View Full Version : Another Fiberglass/Epoxy Question

08-01-2001, 09:20 PM
After years sailing fiberglass boats decided to join the real men and bought a 30' wood trawler. It's a Glen-L design completed in 1990. The boat is built to Glen-L's specifications with a cold molded hull that was encapsulated in fiberglass. I've had the boat for about a month and knew when I bought it that there was going to be some dry rot to repair.

What I've found is the source of the rot is delamination of the fiberglass. I've peeled most of the glass off the hull and the water just poured out. What I'm wondering is why such extensive delamination of the glass and what do I do now to seal up the hull now?

What I've gathered from the discussions in this forum is that CPES is probably where I should start, but there seems to be a difference of opinion about what to do then. Re-glass? Glass the seams and epoxy the rest? I'm also concerned about the interior of the hull and if it's water tight. I've considered using SANI-TRED to seal the bildge and as no skid for the deck. Has anyone out there heard of this stuff. They make the same sort of claim that CPES makes. I thought CPES was too good to be true until I read comments about it in the forum.

I've done a lot of work with wood, but not much on boats. I'll appreciate your comments.

Ed Harrow
08-01-2001, 09:47 PM
A guess, but that never stopped me before, LOL. Probably the glass was not put on with Epoxy, but with the lesser googe, which simply doesn't hold as well. Someone wiser than I will likely echo this opinion, and advise you to peel it all off. The good news is that it's not adhering very well, which you've already found out, so getting it off might not be as difficult as you imagine. (Not to say that it will be fun...)

George Roberts
08-01-2001, 11:59 PM
What you have is a 30' hole in the water to poor your money and time into.

Polyester might have been used. epoxy might have been used.

Peel it all off and let the boat dry for a few months.

Replace all of the bad stuff and loose stuff.

Turn the hull upside down and put on new glass/resin. Take you pick of brands and amounts.

Turn the boat upright and do the same on the inside.

By now the boat costs more than a new boat and you have more work to do.

(I disable the smilies but ...)

08-02-2001, 01:38 AM
You said the hull was cold molded. So why put anything back on it? There are only three reasons for putting glass over a wood hull in the first place: added strength, abrasion resistance, total lack of knowledge and trust in wood. There is some merit to the first two but the third is simply stupidity.

You need to look at the WOOD hull, at the thickness of the skin (and it's integrity) as well as the frame and ask yourself (or a knowledgeable WOODENBOAT surveyor) whether or not you really need to have that glass covering. I rather doubt that you really need the added abrasion resistance for a thirty foot boat and while the glass added some strength, if it was only one or two layers it probably didn't add enough to be worth replacing.

I would recommend that you let the boat dryout for a few weeks (not months) while you work around the hull and attack some of those rot pockets. Don't try and simply stiffen up the rotted areas with preparations such as "Get-Rot"; these preparations have their place but they don't kill the fungus. Cut out the rot back to good wood and then some (rot fungus sends microscopic tendrils into the good wood for some distance). After the wood has dried and before you paint treat all of the areas (including the edges) around the former rot sites with Cuprinol (copper napthenate). This stuff is also known as 'Green Death' and is very effective against rot. Don't use it on wood you intend to varnish unless you like a green cast to your bright work. Once repairs are made and the hull is painted (epoxy paint) then GO SAILING.

PS: Any activity which doesn't make a substantial profit can be cynically described along the lines of being a "hole in the water into which you pour money". It is a rather tired old saying that really wasn't worth saying the first time........

Keith Wilson
08-02-2001, 09:58 AM
A few more specifics might be helpful. Which Glen-L design is it? I looked at their web site, ( http://www.glen-l.com/ )and all of the powerboats of that size I saw were plywood-on-frame construction, rather than cold-molded. Just to be clear on definitions, cold molding is a method of glueing up a hull (usually round-bilged) out of layers of veneer, so that the whole hull is in essence a single boat-shaped piece of plywood. Plywood construction uses commercially-produced sheets of plywood to plank the boat (usually hard-chined). Sorry if I'm stating the obvious - just want to make sure we're talking about the same thing.

Just to quibble, there is another valid reason to use reinforcing fabric (glass, Dynel, Xynole, whatever) in epoxy, other than added strength and abrasion resistance. It can be used to reinforce the (mostly) waterproof epoxy layer, allowing a thicker and more waterproof layer of epoxy. An epoxy film by itself will crack and leak if the film thickness is too great. Keeping the wood reasonably dry is a good thing.

Polyester resin (the same stuff they build fiberglass boats out of) has sometimes been used with glass cloth for sheathing on wooden boats, mainly because it's about 1/3 the cost of epoxy. The results are often as unpleasant as what you describe.

