Well, here we are waiting for the hull to dry out on Shamrock hull 92. Svendsen’s Marine in Alameda,CA. is doing an excellent job. Svendsens peeled down past the 7.5 oz. mat to remove all the blisters and the bulk of the moisture. We had a multitude of voids, air pockets and lay-up contaminates in the mat and first few layers of cloth, even found a few small chunks of wood in the cloth. Don’t panic, this is typical of production boats, even the multi-million dollar boats.
The peeler they are using is called a Gelplane, incredible tool, makes quick work of the peel process, 1.5 days to peel, 2 days to trim, sand, pry off any loose layer of glass and fare the hull for glass lay-up.
We are down to green, clear glass, plenty of hull thickness left, still 3/4" at the head discharge thru-hull near the keel, 3/8-1/2" at the thru-hull fittings higher up the hull; after laying up 3 layers of glass and epoxy, we should be back up to the original hull thickness.
Moisture readings over the entire hull bottom prior to peeling were over 30%, we only have one area at the keel, center of the hull which is at 25%, remainder of the hull is around 12-15%, moisture levels dropping like a rock, down 5% since last night.
In retrospect, we feel we made a good decision to peel and not screw around with grinding and patching. We had a lot of pressure from friends and others to patch and sail or sell, passing the problem on to the next party, not something we are acustomed to doing. The guys at Svendsen’s Marine are some of the best in the industry at glass work, have see may examples of their work over the years, when our hull is complete, I suspect Shamrock will be as strong as, if not stronger than the day she was built.
In researching osmosis, I did not find one boat manufacturer that didn’t experience osmotic blister in one form or another through their entire production run, I seen hulls built before and after a hull which had blister, have no blisters at all; have seen two hulls built side by side with the same crews and materials, one got blisters and the other did not. In other words, no manufacturer is exempt, popular opinion regarding osmosis is, it not a matter of if a hull will get blisters, it’s a matter of degree of severity and when it will occur. No product, polyester, vinylester or epoxy will totaly elimate osmotic blister in FRP boats, better products like vinylester and epoxy will definately slow the process. Nothing lasts for ever; I think our Mr. Cofee machine is #50 in the line-up.
Fiberglass hull building is a nasty, filthy, toxic environment to work in; I can remember when we worked in blue jeans, t-shirts and sneakers, no respirators-protective clothing, sticky from head to toe with resin and glass particles stuck everywhere. Back then, we didn’t know removing resin from our skin with acetone was a stupid thing to do, draws the resin directly into the skin, use white vinegar. We worked in a shed with a rock floor often still damp from the last rain, air, wind, dust and rain coming through the cracks in the wall; slapped together plywood tables for laying out glass, bare plywood holds moisture, leave a piece of cloth on the table overnight and it picks up moisture, can’t feel it, but it’s there. Still make me itch just thinking about it, it wasn’t until years later that we learned how toxic epoxy was to work with, suprised our son didn’t come out with two heads in stead of one…
Work place hygene, clean lay-up areas, protective clothing, respirators, all contribute to safer and healthy working environment;, better construction material products, tools and techniques are helping to produce more durable products.
We are still very much in love with Shamrock, the SLM folks did a heck of a job building her.
If we didn’t own a BCC, we would still be out there looking to buy one.
Cheers,
Marty & Linda Chin
BCC Shamrock