Glue for strip construction

[Ted Schmidt]

HI, this is a repeat post. The first time I posted on the wrong forum. I am getting ready to start stripping the hull on an Elver I am building and wanted to get some suggestions on the type glue to use. Epoxy would be the strongest and most expensive way to do it. But I am wondering if titebond III would work if I glassed the hull anyway. It seems epoxy would be overkill.
The other option is to use epoxy between the strips and then just varnish the hull and not glass it.

[JimD]

If it were me I would epoxy glue and sheath with your fabric of choice, not necessarily fiberglass.

[Tom Hoffman]

I have been building a 20' Whitehall pulling boat, using 3/8 X 3/4 strips bead and coved. I have been using Titebond III and it has been very satisfactory, info recently posted here on the forum under the topic adhesives, further down the page gives it testing history it seems that they have worked very hard to make it as strong as possible for a one part waterproof glue, if you are going to leave the wood un-fiberglassed and use the glue joints themselves to hold the boat together, then I would agree with the previous post and go with epoxy glue. Otherwise if you are going to epoxy and glass over the boat, I think you will find Titebond III is very strong and very economical too. E-mail me and I can send you a PDF File with all the Titebond III info in it.

tomhoffman@starband.net

[George Roberts]

I let everyone make their choice. (Perhaps you should follow the designer's suggestions.)

I think there are some issues with epoxy and wet wood.

[RodB]

Yes check with the designer. He should have feedback and experience with this design and how specific construction procedures have held up.

I would think in many cases the fiberglass cloth plays a structural part of the construction not to mention the tremendous amount of protection offered by the sheathing. Additionally, in many cases a hull would be considered to not be a "balanced" structure if the entire structure is not sheathed (ie., if you are going to sheath part of it sheath it all...).

RB

[Jamaica Mike]

I built a strip canoe over 25 years ago using a glue very similar to Titebond, and covered the boat with glass and epoxy. Still tight as a drum and no troublles.

One thing I did notice, when I was finishing the outside of the hull using a small (very sharp) hand plane, the dried glue beads from squeeze out were cut right off with no touble. This has not been my experience with epoxy.

[Charlie Santi]

I built a strip kayak a few yews ago and I used Titebond II and was very pleased with the results.

[ssor]

I have glued cypress scraps with titebond 2 and thrown them out in the yard for weathering and after several years I found that the pieces were still intact.

[Venchka]

Originally posted by ssor:
I have glued cypress scraps with titebond 2 and thrown them out in the yard for weathering and after several years I found that the pieces were still intact.Ross,

Wouldn't that test be more useful if you anchored one end and hung a weight on the other end? Maybe a damp, constantly loaded joint would behave differently?

Buried somewhere in Building/Repairs is Norm's account of building Prairie Islander with red cedar strips, Titebond II, 1/8" oak dowels and glass cloth outside and I think inside as well. By all accounts, the system worked.

Wayne
In the Swamp. :D

[ssor]

Wayne, I once glued some tongue depressers in pairs in a "vee" shape with titebond 2 and 3 and with probond polyurethane and generic epoxy let them cure for a week and then put them in water to soak for a week. When I tried to take them apart the tite bond failed but the urethane and epoxy broke the sticks. I think that titebond will survive soaking and drying but not high stress while wet.
Ross in Bel Air

[ 05-30-2005, 10:06 PM: Message edited by: ssor ]

[Venchka]

Thanks, Ross. Kinda what I thought. On the other hand, with edge nails or dowels, epoxy and cloth, I reckon the Titebond is just one of 3 things in a complex matrix holding the strips together.

Wayne
In the Swamp. :D

[ssor]

With an epoxy and cloth sheath it should stay reasonably dry. The bond you get with titebond adhesives is stronger than the wood in most cases and very forgiving of less than perfect joints and careless clamping.

[Doug Canada]

Assuming that you will be glassing inside and out.
The type of wood glue is some what important.
Things you may want to consider;
-good physical and / or chemical bond.
-colour of glue so that it matchs your wood.
-sanding properties!
-cost

I do not believe you need a waterproof glue if you are glassing the hull.
I may be concidered over kill and expensive.

