white oak laminations

[stormsvala 1]

happy thanksgiving everyone, just had a lengthy discussion at the dinner table about the use of white oak laminations in the restoration of a wooden hull. my brother steve (fiberglass owner, though i think i've got him converted) is very skeptical about the use of epoxy laminants in reconstruction, especially with white oak. i've seen numerous posts and have read extensively on the subject and think that if prepared correctly that they are fine. i have seen some use 5200 and i've seen some that won't even go near the task. just wondering what the forumites think.

[sdowney717]

Ok, I will tell you exactly what I have experienced when gluing in 1/2 inch 1 inch long white oak face grain plugs into the stem using epoxy. The plugs pulled out when the plank screw pulled the board tight to the stem.
2nd try using permaflex polyurethane as an adhesive from www.sanitred.com (http://www.sanitred.com) , the plugs held as the screws pulled the plank tight to stem.
So epoxy is a no go from my limited experience gluing white oak, but the permaflex glued the white oak with no failures and held under pressure. So, I am assuming 5200 would work as well. In fact I have glued up tons of stuff using permaflex and no failures.

[Mrleft8]

5200 never hardens. I'd use Resourcinol.

[sdowney717]

why not use pl premium poly construction adhesive?
Easy to use, waterproof, cheap, cured by the next day, no long waits like 5200.
Try a test glue up some laminations of white oak, soak em try to break em, etc...

You can get this to cure in thick layers by adding sawdust.
I bet it would work.

[Jay Greer]

According to extensive tests made by the US Forest Lab, US Dept. of Agriculture, polyurathane glues are now emerging in new form and may prove to be the new age adhesive for boat building. Although the foaming action of the glue negates its use for gluing bungs, it has been reported to have excellent holding properties for laminating both oily and hi acid content woods. The report can be found by looking up.
Fracture of Adhesive-Bonded Wood Joints BryanH. River Forest ProductsLaboratory, USDA-ForestService, Madison, Wisconsin

[sdowney717]

yes I know it is good, but some have noticed that 5200 can let go after an extended time with wet wood and I think this has colored opinions negatively against polyurethanes, but they are not all the same are they, they are a large diverse group.

[Graham Knight]

Although the foaming action of the glue negates its use for gluing bungs Low foaming PUs are fine for gluing bungs (do you mean plugs?), I've just done about 40 white oak screw plugs with no problems at all.
I've also been laminating white oak with epoxy, as long as you leave the laminations rough sawn, don't plane or sand them, and use a fairly thin epoxy mix with a slow hardener to allow it more time to penetrate, it holds really well.
I brushed unthickened resin on both surfaces first, then thickened the remainder to about custard consistency and applied a second coat, it oozed everywhere when it was clamped and made a real mess, but once cleaned up it looked good and was virtually indestructible.
I'll be very surprised if it ever delaminates.

[imported_Jimmy]

I have about a dozen laminated white oak sister ribs in my boat that I put in about 2 years ago and so far they are doing fine. I started using G2 epoxy which is supposed to be specifically formulated for oily and acidic wood, but was unhappy with it's cure time and switched to Cold Cure epoxy, made by the same company. Both seemed to work fine. I did wipe down all surfaces with acetone prior to glueing. No failures yet.

[pcford]

I've also been laminating white oak with epoxy, as long as you leave the laminations rough sawn, don't plane or sand them, and use a fairly thin epoxy mix with a slow hardener to allow it more time to penetrate, it holds really well.
I brushed unthickened resin on both surfaces first, then thickened the remainder to about custard consistency and applied a second coat, it oozed everywhere when it was clamped and made a real mess, but once cleaned up it looked good and was virtually indestructible.
I'll be very surprised if it ever delaminates. This is an ancient subject here and elsewhere. Those wishing a long discussion can find it already existing for you.

Often a person sticks white oak together, it stays stuck and he concludes there is no problem. I have done this and when a chisel is applied to the glue line, it sometimes snaps smartly apart.

Having a rough interface at the glue line is often no help. People often suggest this as if it is some kind of new discovery. Even with a rough surface white oak/epoxy bonds sometimes will fail.

