Glue for cedar strip boat

[Jack Barber]

I'm building a cosine wherry and the kits i have enquired about all list marine resin to glue the strips together.As the cedar will be coversd with a minimum of two layers of fiberglass and epoxy why would you use waterproof glue. It seems to me that any glue would work as the epoxy coating is waterproof. Any comments?
Jack Barber

[Canoez]

I'm building a cosine wherry and the kits i have enquired about all list marine resin to glue the strips together.As the cedar will be coversd with a minimum of two layers of fiberglass and epoxy why would you use waterproof glue. It seems to me that any glue would work as the epoxy coating is waterproof. Any comments?
Jack Barber

It would be both difficult and overkill to use a waterproof adhesive. If you have water attacking the glue used to hold the strips together in a Fiberglass/epoxy covered hull, you have bigger problems.

For cedar-strop canoes, we use either Titebond I or II adhesives to bond the strips together. Personally, I prefer the Titebond I as it is a bit more "brittle" and comes off nicely when fairing the hull after stripping. The Titebond II is a bit more water-resistant, but people here have noted difficulty in bonding to surfaces contaminated with the it (i.e. it doesn't bond well to itself) Most good wood glues that you would use for building furniture would do fine (but NOT hide glue....)

Some will go to the trouble to use polyurethane adhesive for specific applications such as laminating of stems, but I've had no problems using the Titebond for this purpose.

[Bob Smalser]

...I have enquired about all list marine resin to glue the strips together.As the cedar will be coversd with a minimum of two layers of fiberglass and epoxy why would you use waterproof glue. It seems to me that any glue would work as the epoxy coating is waterproof.

I recommend reading this. Water resistant is only part the problem.

Are Your Glue Joints Repairable?

I'd use epoxy throughout, but if I didn't I wouldn't use any glue not fully compatible with epoxy. UF Resin is, and is cheap, but except for the expensive imported flavor requires more clamping pressure than is convenient using strips. Polyurethane is, but is expensive, and except for the thick construction adhesives is a relatively weak glue. Resorcinol is, but also requires lots of clamping pressure. Titebond however, isn't compatible at all.

Titebond is cheap and convenient, but no other proven marine glue sticks to it if you one day have to repair the boat using a feathered-edge patch. Look at the width of the glue residue in the fresh, laminated mahogany feather edge with the bevel resting on it....gluing it in place using an incompatible glue would problematic, and most holes in strippers will have much more old glue residue to glue over:

[Canoez]

I recommend reading this. Waterproof isn't the problem.

Are Your Glue Joints Repairable?

I'd use epoxy throughout, but if I didn't I wouldn't use any glue not fully compatible with epoxy. UF Resin is, but requires more clamping pressure than is convenient using strips. Polyurethane is, but except for the thick construction adhesives is a relatively weak glue. Resorcinol is, but also requires lots of clamping pressure. Titebond however, isn't compatible at all.

Titebond is cheap and convenient, but no other useful glue sticks to it if you one day have to repair the boat using a feathered-edge patch. Look at the width of the glue residue in the fresh, 2-lam feathered edge....gluing it in place using incompatible glues would problematic, and most holes in strippers will have even more old glue residue to adhere to.:

First, using epoxy to bond strips would be a pain in the butt. The same with Polyurethane, Resorcinol and perhaps UF resin - if it is going to be a "clear finish" those might be difficult to clean up as they penetrate pretty well.

Bob, I don't know exactly what you mean about "compatibility" with epoxy, but we've never had issues with putting a layer of fiberglass and epoxy on canoes built with Titebond I, Titebond II, Elmer's Glue-All and other "carpenter's" type glues... Nor have we seen any long-term problems with bonded areas on either the inside or outside. Countless other canoe builders have had the same experience. It works.

On something larger than a cosine wherry, you may have a good point, I don't know.

I think you may be making a blanket statement there regarding the Titebond. I've had decent luck with Titebond I sticking to itself for repairs and haven't tried to bond Titebond II to itself.

[esingleman]

"and except for the thick construction adhesives is a relatively weak glue."

What is the current feeling on polyurethane construction adhesive for boat building applications? I remember a thread a few years ago where people were talking about its potential but there was no real history in boat building to go on.