I have used Titebond II and a Lee Valley cabinet makers glue on my canoes & kayak with success.

Good luck,
Doug

.

[Bob Smalser]

You fellas tested this new glue to see if you can glue over it? How do you figure your hulls will be repaired some day?

Epoxy is by far the best glue to repair. Resorcinol glues over....so does urea formaldehyde and polyurethane.

Titebond and other aliphatic joints can only be repaired by cutting back to fresh wood...and that may be tough when there is one gluejoint per inch.

Picture the hull being holed and you have to feather in a large patch. Then you'll have sound epoxy bonds on fresh wood riddled with unsound pinstripes at every plank edge.

And just what is the small-boat price difference between a repairable hull and a premature marshmallow roast? If it's 75 bucks I'll eat my hat....Titebond ain't free either.

[ 06-23-2005, 10:27 PM: Message edited by: Bob Smalser ]

[Andrew S/Y Rocquette]

Rocquette was built in 1964 with 2 layers of thin carvel planking edge glued and Resorcinol-glued between the layers, with seams in the outer planking falling in the middle of the inner planking. Still holding tightly 41 years later...

[Jim Mathieson]

Titebond 3 's label reads.... not recomended for use below the water line.
I'd go for Epoxy.

[Bob Smalser]

Originally posted by Bob Smalser:
You fellas tested this new glue to see if you can glue over it come repair time? Guess what I'm gonna do this week?

http://pic3.picturetrail.com/VOL12/1104763/7738131/101844452.jpg

[ 06-23-2005, 10:34 PM: Message edited by: Bob Smalser ]

[Venchka]

Thanks, Bob. Your efforts are appreciated. By this wannabe Cajun anyway.

Wayne
In the Swamp. :D

[RonW]

Hey Bob, just as a pont of info, I don't recognize your brand of polyurethane. But at any rate it is a bottled polyurethane, and all of these that I have tested I have been sadly dissapointed in their strength. All that I have seen, say dampen the wood, the moisture activates the poly and it also foams, with the worse offender being gorrila glue, that in my opinion is a joke.
Anyhow I am a fan of the polyurethanes, but I believe in the tube polyurethanes, not the bottled ones. I have found the tube ones, like P.L.premium to be much stronger then the bottled ones. But most people put it on way too thick, which lessens it's strength. As for glueing over, I think you will find a lot of wood rippage, and I would clean the joint up, at least to some degree, which shouldn't be that hard to do, unlike aliphatic as you say.

[Bob Smalser]

Elmer's Probond poly.

Poly's require the right amount of moisture and a whole lot of clamping pressure. I've had excellent results with them when I got that right....and bad results when the wood was too wet or the clamping insufficient.

Same with epoxy....dollars to donuts most of the epoxy failures even old pros talk to are because there was too much clamping pressure, resulting in a starved joint. Easy to do when pulling in a joint that's "out" a bit with clamps....and especially so when working with thick stock.

Gluebond strength is relative....few glues are as strong as resorcinol, but they only have to be strong enough to do the job. Some of the longest-lasting glue joints in museum furniture are tabletop layups with weak hide and fish glues now 400 or more years old.

My issue with glues is in repairs...not raw strength....something I've never seen manufacturers or the USDA talk to, but something repair folks have to deal with every single day. Can their joints be reglued using epoxy when the faying surfaces are still contaminated with the old failed glue?

It's real simple. If your work can't be easily repaired, it will have limited life and limited value.

[ 06-24-2005, 12:17 AM: Message edited by: Bob Smalser ]

[RonW]

You are right, repairability is not being disscussed. And I will throw in another one. Ease of use with reliable and consistent results. Glue starved joints are the number one reason for glue line failure.
And since it is a boat, you can add a few more problems like, waterproof, U.V. resistant, flexibilty, lifespan.

Going back to the original question on strip planking a elver, I will suggest using square strips, with the vertical grain to the outside of the hull and properly pinned and fitted strips, there is no need to use glue at all. Just paint it, no epoxy and cloth either.