Anyway, that said, listen to PugetSound, he knows of what he speaks. Get rid of the old covering, for whether it's epoxy or polyester, it obviously didn't work. Dry it out well, cut out and replace any rot, take the surface back to wood, then (maybe) resheath with glass or other reinforcing fabric.

Two reliable epoxy suppliers are System Three ( http://www.systemthree.com/index.html ) and Gougeon Brothers ( http://www.westsystem.com/ ) There are others. If you don't know a lot about epoxy, (or even if you do) I'd heartily recommend downloading System 3's "Epoxy Book". It's probably the best introduction to techniques of working with the goop that there is. Again, sorry if I'm stating the obvious. Good luck!

[This message has been edited by Keith Wilson (edited 08-02-2001).]

08-02-2001, 03:59 PM
Keith the boat is a Glen-L Jolly Roger. The hull is done in two layers of criss crossed plywood. The front third of the boat is in narrow strips to allow for bending to get a nice round shape. The back of the boat (hull) is in larger panels.

I haven't checked Glen-L's construction description in a while, but I thought I remembered them describing it as cold mold. Maybe not. My understanding of cold molding (admittedly limited) was that two or more layers of ply were laid perpendicular to each other and glued. Like I said, I just joined the real men.

By the way, as a general comment. This will be my forth "hole in the water". I've never owned a boat that didn't require pouring money into. It happens that my wife loves this boat and has agreed to live on it with me. Something she has never agreed to before. So if it takes me a couple of years to bring it back to life and a few more dollars than I expected, it will be worth it.

PugetSound your comments make me feel like I'm headed in the right direction. You might be interested in knowing that the boat came out of Tacoma. More of my foolishness. Lake Superior sailor buys Puget Sound boat.

Thanks to ALL of you for the response.

George Roberts
08-02-2001, 07:46 PM
I build boats. I repair boats. I do not build or repair "holes in the water".

A "hole in the water" is a "boat" that after repairs is worth less than the cost of repairs.

If you like the boat, fix it.

Scott Rosen
08-03-2001, 08:53 AM
What you've got is not technically a cold molded hull. You've got a plywood strip planked hull. That's a big and important difference. The giveaway to me was the rot. Cold molded hulls are virtually impervious to rot because everything is encapsulated with epoxy. I've never actually dealt with plywood construction of the type you describe, but I can surmise the following. Your type of construction may be prone to delaminate from exposure to water. The glass was probably recommended by the builder to keep the wood dry to prevent delamination, and not likely for any other reason. The glass job on your boat was not properly done. In fact it sucked. If done properly, water should not get between the glass and the wood. In fact, the glass on your boat actually made the rot worse. My guess is that it was applied with polyester resin, which is known to absorb water and to have poor adhesion to wood.

I would follow the advise to strip off all the glass, let the wood dry and repair the rot. Contact the designer and find out if glass is really necessary. If it is, then you should use an epoxy system. Many are available and many have been discussed on this Forum. The system made by Smith & Co., which would include their Clear Penetrating Epoxy Sealer and Lay-up Epoxy, gets the higest praise from those who use it. If done properly, it should stay glued to the wood for a good long time.

Do a search under CPES and you'll find lots to read.

Mike Keers
08-03-2001, 02:16 PM
I think I have to take issue with your statement:
"What you've got is not technically a cold molded hull. You've got a plywood strip planked hull."

To my understanding, strip plank construction involves lumber, let's say 3/4" square, edge fastened together and formed up over molds. It is sometimes sheathed with cloth and poly or epoxy, or even cold molded veneers applied over. The old Controversy sloops were an example of this (sans veneer).

I believe what totrecal is describing, double diagonal planking, would be considered cold molding IMHO. Whether it is done with veneers or plywood strips, the double diagonal method would certainly fall under cold molding in my book. I stand ready to be corrected by those more knowledgable.

I am currently building a 28 foot sedan cruiser, planked with four layers (double-double diagonal) of 1/4" plywood "planks". It is all epoxy glued and encapsulated, and the designer, Karl Stambaugh refers to it as cold molded, I term I would agree with. The hollow entry is a marvel to see develop, and would only be possible with this method.

BTW, the plans call for FG tape on the chines only, not the whole bottom being cloth covered. Three layers of epoxy in and out. I'm not sure yet if I'll go with Dynel or similar, as this will be a trailer boat and the abrasion resistance might be nice.

Scott Rosen
08-03-2001, 03:54 PM
Mike, we may not agree on terminology (and I'm no expert, that's for sure), but I think we agree on the structural issues. I've always thought of cold molded hulls as being bullet-proof and as having essentially no seams. Don't you find it strange that totrecal says "Glass the seams and epoxy the rest"? I can't picture a cold molded hull designed in such a way that you would have "seams" enough to glass. Maybe he means glass the chines, but I can't tell.