Seems to me some simple testing would prove or disprove certain applications. Isn't 3M 5200 basically a polyurethane adhesive?

[Bob Smalser]

...but we've never had issues with putting a layer of fiberglass and epoxy on canoes built with Titebond I, Titebond II, Elmer's Glue-All and other "carpenter's" type glues... Nor have we seen any long-term problems with bonded areas on either the inside or outside. Countless other canoe builders have had the same experience. It works.

I think you may be making a blanket statement there regarding the Titebond. I've had decent luck with Titebond I sticking to itself for repairs and haven't tried to bond Titebond II to itself.

I agree it's not a problem in an intact boat. The Titebond gluelines are very thin, and the glass and epoxy spans them but doesn't stick.

As I said the potential problems are in feathered-edge repairs, something that may never be needed with most boats. But I don't recommend ignoring the potential problems. What you get by with may be a disaster for someone else. Test your rebonded Titebond glue joints and see how strong they are. They certainly don't hold up very long in chair repairs. There are no shortage of furniture restoration specialists who'd like to know how to solve one of their biggest banes....how to repair original hide glue and resin joints reglued with Titebond without recutting the joint.

I've found cyanoacrylate glues will relglue Titebond residue, but they are so brittle they are useless in general construction. PL Premium Construction Adhesive has a high cyano content, and that appears to reglue Titebond residue too, but I'd hesitate before using it on a fine antique that may have to be dismantled for further repair several decades hence. But if I had to apply a patch to a Titebond-glued boat, that's what I'd probably use, because nothing else sticks well to Titebond glue residue, even more Titebond.

[cs]

My first canoe was a doug fir stripped Micmac that was glued with Titebond and clamped with duct tape and sheathed in fiberglass and epoxy and it has held up fine.

On the 10' cedar strip pack canoe I will be using Titebond III.

(for some reason I can't get the photo to upload)

Chad

[Canoez]

I agree it's not a problem in an intact boat. The Titebond gluelines are very thin, and the glass and epoxy spans them but doesn't stick.

As I said the potential problems are in feathered-edge repairs, something that may never be needed with most boats. But I don't recommend ignoring the potential problems if you're doing this commercially. Test your rebonded Titebond glue joints and see how strong they are. They certainly don't hold up in chair repairs. There are no shortage of furniture restoration specialists who'd like to know how to solve one of their biggest banes....how to repair original hide glue and resin joints reglued with Titebond without recutting the joint.

I've found cyanoacrylate glues will relglue Titebond residue, but they are so brittle they are useless in general construction. PL Premium Construction Adhesive has a high cyano content, and that appears to reglue Titebond residue too, but I'd hesitate before using it on a fine antique that may have to be dismantled for further repair several decades hence.

On the highlight - been there, couldn't do it.

Cyanoactrylate adhesives (at least in my experience with medical devices) don't stand any moisture. They turn chalky in a big hurry and fail.

When we repair strip construction, we ususally have some small form scrapers to clean and reform the cove and bead. The scrapers, BTW are usually made from old Stanley utility knife blades ground for our purpose.

We start by removing the de-laminated glass and we cut back the wood from the damaged area, remove most of the material to the next "good" joint and scrape away to bare wood using the form tools. We then stagger feathered repair joints to avoid a weak or unfair spot and then clean up and re-glass. When the repair is done, it is with Titebond and all the joints are clean wood surfaces glued to clean wood surfaces. The toughest part is to get the repair pieces in without splitting more of the hull.

I think it works pretty well - at least for a small hull.

I'm going to spread a large zone of a few glues on a board and see how a layer of fiberglass and epoxy sticks.

Question, Bob - did you "rough up" the surface before trying to re-bond in your previous tests or just leave the surface "as-is"?

[Bob Smalser]

Question, Bob - did you "rough up" the surface before trying to re-bond in your previous tests or just leave the surface "as-is"?

Yes.

And surprisingly, I had a lot of unexpected trouble getting fresh West epoxy to bond to cured West epoxy. I found I had to wash off any traces of amines raised to the surface by sanding using soap and water. Regluing resorcinol, poly and UF resin using epoxy were in cinch in comparison. Reglued Titebond joints using either epoxy or more Titebond could be broken apart using fingers. Heat helps when gluing new Titebond to old Titebond, but the joints don't last if there is any stress on them.

