PDA

View Full Version : Laminated rib glue



mariner2k
01-10-2007, 12:34 PM
I'm planning on putting in some laminated white oak sister ribs. With all of the glue possibilities, I need some advice on what would be the best glue for the job.
kevin

Thorne
01-10-2007, 01:12 PM
More info would help -- size of boat, dimensions of frames, conditions (boat in water?), current wood used for frames, frames rotted or cracked, etc.

From the general consensus on gluing white oak, you'd be better with something other than epoxy. However if you want to use epoxy, Smith & Co in Richmond CA makes one for oily woods that you *may* wish to check out.

http://www.glueoakandteak.com/

Thad Van Gilder
01-10-2007, 01:30 PM
The Virginia's oak frames looked to be laminated from resourcinol glue.

-Thad

Bruce Hooke
01-10-2007, 01:45 PM
Sometimes problems crop up with epoxy and white oak. For this reason the preferred adhesive for white oak is often Resorcinol. HOWEVER, to work properly Resorcinol needs warm temperatures (70 degrees plus if I remember correctly), tight fitting joints and high clamping pressures. There are almost always ways to deal with the heat problem. Tight fitting joints in a laminate is usually not too big an issue. High clamping pressures can be a serious problem, especially if you are trying to laminate in place.

If that is the case, then in your situation I think I'd probably do some tests using the white oak I planned to use and the epoxy I planned to use. If the results of the tests are good (try splitting the wood along the glue joint -- it should split in the wood, not the glue) then I'd probably use epoxy.

Tom Kenny
01-10-2007, 04:57 PM
I have been sistering white oak frames with epoxy and screws for some time now and there are no signs of things coming lose. Look at the web site. Click on “Repairs” then select “Owners Cabin”. Scowl half way down and you will see and read how I am doing it.

I am not sure there is a right or wrong way only things that have been proven to work and things that have not worked.

Tonyr
01-10-2007, 05:00 PM
I have used PL Premium for this job, but not specifically on oak for frames. It seems to work well on oak, though, for another application. This adhesive likes to be clamped really hard, and is generally forgiving.

Tony.

mariner2k
01-10-2007, 05:00 PM
Thorne, the boat is a 48' 1931 Alden ketch...The old ribs (oak) aren't in bad shape.. a couple are cracked along the grain a bit. They are roughly 2"x2"...the boat is in the water and will be pulled in the spring for fastening and bottom maintainance. So the application will be a bit difficult , and slow but not impossible. Clamping will be an adventure.... The boat is well heated.. even though winter appears to be finally arriving in little Rhody
I'm not sold on epoxy for this app at all. the wood will probably still be a little green. I am wondering about polyurethane glues or resourcinol
kevin

mariner2k
01-10-2007, 05:05 PM
I have considered PL premium. I have used it for less critical applications on the boat and the stuff is truly amazing.....and forgiving. But I'm not sure how time tested it is on and application like this. I have used epoxy in the past on my old boat (kings Cruiser) and it worked well but the oak was drier. than what I will be using this time.
kevin

Bruce Hooke
01-10-2007, 05:48 PM
At least according to the official specs, to apply sufficient clamping pressure for Resorcinol to develop its full strength you need the equivalent of a C-clamp every few inches. This is fine if you are laminating outside the boat. Trying to achieve anything close to that sort of clamping pressure in place in a boat with the planks all still in place is going to be a LOT harder. A bunch of screws won't cut it. Also, pay attention to the temperature. I know you said the boat is heated. I think resorcinol wants to be at 70 or better. You are likely to feel comfortable working in the boat at a good bit less than that. I've heard reports of people who fudged a little on the temperature and ran into problems.

Polyurethane is still relatively new. I still go by the article a few years back in WoodenBoat that raised questions about how reliable it would be in very wet applications, but it seems like some people are reporting success with it.

