Visit our Popular Forums

PQDC · 23-02-2019, 13:09

Quote:

Originally Posted by Mike Banks

Considering a plywood boat is fine.

Buying one is something I would never do again.

Why is that Mike?

captlloyd · 23-02-2019, 14:54

Quote:

Originally Posted by PQDC

Why is that Mike?

Probably because he bought one that was problematic so that makes them all bad. Some divorced people feel that way. Look, if a boat is well built and maintained well, you are golden. That is what surveys are for if you are not knowledgeable enough. There are good grp ( glass reinforced plywood) boats around that are decades old. Good luck!

By the way, I just looked at the pictures of that boat and I see a very well cared for boat. Excellent.

**boatman61** · 23-02-2019, 15:51

Just had a look myself.. a beaut example that looks well loved.. and she has a Bruce.. Awesome..

billgewater · 23-02-2019, 15:59

Over the years I have seen many plywood boats and boats with plywood structures/decks etc.
Some observations. The first is that if the plywood is kept dry inside the boat with a lick of paint it can last forever. It is relatively cheap, strong, light and easily tooled. It can also provide very attractive veneered finishes found on the most expensive vessels.
Timber boats also have a more homely feel with good thermal and sound insulating properties.
If a plywood hull is sheathed using epoxy processes and painted with UV proof paints to protect the epoxy and plywood, it can also last forever. This is conditional on the plywood being very dry during all construction phases.
Nearly all the problems I have seen stem from the simple matter of drilling holes for through bolt or screw mounted fittings.
This applies particularly to metal framed screwed on windows on deck houses, bolted on stanchions, cleats, deck tracks, et cetera.
Wherever a screw or bolt passes through the plywood, then irrespective of any amount of sealant used, then ONE DAY some water will enter. Just one slightly damp spot and the rot will start and the veneers will spread the rot rapidly in ALL directions.
But there is a simple way to prevent this. When the holes are initially drilled for the mountings, redrill and oversize the holes then fill the holes with laminating diluted epoxy resin. Then after curing, redrill the holes. This means that when the water does come in via the screw or bolt hole then that water can’t make contact with the plywood.

Think about it. In any forest, the continued survival of the forest depends on the fact that all timbers eventually rot in the presence of fresh water, allowing the recycling of nutrients. (OK, some like Huon Pine, also require air as well) Perfectly sound timbers have been removed from dry 3000 year old Egyptian burial sites. Many old ship wrecks have large pieces of timber surviving in saline conditions. But it is the fresh water that is the culprit. Keeping dry is the answer.
If a plywood vessel has hard chines, then great care must be made to ensure that these high stress and abrasion areas are cared for.
In smaller vessels the very high stiffness and low cost of thin plywood is definitely an advantage when building one off boats. It can be curved into fair conical sections and can be readily laminated where needed. That’s really why there were so many of them in the 1950’s and 60’s. The arrival of water proof glues (e.g. resorcinol) and ultimately epoxies and now polyurethanes has enhanced the building and survival of plywood structures.
Also be aware that fresh water in the bilges can be problematic. Products such as Everdure are often used there to seal things.
My comments about sealing the through holes also applies to ferro-cement structures. Oversize the holes, epoxy fill, redrill. Ferro cement, if well built, is not as susceptible as ply or wood, but it still pays to be careful.
Note that polyester resins are definitely not part of the prevention. Polyester resins have much poorer adhesion to wood and are also can allow osmosis along reinforcing fibres. Suddenly the whole vessel is doomed.

Hardhead · 23-02-2019, 17:27

This is a little off topic, but is that an expected amount of pre-bend in that straight up angled photo of the mast? Not that it's an issue by any means, and I'm certainly no expert. Could also be the camera lens as well. Good looking boat-

picklesandjesse · 23-02-2019, 20:00

Nothing wrong with a well built and maintained plywood boat. Stormvogel is probably the most famous example. Won many races around the world. Got to know her when the movie Dead Calm was made. We were the other vessel in the movie, the one that burnt and sank at the end, that was a replica built by the art dept. Kennedy Miller who made the film had a problem with the owner of the Golden Plover and she never got a mention in the credits at the end. My cockatoo really liked Sam Neill too.

Mike Banks · 24-02-2019, 14:13

Plywood needs to be SATURATED with epoxy resin thinned properly, and repeated to refusal. That makes it durable but heavy.

I lived in the wet tropics and had constant problems with mould and rot. It NEVER stopped coming--I gradually replaced most of the decks in the way of the vital points of cleat fastenings and the rotten stanchion positions. The aft cabin roof and sides was replaced with one-piece fibreglass. The coach house panels were refastened using moulded fibrelglass. I learned as I went what was effective and what wasn't.

In the wet tropics one multiplies the wear and tear and deterioration of a wooden vessel by a factor of about town. A good course of hands-on and theory studied from the texts of masters--but during all of this time my friends with their fibreglass cats and monos were out and about doing other stuff, visiting other places and enjoying life while I was fixing, grinding, sanding, replacing plywood panels with pressure treated plywood and even that was dried out turning frequently and when dry epoxy saturated and glassed, just so I would not have to do it again in the foreseeable future.

I did get to do some of the fun stuff--of course I was not always constantly busy--but it never stopped deteriorating and I never stopped repairing it in one way or another right until the day I sold it. Expensive to fix, time consuming and how much time does one have?

I saw a lovely Jim Brown 40 Trimaran for sale with a Perkins diesel for $4500. The diesel and gearbox was probably worth about that--let alone the masts, winches etc.

I walked away from it whistling--

PQDC · 24-02-2019, 21:58

Thanks for the replies everyone - it's been invaluable.

We've now moved to the survey stage. I don't suppose anyone knows a decent, and not overpriced surveyor in the Sydney / Pittwater area. I've started with emailing the usual suspects but most who have got back to me want about AUS$1,000 to survey the boat, plus about $400 to lift her for an hour. Seems a bit steep for 3 or 4 hours work, but I could be wrong.

picklesandjesse · 24-02-2019, 22:51

Yes, i know one. he does mostly wooden boats and might do a deal. Stand by a bit and I will check past emails etc. He's the same age as me and a bit crazy, the French..... you understand. It might take me a few pages to find him. Used him 3 times. If you tell him the asking price he might understand that you don't want to spend too much on the survey etc. I think he was around $600 a couple of years ago. Someone else here might know him too. All the brokers know and fear him !!!!

Fore and Aft · 24-02-2019, 22:59

If you were in Brisbane I would charge you $640 for the survey. 3 or 4 hours work is a bit optimistic, there is travel time, time spent surveying the boat, then time writting the report. Your surveyor should also have endemnity insurance as well which is not cheap.
As an example the other day I had 9am survey, by the time they got the yacht out of the water due to a few delays it was already 11am, then she badly needed a clean. By 1.30pm I had only done half the survey and had to leave for another job. Then I came back the next day to finish the survey. So for that job I ended up being on site for 7 hours without even considering the traveling and report to be written.
Cheers
foreandaftsurveyors.com