Can you make a sound, feathered-edge repair to a Titebond stripper using more Titebond covered by glass? Perhaps. But not as sound as an epoxy repair to an epoxy boat.

[Canoez]

Yes.

And surprisingly, I had a lot of unexpected trouble getting fresh West epoxy to bond to cured West epoxy. I found I had to wash off any traces of amines raised to the surface by sanding using soap and water.

That's funny - which West System resin/hardener were you using? They claim that the 105/207 product system is "Blush Free..."

[Bob Smalser]

That's funny - which West System resin/hardener were you using? They claim that the 105/207 product system is "Blush Free..."

I was using 105/205. Not blush free. But using 207 I'd wash off the joints anyway just to be sure.

[kc8pql]

Way back when I was a little shaver a furniture restorer/conservator took me under his wing and gave me my first real lessons in quality woodworking. His first and cardinal rule was never try to glue glue to glue. The first step was always to remove the old glue, even if it meant cutting a tenon or whatever down and adding a piece to get back to the proper thickness. I've followed this rule for a long time now and have never worried about a repair not holding. This business of what glue sticks to what isn't important. You shouldn't be doing that anyway.

[BrianR]

i built a Melonseed using strips and titebond. No problem at all. I sandwiched the strips with epoxy and glass too.

[Bob Smalser]

This business of what glue sticks to what isn't important. You shouldn't be doing that anyway.

Really? That's why hide glue remains the best choice today for those round-tenon chair joints that break every 20 years. You can easily renew it atop itself, and also dismantle and reassemble the chair to do it properly.

And it's impossible not to glue over glue residue applying a feathered patch to a stripper.

[George Roberts]

Titebond is easy to reglue with titebond.

One applies fresh glue and then applies heat.

A simple test of the technique is to apply titebond to a flat surface - clamp together wood, glue, waxed paper, and more wood. After the glue cures remove the waxed paper and let the glued surface age for a few weeks or years. Clamp together the wood/glue from the above with fresh glue and wood. As the glue cures apply heat. Let cure and cool. Do a sample test.

[Canoez]

Based on the Franklin website data:

Bond Strength ASTM D-905(On Hard Maple)

Temperature Strength psi % Wood Failure
Room Temperature 3,750 72
150°F. Overnight 1,750 6

Doesn't look like heat improves the bond strength in this test.

[Todd Bradshaw]

Chair joints have nothing to do with stripper construction and neither do feathered-edge repairs. When you repair significant damage to a stripper you cut out the old strips, stick some sort of temporary forms behind the hole, glue some new strip bits in there using butt joints, little scarfs and/or bead & cove edges if you have them, fair the wood and glass over it, inside and out. The main strength of the whole works is the fiberglass in a very big way.

Tightbond or similar carpenters glues work fine for most people. I don't like them because they get gummy when attacked with a big disk sander which is what I've always used for sanding both the wood core and the fiberglassed hull. My favorite glue for strip-to-strip joints is Weldwood UF powder mixed with water. It's cheap, it sands well because it's fairly brittle, has decent gap filling capabilities without running out on the floor, good, wood-like color (just in case any of those gaps show a bit on tight curves with square-edged strips) and strength-wise it's perfectly adequate to do the job. I actually don't know whether they still even sell it as I've been using the same big can of it for decades. I have boats that are almost 35 years old made that way and they're doing just fine. If your stripper breaks, the strip-to-strip glue joints in the core are not the reason - or the problem.

[Bob Perkins]

When I did my strip canoe 10+ years ago - I used a brown powder glue that I mixed and put in a little plastic syringe and squirted into the cove. It was not Weldwood - but sounds like the same thing.

It dried hard and brown, I could mix exact amounts and it cleaned up with water. After drying - it was rated as water proof, not that it matters in a glass covered boat.

I've heard that Titebond - in the Sun - doesn't always behave well in a strip canoe. But I have never seen it myself.

For glassing - all of the best canoe finishes at the WoodenBoat show (and now on my project) used MAS epoxy.. it wets out better than West System, it is easier to use and you can't see the glass fabric once done..