Andreas Jordahl Rhude
01-11-2007, 06:49 AM
Yes Thad, the Virginia's frames are all heartwood white oak glued laminated timber bonded with phenol resourcinol adhesive. The members were manufactured in Wisconsin by Sentinel Structures, Inc.

Andreas

mariner2k
01-11-2007, 07:32 AM
How is resourcinol on less than year old oak?

Roger Cumming
01-12-2007, 12:40 AM
Many years ago I used resorcinal on ash sister frames in a Dragon framed in ash. I used nuts and bolts instead of screws for plank fastenings into the sister frames, the fastenings supplying the clamping pressure for the laminating plus a few shores here and there. It seemed logical and it worked. There was no interior in the boat to get in the way so it was relatively easy.

I've also done laminating of white oak using resorcinal that worked well on parts above the waterline, unaware that others have had problems laminating white oak.

Bob Smalser
01-12-2007, 01:13 AM
How is resourcinol on less than year old oak?

Moisture content must be 15% or lower for resorcinol by Navy Bureau of Ships tests. In 4/4 oak that hasn't completed one full drying season, 15% is unlikely. Borrow a moisture meter to be sure.

A polyurethane like PL Premium Construction Adhesive or Elmer's Probond is required to glue wood wetter than 15%. Neither is a proven marine glue....in contrast, resorcinol has been used successfully to laminate oak frames for well over 50 years.

http://pic20.picturetrail.com/VOL12/1104763/3075040/214182916.jpg

Jay Greer
01-12-2007, 01:24 AM
The US Forest Products Lab has made an extensive series of tests on Polyurathane Glue. The results can be found at:
http://www.fpl.fs.fed.us/documnts/pdf1998/vick98b.pdf
I many cases, polyurathane out performed rescourcinol bonded joints.
According to the report, commercial grades of the new adhesive have been modified to make the product even more effective.
My personal opinion is that this glue may be what we in the boat building industry have been seeking for many years, a glue that will work well when dealing with woods that are historicly nearly impossible to glue with the adhesives that we have depended on in the past.
Jay

Bob Smalser
01-12-2007, 01:28 AM
But poly glues aren't open ended on moisture content, the upper limit being 20%. This from the Gorilla Glue spec sheet:

http://www.gorillaglue.com/pdfs/technicalDataWood.pdf


Moisture of Content of wood varies:
• Most kiln-dried wood is 8 to 10%
• The glue reaction in the glue line will accept moisture content in the range of 10 to 20 %
• When gluing open grain wood, wood with up to 25% moisture content may be controllable

PL doesn't specify recommended moisture contents, but I suspect they are similar. Moreover, my experience using poly to glue green wood is that the wetter the wood, the weaker the bond. I'd be conservative and dry the wood to 15%, whether using poly or resorcinol.

Paul Fitzgerald
01-12-2007, 05:35 AM
Jay, that study seems to imply that the polyurethanes are equivalent to resourcinol in most applications other than laminating. There are also differences between the polyurethanes in water resistance.
The best one to use contains HMR, but the study does not identify brands.
Do you know whiuch brand of polyurethane they were referring to?

mariner2k
01-12-2007, 09:44 AM
While doing some online research, I also read the study on polyurethane. They wouldn't give names of the pu glue, so that remains a mystery. The other thing was some of the poly glues didn't do as well in the boil/dry /boil test. Once again...which ones?
Also just for the heck of it I emailed the PL manufacturers to ask their recommendations. Their reply was "we don't recommend any of our products for boat building", but I'm sure liability was considered in that statement.
It's that old "rock and a hard place". I need would flexible enough to bend the laminates, yet dry enough to glue. A really tight clamping, other than screws, may be difficult. As far as heat, in an older WB thread Bob Smalser mentioned an electric blanket. Simple genius.
As far as moisture content I haven't looked for the wood yet so I'm hoping I can find something suitable.
kevin

Bob Smalser
01-12-2007, 09:57 AM
While doing some online research, I also read the study on polyurethane. They wouldn't give names of the pu glue, so that remains a mystery.

