Resorcinol - what gives?

[Ruaridh]

A while ago I had some brief correspndance with a well-known naval architects company here in the UK, about a design of theirs I am interested in and bought some drawings for.

The outline spec calls for Mahogany-laminated keelson and stem (and other structural parts). Thinking I might be able to acquire oak more easily, I enquired if oak could be used for these parts, laminating with resorcinol if large enough pieces weren't available.

They replied that oak was ok but that they would NOT recommend using resorcinol because it is likely to soften in 15 to 20 years with disastrous consequences!

In all I've read/found out about the problems of using epoxy with oak, the solution given has been to use resorcinol instead. Can anyone shed any light on this? Am I incorrectly using the term 'resorcinol' when I should be referring to a higher grade of formaldehyde-type glue?

This has been nagging un-resolved in the back of my mind since I heard it, so I thought I'd check with you guys.

Thanks,
Ruaridh.

[NormMessinger]

Man, that does not jibe with what I've picked up over the years. We have a participant here, who I've not heard from for a while, that is in the buisness of making laminated beams for the ship and building trade. If I got it straight they use recorsinol because it lasts forever. What we have here may be a failure to communicate.

Next.

[Tom Lathrop]

I hope it is not true since the spot where I am sitting now is supported by several yellow pine beams laminated with resorcinol that are 15 years old.

I had a sailboat built with resorcinol glue that is now 36 years old and is going strong.

I think you got some bum dope.

[On Vacation]

Before there was epoxy, there was Resoursinol glue. The joints and fit should be better if you use it than the epoxy joints. I just finished a redo of a windmill sailboat, 38 years old, scarfed joints, chines glued, keel glued, seat and mast parts , all glued with it. Not one failure. But make sure the fit is right. Lamination is not as critical since you will be bending it into a shape. Just don't attempt to make it too thick in between the layers. my .02 cents worth from recent exposure to old work.

[Ron Williamson]

This may be the one of differences between urea-formaldehyde(Weldwood,Plastic Resin)and phenol-formaldehyde(Resorcinol).
I am aquainted(sp) with a pre-WW2 Firefly that is still OK
R

[Ruaridh]

Hmmm, pretty much exactly what I was thinking.
Oyster - I hear you re the glue thickness. The only slight problems I had laminating white oak / resorcinol frames in-situ in my Folkboat was where I couldn't quite get them clamped together well enough.
For laminating up structural parts in out-of-boat shop conditions it should be possible to get all the surfaces near perfect.
Interestingly the opposite seems to be true for epoxy - I've heard it recommended to be careful not to squeeze all of the glue out of the joint when laminating.
Could well be a communication problem. I wonder if others could shed some light - there used to be a pretty good Chemist on here...?
Ruaridh.

[On Vacation]

There is an alternative to clamping in construction. In the U.S. we have sheetrock screws that can be used in lieu of clamps. This method can be used in sistering, and laminating with limited access. You can also do this lamination in layers or stages. Yes, with epoxy, the joint can be wider, and also the filler is key to the strength of the larger glue joint.

[George Roberts]

If I get this right, you consulted a "well-known naval architects company" and you want to not follow their advice.

If you believe that the people here are more reliable, then you should not have consulted that "well-known naval architects company."

[NormMessinger]

They replied that oak was ok but that they would NOT recommend using resorcinol because it is likely to soften in 15 to 20 years with disastrous consequences!

Yes, but George, if they say resorcinol will soften in 15 to 20 years, what do you think they are know for. Do you know something about this glue you would be willing to tell us.

[Ruaridh]

George,
It's not a matter of whether I will or won't follow their advice. Did I say anywhere what I was intending to do?
You seem to be implying that I didn't in fact hear this from a reputable source. I didn't (and would rather not) name them for the very reason that I may have got the wrong end of the stick, and I don't want to call their expertise into question.
I'm a long way off having to act upon the outcome of this issue, and like I said it's something that's been nagging at me.
The folks on here usually seem quite happy to mull over these types of discussions - if you think I should take the advice of one source only and/or shut up then that's up to you.
I generally find there's more to be learned by asking questions from anyone I can who has expertise and knowledge greater than mine (like most folks on here) and trying to take the best from that.
Unfortunately many of these issues aren't so cut-and-dried as you seem to think they are. And if you think the advice on this forum is so worthless, why are you reading it??
Like Norm says, if you know something about the subject, please do tell. Otherwise, your comments are unhelpful and I assume you just like the sound of your own voice.