Good luck

[Thorne]

I think that Bob Smalser's point is that discussions like this create recommendations that tend to get applied more widely than they should, hence the bits about chair legs and edge gluing.

In a totally sealed strip boat you might be able to 'glue' it up with chewing gum, provided the fiberglass never leaked == but that's not a good general adhesive for boatbuilding.

;0 )

For example, folks on this forum recommended that I use Weldwood resin to glue up the two DF 2x4's for my mast.

I didn't get either the required clamping pressure, temperature, or both = so the glue failed at the base. So knowing that I couldn't overglue that adhesive, I cleaned it out and reglued with epoxy (which I would have used in the first place).

[Bob Smalser]

Chair joints have nothing to do with stripper construction and neither do feathered-edge repairs.

They do when someone takes hasty recommendations originating with lightweight kayaks and transposes them to a much larger boat. A 12' canoe loaded to 180lbs doesn't hit waves and obstacles with anywhere near the force of a 18' sailboat loaded to 700lbs or more.

But you are right....these aren't chairs, they are much more important. You can probably get away with a lot if the wherry is only 12' and 100lbs. But Jack if you are planning a boat even slightly larger than that and you want it safe for your family, don't take shortcuts. Scarf instead of butt your strips and use only proven marine glues. The thought of a heat-bonded Titebond glueover protecting your family in a stiff breeze crossing a ferry lane makes my pits sweat.

[Canoez]

For a (relatively) light weight hull fabricated with cedar strip, the glue joints we are talking about will be much stronger than 1/4" or 5/16" thick cedar strip. When we see failures, we don't see it at the glue joints, we see it through the cracking and crushing of the wood fiber and delamination of the fibeglass and epoxy coatings. This type of construction is pretty tough, all in all, and even these types of failures are rare. Repairs, as we have noted should be done with proper methods and take the surfaces back to bare wood, bond them in and re-glass.

Strip-built boats that are designed to have fiberglass reinforced epoxy on the inside and out are a stressed-skin composite and the strength of the hull lies in the reinforced fiberglass, not the core wood. Ultimately important is the right weight/type of cloth for the hull size and design.

If the designer calls for special materials and adhesives, by all means use them as it only makes sense. If they've left it up to the builder or it is ambiguous, I'd call the designer and see if they can clear up the choice of materials, adhesives coatings, cloth weights and the like.

[George Roberts]

"if you are planning a boat even slightly larger than that and you want it safe for your family, don't take shortcuts."

Looking at the scantlings that several engineers have published ....

There is no mention of glues to use or to avoid. The only issues that relate to the overall strength of a strip built boat are:

The core thickness and the ratio of core thickness to face thickness.

[pcford]

I think that Bob Smalser's point is that discussions like this create recommendations that tend to get applied more widely than they should, hence the bits about chair legs and edge gluing.

In a totally sealed strip boat you might be able to 'glue' it up with chewing gum, provided the fiberglass never leaked == but that's not a good general adhesive for boatbuilding.

;0 )

For example, folks on this forum recommended that I use Weldwood resin to glue up the two DF 2x4's for my mast.

I didn't get either the required clamping pressure, temperature, or both = so the glue failed at the base. So knowing that I couldn't overglue that adhesive, I cleaned it out and reglued with epoxy (which I would have used in the first place).

Not good. Weldwood always fails in a marine environment, it's just a matter of time.

[George Roberts]

"Doesn't look like heat improves the bond strength in this test."

What the heat does is reactivates the old glue so that new glue will bond with it.

[Bob Smalser]

Looking at the scantlings that several engineers have published ....

There is no mention of glues to use or to avoid. The only issues that relate to the overall strength of a strip built boat are:

The core thickness and the ratio of core thickness to face thickness.

Yes. And the tighter the engineering, the more perfect the construction required.

Most of these failures in hull sandwiches were well-engineered, but they were built by inexperienced labor:

http://www.yachtsurvey.com/core_materials.htm

[Todd Bradshaw]

Bob, you are not thinking in terms of a cored, hybrid wood/composite construction - which is exactly what the wherry will be. As Canoez mentioned, the weak spot in the core is the grain strength of the wood, which will be exceeded by just about any glue. The strength of the construction is the fiberglass sandwich. The core is primarily there as a spacer to separate the load-bearing layers, creating hull rigidity. This is why you can build a Farrier F25A trimaran from a similar construction, but use 1/2" foam for the core with glass on both sides and it will stand up to in-use forces that are probably fifty times what this wherry will ever experience.