I think, (and based on no rigorous investigation) that the white oak/epoxy arises from the acidic content of the wood. Furthermore, I believe this varies, thus accounting for some successes in adhesion of white oak and epoxies. I have made no exploration of the epoxies that advertise themselves as being specifically formulated to glue white oak. There are a few.

An old, old bitch of mine is the question of why formulators do not note this problem on the bottle. (The problem has been known to professionals for twenty years. Novices are not aware.) The answer, from an owner of an epoxy line that you would recognize, is that if they state this problem, they would be liable for any incompatibility instead of leaving it up to the user.

[Graham Knight]

Often a person sticks white oak together, it stays stuck and he concludes there is no problem. I have done this and when a chisel is applied to the glue line, it sometimes snaps smartly apart. FWIW I was suspicious of this method and I tried the chisel test on some offcuts, there was no way I could make it split apart on the glue line, not without the glue taking a big chunk of wood with it. I used West System which afaik makes no specific claims of suitability for oak.

[Hughman]

Graham, was your test on a new piece?

Some anecdotal results suggest the failure of oak/epoxy is related to the age of the joint and the moisture content of the wood, which exacerbates the acid reactions within/adjacent to the glue-line.

In other words, a time bomb.

[helvit]

Gougeon Bros. rep says "rough surfaced it works fine, but if you're anxious about it, use a fastener for insurance."

Could be the tyloses that cause problems if there's no tooth to mechanically get into.
http://www.uwsp.edu/papersci/biasca/ps350/tyloses.htm

[emichaels]

Not sure if this applies directly but Walsted had problems well after the fact using Mercol adhesives on laminated white oak frames on the Aage Neilsen boats early on. The planking was, fortunatley, copper riveted to the frames resulting in a mechanical restraint that persisted even when the glue failed. I know boat builders, sometimes, like to use WO for laminations, though, in furniture we would never do it. Probably becaue, furniture does not see the stress a frame does, but also because furniture makers typically would laminate cherry or mahogany not white oak. I have read about the benefits of laminating frames but with a wood as strong as WO why bother ??? Are you really gaining anything expcept a whole bunch of static fracture barriers ?

Eric

[ 11-25-2005, 09:19 PM: Message edited by: emichaels ]

[emichaels]

I noticed someone mentioned maechanical bonds with epoxy and rough wood. Does epoxy form any other kind of bond ????? I thought it was based on mechanical bonding and as much surface area the better ??

Eric

[Mrleft8]

I've done hundreds of bent laminations with White Oak in furniture situations, and never had one failure. Of course, it should be mentioned, that I used "yellow" glue for those lams. I think, possibly, that it's the moisture content, not the acidity that's the issue. I've done several "green wood" bent laminations with White Oak using Resourcinol. and over 25 years have had no issues.

[pcford]

The point is that _sometimes_ white oak/epoxy does work.

However, unless someone comes up with a product or procedure which _never_ fails, I'm not using epoxy to glue white oak.

"It worked for me." "My frames did not delaminate" ain't sufficient.

You have thousands of dollars in time and materials invested. Want to gamble?

[Jay Greer]

I am always astounded by the "What if's" in answere to documented information and first hand experience concerning various relatively new products to either glue, caulk or coat the various materials and components that are used for building wooden boats.

The technology and accumulated knowledge of wooden boat building dates back nearly two thousand years! I have only been building wooden boats for a mere fifty. But in my time I have tried damn near every new "zap on" and fast glue product that has come down the pike! My own experience has been that while epoxy is ok for a quick bounce in the glue bed, it is not a lasting marriage for wooden boat components, be it masts, frames, keels, plugs, bungs or bung holes.
JG

[Graham Knight]

Graham, was your test on a new piece?
Yes it was, of course only time will tell how long it lasts, but then that's true with any of our glued construction because none of the adhesives have been around that long.
I laminated my stem, but I've also used brass screws and epoxy to attach the outer stem to the inner, where oak and some other hardwoods are concerned I'm quite happy to back them up with fasteners.

I take pcford's point
unless someone comes up with a product or procedure which _never_ fails but does anyone know of any product or procedure that never fails? I certainly don't!
I don't care what timber you're using, what adhesive you use to glue it together, or what preparation technique you use, you can never guarantee that it won't fail.