[On Vacation]

Originally posted by Ron Williamson:
This may be the one of differences between urea-formaldehyde(Weldwood,Plastic Resin)and phenol-formaldehyde(Resorcinol).
I am aquainted(sp) with a pre-WW2 Firefly that is still OK
RYou hit the nail on the head. I went back and read your reply, and yes, there is a major difference with the plastic resin.

[Billy Bones]

In decades of woodworking and laminating I have seen only one failure of epoxy, due to a contamination of the lumber, with no fault in the epoxy itself. In that time I have seen several compromised resorcinol (aerodux and others) joints--most catastrophic. My experience clearly runs against what others say, but I believe what I see. (Particularly when it costs me money.)

FWIW,

[George Roberts]

I am always oppossed to people shopping for information. In general, those people have a plan and they shop until they get validation from some source. I find that practice to be less than worthwhile.

I suspect the "well-known naval architects company" has had experiences with small builders and have reason to believe that resorcinol glue will be applied in a manner that will lead to failure. (DIYs seldom have the ability to control temperature and humidity and surface fit and finish.) I suspect that their advice would be different if it was given to a large shop where the people had the ability to control conditions.

This is not a dis of any one. It is simply a fact of life that we often get by with less than ideal conditions.

[Ruaridh]

Fair point. There's obviously the temptation to keep asking until one hears what one wants to hear.
If you must know, I had actually decided that if I'm ever making the parts in question I would go for epoxy and an epoxy-friendly timber, for the reasons outlined above plus the fact that I've got much more experience with it.
It's just that every time I saw laminated oak parts in boats or homebuilding products it got me curious, so I thought I'd run it by the forum.
In that light I still think it's a fair enough question and think you're being a little bit cynical, George, with your 'shopping for information' remarks, but I appreciate that you're not obliged to suffer fools lightly :rolleyes:
I've always found stuff out by asking questions, and I don't think I'll stop now. :D

[Andreas Jordahl Rhude]

Structural glued laminated timber has been successfully manufactured using resorcinol, phenol-resorcinol, phenol-formeldehyde-resorcinol adhesives for half a century and more. My firm's experience with gluing white oak with resorcinol goes back to World War II. Boy oh boy, if white oak can't be glued with resorcinol according to your source, there are plenty of naval ships in dire conditions. Let's go back to the Korean War in the early 1950s. Numerous ship yards were making glued laminated white oak frames bonded with resorcinol for minesweepers (AMS class and others). Our firm made frames, etc... for Tampa Marine; Burger Boat; Hodgon, Goudy & Stevens; Frank L. Sample, and others. Ship yards such as Higgins in New Orleans, Peterson Builders in Sturgeon Bay, WI; and Luders in CT were gluing their own frames. I am not aware of any catostrophic failures.

In 1956 we glued FCAP treated red oak with resorcinol into frames and other components for the USS Bittern, MHC 43. Consolidated Shipyards in City Island, NY built her. This ship is now Aqualab and she's berthed in Portland, Maine. Our president inspected the wood and glue lines several years ago and found everything to be in ship shape!

Right now we are gluing white oak frames with resorcinol for the schooner Virginia. We recently shipped white oak glued laminated timbers to Old Ironsides. I don't expect failures in 15 years.

Check with the American Institute of Timber Construction (www.aitc-glulam.org) for information about adhesives and wood species.

[Andreas Jordahl Rhude]

More thoughts...there are plenty of buildings supported with glued laminated timbers bonded with resorcinol adhesive that have been standing for decades. Typically, however, up to about 1970, casein adhesive was used for beams, arches, trusses, etc... intended for interior applications. If kept dry this is a great adhesive that lasts forever. There are plenty of arches and beams made in the USA in the 1930s that are a testiment to this. Resorcinol replaced casein adhesive as the prefered choice for all commercial laminating about 1970 mainly due to the ecoomics of it. The price came down and was about the same as casein adhesive.

[John Blazy]

That seems like the last word if I ever heard it AJR. Appears like the naval architectural firm must have stereotyped the average home boatbuilder (Ruaridh, here unfortunately) as not qualified to laminate resorcinol correctly, since it requires better joinery, but C'mon now, most home boatbuilders generally over-perfect their joinery from what I've seen. Hard to believe that a naval architect firm would be so foolish not to see the validity and acceptance of resorcinol. Must have been a misunderstanding somewhere?