For wooden-cored boats, I'll offer this one. It's 22' long and holds up to six or seven adults empty or four to five with their camping gear. It has 1/4" strips on the sides, 5/16" strips on the bottom, glued with weldwood UF powdered glue. It has ten ounce glass on both sides, doubled over the bottom and is so old that I built it before boatbuilding epoxy became available using Techniglass 329-2 polyester laminating resin. Weight is about 145 lbs. It's up in the loft of my garage, sitting upside down on horses getting some fresh paint and varnish work done if you would like to stop by and jump up and down on the bottom. The boat won't mind.

[Bob Smalser]

Bob, you are not thinking in terms of a cored, hybrid wood/composite construction...

What I'm thinking of and basing my advice on is a first-timer constructing it.

Think all those dozens of glue joints will be perfectly done and no work will be done twice? Epoxy remains the most forgivable and the most repairable glue out there.

[Todd Bradshaw]

No, I'm just about positive that the glue joints won't all be perfect and in some spots they will likely be barely even strong enough to hold the wood together. But with this type of construction it really doesn't matter because the wooden core is not providing the strength, impact resistance, or transverse stiffness of the hull. The laminations on either side of the core are doing it. If you could figure out how to hold the strips in alignment while you faired the core, you could build a canoe, kayak or small-to-medium-sized boat (including this wherry) from this method without even glueing the strips together and as long as the designer had his glass scantlings right, it would be just fine. This is why these boats and boats like the Farrier trimarans can also be built from downright flimsy core materials like Duracore strips (finger-jointed balsa strips with a thin veneer face) and from foam-cored constructions - and generally without making any major changes in the composite layup if it's correctly designed in the first place.

If you want to emphasize safety and solid, high-quality construction for boats of this type, the thing to aim for is urging people to learn how to do high quality fiberglass work and to learn what makes it such. That's what will make these boats strong and safe, and that's nearly always the source of the problem when failures happen.

[Canoez]

If you want to emphasize safety and solid, high-quality construction for boats of this type, the thing to aim for is urging people to learn how to do high quality fiberglass work and to learn what makes it such. That's what will make these boats strong and safe, and that's nearly always the source of the problem when failures happen.

Agreed.

In addition to doing this high quality fiberglass work is not to try to use lighter weight materials and cloth than have been called for by the designer. As Todd has mentioned in previous posts - people often cause problems by using a lighter weight cloth on the INTERIOR of this type of hull construction than recommended.

Also, when starting a project like this, most people are familiar with using wood glue. They tend to be able to get halfway decent results from it. If you start someone using a new adhesive that they are unfamiliar with and don't necessarily have a full understanding of how to get good results from (as Thorne noted) it can be even more difficult to get good results. Better to avoid making the learning curve any steeper than it has to be.

[CundysHarbor]

Since no coating (fiberglass in epoxy for example) is totally waterproof when exposed to constant imersion, why would anyone even think about using a water soluble glue to build a boat? I would not use carpenter glue for any boat hull, whether she is kept in the water or on a trailer. But then, I hate to think about going for a boat ride and having to swim home.
Dave

[Canoez]

Since no coating (fiberglass in epoxy for example) is totally waterproof when exposed to constant imersion, why would anyone even think about using a water soluble glue to build a boat? I would not use carpenter glue for any boat hull, whether she is kept in the water or on a trailer. But then, I hate to think about going for a boat ride and having to swim home.
Dave

Good question. As has been noted above, the strength is really in the skin, the bond of the skin to the core and the core's thickness. (side note - As an engineering student, I was amazed to find out that the stresses in the center of an I-beam's web are virtually zero. Stressed skin construction has some of the same merits of an I-Beam in terms of stress distribution - tension or compression on the outside and shear where attaching to the connecting web.)

If your arguement that water migration through epoxy enough to damage the core materials held water, I'm sure that you wouldn't see this type of construction used at all. In addition, I'm sure that you would see that marine insurance companies would refuse to insure all sorts of boats including fiberglass with balsa core.

