rotten deck under the helm

[wildegroot]

Has anyone here ever had to deal with a rotten deck under the helm? We have an Oday 35 and I'm thinking of cutting out the entire deck surface in the cockpit (leaving a flange for mounting a new plywood floor). Besides the rotten wood, having the old deck out of the way would allow me to replace the fuel-level gauge and make a window in the new deck so the gauge can be easier to read, I could service the steering cables, frozen adjusters and and fix the broken-off grease fitting on the rudder shaft tube. Any advise or experience would be very much appreciated.

 

[jssailem]

Big project.
I have not experienced such on any boat. This maybe the luck of the draw.
Andy over at BoatworksToday.com has removed decks on boats and replaced them. You might gain some insight on such a project from one of his videos.

 

[kappykaplan]

I had an issue several years ago where my helm pedestal was pulling out of the deck. Turned out the cockpit sole had rotted. We cut the top skin out, removed all of the rotted wood, replaced with a water-impervious foam, and reskinned. It was a big job, but well worth it. Added benefit of the foam was reduction of engine noise in the cockpit.

 

[wildegroot]

Big project.
... videos.

Thank you. I will check out boatworks.com

 

[wildegroot]

I had an issue several years ago where my helm pedestal was pulling out of the deck. Turned out the cockpit sole had rotted. We cut the top skin out, removed all of the rotted wood, replaced with a water impervious foam, and reskinned. It was a big job, but well worth it. Added benefit of the foam was reduction of engine noise in the cockpit.

Thank you. Do you happen to have any photos of the operation?

 

[kappykaplan]

Thank you. Do you happen to have any photos of the operation?

Unfortunately, no.

 

[dlochner]

If you have good access from below, removing the inner skin and recoring from below might be easier as cosmetics won't be quite as important and the non-skid will not have to be replaced.

 

[dmax]

Dave, on an O'Day 35 attacking it from above is MUCH easier - difficult to even access the underside of the cockpit.

 

[wildegroot]

Unfortunately, no.

OK, thank you for the reply.

 

[wildegroot]

If you have good access from below, removing the inner skin and recoring from below might be easier as cosmetics won't be quite as important and the non-skid will not have to be replaced.

That's the problem. Access under the helm is terrible! In order to read the mechanical fuel level gauge on the tank I have to shove my phone between the gauge and the deck to take a picture. The dial is obscured by crud on the inside of the lens so reading the picture is difficult and If I want to replace the gauge I have to remove the tank from a cramped location under the helm.

 

[wildegroot]

Dave, on an O'Day 35 attacking it from above is MUCH easier - difficult to even access the underside of the cockpit.

This is Wil. Sandy started this thread but it's been mostly me talking.

Exactly Dave! It's a horrible situation. There is barely enough room to get one arm under the helm deck. Forget about doing any real work under there. For example: The adjusting turn-buckles for the steering cable are frozen on my boat and pretty much unserviceable in that state. For now I have a universal automobile parking brake adjusting clamp on the steering cable and it took out most of the play in the steering wheel but I would prefer adjusting/replacing the cable the correct way.

I want to hack out the entire T-shaped non-skid surface right on, or just inside, the parting line between the smooth and non-skid surfaces, cut out the second layer of fiberglass and do all the repairs below with full access. Then I would like to dig out the rotten wood between the remaining fiberglass deck layers, fill that area with epoxy and then install two layers of marine plywood on top of the remaining perimeter flange, maybe even a removeable deck for future maintenance work. If it leaks a little, the water can just run piddle into the bilge. I'm hoping someone else has experience, and or opinion, of/with my admittedly radical idea.

 

[dlochner]

A few thoughts.

Shop around there are watertight hatches designed for decks. Mostly they are aluminum and not fiberglass. Check HamitonMarine.com for hatches. They support the Maine commercial fishing industry which uses more deck hatches than recreational boats.

For large cored areas, plywood of any kind is a poor choice. The problem is bonding to the plywood. Epoxy or polyester resins won't penetrate the hard sections of grain in the plywood. The bonding will be poor which can lead to the fiberglass cracking. Use a foam coring material or use end-grain balsa wood.