Be that as it may, if a "molded" plywood hull is not sealed with epoxy and has wide seams and is then improperly sealed with glass, there are going to be problems no matter what you call the hull.

Mike Keers
08-03-2001, 04:30 PM
I certainly wasn't attempting to be argumentative, and I guess you didn't take it that way.

As soon as I'd posted (as always, gather the facts after pronouncing http://media5.hypernet.com/~dick/ubb/wink.gif I went and dug out a few books....you are correct, it is definately a terminology thing.

First off, Glen L. Witt himself in his "Building With Plywood" book heads up the section on double-diagonal plywood planking with the title "Plywood Strip Planking",(touche!) altho he doesn't refer to it as such anywhere else but the title of the section. He doesn't call it double-diagonal either tho. Just "double plywood".

What I had in mind with my original post was Ian Nicholson's definitions as in his excellent book, "Cold-Moulded and Strip-Planked Wood Boatbuilding".

He clearly makes the distinction (that I had in mind) that wide, thin planks, whether solid wood veneer or thin ply, applied double-diagonal fashion is "cold moulding", and that strip planking is defined by longitudinally applied lumber, generally square-ish in section, or wider than thick, up to about 1-1/2 times the thickness in width.

Now Robert M. Steward in his "Boatbuilding Manual" agrees with my perception of strip planking, but calls what I'm terming 'double diagonal cold molding' as "molded plywood planking" I believe he means using solid lumber veneers, not plywood per se. It is the layers themselves, taken as a structure, that he calls 'plywood' in the finished boat.

Steward's primary distinction between "molded plywood" and "diagonal planking", altho the processes are identical, is the thickness of the planking used.

Of course there are variations...Steward mentions a 'double planked' hull with plywood sheets under solid lumber. And Nicholson mentions a strip planked hull with a layer (diagonal?) of veneer outside.

Finally, and for Cleek, I happened to come across this in Nicholson's book..."a well built cold-molded boat should last as long as a carvel-planked one, say 50 years; however, strip-planking is not likely to have the same longevity."

He must mean cold-molded with all that epoxy. http://media5.hypernet.com/~dick/ubb/tongue.gif

Todd Bradshaw
08-03-2001, 09:04 PM
Something that keeps occurring to me as I read this thread is that the delamination of the glass may not be the cause of the problems - it may be the result. If water got into the ply from inside, it would eventually cause rotten wood and fiberglass sheathing delamination of either polyester or epoxy saturated cloth. Standing bilge water and improperly sealed seams, chines, etc. would be a perfect way to begin a self-destruction process that would go all the way through the hull.

It really doesn't matter at this point, as the repair process is the same, but the concerns about being sure the inside is sealed properly are just as important as concentrating on what fabric, how much and which resin to use on the outside.

08-03-2001, 09:09 PM
Okay guys. Here's what I seem to be getting from this discussion.

1. I did a stupid thing buying a poorly built boat that my wife happens to be in love with.

2. I should strip off the glass that, BTW, is almost done. It's been like peeling a 30' bananna.

3. CPES is definitely part of the solution.

4. MAYBE I should glass the bottom, but I probably should glass the seams. FYI with one exception all the seams are less than 1/8 of an inch.

5. Cut out the rot with reckless abandon and give the boat a healthy (?) dose of the "green death".

I expect to retire in the next three years. Am I likely to have all this done before then? That is if I haven't spent my retirement fund fixing the boat. Maybe I should follow George's line and set the boat on fire to collect the insurance; but, given Scott's occupation, he would advise against that. http://media5.hypernet.com/~dick/ubb/smile.gif

Mike Keers
08-03-2001, 09:16 PM
You raise valid and important observations and points. Sealing a plywood boat on the outside with glass and googe, but not the inside is a prime cause of fatal rot in my experience...I've seen it a number of times, and I have two boats (given to me) here in my yard now that prove it...both rotted from rain water sitting inside, and I imagine working it's way into everything, with no chance of exit or drying from the outside.

The key is as as you say, the inside must be sealed as well as the outside if that is the building method chosen (external encapsulation).

The boat I'm building calls for three coats of epoxy on everything, every stick or surface in the entire boat. I'm paying particular attention to the bilge areas and any place else where water might collect.

I'm not sure coating the inside with Cuprinol or similar, but glassing the outside is much of a cure, as the same destructive situation exists, the water can't get out or the wood dry from the outside. But at least the preservative might help stem rot from fungus....but for how long? CPES seems like a viable alternative in this situation, perhaps a superior one.

