Soft decking
- Thread starter Go Blue
- Start date
49208
Tentmaker
Good question - Here's my understanding, but let's backup to the construction of the deck:
fiberglass reinforced plastic on both sides of a foam core (IIRC the core used is Airex foam)
This makes for a light, stiff, panel, but like many cored panels can be damaged by impact and/or repeated flexing. The damage can be either a delamination between the skin (the frp laminate and the core) or shearing/disintegration of the core itself (where the core material actually breaks down from a single joined mass into smaller pieces and eventually to a powder like consistency)
Impact or repeated flexing occurs typically in the deck where one sits. Some examples:
Occasionally you find yourself standing in the cockpit, a wave comes along, you lose your balance and fall butt first right into the middle of the deck between the cockpit edge and the rail. Depending on your weight, you may do little to none, or you may cause enough impact that you start the delam process.
Repeated flexing - every time you tack and sit on the new side, while it may not cause impact damage, you may be flexing the deck - take all the tacks over a number of years and you start the delam process and/or shearing of the core. Other examples of this are repeating hiking when you are aren't fully hiked, but instead with your butt in the middle of the deck
There are many additional ways to make the deck softer, once you understand what the causes are, then you can work to avoid them
How much is acceptable is a judgment call based on the intended use of the boat and the expectations of the owner/skipper. A hardcore racer is going to want a stiff deck so all movement is transferred into forward (hopefully) motion. At the other end, a casual day sailor may only be concerned that the deck is in one piece and watertight, and a flexing deck can certainly be both of those.
fiberglass reinforced plastic on both sides of a foam core (IIRC the core used is Airex foam)
This makes for a light, stiff, panel, but like many cored panels can be damaged by impact and/or repeated flexing. The damage can be either a delamination between the skin (the frp laminate and the core) or shearing/disintegration of the core itself (where the core material actually breaks down from a single joined mass into smaller pieces and eventually to a powder like consistency)
Impact or repeated flexing occurs typically in the deck where one sits. Some examples:
Occasionally you find yourself standing in the cockpit, a wave comes along, you lose your balance and fall butt first right into the middle of the deck between the cockpit edge and the rail. Depending on your weight, you may do little to none, or you may cause enough impact that you start the delam process.
Repeated flexing - every time you tack and sit on the new side, while it may not cause impact damage, you may be flexing the deck - take all the tacks over a number of years and you start the delam process and/or shearing of the core. Other examples of this are repeating hiking when you are aren't fully hiked, but instead with your butt in the middle of the deck
There are many additional ways to make the deck softer, once you understand what the causes are, then you can work to avoid them
How much is acceptable is a judgment call based on the intended use of the boat and the expectations of the owner/skipper. A hardcore racer is going to want a stiff deck so all movement is transferred into forward (hopefully) motion. At the other end, a casual day sailor may only be concerned that the deck is in one piece and watertight, and a flexing deck can certainly be both of those.
marvin-miller
Arrrr...
Some of the older boats were made with a foam with very low shear strength. A friend of mine took his deck off (12xxxx series) and replaced the foam in his. It looked like polyurathane rather than PVC. The boat is now much stiffer and faster than it used to be although it took a lot of hours to fix it. I wouldn't have bothered and would have looked for a newer hull.
My son has a 15xxxx boat that is still very stiff and very fast. Its competitive with the 19xxxx series boats at our club, maybe better. I don't think its inevitable that the decks will go soft. It depends on materials used and the build quality at the time as well as the care you take of it.