Then I would like to dig out the rotten wood between the remaining fiberglass deck layers, fill that area with epoxy and then install two layers of marine plywood on top of the remaining perimeter flange,

I'm not quite understanding the plan here. Without the bottom skin how do you intend to keep the glass and core in place? When you say, "fill the area with epoxy" what do you mean. Epoxy by itself is very brittle and will crack under load. All resins need reinforcement with a fabric and/or thickening material, like talc, milled fibers, colloidal silica.

Leave the bottom skin intact and remove the top skin. dig out the rotten core and clean it up. Sand it with some 80 grit to have a good clean bonding surface. Grind back 3-4 inches on the vertical sides of the cockpit. The gelcoat should be removed and a bit of the first later of glass. Template the core material, spread a thin layer thickened epoxy and press the core material into the thickened epoxy. Once that has cured, then tab in the core material with strips of glass between the floor and the sides. Use at least 2 layers of tabbing. The outer tab should be a little smaller than the inner tab. Wet out the core with neat epoxy and start laying up the glass. When finished you will need to have the glass as thick or a little thicker than the original skin. Now comes the fun part, after removing the pqelply or washing the amine blush off, sand the new glass and begin fairing. It will probably take a couple or more passes with fairing compound to get a good surface. Prime and paint when that's all done.

Once the new floor is in place, decide where you want the hatch. Cut an opening in the floor for the hatch and install. Remember you'll need access to the base of the steering pedestal so it can be reinstalled. Go Sailing.

For more information, WestSystem.com has good technical information. Tech support at TotalBoat.com is good and Andy Miller's YouTube channel Boatworks Today is a treasure chest of information on working with fiberglass.

 

[wildegroot]

A few thoughts.

Thanks for all that information! I shouldn't have used the word "epoxy". I know epoxy resin doesn't work with glass fibers. I would use polyester resin with thickening powder and chopped fiber to make a paste. What I meant with 'filling the area between the upper and lower fiberglass layers' was my thinking of joining together (and sealing) the upper and lower deck panels in the helm area with wads of fiberglass/resin paste, after sawing through both layers and after pulling out rotten wood. My idea was to leave a big open hole where the non-skid deck was and leaving the smooth white perimeter as a flange to bolt a plywood deck panel to.

Your idea of placing a few deck hatches in strategic places is definitely a more sober solution to access equipment under there. I looked at the Hamilton Marine website and saw the the aluminum deck plates. I had no idea they existed! Also, salt water resistant Almag aluminum alloy is one I'm not familiar with but very interesting! (I'm a car guy who only recently got into an old sailboat.)

Since you seem to know quite a bit about fiberglass boat repair: This repair is going to have to be done outdoors in the off season. Have you ever successfully used polyester resin in low temperatures. Even New Jersey summer nighttime temperatures can cause a batch of activated resin to refuse to harden.

Thank you for the marine fiberglass work information sources.

 

[dlochner]

know epoxy resin doesn't work with glass fibers. I would use polyester resin with thickening powder and chopped fiber to make a paste.

Epoxy works well with all fiberglass except for chopped strand matting. Chopped strand is held together with a sizing compound that dissolves in styrene (a polyester resin solvent) but not in epoxy. This makes wetting out matting with epoxy difficult, it can be done but it is time consuming and the resulting laminate is resin rich.

For a repair like this, I would use epoxy, not polyester. Epoxy adheres better to old work than polyester and has a longer working time. When laminating epoxy and polyester about equal because in laminating it is a chemical bond between the laminates. In this repair you will be making an adhesive bond to the existing structure. Epoxy is much much stronger in this application. It also has a longer working time and longer shelf life.

When polyester and its progeny gelcoat do not cure there are 2 primary causes, the resin or catalyst is older than 6 months and an insufficient about of catalyst was added. Additionally, there are 2 types of resin, laminating and finishing. Finishing resins contain wax which floats to the surface and cuts off exposure to air, laminating resins do not have wax. Same with gelcoat, some gelcoats have wax others do not. Using the incorrect resin or gelcoat will prevent the resin from fully curing.

Give West or TotalBoat a call and talk to them about your plans and the cold weather considerations. Atlantic Highlands does get cold in the winter, however, there are plenty of days in the fall and early spring where the temperature is high enough to work with epoxy. It is also possible to use a heating blanket to keep the resin warm until it cures. Over on Ran Sailing, they are building a boat in Sweden and doing a lot or epoxy work in the dead of winter in a cold barn. Good clues there on working in the cold. Also on some older videos on Sail Life, Mads deals with epoxy work in a cold barn.