08-03-2001, 09:18 PM
Todd, that was also my concern; but as I remove more glass I'm finding moisture way above the waterline. This boat was poorly sealed all over. None of the deck hardware was bedded and deck drainage was very poorly done. I know, you're all asking why did this bonehead buy this boat.

08-03-2001, 10:48 PM
totrecal,welcome to the club.
The word bonehead is used with great reverance here.
I'll bet you a peanutbutter and jelly sandwich that 99.9% of the souls on this forum have"been there done that"when it comes to making a bonehead decision about a boat.
Of course I am the .1% that has always made totally correct and informed choices in boats.I'm writing this while SWMBO is asleep.

Bob Adams
08-04-2001, 09:52 AM
Hang in there amigo! I just returned from a wooden (Egg Harbor) boat rendzvous where my welcome mat said "Welcome aboard the luckiest boat on the planet". Why? Because anyone with any "real" sense would have sent her to the chainsaw.I saved her and she knows it, and she rewards me every time I look at her. Wood boats have soul, can't say that about tupperware.You're not a bonehead, you're in love. Good luck

Scott Rosen
08-04-2001, 10:30 AM

You've just shown remarkable wisdom. There's only one good reason to buy as poorly a built boat as yours: Your wife loves it. That very fact will have you thanking your lucky stars that you bought this boat. Especially as the bills start to mount and you find yourself spending much more time on the boat than on the "honey do" list.

By the way, I don't think anyone here faults you for buying the boat. Everything you describe is repairable by someone with average skills and lots of patience. You should be able to complete the job before you retire.

You will only be a bonehead if you make boneheaded repairs. In other words, if you didn't repair the rot and just slathered a bunch of goop and glass on the boat, that would be boneheaded. But you're already thinking along the right lines, so I'd give you a less than 5% chance of being a bonehead.

You're right about my advice. Don't torch it. Even if you got away with it, your insurance wouldn't pay you enough to buy a better boat.

Pat McMahon
09-18-2001, 08:45 PM
I am new to this forum, but I find myself really enjoying the banter back and forth - this topic sems to be one of many where it is going on.

At the risk of stating the ponderously obvious, my fellow sailing club members, (all ****** boat owners, damn keen sailors and hail fellows well met, every one) would say that all of us are boneheads for even thinking about owning wooden boats. When they hear stories like this, and reply that annual maintenance for them is a garden hose and a bottle of "Sof'Scrub", it is not a point easy to argue. If one of these guys actually varnishes a tiller, he is likely to break a bottle of champagne over it!
Anyway,I just wanted to share the observation that, in the "real world", we're probably all boneheads!!
As to the rot issue, I don't know that much. I do know that dry rot spores are in the air you are breathing right now, unless you are in an oxygen tent! They have access to all surfaces. When in contact with wood, they will grow and consume part of the wood fibre, so long as it contains a certain percentage of moisture, (can't rememebr the number, but it is in the 20% range, not sopping but not dry). This is absolutely certain, unless there is some fungicide present to kill the rot spores. It is therefore logical that, if some cladding helps to sustain a dampness in the wood, such as a ****** skin could do, the conditions for rot are worse than if the wood were completely soaked or left to dry out. The solutions mentioned that completely encapsulate the wood in the hull COMPLETELY, inside and out, every surface of every piece, seem to be the only ones that will work. And I wouldn't mind hearing more about the health concerns associated with living, eating and sleepping inside a wooden enclosure saturated with cuprinol or other such fungicide - you do hear some dire warnings about it - although I confess to putting a bit on the outside of the keel before bottom priming.
Anyway, hang in there, boneheads. 'Tis a far, far greater thing you do......"

capt jake
09-18-2001, 09:13 PM
Just to throw my two cents worth in. Don't torch the poor thing, the statute of limitations applies to everything EXCEPT; arson an murder! Don't burn her! work with your beloved and rebuild her to her former youth!

[This message has been edited by capt jake (edited 09-19-2001).]

09-19-2001, 12:17 PM
Jake & Pat, thanks for the moral support. In all my years of boating I've been avoiding wood. Actually my first boating experience was as a teenager when I owned a 12 ft. wooden skiff powered with a 10 horse Mecury. As I remember that boat suffered from some pretty severe rot, but never left me to swim home.

Just to bring anyone reading this string up to date. The boat is pretty well stripped of all her fiberglass (I don't mind using the f******** word). She's about to be housed in a weather proof building for this and who knows how many winters. I expect to be CPESing next summer along with removing the rot and patching.

In my experience with motorcycles, antique cars, and boats it's not so much arriving at the destination that's important. It's the journey. http://media5.hypernet.com/~dick/ubb/wink.gif