Originally posted by George Roberts:
I am always oppossed to people shopping for information.That appears to mean, "I am against people using their brains".
Which implies, "The more ignorant people are, the better", or "Dog gone it, if people begin seeking more truth, than they may find out how much I am B.S.'ing them"
I kindof get where you were coming from George, but if you want to come off a little more authoritative, then choose your words a little more wisely smile.gif .

[Nicholas Carey]

WRT to what people have said about resorcinol's need to thin gluelines, clamping pressure, etc.:

Bear in mind that using resorcinol successfully requires much more care than many other adhesives in order to achieve good bond strength. For starters (from DAP Weldwood's instructions and other sources):

1. The temperature — of the wood, the glue and the work area — must be not less than 70°F. If less than 70°F, bond strength will be insufficient.

2. Resorcinol's cure is sensitive to relative humidity. Moisture content of the wood should be between 8-12%. Wood moisture content of less than 5% or more than 15% compromises bond strength.

3. The glueline should be about 0.005 inches in thickness — that's 1/200 inch or 1/8 millimeter — or bond strength is compromised. Too thin and there's not enough adhesive in the joint. Too thick and the adhesive fails rather than the wood.

4. Resorcinol requires extremely high clamping pressures. DAP recommends clamping pressures of 25-75 psi; other sources (FPL and its Australian and Canadian equivalents) recommend clamping pressures of 100-200 psi in order to optimize bond strength.

It's exceedingly hard to achieve these kinds of pressures uniformly without specialized equipement. Bear in mind that even vacuum bagging, considered a superb means of applying high clamping pressure for gluing, can achieve only a theoretical pressure of 14.7 psi at sea level. Resorcinol requires 2-10x that. And mechanical clamps, unless you use a lot of them, don't supply uniform pressure.

Epoxy's ease of use and tolerance for imperfect gluelines, low clamping pressure and temperature have lot to do with why it's as popular as it is.

[ 03-17-2003, 07:24 PM: Message edited by: Nicholas Carey ]

[George Roberts]

John Blazy ----

It has been my experience that people shop for information with the intent of stopping when they get the answer they want. Not when they get the right answer.

Ruaridh asked a question and many people jumped on the "well-known naval architects company" claiming that they as individuals knew the truth and the "well-known naval architects company" must be either in error or misunderstood. I suspect that is the answer that Ruaridh was shopping for.

I suspect that Nicholas Carey's post is closer to the truth (he was more precise than I was), but like me he will learn to keep his mouth shut.

I surprised that no one asked thechemist to bless an answer to this question.

[Dave Fleming]

Well time for me to put my 11 EEs in the water,so to speak.
UF, that is the whitish powder mixed with water till creamy is also sensitive to heat and cold and also needs much clamping pressure. It does fairly well when exposed to the elements.
Witness my benches made of old growth Redwood and outside the Sonoma, CA., Cheese Factory for close on 30 years with no maintainance at all. Rain,heat lots of heat and sun and they as of last Mother's Day still looked OK, not great but NO delaminition of the glue joints.

RR, that is the red stuff, two part, is even more tempermental than UF.
In the late 1950's and early 1960's it was touted as the best thing since red lead paint. Well it wasn't, at least how many a yard applied it. People forgot to read the directions ( sound familiar?), and there were many failures, some drastic. Marinette Marine, building Wooden Minesweepers during and after the Korean War developed a technique for laminating OAK frames and other structural members for the sweepers. The 4 part paperback US Govt. publication for the Navy, Wood:A Manual for its use as a shipbuilding material, has several photos taken at the Marinette Marine shops showing just how they did it. Iron workers platens, those 4x4 or 5x5 feet square CI slabs with holes in them like peg board were fitted with steel vertical brackets and with pneumatic clamps in a temperature controlled building was the system used.
RR squeeze out is almost brittle, we would take our pocket chisel ( we wore blue JCPenny overhauls and the right hand lower leg pocket was for carrying a 1 inch chisel, a beater, a Stanley yellow handle in a stout canvas or leather sheath)
and just slick off the squeeze out when it was cured or a belt sander would be used.
NOW, that was then and this is well...now, so I don't know if the formulation has changed or remained the same but I do know that many a replica has been built with RR glued frames done bye some outfit back east so it must be OK when fabricated in production conditions.