[stormsvala 1]

appreciate all the insight, and i am still at the same crossroads. some are believers and some not so much. i just e-mailed gougeon bros product info to see what they had to say and will let you all in as soon as they get back to me. i have already laminated the first ten stations from the stem back and have had nothing but strong bonds thus far but the boat is on the hard and dry so take that as you will. i also laminated a couple of test pieces, some with a correct ratio and then some with sligtly off measurements to see what effect that mismixing them would do to the bond. i then tossed the pieces into the saco river and will see how they hold up in the next couple of weeks. thanks again

[stormsvala 1]

appreciate all the insight, and i am still at the same crossroads. some are believers and some not so much. i just e-mailed gougeon bros product info to see what they had to say and will let you all in as soon as they get back to me. i have already laminated the first ten stations from the stem back and have had nothing but strong bonds thus far but the boat is on the hard and dry so take that as you will. i also laminated a couple of test pieces, some with a correct ratio and then some with sligtly off measurements to see what effect that mismixing them would do to the bond. i then tossed the pieces into the saco river and will see how they hold up in the next couple of weeks. thanks again

[Gary E]

Think on why epoxy was invented and by who..

I think it was invented by a lazzzzy Dad who as a kid grew up building model airplanes and boats etc out of balsa etc... If your old enuf you remember stealing the pins from your Mom's sewing basket to hold the joint together till the Testors or other "glue" set up... therefore the modern Dad, he didnt want to wait for anything, hey, microwave ovens, instant on TV set, fast dry paint, instand messages on this funky tv set with a typewriter keeyboard, why should the kid wait for a louzzy glue to set?...

Back to the lab, mix some chemicals together, try this, try that, try the other, and opps my fingers are stuck together and ......Shazam... EPOXY.. !!!!!!

Inotha woids... EPOXY, THE NEW FANTASTC GLUE...or maybe not..ahh ...SCREWIT...

[Bob Smalser]

If you can achieve consistent high clamping pressure throughout the lam and 70 degrees or more of temperature for an overnight cure, then resorcinol is a well-proven glue to use on WO. The Navy used it on minesweeper frames in WWII and Korea that are still intact today, and their tests and experience are well documented in "Wood, A Manual for use in Shipbuilding" available for forumite DN Goodchild. Too bad they didn't have marine epoxy to test.

http://www.dngoodchild.com/xl1_top.htm

My experience with 3M 5200 is that it requires as much clamping pressure as resorcinol for a good bond, and without it, it pulls out of a water-saturated joint like rubber rope. As it was engineered as a sealant and not a glue, I also wouldn't trust it not to creep.

I've done some minor lamming of knees and other easily-replacable parts with liquid poly to try it out. It makes for a lighter assembly than heavier epoxy, but it needs a lot of clamping pressure and it doesn't fill gaps at all, requiring epoxy fairing compound...which sticks to it well...for cosmetics. We'll see how it holds up in use.

An unproven glue that shows promise for laminating is a polyurethane goo, PL Premium Construction Adhesive, which was designed to fill gaps in rough surfaces. It applies like 3M 5200, but cures hard like liquid poly instead of rubbery 5200, and doesn't seem to need as much clamping pressure as either, although I'd like to test that more before committing to it. Unlike epoxy, which likes wood at around 10% moisture content (airdried WO is often much wetter than that) it appears tolerant to a wide range of moisture contents. It adheres as well as resorcinol and epoxy to high-acid-content cedar allowed to water saturate for 6 months (as did both liquid poly and 5200 as well). It appears a very strong glue with a high isocyanate content for sticking power....it's the only general-use glue I've found that will adhere to difficult aliphatic white and yellow glue residue. It is also very repairable....it glues over its own residue and both epoxy and 5200 adhere well to it.

[ 11-26-2005, 12:23 PM: Message edited by: Bob Smalser ]

[pcford]

I take pcford's point

quote: unless someone comes up with a product or procedure which _never_ fails

but does anyone know of any product or procedure that never fails? I certainly don't!
I don't care what timber you're using, what adhesive you use to glue it together, or what preparation technique you use, you can never guarantee that it won't fail.As soon as I wrote that I knew that someone would pick that nit. Of course nothing ever works all the time. But the failure rate of white oak/epoxy is very high in my humble opinion.