Read it again. It's a 1998 study. They didn't use any of the poly glues available today and have a disclaimer about that up front.

So is PL Premium a better choice than, say, Gorilla Glue in oak frames? Having used both, I suspect so...but I don't really know, and I'd sure like to see a specific test like the Navy did with resorcinol. That's why I say we are on unproven ground using poly glues in marine applications.

Thorne
01-12-2007, 10:26 AM
My admittedly limited experience shows PL Premium to be a much stronger glue than Gorilla Glue -- the latter seems to expand much more, into lighter 'foam', breaks easier. I've had to re-glue several jobs with PL Premium after the GG failed.

This is on dry woods in various household and boat applications. Not on wet woods, no boil tests, just 'common' glue chores. Still don't think I'd consider it for critical elements like frames!

Why can't you dry the oak enough for resourcinol?

Bruce Hooke
01-12-2007, 11:29 AM
Why can't you dry the oak enough for resourcinol?
I think the big problem with Resorcinol on this application is clamping pressure...

mcdenny
01-12-2007, 12:02 PM
Here's a PU glue recommended for marine use http://www.holdich.demon.co.uk/chemical/balcotan.html
sounds a lot like PL premium.

michigangeorge
01-12-2007, 12:28 PM
I read about Balcotan some years ago in Classic Boat. Seems to have been used successfully for some years in the UK. Maybe some Brits can give us some more imput on this.

Bob Smalser
01-12-2007, 01:09 PM
Do not use timber with more than 25% moisture when gluing with Balcotan 100. If the glued piece is transferred to a drier environment the inevitable shrinking of the wood creates stresses which could deform the piece, cause it to crack or split at the joint. Green oak does not glue well with Balcotan 100 as the strongly acid tannin in the unseasoned oak may damage the adhesive.

http://www.holdich.demon.co.uk/chemical/balcotan.html

There's a "Catch 22", if I ever heard one. "Green oak" as I know it is a whole lot wetter than the 25% maximum for this glue....more like 40-80%. What do they mean by "green"? Airdried Oak at their 25% maximum? What moisture content is "seasoned oak"....20% for a keel or 7% for a living room table? Much of the experience with epoxy failures in White Oak indicates a fresh surface that exposes fresh tannic acid may be the culprit, not moisture content alone, and that epoxy works better on weathered surfaces.

Balcotan recommends their product for marine use where none of the other manufacturers do. Is that because Balcotan has a true marine product and the others don't, or is it merely because of a different product liability climate where Balcotan is manufactured?

The problem I'd ponder if I intended to laminate oak frames using poly is which glue? Without further testing, other than the manufacturer's claims, it's impossible to determine the difference between Balcotan above and Elmer's Probond....

http://www.elmers.com/msds/mp9401.htm

....or Gorilla Glue:

http://www.gorillaglue.com/pdfs/msds.pdf

PL Premium is a bit different, a less expensive product with a high isocyanate content for greater stick and thickening agents to make it gap filling where liquid poly's are not....but with good joinery, are there any advantages other than cost, and will any of these hold up as well on White Oak as resorcinol over the long haul?

http://www.osiliterature.com/Image/PDF/sP20130.pdf

As much as I'm growing to like poly glues, I'd sure like to know a lot more before betting a multi-thousand hour project on them.

