying a knot in the tackle line to keep the vang from lengthening beyond its maximum position so that the dead end of the wire part of the purchase won’t jam in the turning sheave.
Hall Spars and Rigging engineer P.J. Schaffer told us that when the vang’s not being used, the tension on the tackle should always be eased.