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GreenEarth 06-24-2001 03:14 PM

Glassing hull
Has anyone had any experience with glassing the hull of a large wood sailboat - an old one? Who does it - should you glass the interior as well? What kind of cost are we talking about?

svdragonseeker 06-26-2001 04:43 AM

Glassing hull
There is a book about this subject it tells how to do it in good detail, lots of pictures. Probably available through Armchair sailor, or Bluewater books. Gugeon brothers also puts out a booklet on this subject. Possibly available through Sail net. Also I recommend adding a thin layer of new wood over the old wood.(cold moulding) This will give a better, clean, fresh layer upon which to attach the glass to. Do NOT use polyester resin use epoxy. The poly resin is not as able to flex as epoxy and cracks. it does not adhere to the wood as well as epoxy, especially to old wood that has been in the water soaking up all sorts of oils and who knows what. When the dry boat is put back into the water and swells the glass, if improperly attached has been known to fall off. Also the old caulking could be taken out and filled with either a wooden spline or epoxy, before the new layer of wood is attached. Small bronze or stainless ring nails and epoxy can be used to attach the new layer. If you do nopt want to spend the money for the special cold moulding veneers sold, then get ceder 2x''s, or the closest type of wood to the type that the boat planking is made of from, and cut it into as thin strips as you can and attach them to the hull. One layer should probably do the job, two or three even better. I found that if you do it vertically (90degrees to the planking) that it is easier. This also will tye all of the planks together and you will not have to worry about a but block letting loose.

GreenEarth 06-26-2001 12:03 PM

Glassing hull
Thank you so much. Lots of good information. I hadn''t heard about the cold moulding beforehand - seems to make good sense. I appreciate your time and your guidance. Paula

VIEXILE 06-26-2001 12:33 PM

Glassing hull
I''ve read a book by a gentleman out of Mattapoisett, Mass about fiberglassing wooden boats - probably called Fiberglassing Wooden Boats, as a matter of fact. He came across as a firm believer, if done correctly. (Don''t know where the book went when I moved to the VI.) This means thousands of the appropriate type and material staples, the correct number of layers of chop/biax/chop or whatever and good hull preparation and layup planning. There''s hundreds of old lobster boats in Maine with glassed-over hulls. The old guys used to simply careen the lobster boat on the full moon tide as far up as they could get it, glass one side, jockey it over, glass the other and launch on the next full moon. Sure, Epoxy is great, but polyester resin is MUCH less expensive. Don''t ask us non-experts, though. Track down the book.

JeffH 06-26-2001 07:01 PM

Glassing hull
(This is very long so you may want to print it out)Glassing a wooden boat is not something that should be undertaken lightly. At best it should be the last resort when there is no other way to salvage a boat. Oddly enough if the boat is in halfway decent shape glassing a wooden boat actually is shortening its useful lifespan.

The success of glassing a wooden boat is heavily dependent on the construction and condition of the wooden boat, and the materials and methods used to glass it.

Boats that are strip planked, plywood and splined and edge glued construction are easier to glass successfully. Carvel planked boats are much harder to glass successfully and lapstrake cannot be glassed at all. Softwoods and soft hardwoods are easiest to glass. Materials like Oak or Teak are next to impossible.

In terms of materials, using epoxy resin greatly increases the chance of a successful job. Epoxy offers a combination of much greater adhesion, greater ability to withstand flexure and excellent impermeability. Obviously epoxy is more expensive, can be more difficult to work and has fewer laminate choices. On the other hand, its properties are so superior that unless the project is a quick and dirty job with an acceptable lifespan less than a few years, I would not even consider using any other type of resins with wood.

To glass a wood hull, the hull needs to be very dry, both inside and out. It is much easier to glass a boat when it is upside down and it may actually be worth while to empty the boat, remove the tanks and engine, drop the ballast keel and turn the boat upside down.

The process starts by removing every bit of the existing finishes on the hull. All cracks, seams, dings and dents are raked clean. The hull needs to be refastened as necessary to connect the skin to the internal framing of the boat. Any damaged frames should be sistered or replaced. The boat is jacked as close as possible to its lines. High spots are faired as much as possible.

The hull is then thoroughly dried and then saturated with un-thickened epoxy, which will require 2-3 coats depending on the species of wood. Once the surface is completely saturated and sanded all over, the seams are filled with thickened epoxy. It may be necessary to run a Skillsaw or panel saw with a shallow blade setting along each seam to get a clean faying surface for the epoxy. Next the hull is thoroughly faired with thickened epoxy. This is a fairly tedious process of filling and long boarding.

You also have the problem of what to do about the ballast keel. Often the ballast keel is glass encapsulated. If you are going this route the keel bolts and floor timbers should be replaced and or repaired. This will be the last chance to replace the keel bolts easily. If you don''t encapsulate the keel then the keel should be dropped and the glass carried into the hull to keel joint.

Once the boat is completely fair you are ready to start glassing. You will want to precut the laminate and be able to do each lay-up in a continuous pattern. Pre-pregging the fabric, vacuum bagging and post curing can increase the ease of lay-up and or your likelihood of success.