Bruce Hooke
01-12-2007, 03:54 PM
Do not use timber with more than 25% moisture when gluing with Balcotan 100. If the glued piece is transferred to a drier environment the inevitable shrinking of the wood creates stresses which could deform the piece, cause it to crack or split at the joint. Green oak does not glue well with Balcotan 100 as the strongly acid tannin in the unseasoned oak may damage the adhesive.
What this also says to me is that if you have dry wood and glue it with Balcotan and then the wood gets wet and expands, the glue may well not be able to withstand the stress. This can also happen with epoxy, which is why some advocate coating in epoxy parts that are laminated with epoxy. The only glue I know of that does not (reportedly) have this problem is Resorcinol, but I do not claim to know anything about the poly glues...

mariner2k
01-13-2007, 09:01 AM
Lots of interesting stuff on this thread. So far the only thing I'm sure of is the wood cannot have too much moisture content. I still have time for more research. If anyone else finds out anything.......? One of the problems with a lack of flexibility in the wood is the stringer I need to sneak it under. A moisture meter is a must...then to find a reasonable thickness to rip the wood. Any one who has done this, suggestions are welcome.
thanks all, kevin

Lazy Jack
01-13-2007, 09:51 AM
Why must you use white oak? It seems a different species (Doug fir, black locust, hackmatack) might serve just as well and allow you to use epoxy...

pcford
01-13-2007, 11:16 AM
The US Forest Products Lab has made an extensive series of tests on Polyurathane Glue. The results can be found at:
http://www.fpl.fs.fed.us/documnts/pdf1998/vick98b.pdf
I many cases, polyurathane out performed rescourcinol bonded joints.
According to the report, commercial grades of the new adhesive have been modified to make the product even more effective.
My personal opinion is that this glue may be what we in the boat building industry have been seeking for many years, a glue that will work well when dealing with woods that are historicly nearly impossible to glue with the adhesives that we have depended on in the past.
Jay
Polyurethane doe not look good to me. Conclusion section of test:

CO N C L U S I O N S
The dry shear strength and wood failure
values indicated that the one-part
polyurethane adhesive bonds were at
least as strong as bonds of a resorcinolformaldehyde
structural adhesive on yellow
birch and Douglas-fir. Wet shear
strengths measured after three different
water-saturating test procedures indicated
that polyurethane bonds were as
strong as those of resorcinol. However,
measurements of wood failure indicated
that polyurethane bonds were not equivalent,
and they developed very low levels
of wood failure relative to those of the
highly durable resorcinol adhesive. A
moderately severe two-cycle boil test indicated
polyurethane bonds varied from
high to low resistance to delamination,
while the resorcinol bonds were completely
resistant to delamination. A very
severe cyclic delamination test that qualities
adhesives for structural laminated
wood products for exterior exposure
caused severe delamination of polyurethane
bonds in lumber laminates of yellow
birch and Douglas-fir.

mariner2k
01-13-2007, 11:30 AM
LJ, The only reason I picked white oak at this point is the availability. I not sure of the qualities of locust (strength, resistance to rot), or of the availabilty. I may experiment with doug fir. I assume vertical grain is the best??
PC , as Bob pointed out that was a 1998 study. It would be nice to find a more recent one to see if any of the glue properties have changed.

Bob Smalser
01-13-2007, 11:34 AM
Frankly, I don't know why anyone would be hesitant to use resorcinol.

Make male forms that'll take sufficient clamps, and buy some old electric blankets from Good Will. The only difference between using resorcinol and using epoxy is more clamping pressure and more heat. And high clamping pressure is easier to achieve than the bare minimums epoxy likes best.

MRJarret
01-13-2007, 05:34 PM
As can happen above the bilge, this thread has some good discussion.
Bob Smalser -- If Kevin were to follow your advice for male molds, would you consider simplifing things (and stay in tune with original construction of that vessel) and just steam frames?
Kevin -- I got some black locust (quite reasonably $) from CT, and had it shipped to Thomson's Sawmill in RI. It takes a little more effort, grain-wise, than white oak, but it's beautiful stuff.

mariner2k
01-13-2007, 06:45 PM
Steaming isn't an option here. Too much stuff to go around. And I'm not sure how to construct a male mold, though I'm sure I can do it with an explanation. If I can figure that out, resorcinol it is.
kevin

Bob Smalser
01-13-2007, 07:05 PM
...If Kevin were to follow your advice for male molds, would you consider simplifying things (and stay in tune with original construction of that vessel) and just steam frames?