[Scott Rosen]

For what it's worth, I think Nicholas is on to something. A couple of years ago, I had to do some mast repairs--the joints were separating after about 30 years. Originally, the mast was glued with resorcinol. I considered doing the repair like the original--with resorcinol--but I had to admit to myself that I could never get the optimum conditions. Cleaning out the old glue from the joints left me with less-than-perfect fits. I had to do the work outdoors, in the spring, where temperatures drop way below 70. And I couldn't be sure of getting the right clamping pressure.

I used epoxy, and I'm glad I did. Epoxy is strong and forgiving of less-than-ideal conditions.

[Bob Cleek]

What Dave and Scott said, in spades! Funny thought comes to mind here. Some years back, I had discussions with a very highly respected, hell, world class, British naval architect, about building to one of their firm's designs. (May still some day if I win the lottery!) In the beginning of our correspondence, he was hell bent on convincing me to build this boat strip planked (which I gather to them is something akin to what we call epoxy lamination or "WEST System") When I requested information on this very traditional carvel planked vessel, he wanted to send me their modified plans for a cold molded version. He told me their extensive experience with DIY builders led them to the conclusion that this was really the best way to go for the "home builder." As our rather extensive correspondence progressed, he came to admit that he hadn't realized that I had more experience butchering boat wood than the average inquirer they have coming through the door. No more was said about strip planking and he suddenly was very enthused that someone was interested in building their design "properly, the was it was intended." LOL I imagine that in that line of work, a firm has to consider its audience. They won't last long selling plans that customers can't build, or advising construction techniques that are beyond the average builder's abilities or resources.

[Ruaridh]

Bob - from reading your previous posts I think we may be talking of the same people, but I still do not think it appropriate to mention their name in this discussion.
I fully appreciate and agree with the points made that they may be effectively warning amateur builders away from more difficult techniquies. They must have to deal with their fair share of 'time wasters', which is effectively what I am seeing as I haven't at present got the site or the resources to start on the project. (But that doesn't mean I won't ever). That was why I came to the forum rather than pester them for a more detailed explanation. Having said that they were extremely friendly and helpful with my initial enquiries.
Funnily enough, while I don't yet really have that much experience 'butchering wood', I've also come around to the idea that I'd rather build carvel-planked than strip / west system. For some reason I've got it in my head that the pace and sequence of events would be much nicer (OK it'll take longer) and the learning experience would be much more fulfilling. And at the end of it some might even consider me a 'proper' boatbuilder! Plus I couldn't really get my head around the sheer amount of plywood I'd have to buy and cut up at the outset for the framing in the strip-plank design. I like the idea of laminated frames which was part of the reason I came here with this question.
Thanks to all those who provided such good technical details.

NOW, Mr. Roberts, we're all entitled to our views, but while I may be an amateur, you seem intent on making me out to be the kind of bodger who is hell-bent on doing things their own way regardless of what anyone tells them. And by implication the higher minds of expertise in a given subject shouldn't lower themselves to answer my stupid questions.
I flatly dispute that I am 'shopping' for a particular answer and will only be happy when I get it. This may well be all that happens in your experience, but then maybe you've only had bad experiences? (I'm tempeted to draw attention to my comments about using epoxy in my previous post but do I have to justify myself?)
Nicholas Carey's post wasn't in the same vein as yours at all, I'm not sure why you think he might 'learn to keep his mouth shut'.
Internet forums aren't for everyone, it's a strange new way of disseminating information that we're all just learning how to get the best out of. If the kind of discussions people want to carry on here are an affront to you then I would suggest you stop reading them, because I doubt if you or your like are going to change them.
Like most people, I've cut corners, jumped in with both feet, thought I knew far more than I did and generally made a complete b*lls up of plenty of things in my time. So I feel that your appreciation of the right answer over the answer one might want is not quite as rarified as you might think.
With respect,
Ruaridh.

[Harry Miller]

, you seem intent on making me out to be the kind of bodger Why can't a guy who builds chairs be a good boatbuilder? ;)

[Nicholas Carey]

ANSI/AITC Standard A190.1, American National Standard, Structural Glued Laminated Timber provides details on layup requirements.

It and other helpful standards regarding the design and manufacture of structural glued laminated timber may be purchased from http://www.aitc-glulam.org/ at reasonable prices (for example, A190.1 is $11.00).