You don't need glue for a carvel hull, or traditional lapstrake, double planked or strip planked. Maybe we have become too dependent upon glue and use far too much of it, and cry when it fails.Not trying to be a hard core traditionalist, but most things have a lifespan and limit to their abuse ability, or missuse.
But most of us just don't have the nerve not to stick a little goo in the joint for added piece of mind and so as not to become fish food.

[pjwalsh]

I think I would go with epoxy on an Elver - Titebond II is probably just fine on a small boat like a canoe or whitehall that will be glassed on both sides and I know many stripper canoes are built this way. However, the Elver is big enough that I would want a strong, tough and durable adhesive between the planks to ensure that they are working in unison to support the sailing loads. Titebond II is strong, but not particulary tough and not as water resistant as epoxy.I have noy used Titebond-III but just the fact that there is a III version implies that II is not the last word in water resistant glue. Also, in my view, the gap filling ability of thickened epoxy would be enough of an advantage by itself to justify its use.

On urethane glues, I am with with the previous poster - although the adhesive qualities are very good the mechanical strength is compromised by the foamed glue line.

Drop Steve Redmond a line and get his ideas. He is very practical about materials selection and design in general.

[ 06-25-2005, 10:28 AM: Message edited by: pjwalsh ]

[outofthenorm]

Bob, any chance you could include some PL Premium adhesive in your test?

- Norm

[Bob Smalser]

I hadn't even considered construction adhesive goo's akin to 5200....I'll have to think about it as they aren't the same critters as what most consider as glue.

They also take a couple weeks to cure.

[ 06-25-2005, 10:23 PM: Message edited by: Bob Smalser ]

[outofthenorm]

Re: PL Premium. There's been so much back and forth about the tube version of Poly glue, I'd be real interested in a side by side comparison to all those "real" glues. Inquiring minds and all that.

[RonW]

They also take a couple weeks to cure.

Sorry but on my tube of P.L.Premium it says,--
Many applications will develop full strength in less then 24 hours.--

It has always been my experience that it does.

[Meerkat]

I've read that one good way to test glues is to glue up your test piece, let it dry completely and then cycle it through your dish washer a half dozen times. Think of it as accellerated life testing ;)

Also said to be good for testing plywood quality.

[ 06-26-2005, 04:04 AM: Message edited by: Meerkat ]

[Bill Bliss]

I used regular PVA for building my strip-planked dinghy -- it was what the designer recommended and is commonly used for canoes. Since my boat is stored dry, I think this suffices.

I look forward to seeing the results of Bob's test. I used epoxy for all joints other than the plank edges (I even used epoxy to join planks to transom and stem). I used epoxy successfuly to bond white oak as well -- although I have since learned that there are issues with this.

I once tossed a small epoxy-bonded scrap of oak into by steambox while steaming an oak stringer -- it fell apart with no effort. I don't know if this was beacause of the oak or the heat or both. but, definitely, one of the limitations of epoxy is heat-endurance.

-wcb

[Venchka]

Originally posted by Meerkat:
I've read that one good way to test glues is to glue up your test piece, let it dry completely and then cycle it through your dish washer a half dozen times. Think of it as accellerated life testing ;)

Also said to be good for testing plywood quality.Or 6 months even.

Wayne
In the Swamp. :D

[George Roberts]

Repairs can be done in many ways.

The titebond types of glues seem to do well at repairs if the new glued areas are heated to the heat deflection temp and then allowed to cool.

The epoxies will bond together but getting the underlying wood dry may be difficult.

6 problems with one half dozen with the other.

[Bob Smalser]

OK....bought a tube of PL Premium on the way home from church and I'll include both it and 5200 as a comparison. 24 hours for the PL to cure and 7 days for the 5200.

All I'm gonna try to do is measure (more anecdotally than scientificly) whether epoxy bonds to these cured glues by whether the wood or the gluejoint breaks first.

[RonW]

Glues are a lot more technical then the general discussion on them ends up being on this forum.

If the test is to see how well epoxy glues over them, I question, and it will be interesting to see how things work out on the p. l. and much more interesting to see the results of the 5200. I question if it works very well particularly with the 5200. But on the other hand if you turn the experiment over, I am positive that the 5200 or P.L. will bond quite well to the dried epoxy.