To steam frames that don't eventually crack under stress, you need oak with almost zero grain runout both radially and tangentially. Preferably airdried oak from the first heartwood beneath the bark of sun-grown trees, too. Many or even most of the cracked frames you find in old boats were caused as much by the sawyer milling it as the builder selecting it.

You won't find that kind of stock in your local lumberyard, and if you can't find it at all, properly-laminated frames will last longer.

Most hardwoods I see marketed to furniture builders have substantial runout on at least one plane, as does much of what's bought from your local Woodmizer operation You should learn how to measure grain runout if you intend to steam bend. Just because you get it in the boat uncracked isn't a satisfactory standard otherwise. From what I've seen for sale, you're better off buying a lower log from an arborist and splitting your stock out with wedges and froe before drying, jointing and planing it.

Lazy Jack
01-13-2007, 09:24 PM
Steaming isn't an option here. Too much stuff to go around. And I'm not sure how to construct a male mold, though I'm sure I can do it with an explanation. If I can figure that out, resorcinol it is.
kevin

TO make a male mould, I'd rip a couple dozen thin lathes from the edge of 2 x whatever construction lumber and cut a point on one end. The point is placed against the inside of the planking and the other end is hot-glued to the face of a plank propped edgewise over where the frame is to go...one end on the keel or clamped to a floor timber or something, and the other end fixed to the sheerclamp. In effect you are building a giant crooked tooth comb with the points of the teeth picking up the inside of the planking. Once you have enough picking up the inside curve, lift the comb out and set it lathe side down on top of your mould stock (probably made up of construction grade SPF or the like. Mark the end of each tooth onto the mould stock, flex a batten through your points and voila! Cut along this line and you have a FEMALE mould. To make the MALE mould, Subtract your frame thickness from this curve and cut along the smaller one. I find a male mould much easier to glue against.

This method will work fine at the midship sections where there is minimal bevel to the frames. You may run into some problems with this method at the ends of a full ended boat where there is a lot of bevel or twist. In this case you would pick up the broader edge of that frame section with your pointy sticks and then bevel the frame by hand once it is glued up...pain in the butt but effective...

mariner2k
01-14-2007, 09:10 AM
Thanks LJ, very simple, very easy. My bow isn't too bad as far as bends. The stern area is by far going to be the most difficult. But that's next year.
Now, in the interest of turning over all stones.... Smith has a glue which is specially made for oak and oily woods. This may have been mentioned. Has anyone had any experience with it?
kevin

Thorne
02-15-2007, 11:30 AM
I recommended it but haven't tried it, as the standard Smith epoxy has worked **for me** on white oak. Why not call them and see if you can talk to him directly -- he is very technical and should be able to answer any questions you may have, and can recommend surface/wood prep procedures also.

pcford
02-15-2007, 12:21 PM
Preferably airdried oak from the first heartwood beneath the bark of sun-grown trees, too. <snips>
You won't find that kind of stock in your local lumberyard, and if you can't find it at all, properly-laminated frames will last longer.



Bending oak should be "green." Maybe that is what you mean by air-dried...don't know. At any case, it is readily available at Olsen Lumber on Aurora in Seattle. Certainly won't find it at a "big box" store.

And I am not so sure about laminated frames. Maybe. The problem is that most people laminate with epoxy. Also, years ago, there was an article about laminations and moisture cycling in WB. If I recall correctly, it was not enthusiastic about member laminations on boats. At least there were a basketful of provisos.

andrewe
02-15-2007, 12:45 PM
Brit. chipping in here: Balcotan have a new version, Type 190 certified as structural to various standards in construction. Highly recomended for boatbuilding. I´m not sure how it compares--PL Premium? Not cheap either at £20 GBP /kg. Google "Melco bonding supplies" and have a look. Not sure about this application either.
Andrew

David Roberts
02-15-2007, 12:55 PM
My .02 is that Resorcinol doesn't need as much clamping pressure as they say. Make up some test pieces with your material and see what you can get away with. Whatever you do, you know it won't be MilSpec. My method of fast aging for glue joints is to run them through the dishwasher a few times. Then test. Try it with a couple of epoxies, too. Whatever you spend on trials, it won't begin to compare to the cost of failure!