B. Smalser wrote: If you can achieve consistent high clamping pressure throughout the lam and 70 degrees or more of temperature for an overnight cure, then resorcinol is a well-proven glue to use on WO. The Navy used it on minesweeper frames in WWII and Korea that are still intact today, and their tests and experience are well documented in "Wood, A Manual for use in Shipbuilding" available for forumite DN Goodchild. Too bad they didn't have marine epoxy to test. It's my understanding that epoxy is not allowed on minesweepers.

It wasn't my intention that this thread would stretch on so long, since all these discussions have taken place many times.

However, every time this discussion comes around some novices are brought out into the light...pie-eyed and blinking.

[sdowney717]

If you mix sawdust into PL Premium Const Adhesive it will harden all the way thru thick layers of glue and makes a nice filler.
Otherwise it is limited to about 3/8 inch in glue thickness. I find it gives a lot of glue power for the money and very easy to use. Buy the large cartridges as it is much cheaper.

I even notice the difference in the feel of the white oak compared to red. WO to me has a smooth non splintery greasiness sensation when I run my fingers over it. Maybe it is just me and my old keel, anyone else sense this?

Exploring WO glue properties, sure it is an old subject but still good to see if anything new is out there. After seeing it fail, I just dont trust it with epoxy, and enough people have had failures to convince me of a problem. A glue problem might not show up for a while,then when it fails you will never want to use it again.

[seo]

Seems like most of the companies that build boats with laminated parts use some wood other than oak, no matter what the glue. Weren't the minesweepers mentioned above framed with laminated fir (or welded aluminum) and then strip-planked with edge-glued fir?
I've seen boats framed with glue-laminated mahogany.
The "Californian" (a sail-training boat that's a sort-of replica of a Revenue Cutter by Melborn Smith) was built with laminated yellow pine, manufactured by a company down south (Alabama?) that specialized in building the laminated arched roof beams that you see in gymnasiums and some churches. They had very tight glue lines, and were sawn to profile and bevel with admirable precision.
At the time I saw the Californian she was under construction. I was sailing on Smith's first "masterpiece," the Pride of Baltimore, and the Californian looked good in comparison. Which wasn't saying much.
seo

[Frank Wentzel]

If you want to use epoxy to laminate white oak:
- Sand the faying surfaces with 80 grit sandpaper
- Wipe the faying surfaces with a dilute baking soda solution (sodium bicarbonate, 3 or 4 tablespoons to a pint of warm water ) to neutralize the tannic acid.
- Dry the joint thoroughly and glue.

If this doesn't appeal to you - fine! But to say that you don't trust epoxy, so I'll use something else that is either more critical in its use parameters, or even better, use something that has little history (my sister's brother in law's friend said that he heard it was great!) doesn't make much sense to me.

But then that is just how we will get data. As people use the new panacea for the world's ills we will find out how well it works. Of course, even if it is the maiden's prayer, there will still be those who use it outside of it's proper parameters and then claim it's just plain worthless.

/// Frank ///

Anthing will work if used according to it's properties --- Nothing will work if "common sense" is used in lieu of reading the instructions.

[pipefitter]

Just about any laminated frame,stem or whatever is surely going to have fasteners from the planking and other parts running well into it to help hold these lams together making just about any glue as good as overkill,right?Wouldn't most agree that most places that use laminations of any wood be used with fasteners most likely? It would seem that anything structurally that important, wouldn't want to rely solely on glue alone anyways, no matter how good it is.
I have seen laminations that use no glue at all and stay together just with fasteners alone. Design the lams properly with some kind of backup engineering and they will be fine.Pretend that the glue is only a clamp to hold them together or in shape until installed.
All components in a good structure should compliment eachothers strength and if not,shouldn't be considered as more than trim.