It's all about the rate of water migration through the epoxy to the core materials. If it wasn't insignificant, you would see the wood core breaking down as well as the adhesive failing. We've noted here and in other threads that if the skin is compromised enough to admit water, you have other problems.

Besides, the Titebond II adhesive (as well as other "wood glues") are considered water-resistant and applicable for use on projects used outdoors.

[Frank E. Price]

Never built this way, but I am curious. Do I understand correctly that essentially a boat built with the construction method used in the Cosine Wherry is not really a wood boat, but is a cored double skin resin and fabric boat, whose core happens to be wood?

Frank

[cs]

Correction, it is really a wood boat, it is just a wood composite boat.

Chad

[kc8pql]

As is cold molded wood/epoxy in all the various flavors.

[Todd Bradshaw]

We could spend years discussing what is or is not a "wooden" boat. It's been done here in the past and for the most part, it is a total waste of time. A stripper-built wherry or canoe, kayak, drift boat, sailboat, etc. is a hybrid wood/composite structure where the skins do most of the strength work and the core spaces them apart. The distance created by the core separating the skins allows the hull to gain sufficient rigidity with far less fiberglass than would be needed to build a stand-alone glass hull. If you removed the glass layers from a stripper and examined them, you would find them to be about as solid as a plastic milk jug. The core structure is not strong enough to be a boat without the glass and the glass layers are not sufficient to make a boat without the core. However, once you get the proportions right with the proper amount of core and the proper amounts of glass skin, the result is a light, stiff and generally pretty durable boat.

Materials other than wood could be substituted for the core and composite materials other than fiberglass cloth could be substituted for the skins. Woods like cedar, spruce and other softwoods just happen to be some of the better materials for coring this type of construction. They're a nice blend containing a certain amount of lengthwise stiffness, crush resistance, gluability, reasonably light weight, easy availability, good workability with simple tools, moderate cost and when sheathed with epoxy/fiberglass, decent sheer strength that keeps the glass from delaminating - oh...and wood also looks nice. The other available core materials that would do the job - mostly various foams along with some exotic constructions like paper or aluminum honeycomb coring or sheets of end-grain balsa blocks held together with a light scrim (those stale little marshmallows in Lucky Charms would work if you glued them together into sheets) fall short of plain old wood strips in some of these criteria and are usually less desirable for most boats. If your goal is a twelve pound, 16' solo marathon racing canoe, then you'll probably be looking at carbon fiber with honeycomb coring and you'll be praying you don't hit anything but for a general purpose boat, especially one that you can build yourself, plain fiberglass over wood strips works pretty well if it's properly built. It can also be quite easy on the eyes. Is it technically a wooden boat? Hell, I don't know and don't much care. It's certainly not traditional, but if you were to find a nice one and could somehow extract the wood out of it, what's left wouldn't be a boat.

[KMacDonald]

I really dont think it makes much difference what glue you use. In my case I chose epoxy but WS tech support even said titebond works well. The glass on the inside and outside will hold the strips together without any glue between the strips as Todd said. The glass is the strength around the hull and the strips are the strength in the for and aft direction. If the strips become saturated with water, its pretty much game over for that hull reguardless of the glue used.

I chose epoxy because EVERYONE agrees it is well suited for this purpose but only SOME people agree that titebond is suitable.

[Thorne]

As Todd says, trying to define "wood boat" is a waste of time.

My favorite thread on that was the one where we decided that the only pure non-composite wood boat was the dugout canoe...

;0 )

[Todd Bradshaw]

You should have been around in the early days of WoodenBoat (before the internet, forums etc.). Those of us building strip canoes were treated like the bastard step-children of the wooden boating community. The folks running the magazine were OK, but many of the readers treated us as if we were some sort of charlatans building fake wooden boats and trying to swindle unsuspecting buyers with them becaused they contained fiberglass, too. Woodenboat ran an article in late '79 or early '80 (#31 I believe) on Ted Moores and the strippers he was building at the Bear Mountain Canoe Company and some of the letters to the editor in following issues were pretty nasty. These were from subscribers who were offended that WB would promote these "fiberglass-covered fakes".

