FRP / Plywood Deck Repair on a Rosborough 28

Our club race committee boat is a FRP Rosborough 28 which I believe was initially used for lobster fishing in Nova Scotia up until about 1990 when we converted it for use by our club. Over time the aft deck sole which is comprised of plywood sheeting with a fiberglass laminate outer layer has deteriorated due to moisture intrusion from the elements and as a result has weakened considerably to the point where we deemed it unsafe and a repair was necessary.

To that end after the boat was hauled for winter storage last fall we began by shrink wraping the entire boat leaving enough head room to allow for an adequate working space above the aft deck. We also installed a hindged plywood door for easy access. This past week myself and a couple of  other members, Mark Backman  and Bart Bies began the repair and re-construction of the deck sole.

The first step was to remove the FRP laminate layers from the rotted plywood. To do this we utilized a curcular saw with the blade depth set at approxametly 3/16″ and cut through the laminate layers in the required areas.

FRP saw

Cutting through the FRP layer to separate it from the plywood

After the cuts were made the next step was to searate the FRP outer skin from the rotted plywood panels. For this we untilzed a variety of wrecking an bars and a hammer. Actually due to the deteriorated condition of the plywod that FRP skin came off rather easily. The rotted plywood was removed as well.

FRP removal from plywood

Removing the FRP from the plywood.

The plan is to re-used the existing FRP skin over the new plywood after a re-build of the structural components.

frp and plywood deck

After removal of the bad stuff and a thorough clean up this is what we had.

So far this represents about 5 hours of work and the next step will be a re-construct of the transverse sole suports.

More to come.



Marine Survey Inspections and Reports

We haven’t discussed marine surveys in a while so here goes. It’s late winter here in Canada and as we head into spring we ramp up into the busy season for us marine surveyors. I thought that a few posts on the processes of the marine survey inspection might be in order.

A Marine Survey is an objective report on the condition and value of a particular vessel paying close attention to the structure, installed systems, sails, rigging and motive power components. Survey reports are subject to the condition and accessibility of the vessel at the time of the survey. This is an important statement because the state of the vessel, as presented can affect the depth in which the surveyor can go to test and evaluate the vessel and its installed systems. For example a hull inspection cannot be performed without the vessel being hauled from the water. Electrical systems cannot be tested without charged batteries on board or available shore power.

When performing inspections test methods used by surveyors are usually of a non-destructive nature. What this means is that the vessel in question will not be disassembled by the surveyor for access to systems or components. If minor disassembly is required such as the removal of an electrical distribution panel the owner may be asked to sign a release absolving the surveyor of any issues that may occur as a result of his or her actions.

Hulls and decks are inspected visually for condition and structural soundness. In the case of fiberglass or wood construction moisture levels are verified and measured by percussive sounding and electronic detection.

Electrical and electronic systems are tested by powering up only when authorized, and providing power is available. If not visual inspections of all accessible wiring, fixtures and equipment are performed.

Plumbing systems are inspected for leaks and wear evaluations are based on visual inspections and reported life of the components.

Mechanical systems, engines gearboxes etc. are inspected for leaks, static functionality and overall general condition. If possible the engine may be started and certain dynamic run up tests will be performed.

Interior joinery is inspected for appearance, condition and structural soundness.

If the mast is stepped at the time of the inspection, rigging and spars are inspected from the deck only. For a thorough inspection arrangements should be made to de-step the mast. Sails should also be made available for a full inspection as well.

A pre purchase situation starts with all of the above and may also include a full engine and drive evaluation. Engine compression and oil pressure may be checked. On gasoline engines spark pugs may examined for telltale signs of problems such as oil consumption and internal component degradation.

At this point a sea trial will facilitate a running inspection of all spars, rigging, sails and loaded run up and tests of the all motive power components.

Survey reports should be subjective, concise, detailed and include pictures that not only indicate problem areas but also give a good general description of the vessel being surveyed. The report should deal with appearance and cosmetic issues only when they affect either vessel value or safety related issues. Current safety standards and regulations should be quoted where applicable. Although many vessels were manufactured before current standards were put into place and compliance may or may not required by law it is always good safety practice to ensure that any vessel is maintained as close to current standards as possible. Insurance providers may require compliance with certain current standards as well.

Reprinted From “The Seaworthy Surveyor” Ontario Sailor Magazine

Original Article By David Sandford AMS®


New EBook “A Guide to Sailboats and Their Systems”

I’ve just published my first EBook. “A Guide to Sailboats and Their Systems”

ebook guide to sailboatsEach year in my profession as a marine surveyor I get involved in a number of pleasure craft pre-purchase situations. Many of these involve first time boat buyers who, while they may have considerable sailing experience either with friends or chartering will often find themselves with little or no practical knowledge about the mechanical aspects of the boats that they wind up purchasing or how the onboard systems operate. As such I am often called upon to explain and demonstrate how these on board systems and devises operate.

That’s what this book is intended to do, provide both new and seasoned boat owners with some insight as to how various on board systems function and hopefully address some of the common questions that do arise. Whether it’s a safety related issue as to “Why is there a polarity indicator on my shore power panel?” or “What does the pressure gauge on my propane supply regulator do?” I’ve tried to answer them all and hopefully provide boat owners with some valuable insight as to how their on board systems function.

I’ve also included discussions on sail design and construction, an explanation of the different types of sailboat rig configurations and some good information on the basics of fiberglass hull and deck construction. There’s also a chapter on auxiliary power and the necessary systems that allow our on-board engines to function.

The intention here is to present a detailed overview to both rookie and seasoned sailors on how sailboats and their systems function.

So whether you are a new or seasoned sailor or are you just moving up to a larger more complex boat I hope that as a reader you find some interesting information here.

Available at all leading EBook retailers including

Capacity Calculation for a Marine Starting Battery

I was asked how to determine the battery size (capacity) for a typical engine starting battery. To that end I have come up with some information on how to do just that.

Starting Battery Ratings: Marine Cranking Amps (MCA) or Cold Cranking Amps (CCA). 1 CCA = 1.3 MCA. The ratings are calculated by the same process just at different ambient temperatures.

Minimum Size for Starting Battery: Engine Displacement (in cubic inches) X 2 (Cranking Requirements) X4 (Reserve Capacity) = Required Battery Size (CCA)

I should note that this calculation will give you the minimum size requirement for a starting battery and I sure won’t hurt to increase the size somewhat. I an also a fan of using a deep cycle rated battery as your starting / reserve.