[ 11-27-2005, 01:30 AM: Message edited by: pipefitter ]

[seo]

"Just about any laminated frame,stem or whatever is surely going to have fasteners from the planking and other parts running well into it to help hold these lams together making just about any glue as good as overkill,right"

Maybe, if you are riveting or bolting the planking. But if you're using screws or nails the innermost lamination will be barely fastened, if at all.
The problems I've seen with delaminated once-laminated frames are these:
1) The inner lam peels loose.
2) Water wicks up along the former glue lines, and cause rot.
3) The bolts commonly used to fasten floors to frames are the site of breakage and rot.
If I were going to use laminated frames in a sailboat, I would not use the typical floor/frame bolting. Instead I'd be very sure that there were big and long screws fastening the planking to the floors. Extra size because they're being ask to hold in end-grain, or maybe oblique, grain. Then I'd bolt the garboard and first broad strake to the laminated frame, to hold it together. The planking would be the cleating holding floor and frame together. This is how the two futtocks of double-sawn frames are held together, and it works.
I dunno what I'd do to fasten stringers, but they seem like nothing but trouble to me.
seo

[pipefitter]

Good points seo.
I dont think I would want to use lams in anything other than a dry sailed boat.

[ 11-27-2005, 10:49 AM: Message edited by: pipefitter ]

[TimothyB]

As Mr. Smalser said, The US Navy only trusts Resorcinol for gluing white oak for structural components, but as I recall the milspec for white oak in particular was actually holding the glue line to 150 degrees for 8 hours.

That being said, the frames that were laminated in this fashion have never come apart, nor exhibited any stress fracturing around the glue lines.

So, if you want an absolutely bulletproof laminate, Resorcinol and a space heater inside a tent over the work would do it.

[ 11-28-2005, 08:42 AM: Message edited by: TimothyB ]

[Thorne]

"pie-eyed and blinking" newbie here...

;- )

Bob's recommendation for PL Premium looks like the best bet, but I was wondering if anyone had experience using Smith's _Oak & Teak epoxy glue_, designed for oily woods?

One of the interesting things in the product PR material is the recommendation not to clamp it too tightly.

http://www.glueoakandteak.com/

http://www.smithandcompany.org/OT/images/banner.jpeg

[George Roberts]

stormsvala 1 ---

Engineering decisions are really hard to make.

I am told that the polyurathane glues have very little shock strength.

I would use epoxy, but then I always engineer my laminations.

[pipefitter]

I agree with properly engineered lams.It goes well beyond using just thin strips of wood. Some would need solid, shaped cores where heavy fastening was needed.Lams should be as continuous as possible without butt end exposed grains,etc.
In alot of cases,what the lams give up in fastening strength,they would make up for in dimensional stability. Movement of solid timbers in some instances is enough to work screws loose causing different problems.
The stem in my Simmons is not constructed as a bentwood lam but of 3 layers of 1x with the grains alternated.It is more like a combination of a laminate and a sawn solid wood construction.It would hold whether the epoxy fails or not.I used long enough screws on the planking ends to penetrate into the core.

Steam bent frames can break in tight radiuses and depends alot on the ability to obtain ideal bending wood.Seems that no matter what the construction,it is possible to have failures of some sort. Maintenence is still going to be what decides the fate of any construction. If it is at a fault beyond that then the parts are not substantial enough to begin with.

[stormsvala 1]

thanks again for all your insights, i think that what i pulled out of all this is that a bunch of you seem to be leaning towards the pl adhesive as the new wonder glue, some have "stuck" with their view of epoxy mixes. i personally feel that if all the oils are dealt with in the prep and correct mixtures of epoxy are used with adequate clamping that i should have no trouble with using epoxy. i just wonder if the pl adhesive found at the bigbox would do the same job at a deflated price. i don't mind spending the money for the epoxy if it works better thn the pl, but if their result is the same why wouldn't one fly up to the HD and use the much cheaper, cleaner, less brain numbing alternative?

[SailBoatDude]

Being very alkaline, epoxy will have difficulty finishing it's crosslink, resulting in an incomplete reaction on any acidic material. Vinegar, being quite acidic, cleans up epoxy for the same reason, it stops the reaction. Decreasing the acidity of the surface is the only reliable way to insure good bonds. Resorcinol is an option that works on white oak, but has restrictions that epoxy doesn't struggle with (close fitting joints, temperature control, gap filling ability) I've had good success with thin laminations (less then 5/16" thick), also cleaned the wood carefully and sometimes used a solvent or temperature drop, to draw the epoxy down into the wood.

[Bob Smalser]

I understand there are problems with epoxy and WO, but I don't go to sleep at night thinking I know why.

There's a much higher concentration of picric acid in WRC wood than there is tannic acid in WO wood, yet cedar glues with 100% reliability. The tannic acid in WO is most highly concentrated in the bark.

