1998 Sea Ray 210BR - All Fiberglass, or still some wood?

[ColoSR]

Not sure if it helps, but my 2003 sundeck 220 transom is certainly wood encapsulated with fiberglass. In my case, water on the backside of the transom swelled the wood and caused a big leak at the transom. Multi boat buck repair to replace transom mid-season

 

[COOPER W NORMAN]

Several repair shops here on the Gulf Coast have quoted four to six thousand, depending on what they find when they open it up. NADA values this boat as equipped at about $9000 and I already have some substantial investment in the project, although i am still somewhat below that number not placing a value on my sweat equity. A repair of that magnitude of cost would seriously call into question the wisdom of that move.

On the otherhand, poking around it appears that the rot has so far only taken out wood on both sides of the drain plug, maybe up to a foot each way, with solid wood still bridging over this area.

I will go in with a boroscope in the next couple of days to firm up that impression, thinking that i might be able to insert a pipe section into the drain path, preserving that opening when i drill through the hull and pump in a rot proof fill material -- still to be determined. I am considering a two-part urethane sealer (if the cavity is limed to this small area, I wont need to restore the structural strength of the original wood) or two-part epoxy (though it may not seal well to the surfacds of the cavity, leaving the possiblity of continued water entry that, even in a vastly reduced volume, still would have the potential to moisten the wood above).

Water is the only factor that can be managed in a wood rot situation. Fungus spores float by the millions in every breath you take and they are the organisms that feed on wood, causing deterioration and rot. They thrive in same conditions that we need to live -- oxygen, temperate warmth, organic material to feed on, etc. The only factor we can even begin to manage is moisture.

Wood moisture content over 14 to 16% is all that these fungus spores need to grow. Below that, they go dormant and and are harmless. Higher than that, the more virulent forms can take hold and do their work.

So sealing this against passage of moisture and then treating the remaining wood to immunize it against future fungal attack (or arrest an existing infestation) is what I am laying out as a work plan.

Jamestown has a penetrating expoxy that is thinned with acetone that might be injected through bore holes, though the potential depth of penetration is an unknown, deeper meaning fewer boring of holes into the hull core. Stop-Rot sold by West Marine is another intended for this purpose.

Two part repair epoxy will be used to seal the holes after treatment.

 

[El Capitan]

Very interesting thread and central to both Sea Ray owners and old boat owners.

If you have moisture in the transom then there’s a very high probability you have moisture in the stingers at least aft.

Note how water intrusion travels in every direction including vertically up from keel.

I know of no boats of 1990’s vintage from Sea Ray that did not use wood in the stringer system.

There are newer vintage fishing boats that are 100% wood free. My in water experience w them is that they behave like a cork in water.

 

[BEH]

View attachment 60623

Mine is 1989 and they used painted plywood (3/8" to 1/2", varies) below deck serving as forms for the pour in floatation foam and substrate for seats, etc. This was also decked with plywood and carpet. All of that rotted out and I replaced it with 1/2" treated plywood decking and miscellaneous supports, with added 2" x 2" stringers for attachments in some locations. Treated materials are a must: it's heavier but will not rot in our lifetime, finished with marine carpet and adhesive. Cautions not to use treated lumber are rooted in fact that any new epoxy attachments needed to secure or serve as deck finish is not feasible -- these new fiberglass materials are incompatible with treated wood substrates; but treated wood is substantially less costly than marine grade plywood and non-wood composites. Hey, I had to do this with a careful eye on service versus costs.

If you pull the floor panel over the fuel tank, you should be able to easily inspect the form material used on yours. None of that work served as primary structure, although it did provide attachment points for finishes laid over it. The engine is mounted on heavy glass enclosed timbers and appear to be isolated from the referenced secondary form work. Those timbers are the only primary structure, and do not extend beyond the bilge will/engine compartment on mine.

My transom only had 1-inch thick wood core, embedded in heavy (1/2" thick) fiberglass construction; and is now subject of an attempt to arrest rot that I discovered around the drain plug. This wood and fiberglass assembly only extends up to a height of about 16-inches above the keel, with the top section serving as a much more robust structure above that. Geometry plays a large role in contribution to final strength and the comples shape of the upper top section is way stronger than the flat plane transom section, but 1/2" fiberglass is a hefty section. The top and hull bottom connections provide needed stiffness in the plane section of the transom.

The GMC 4.3L V6 and Alpha 1 outdrive are not sturcturally dependent on the transom; although it passes through it and maintaining a seal is of paramount importance. That load is fully supported on the timber structure.

Wood and fiberglass have similar tensile strength and hence normally work well together as a composite material when stressed. Given the thin wood section (1-inch instead of 2- to 3-inch normally found in transoms) it primarily served as stout fromwork that served as the substrate for the fiberglass overlay; and once that cured, is not a significant contributer to the structural capacity of the transom, where the fiberglass takes over.

We will see. To date, no cracks or signs of fiberglass distress, even with core rot.

I have the same boat as you.
What size propeller are you using?
Thanks

 

[WV 320 Dancer]

So I worked for Georgia Pacific for over 23 years and they are one of the largest producers of plywood in the world. All exterior grade plywood (including “marine” grade) uses the same exterior resin (glue). The thing that makes Marine grade plywood is the grade of the veneers not the glue. Marine grade plywood is always Fir not Pine. The veneers are always high quality with few if any defects. Repair plugs are allowed (these are the patches you will see in the veneer face. Georgia Pacific also made a product called Sea Frame which was a southern yellow pine plywood. Many boat builders and especially pontoon builders have used this product in their production. Pressure treated plywood is treated to “refusal” it is not like lumber where it is rated for above and below ground contact.