You have a number of options with regard to the number of laminations. With sheet, cold or hot molded plywood or splined and edge glued construction you can often get by with a single lamination acting as a moisture proof membrane. On a carvel planked boat you really need to build up a structural outer skin and so a number of laminations will be required. With strip plank you may be able to either. If you encapsulate the keel multiple layers will be required in the area of the hull to keel joint.

Then you start your final fine fairing. Start by sanding and filling any obvious dips and dings. Once fair, below the waterline paint on several coats of untickened epoxy to act as a barrier coat. Above the waterline, start blocking the hull using an appropriate high build primer and a long board to show the high spots. It is a multi-cycle process using spot fillers and died primers. This is a big job but an important one if you want to end up with a yacht like finish. Once the hull is ready to paint throw a couple coats of paint on the protect the Epoxy from UV and then turn the boat over.

Strip all finishes on the inside of the boat and completely saturate the planking and frames with epoxy to keep the planks from swelling and contracting. Flood seams and cracks in the wood and joints at butt blocks and frames with un-thickened epoxy. This process is enormous work. You can almost build a replacement hull easier and faster using the existing hull as a plug or a mold.

You have other issues about how to do the hull to deck joint. But this covers the basics. I strongly suggest that you stick with quality known products. The two that I really like are WEST System epoxies and MAS epoxies. MAS may have some advantages but both offer good factory support. MAS can be reached on line at

WEST System can be reached at
WEST also has a lot of how to pamphlets and they used to have a very good one on just this subject.

Then there is the affect of glassing a boat on its performance. My old 1939 Stadel Cutter had been glassed. Theis really advesely affected her performance turning a reportedly pretty quick little boat in her day into a real slug. Boats are just not made to take on that much additional weight as a skin. This weight increases stress on rigging and can adversely affect seaworthiness and comfort at sea.

One final point about the guy''s suggestion about the lobster boats being glassed. Lobster boats are generally strip planked and at least when I was a kid they were generally planked in softwoods, more often then not, cedar. These are are good candidates for glassing but glassing a wet hull, especially with a polyester resin is a sure way to have a premature failure of the glass to wood connection.

Good luck

GreenEarth 06-27-2001 12:19 PM

Glassing hull

You certainly went above and beyond the call of duty here. I can''t thank you enough for all your careful and thoughtful information. It certainly has opened my eyes and perhaps this won''t be the way to go. I too have a real fast schooner with numerous trophies under her belt, plus she is the sistership to "Cimba" from the nautical book "Saga of Cimba." She''s a 1934 staysail schooner out of Nova Scotia by Vernon Langille. Obvoiusly my goal is to keep her integrity. Again, thank you so much. Paula

GreenEarth 06-27-2001 12:20 PM

Glassing hull
Thank you for all your advise and the time spent replying - I''ll be sure and pick up that book and continue my investigations.

Thank you. Paula

JeffH 06-29-2001 03:16 AM

Glassing hull
That sounds like a great old boat. She would not happen to be here in Annapolis. There is one being restored down the road from my house at Bert Jabin''s yard.

That is interesting about having a Nova Scotia schooner similar to Cimba and more to the point actually built by Vernon Langille. This is a vry valuable boat historically. Vernon built a lot of boats in his day but not that many survive because of the way they were built. It sounds like yours was actually built as a yacht. The working Novi''s had boomless gaff foresails that overlapped the mainmast and were tacked like a jib rather than being staysail schooners.

The working boats were generally built of green or slightly air dried wood and fastened with iron fastenings. Green wood worked fine in the cold climate and in the rough and tumble world of a workboat. You don''t want to take one of these boats into the tropics. The yacht versions were built a little better using seasoned lumber and non-ferrous fastenings. Also some of them were stripped planked but I don''t recall that Vernon Langille built strip planked boats.

Assuming that the boat is not strip planked and is ferrous fastened, these are probably not a suitable boat to glass over. The comparatively wide and robust planking really can''t be kept dry enough to prevent movement and they eventual delamination of the sheathing. Also adding the necessary thickness of glass for a boat of that size and construction would noticeably slow the boat down even on a burdensome vessel like a ''Novi'' schooner.

Novi''s had heavy internal framing making refastening and replanking relatively easy. The folks restoring the ''Novi''down the road are using pressure treated southern yellow pine for their replanking. I was talking to the guy doing the work. They have been buying the wood from a lumber yard that specializes in tiber for docks and bulkheads. They buy the lumber 4-6 months before they need it and air dry it like green lumber. Once dried out a bit they run the plank stock through a thickness planer and are ready to go. They are careful to pick the individual planks carefully from the pile. The stock that he had was beautifully dense and free of knots.

Enjoy your boat,

JeffH 06-29-2001 03:17 AM

Glassing hull
BTW, is she a knockabout (''Bluenose'' bow) or does she have a bowsprit.


GreenEarth 07-02-2001 05:13 PM

Glassing hull
She has a bowsprit. I''m not sure how she was built but she is yellow pine below and white pine above the waterline. No, she is not in Nova Scotia, she is here on the Central Coast of California in Morro Bay. I''m not sure about not taking them into tropical climates as the "Cimba" did just that and Nelly Bly was on her way at one time too.

As far as Langille''s boats not surviving - I''m not sure about Nelly because everyone says this boat was built "particular." Either way, she is here and still kicking and hopefully will for some time to come.

I would love to know more about Langille so any history or places you know that I can get information I would love to have.

Thank you. Paula

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