That only tells you that certain glues can or cannot be used over certain other glues.

Unfortunately every time there is a discussion on boat glues, half of the posts relate back to brown carpenters glue being used between the strips of a 75 lb. canoe that is then covered in epoxy and cloth. A totally accepted and provened method, but defintely not the glue to be using on a 2,000 lb. and larger boat. Two different animals.

[Bob Smalser]

Unfortunately every time there is a discussion on boat glues, half of the posts relate back to brown carpenters glue being used between the strips of a 75 lb. canoe that is then covered in epoxy and cloth. A totally accepted and provened method, but defintely not the glue to be using on a 2,000 lb. and larger boat. Two different animals. Yellow glues? That's a heck of a stretch, don't you think?

What you hear from me is about repairability. Use a glue that can't be glued over well in a stripper, and you have a hull I can't make a sound repair to when the time comes.

Something few seem to think about.

[ 06-27-2005, 01:50 AM: Message edited by: Bob Smalser ]

[Popeye]

Originally posted by Bob Smalser:

All I'm gonna try to do is measure (more anecdotally than scientificly) whether epoxy bonds to these cured glues by whether the wood or the gluejoint breaks first.Bob, about how you measure breaking strength in glue joints: failure in axial ~ radial direction, by shearing force or failure in tension(?) , and consider also static and dynamic loads all affect performance.

There is simply not much information in a single point data set.

[Gary E]

Originally posted by Bob Smalser:
All I'm gonna try to do is measure (more anecdotally than scientificly) whether epoxy bonds to these cured glues by whether the wood or the gluejoint breaks first.Seems to me that testing of one glue adhering to another glue is a waste of time as that is not the way glue is really used.

The better test would be a tension and shear test, to see if the manufacturers claims are reasonable as long as the product is used per the manufacturers recomended intents. Anything else is just folly, sorta like testing weld up aginst a brazed joint in steel, or epoxy up aginst the weld, makes no sense.

[George Roberts]

I am going to join Gary E.

I am also going to suggest that perhaps the proper method of design is to take existing test data (and there is a lot of good data) and use that to determine if the glue is proper.

As I recall the wood types suitable for large boats are not the same as those that are suitable for smaller boats.

[Bob Smalser]

Originally posted by Gary E:
Seems to me that testing of one glue adhering to another glue is a waste of time as that is not the way glue is really used.
Originally posted by popeye:
...how you measure breaking strength in glue joints: failure in axial ~ radial direction, by shearing force or failure in tension(?) , and consider also static and dynamic loads all affect performance.
Originally posted by George Roberts:
I am also going to suggest that perhaps the proper method of design is to take existing test data (and there is a lot of good data) and use that to determine if the glue is proper.

As I recall the wood types suitable for large boats are not the same as those that are suitable for smaller boats.Y'all can consult any USDA Wood Handbook and get all the strength data you like....and the Navy Bureau of Ships Manual for small versus large application, etc.

What you can't do is consult any data I know of on whether a specific glue can be glued over in a repair.

Gluing over old glue residue to repair a joint certainly is how glues are really used....and they are used like that every single day all around the world in gazillions of instances.

Does your glue choice affect the repairability of your work over the long term?

[ 06-27-2005, 01:51 PM: Message edited by: Bob Smalser ]

[Alan D. Hyde]

That's a sensible question, Bob, for which your experiment should provide some useful answers.

Thanks.

I look forward to hearing the results, which I suspect will make resorcinol look pretty good...

Alan

[wyndham]

Seems like a perfectly reasonable test to me Bob. Repairability or lack there of saves or dooms plenty of boats every day.
As far as I know there are really only two glues that are used and have been used for boat construction from the get go. Resorcinol and epoxy. I'm talking about boats built with glue, not boats that are built with glue and then glassed over, just boats built with glue.
Funny how theres lots of glues that people are willing to toss out there for use, but when it comes to real applications like the bowsprit thread only two glues are seriously considered; epoxy and resorcinol.