As my WO stored outdoors likes moisture to the extent that it's usually 5 points or more wetter than my DF or WRC, I've often surmised some of the problems with epoxy and WO in boatbuilding are that the WO used was too wet (well over 12% EMC) to begin with.

[ 12-04-2005, 05:32 AM: Message edited by: Bob Smalser ]

[sdowney717]

http://www.chebacco.com/chebacco_news/chebacc9.htm
Here is another one who had a failure, this time with thin 1/4 inch strips of WO.
Have to edit find the text to read Long text.

'I guess it's true about white oak beiong hard to glue. Just this weekend I noticed that the joints in my stem are letting go. The stem is made up of eight pieces of 1/4" thick white oak. These were soaked, pre-bent together over a form, taken apart to dry, then glued over the same form using epoxy thickened with microballoons. The work was done before the low temperature arrived so I am guessing the failure is due to the white oak. I knew its reputation, but hoped that epoxy would handle it. Another possible factor was the pressure needed to hold the wood to the form, it may have squeezed too much glue out the edges. Chalk one up to experience.

Luckily, I had put in screws every six inches or so, alternating from front and back, after the glue dried. These should help to hold the shape in for now, but I think I will replace them with bolts, with as much epoxy as I can work into the cracks, before I leave it.'

[pipefitter]

I am not sure if microballoons is a good filler for structural joints. The stuff ends up rather mealy and easy to break whereas the wood flour or crushed fibreglass is hard.Microballoons is made for fairing putty because it is easy to sand.
Also,I have seen white oak after it has been ripped on a table saw and even though some what rough, the surface was still burnished/shiney.Not a good glue surface considering the density of WO.

[ 12-04-2005, 12:35 PM: Message edited by: pipefitter ]

[Frank Wentzel]

The Chebacco stem glueup is another example of not following directions. Cabosil (or fumed silica) and epoxy makes a structural joint – Micro balloons and epoxy are used to make a low strength, easily-sanded cosmetic filler. Using microballons in a structural situation is an almost guaranteed waste of time. Microballoons have virtually no strength.

I’ll bet the chebacco builder used them because that was all he had on hand at the time. And his “common sense” told him that they were just as good. Of course, when the joint failed it didn’t even occur to him that he had screwed up. Nope, to him it was obvious: The damned epoxy failed again!

Also, as Pipefitter said, you need to give the faying surfaces a coarse sanding. White oak isn't an oily wood. The "greasy" feeling is the burnished surface. It needs to be sanded with 80 grit sandpaper to break through the burnished layer. White oak will glue well with epoxy if you follow the directions of the epoxy manufacturers and not take the path of least resistance. After all the effort to find good stock, shape it as required and fit-up the joint, don't fail to finish the job correctly!

/// Frank ///

[ 12-04-2005, 04:23 PM: Message edited by: Frank Wentzel ]

[Wild Dingo]

Gidday Jay
Mate I just didnt want your comments to drop out of sight till Id got you to give your recomendations...


Originally posted by Jay Greer:
I am always astounded by the "What if's" in answere to documented information and first hand experience concerning various relatively new products to either glue, caulk or coat the various materials and components that are used for building wooden boats.

The technology and accumulated knowledge of wooden boat building dates back nearly two thousand years! I have only been building wooden boats for a mere fifty. But in my time I have tried damn near every new "zap on" and fast glue product that has come down the pike! My own experience has been that while epoxy is ok for a quick bounce in the glue bed, it is not a lasting marriage for wooden boat components, be it masts, frames, keels, plugs, bungs or bung holes.
JGWhat do you use instead?

Not having a swipe just an honest question from one whos about to to one who has :cool:
Cheers

[pipefitter]

Even the end grain is shiney when you cut white oak. It doesn't look like it wants to absorb anything even if there was no acids. Mechanically,it doesn't look possible without a severely keyed surface. Doesn't the urethane adhesives use water as a catalyst because I am thinking this may be the only thing short of alcohol that would be absorbed by white oak.Maybe this is why the urethane adhesives and resourcinol glues work.The wood may actually let it into the pours. Again this may sound far fetched in comparison but regular pressed beech wood biscuits dont swell in epoxy.
It's great when you can have many years of building something the old,right way but it seems with wood quality getting poorer, then finding out what new goops and materials can take their place.