I'm sure that there are still subscribers (and most likely a few forumites) who still feel that way today. My advice to them is that they need to get out more. The folks at WB seem to have realized decades ago that strip builders buy magazines too and in general, they've always been pretty decent about including them and not trying to draw lines in the sand that can't be crossed.

There was a letter to the editors, I believe in the following issue (#32) from a woman named Deborah Hogue (sp?) complaining about the Bear Mountain spread that really pissed me off. I wrote a rebuttal that they printed in the letters to the editor of the following issue (#33) if anybody has a copy. I don't remember exactly what I wrote, but I believe it was pretty close to the last post I made here. If nothing else, I'm pretty consistent.

[Canoez]

I'm afraid to say, Todd, that I'm not sure much has necessarily changed in the way of attitudes about this method of boat construction. I've even heard people talking in a similar manner about plywood lapstrake.

Still, I think it's important for people here to know that the recommendations that I've made here are based on both my own personal experience and that of professionals who are doing strip construction who recommend using "carpenter's" type glues for construction. These professionals include David Hazen, Mac McCarthy, Gil Gilpatrick, Ted Moores and others who have literally written the texts on the subject and build the boats regularly.

Newfound Woodworks has this to say in an Acrobat file about building strip boats on their website:

We use carpenter’s wood glue to glue the strips together. Either Elmer’s ProBond or Titebond. We are currently using Titebond III. We don't use epoxy in this situation because of the pot life and clean-up. Waterproof glue is not required. The epoxy and fiberglass on the outside is all the waterproofing required. Because of this it is easier and safer to use the simple carpenter's glue. It is plenty strong enough.

I guess I just find myself frustrated that people choose to throw away the experience of others. The anecdotal evidence for successful strip construction with carpenter's glue speaks for itself. When is the last time you heard of someone in a glass-reinforced strip hull experiencing a hull failure on the water?

You can lead a horse to water...

[erster]

Todd, that was a syrupy advertisement. So guys when will the canoists, purists and the misfit builders have a two page thread on canvas fillers? And then we can also talk about replacing canvas with fiberglass. Later.

[Tom Robb]

I think that one Bob's problems (ignoring questions about bigger boats on open water) with carpenter's glue was less with strength as built than with repairability where bonding to the existing glue lines is chancy at best.
This strikes me as an apples-v-oranges discussion.
What about Bob's question? Is repairability a problem?

[Canoez]

Erster, we already do. It's called the WCHA. Don't think those aren't hot-button issues over there.

Tom, I think if you'll look at post #8, you will see that those issues are addressed here. Also, as we've noted, any damage will be covered using fiberglass saturated with epoxy, so the area with the repair is of similar construction to the rest of the hull. When the cloth is put on, the patch is feathered out into an area larger than the damage. This lets the new epoxy and fiberglass bond to the old, prepared surface. Also, the basics of woodworking in getting a good clean surface to bond to still apply here, but once the glass is in place and bonded to the bare surface of the wood, it's not going to be a problem.

I think for Bob's concern to manifest itself, the bonding surface for the epoxy and cloth would have to be contaminated with the glue. As the repaired surfaces need to be faired and sanded before epoxy and cloth, I don't see how this is an issue.

[Todd Bradshaw]

Well gee, I actually own a wooden Old Town 16' Guide that I bought new in 1972 and eventually replaced the defective factory canvas job with WEST epoxy and a layer and a half of six oz. fiberglass. It's not my first choice in constructions for that type of boat, but it seems to work pretty well and still looks quite presentable for a 36 year old canoe. If somebody has nothing better to do we can spend the weekend arguing about that one and whether or not it's a wooden boat, too.

[erster]

Pretty work.... I too own an 1962 that I did the same thing to and is almost in the same condition as your boat, Todd. This early spring I attempted to sell it for very reasonable price and also contacted a fellow in Maine that is also familiar with them and was able to read the disdain in his reply. When I advertised it, I also had an individual that offered me almost double for it since it was purbreed wood as he stated, if I would cut it in half and make matching bookcases with it. Go figur,
Canoez, I have been following the canvas filler thread, the most recent one, causing me to insert the bit of sarcasm on this one.