[Popeye]

Originally posted by Bob Smalser:

Y'all can consult any USDA Wood Handbook and get all the strength data you like....and the Navy Bureau of Ships Manual for small versus large application, etc.

The question is a good one, you might consult ASTM or CGSB etc. before attempting an off the wall experiment and providing results. The resulting 'data' may provide more bad information than good information.

[Bob Smalser]

Originally posted by popeye:
The question is a good one, you might consult ASTM or CGSB etc. before attempting an off the wall experiment and providing results. The resulting 'data' may provide more bad information than good information.Anything I do in my little workshop is anecdotal, not scientific. If any data is out there as a starting point, I haven't found it....and I've looked.

I think I know from decades of restoration work that some glues can't be successfully glued over....and there are some new glues out there I don't know about one way or t'other.

I also think I know...and this is only as old as the little time I've played with web forums....that many new builders don't give Thought One to how their work will be repaired some day, or the consequences of that....and if some older guy pokes a stick in their eye about it, that's probably good.

All I'm gonna do is see if I've been BS'ing myself about what I think I know, and provide photographic evidence of all of it to pass on to my boys....I share it here because the feedback improves my writing....y'all can accept or ignore it as you see fit.

Anyone who (wisely) doesn't trust the results is encouraged to perform their own "test" before they use an unproven glue in any 700-hour investment.

[ 06-27-2005, 03:31 PM: Message edited by: Bob Smalser ]

[Stan C]

Why does anyone have a problem with the tests Bob is doing? While his results will be limited in their proper application, they are also likely to be extremely useful for his apparent purpose of determining which glues should NOT be used in a boat that may someday need repairs. Is there any other kind of boat?

Of course what do I know? I'm just a new student of boatbuilding.

I will be glad to see Bob's results because I haven't reached that point where I can say that I know it all.

SC

[ 06-27-2005, 05:33 PM: Message edited by: Stan C ]

[Bob Smalser]

Originally posted by outofthenorm:
Re: PL Premium. There's been so much back and forth about the tube version of Poly glue, I'd be real interested in a side by side comparison to all those "real" glues. Inquiring minds and all that.Interesting....of all the glues and goo's, PL is the only one that won't stick to wood at all without clamping pressure....whether the wood was dampened or dry.

http://pic3.picturetrail.com/VOL12/1104763/7738131/102357573.jpg

I'm clamping it to cure for 24 hours then will saw thru with a length of piano wire so I can include it.

[Tonyr]

Bob, I use lots of PL Premium, and always clamp it as hard as is convenient in the circumstances. The company, if you contact them, advocate hard clamping. I have been well satisfied with the product, used properly. It is not a universal alternative for epoxy, just one additional (and very good in the right place) adhesive.

Tony.

[RonW]

IN total agreement with TonyR.

The original poster might ask Tony what he thinks of using p.l. in strip construction, since tony just finished a strip planked lobster boat using P.L.as the glue between the strips.

P.L. is designed to be used on clean, dry wood in a joint with either clamping pressure or fasteners. It does not require the tight fits and high clamping pressure of resorcinol, nor will it leave a glue starved joint like epoxy can if over clamped. But on the other hand you can not form fillets out of it like you can with epoxy.

There is no perfect one glue does it all, if there was, then there would be no need to have more then one kind of glue.
Glues should be used as they where designed to be used.That is the difference between success and failure.

[Bob Smalser]

I think I can got the clamping part of it down....I just thought it interesting.

The issue is whether PL and PL residue can be reglued in a repair, either with itself or with epoxy...

...did anybody check that before committing it to a 700-hour project?

[ 06-27-2005, 10:40 PM: Message edited by: Bob Smalser ]

[RonW]

The issue is whether PL and PL residue can be reglued in a repair, either with itself or with epoxy... I am just about positive that all glues will bond to themselves. Or is the question, whether or not epoxy will bond to them.
Simple, make any repairs in accordance with the original construction technique, rather then switching to epoxy.

[Bob Smalser]

Originally posted by RonW:
I am just about positive that all glues will bond to themselves. Don't take my word for it...try it.

You'll find that epoxy will bond resin, resorcinol and poly much, much better than they bond to themselves in the fully-cured state.