At any rate, after reading this thread about white oak laminates,I doubt I'll be taking a chance with it unless I can't get anything else.The extra work needed to get it to take adhesive might well negate the extra cost of mahogany.If not that, then I am just going to use D-fir for the frames or laminated parts.

Has anyone had issue with using epoxy on long leaf pine?

[emichaels]

FWIW. I dug up this old thread because I just finished reading Larry Pardey's revised edition of 'Details of Classic Boat Contruction' I only brought this thread back to the surface so that people that are not aware of this chapter added to the book can seek this out for a very experienced perspective.

This new edition 1999 has a section at the end where LP talks about modern adhesives. For anyone with questions concerning structural joints or laminations using anything other than resorcinol adhesives they should read this chapter.

It is very clear to me, reading this, that I will only use resorcinol adhesives on ANY laminations and joints in any boat I build. I think Larry Pardey is an extremely credible and knowledgable shipwright and has seen many more boats that have been exposed to rigorous use, than most of us.

Eric

[ 01-03-2006, 10:32 AM: Message edited by: emichaels ]

[Bob Smalser]

I can't explain why epoxy fails intermittently with WO, but it does.

Here in airdried stock glued at 8% EMC now at 11% EMC, you can see it isn't even sticking to the wood.

http://pic3.picturetrail.com/VOL12/1104763/2595357/124272456.jpg

[emichaels]

Bob,

In Pardeys book he has a pic of a winch mounting block that looks exactly like your pics. 100% epoxy failure.

edited to add: The wood winch block he has in the pic is mahogany.

Eric

[ 01-03-2006, 02:29 PM: Message edited by: emichaels ]

[carioca1232001]

Bob Smalser wrote:


I can't explain why epoxy fails intermittently with WO, but it does. Epoxy-glue failed miserably when boat carpenters glued the two blocks (end-to-end) of ipê that make up my boat´s anchor pulpit. They had to finally settle for Sikaflex - and it has held well since 1998, as far as I can tell.

As for ipê , George (from Angra) recommends first wiping it down thoroughly with acetone, then torching it before applying epoxy-glue. Have followed his procedure on laminations for sistering frames, but can´t vouch for long-term results.

[sdowney717]

Epoxy on white oak is like epoxy on polyethylene plastic. No stickum at all sometimes. And when it does stick you dont know how long it will keep sticking. I wonder if charring the wood with a torch would help the WO as you say for IPE.
But to me charcoal is not a very sturdy surface.

[ 01-03-2006, 04:36 PM: Message edited by: sdowney717 ]

[carioca1232001]

Well, I have torched ipê as per George´s recommendations, prior to gluing it with epoxy or even, resorcinol-based glues.

He should know as he has built a 60-foot, 19 th century Boston cod-fisher with an ipê strip-planked hull. smile.gif

If the ipê piece is wet, copious amounts of fluids ooze out of it and then ignite in uncontrollable fashion.You could very well char the wood. :rolleyes:

If the ipê piece is well dried, you will notice momentary igniiton of excess fluids (oils) that extinguish themselves despite the incident propane torch :cool:

[SparkG]

Off the subject a bit maybe - Bob Smalser - that was a great glue test you ran a while back, thanks for all your efforts. I'm getting ready to start a Selway-Fisher WoodLark catboat. I was going to strip it with Titebond III but after your tests agreed with your observation that those kinds of glues are ok until you have to do a repair - epoxy won't stick to it - so I was going to go back to epoxy which I'm familiar with from stitch n' glues. In light of what you said above about the PL Premium Construction adhesive what would you say to strip building with it - strips would be 1/2" thick and 3/4" wide on a 13 1/2' catboat? Seems like it would be easier to dispense it with a caulking gun than mixing epoxy and spreading on those long strips. I will epoxy/fiberglass the outside and most likely the inside. BTW, probably going to use clear pine for the strips - cedar or doug fir if necessary.
Thanks for yours or anybody elses thoughts on this.

[Bob Smalser]

I'm not a believer in being an early guy to test new marine products on something as critical as a hull. There's 40 years of real-world epoxy testing out there and almost 70 for resorcinol.