[fair&fair]

Certainly the above gluing experience with white oak on the above boats mention tend to support the resourcenol=ok hypothesis. I had read somewhere, in woodenboat and gougeons I think, that the acidity of oak can cause problems with both resorcenol and epoxy. I have used both adhesives on oak with no problems to date (fingers crossed!). In any case, my boatbuilding intuition tells me that if the wood is of the proper moisture content and proper construction techniques are used i.e. proper clamping, especially with resorcenol, then things sould be fine.

[Charlie J]

Originally posted by Harry Miller:
</font><blockquote>quote:</font><hr /> , you seem intent on making me out to be the kind of bodger Why can't a guy who builds chairs be a good boatbuilder? ;) </font>[/QUOTE]LOL- Was wondering if anyone else would catch that. I happened to have JUST reread an article in Woodwork about a bodger working with a springpole lathe. Quite interesting.

[Ruaridh]

I wondered, but didn't bother asking 'cos I knew you guys would only feed me the answer I wanted to hear.... :cool: :D :D

[Cedarhill Boatworks]

Been shopping?

[Wendy Reymond]

Fair & Fair - did you wash your oak with a caustic soda solution before gluing?
Wendy

[Andreas Jordahl Rhude]

To Dave Flemming, Marinette Marine Corp. NEVER made glued laminated timber frames or other members for minesweepers or other ships during the Korean War or afterwards. Is it possible you meant to say Peterson Builders at Sturgeon Bay?

Other than the first two vessels made by Marinette Marine in 1942 (flat bottom barges) using wood, thy had NO experience in wooden ship construction. Steel was their bread and butter. When they received their first contract circa 1984, for a 224 ft. long wooden US Navy MCM they didn't know a thing about wood. Sentinel Structures, Inc. was their supplier for glued laminated timber members and we had to do a great deal of hand holding with Marinette Marine to get them up to speed with warm and easy to work wood.

During the Korean War wooden minesweepers were made at shipyards such as Peterson Builders; Burger Boat; Tampa Marine; Hodgon Goudy & Stephens; Higgins; and a few other yards. The glued laminated timber framing components used by Burger, Tampa Marine, Luders, Hodgon Goudy & Stephens and a few others were made at Peshtigo, WI by what has been called Sentinel Structures, Inc. since 1973. Higgins Luders, and Peterson glued their own structural components on site.

[Dave Fleming]

To AJR,


To Dave Flemming, Marinette Marine Corp. NEVER made glued laminated timber frames or other members for minesweepers or other ships during the Korean War or afterwards. Is it possible you meant to say Peterson Builders at Sturgeon Bay? With my correction of, one M in Fleming, I stand corrected about Marinette. Been awhile since I had a copy of Wood, a Manual....Mea Culpa.

[ 04-03-2003, 12:56 AM: Message edited by: Dave Fleming ]

[Bayboat]

In building the Denis Sullivan, a 98' LOA schooner, we had advice on laminating timbers from Peterson Builders of Sturgeon Bay, WI.
They glued white oak timbers with resorcinol, but not in ambient temperature. After applying the glue and clamping, they heated the timbers to 180-200 degrees F. Also, the resorcinol was a type made for this process--not the ordinary kind you buy in a can. I don't know for sure, but I suspect strongly that Peterson was following a procedure developed by Sentinel Structures of Peshtigo, WI. In building the Sullivan we did the same thing on a smaller scale. We built a laminating shed in which we glued up the frames and the stem, heating it to about 180 degrees F. with steam jennies. Since it was too long for us to handle this way, we bought the white oak/resorcinol keel from Peterson Builders. Later, we bought some laminated white oak caprails and a jib-boom from Sentinel Structures. All these timbers except the jib-boom are now about four years old, and are holding up well. I suppose more time will tell, but OK so far.

[Ruaridh]

Thanks so much for these on-going bits of information - truly informative.
Still no-one identifying with the 'softening' mentioned in my original post, though: - I now feel much more confident to go back to my original source and ask them to clarify.

I was reading through the whole thread again and think I didn't give enough acknowledgement to Andreas Jordahl Rhude and Nicholas Carey who both mentioned the 'aitc-glulam' source, which I've looked at and will definitely try to purchase the publication mentioned. Thank you, and to all who keep providing insights.

Ruaridh.