Nothing in this world I can find will bond to cured PVA.

PL and cyano I don't know about yet. I'll try some long, edge-grain joints with PL bonding cured PL, if epoxy won't stick to it.

Then I'm gonna take some cedar, conventionally-glue seperate long-grain pieces of it with epoxy, resorcinol, 5200 and PL, then stuff it all under the dock for several months to graphically demonstrate that once your hull sheathings are thoroughly perforated and the cedar saturated, that 5200 loses its adherence entirely. I know how resorcinol will perform here....we'll see how the others do.

[ 06-27-2005, 11:42 PM: Message edited by: Bob Smalser ]

[RonW]

Bob, now you are getting hard core and back to the basics. That is good.

If you are going to glue these pieces up and soak them under the dock for 2 months, this should show a adhesion to water logged wood after the fact, which is important.
Why not throw in weldwood, titebond,and liquid poly as well, and if you want to spring for another $3. and try a tube of P.L. polyurethane window and door sealant. Some has said it is the same as 3m5200, I think it is better. I agree with your conclusions on 5200, and under certain conditions it is not all that it is cracked up to be, such as wet wood, too thick of application and exposure to U.V.

Do your best glue up jobs, and I will be waiting for your results. Although I already suspicion that resorcinol will be the clear winner with a tight race for 2nd, between epoxy and P.L.premium.

[Popeye]

Originally posted by Bob Smalser:


Then I'm gonna take some cedar, conventionally-glue seperate long-grain pieces of it with epoxy, resorcinol, 5200 and PL, then stuff it all under the dock for several months to graphically demonstrate that once your hull sheathings are thoroughly perforated and the cedar saturated, that 5200 loses its adherence entirely. Bob , now you have a conclusion written before the test begins, a sticky situation.

All of this reminds me of a legal challenge I worked on where a sample of material was needed as proof of a noncompliance. The person obtained the sample in a proper container and drove it to the lab for analysis, all was fine until the defence found out the sample was left in a glove box for ten minutes, thus destroying "chain of custody" for the sample. Moral of the story is , one person, who did not follow a simple procedure, undid the work of 10 others.

A lack of Standard Reference Materials, no defined procedure and arbitrary test conditions makes repeatability impossible.

Often, work like this gets published too, some guy glues up a butt joint out of plywood and then backs his pick-up truck over it in his driveway, thus cementing his theory on how well glued butt joints perform.

I know you said, boys this is just my own personal trial, it is a one off, an anecdote. However the boys are belly up to the bar and want to know exactly what rules to adhere to.

[ 06-28-2005, 08:40 AM: Message edited by: popeye ]

[Bob Smalser]

....now you have a conclusion written before the test begins, a sticky situation. A lack of Standard Reference Materials, no defined procedure and arbitrary test conditions makes repeatability impossible.

"Fraid you're wrong on both counts, counsellor.

http://pic3.picturetrail.com/VOL12/1104763/7738131/102357761.jpg

Except for the PL and 5200, the basic test was completed yesterday morning with, unfortunately so far, no surprises. Just haven't written it up yet....waiting for the 5200 to cure.

Repeatability? Make ya a puddle of Titebond, scuff it with sandpaper and then paint a dab of epoxy {or any other glue} on it.

Whutcha wanna bet nuthin sticks to it?

Sounds more like I'm just telling some folks what they don't want to hear. ;)

[ 06-28-2005, 09:30 AM: Message edited by: Bob Smalser ]

[wyndham]

Standard reference materials, repeatablity, published? Throotle back there Popeye. What is it about what Bob is proposing that you have such a knot in your bilge about?
All he's going to do is glue up some pieces of wood and see how the glue stands up to pretty simple conditions.
Do you intend to dispute his findings? Sue him if you don't like the results?
Ninety nine percent of the information gathered on this forum is anecdotal. What don't you get?

[Popeye]

Originally posted by wyndham:

Do you intend to dispute his findings? Sue him if you don't like the results?
No, and No.

I am all for Bob doing this and sharing his results , if the series of simple tack tests show failure mechanisms for variability in repaired glue joints, even better. I made my point, take care in extrapolating too far.