That said, PL Premium was the only glue that pleasantly surprised me, and I think it'll work fine providing you can get some clamping pressure on it. Fully repairable with epoxy, it was incredibly strong, but it also was the only glue that didn't stick to wood at all without at least some clamping pressure:

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

[SparkG]

Right Bob...think I'll stick (pun intended) with the thickened epoxy. I'm not sure how tight fitting I can get those strips to get even pressure on them for PL Premium. Thanks for the quick reply.

[ 01-03-2006, 08:53 PM: Message edited by: SparkG ]

[carioca1232001]

Bob Smalser originally wrote:


I'm not a believer in being an early guy to test new marine products on something as critical as a hull. There's 40 years of real-world epoxy testing out there and almost 70 for resorcinol.
You definitely have a point there.
:rolleyes:

[Bob Cleek]

Fascinating discussion. I admit I've stuck just about everything together with epoxy at one time or another, but I've never been able to bring myself to trust it for structural applications, save in spars. I've sure seen a lot of failures with it, though, my own included. Pardey touted Aerodux, which is a resorcinol based adhesive that is thickened and IS gap filling. This stuff is water activated. Wet the wood and slap it together, with clamps, of course. I've never used it, but it seems to come well recommended. Perhaps, in the end, the answer is really that if you build a boat out of wood glued together, your boat isn't going to be any better than the glue. So, as Dirty Harry sez, "Do you feel lucky?"

I had occasion recently, for fun, actually, to play with a "compass timber" from an oak I cut. I wondered just how difficult it would be to adz out a stem shaped piece. Although I didn't finish the job, I found it was a lot easier than laminating! Just saw down to a base line or thereabouts and adz it flat. Run your planes over it until it was flat and fair. Once you have a flat side, the rest is easy. I ran it through the planer to true the second side. A pattern over that and on the bandsaw would have done the trick. MUCH easier than building a jig and messing with epoxy coated strips whipping all over the place. Oddly, most all crooks and knees end up cut for firewood these days. I'd expect you could find what you need for the asking if you know anybody that is harvesting oak. (BTW... as that crook was green when I cut it, my "masterpiece" took an amazingly nasty twist when it dried... live and learn!)

[ 01-03-2006, 09:00 PM: Message edited by: Bob Cleek ]

[pipefitter]

The twisting and warping problems are what always kept me from wanting to use solid timbers. I know there are ideally grained pieces of wood for these purposes but at times it would seem easier to grow it from start than to have to find it. At least here in the south.Even when willing to pay more for it.So,what is worse,iffy pieces of wood or iffy laminations? I still think the temptation to use wood straight off the table saw because they fit so nicely back together when stacked in a lam is half the culprit.I would still be tempted to cross pin lams biased to the glue lines on something that really mattered.I think if one has to use lams over using inferior solid woods, there is many ways to overcome the glue failure.After all the experiences posted here,I doubt I would ever use WO and DF sure does glue nicely.Either way,If and when I do laminate,I am going to have a backup failsafe for it.

[emichaels]

Originally posted by SparkG:
Off the subject a bit maybe - Bob Smalser - that was a great glue test you ran a while back, thanks for all your efforts. I'm getting ready to start a Selway-Fisher WoodLark catboat. I was going to strip it with Titebond III but after your tests agreed with your observation that those kinds of glues are ok until you have to do a repair - epoxy won't stick to it - so I was going to go back to epoxy which I'm familiar with from stitch n' glues. In light of what you said above about the PL Premium Construction adhesive what would you say to strip building with it - strips would be 1/2" thick and 3/4" wide on a 13 1/2' catboat? Seems like it would be easier to dispense it with a caulking gun than mixing epoxy and spreading on those long strips. I will epoxy/fiberglass the outside and most likely the inside. BTW, probably going to use clear pine for the strips - cedar or doug fir if necessary.
Thanks for yours or anybody elses thoughts on this.FWIW
You might find it usefull and enlightening to read the chapter on adhesives, Larry Pardey added to the revised edition of his book 'Details of classic boat construction, the Hull', before you build your boat.

Eric

[SparkG]

FWIW
You might find it usefull and enlightening to read the chapter on adhesives, Larry Pardey added to the revised edition of his book 'Details of classic boat construction, the Hull', before you build your boat.
It's on order from Amazon as we speak ;)