Sailboat furniture

I've been asked to give a quote for furniture for a sailboat. The customer bought a sailboat built in 1973 and after starting to restore it they realized that they were in over their heads. I will actually see the boat tomorrow for the first time. They want me to quote on a cover for some electronics, a combination air conditioner cover and table and two cabinets. My question is this: they think this needs to be built with marine grade plywood, since its inside the boat is this really necessary? Not using marine grade ply will save them hundreds of dollars.

I've never built for a boat before but I can't imagine that its much different than my usual builds except that it will be, generally speaking, smaller and attached to the walls with glue.

Am I "missing the boat" (pun intended) or is it just a matter of finishing with a water resistant finish. The boat will be in the Great Lakes exclusively (never in salt water).

The high humidity environment on boats might cause non-marine grade plywood to seperate over time. I suspect the marine grade is made with a bonding agent (glue) that is less likely to degrade due to humidity. If the interior pieces are finished carefully and the finish is maintained you can probably get away with a furniture grade plywood. Personally I would spring for the marine grade if they intend to keep the boat for any leangth of time.

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Originally Posted by Bill Sias

The boat will be in the Great Lakes exclusively (never in salt water).

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Fresh water is the arch enemy of wooden boats! Salt water is by far the preferred environment for wooden boats.

But that aside, my first choice for the "furniture" would be solid stock not plywood; genuine mahogany, Spanish cedar, cypress, etc. If marine plywood (BS 1088) is what the customer wants, let the customer have marine plywood.

That helps. I'm all for letting the customer decide except when they will be sorry later.

If the boat is really nice I will suggest wood, otherwise marine ply will be it.

I concur with the solid wood vs ply. In your quote, be aware that being a "shipwright" is somewhat more involved than building "land based" furniture, particularly when it is attached to the hull. There are very few straight square attach points. If you have never used a "story stick" I recommend you do some research.

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Originally Posted by Bill Leonard

If you have never used a "story stick" I recommend you do some research.

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That's good advice even for land based building. One of the first lessons my grandfather taught me was that measuring magnifies mistakes.

I also agree with the solid wood. I've never build anything with ply before except cabinets.

Bill,

Although it is an "interior", the inside of boat will communicate to a great extent with the outside environment. All interior woodwork should be constructed with the idea that moisture levels can flucuate due to possible leaks. One small leak can turn the inside of a vessel into a bit of a green house if it lacks ventilation. There can easily be higher moisture levels in a boat interior than in a house. This can be compounded by the size of the vessel.

If plywood is to be used for partitions, bunk bottoms ect, consider using MDO plywood (medium density overlay). Its made using water proof glues and can sometimes have less voids than "marine grade" (non European grade). Visually MDO looks like it has a thin paper veneer. What we get out here is kinda yellow/brown in color on the outside however I have seen white also. It takes paint very well without having to fill up grain with primer. Also great for drawing/marking on due to its smooth surface. It is substancially less costly that marine plywood. Another alternative is multiple lam Baltic birch. Typically comes in 5' x 5" sheets.

All wood, plywood or solid wood should be sealed and or painted at every surface. If you glue a joint, the glue should be water proof.

For solid wood, look at the other trim in the boat and match it. Adding too many different woods in a small interior will be confusing to the eye and detract from the overall design of the components.

When adding to an interior keep in mind the current theme of the exsisting cabinetry so as not to add a different element or style. This may be as simple as a reoccurring 3/8" radius on trim or a specific detail in the cabinety doors or the frames around them.

The shape of a boat interior can be challenging for someone trained with a square. The nature of different curves and shapes dictates that many times you will relie more on your eye than a square. If it looks right to you, then perhaps it will look right to your client? If there are already components in the interior you'll have lines to help guide your work (verticals and horizontals).

One useful tool I used when I was building interiors was 1/4" foam board mock ups. Sometimes I would create an entire interior of the stuff held together with small cleats and a glue gun. The work goes quick and gives both you and your client a better perspective of component spacing, heights, ect and what remains of the "air space" after the cabinetry is in.

Have fun!

Cheers,

Kent

A few points:

Furnishings in boats are often infills between structural bulkheads. Bulkheads are transverse panels bonded to the hull which carry carry hull and rigging loads. When ever working with boat interiors- FIRST determine if the panel you are working on is a structural bulkhead. If it is you will have to follow fairly strict conventions for how the panel is attached to the hull and the panel strength used. Long panels between bulkheads can sometimes serve as box girders, if this is the case the same concepts apply- make sure you understand the structural roles of these parts first.

The customer is on the right track- use marine grade ply.

Seal your panels on all sides. Before or after installation, but seal it up. Even with marine grade ply- damp and leaks will blow apart the cabinets over time.

Don't use ferrous fasteners anywhere. Use stainless screws for interior and above the water line work and if any cloth work is done with staples- buy monel.

Give some thought to machinery/electrical chases through cabinets. They generally run the long axis and some thought will make the runs simple when the client goes to pull wires or install machinery. 1-1/2" conduit makes good wire chases.

I went to see the boat on Saturday. Its a Viking built in 1973. When the couple bought it they thought they were getting "a steal" since it had been in storage since the late 80's and the owner needed the cash. When they started to work on it they discovered some rotted wood and started dismantling. Their (his) plan was to take thing apart until he got to solid wood (good plan IMO). When he finished he was left with the fiberglass hull, the upper deck, the head and one bunk.

They had an electrician rewire the entire boat.

Then they hired a "finish carpenter" to build the inside. There were gaps of up to 1/4" where I could see the nail joining the boards for the (uncompleted) galley cabinet. There was one gap so large that I could insert my pinky finger tip. The cabinet was attached to the structural member with staples.

The few original interior walls that remain are laminated with a picture of mahogany. The windows don't fit correctly.

The couple are very nice people that got themselves into a pickle. They have so must time (4 years) and money invested that they think they have to make it right. They (he) have made poor decision after poor decision. The tension between them related to this boat is severe. She would like to sink it and walk away. He wants to end up with a boat he can sail with pride.

I can't charge them enough to cover the amount of research I will need to do, yet I'd have to turn other customers away. On the other hand, they really need the help.

If any of you are interested in the job and near western Michigan (the boat is in Saugatuck) I'd be happy to introduce you to them. If not I may give it a go on a per hour basis.