You might also experiment with lamination thickness. With that wetish oak, it might make a difference. For example, I find that 3/16" material can be held by glue against shrinking and swelling, but thicker stuff can break the bond. Try drying your test pieces in a slow (under 200) oven after you're done with the dishwasher. If nothing works, you might need to change species.

jimmy
02-15-2007, 03:33 PM
I don't know if I have missed something, but one thing that nobody seems to have asked is why are you sistering ribs? Early on you mentioned that the ribs are in good shape with only a few longitudinal cracks. If this is the case adding sisters just means you have more holes in your planks making them weaker. Assuming you do have a problem that needs to be fixed (make sure you really do) serious consideration should be given to replacing ribs instead of sistering them, repairing ribs, sister placement, sister length, etc.

The subject of laminating white oak ribs and which glue to use has been beat to death, try searching some of the old posts. One of the old posts is mine and I ended up laminating with epoxy and white oak. I used 2 different types of epoxy and although it has only been 2 or 3 years so far there has not been any failure. I took a lot of flack over sistering in the first place rather than replacing ribs, which annoyed me a bit at the time, but now I appreciate it. I think more consideration should be given to whether you are going to do it at all, and if so all the structural considerations rather than what kind of glue to use. Half of the ribs I did (the ones not under ceiling) could easily just be taken out again and re-done if there was a glue failure.

If I was going to do it again, I would try to replace whole ribs first (often not practical), then try to repair ribs with a dished scarf or similar technique, and if I couldn't do that I would laminate in ribs with epoxy like I did last time. I also did a lot of wiping with acetone and tried a special epoxy for oily or acidic wood, but I switched to regular epoxy when the special one was taking too long to cure and often forgot to use the acetone and everything is still holding together.

mariner2k
02-15-2007, 05:47 PM
Jimmy, Unfortunaltely I will probably end up sistering. I'll check the originals more closely, but they are 75 years old and I may have been generous in describing they're condition.
On the swelling and shrinking I'll probably go with 1/4" to 5/16. This shouldn't be an issue. I did contact Smith and was told the wood should be around 12% moisture content. In any event it's to cold around here now to glue. I do have faith in epoxy if applied right.
Clamping resorcinol could be tricky but as David explains maybe I can get it tighter that I think. When the time comes I'll repost to let you all know how , whatever I do, works. Thanks for the help.
kevin

jimmy
02-15-2007, 06:40 PM
My boat is 80 years old. I thought I had to get the repairs done quickly before the boat fell apart. When I got to the part where I wanted to cut out the broken sections of ribs that were causing a hard spot, it was difficult to cut them out with an angle grinder and zip disk they were so hard. There was only slight deterioration (a few mm) inside the break where water had probably been trapped. Other than that the ribs are fine, age has nothing to do with whether you need to replace or sister them.

I won't try to talk you out of sistering your ribs, because I don't know anything about you boat, I just suggest you do a lot of reading, consider all your options, and get lots of opinions before you start putting more holes in your boat. There's lots of good books out there on this subject, but there are also some bad ones so look at several if you haven't already.
J

mariner2k
02-15-2007, 09:12 PM
I can't say I disagree with you. Like a said, a closer look is in order. It is amazing how hard the old wood stays. Minor surface deterioration wouldn't bother me too much, but I'd have to be damned sure it's minor. I know of at leat two that need serious help. I always want to be sure I did my best while the 55' mast is trying to push its' way thru the keel. (Almost sank that way once, off of point judith,RI.... Good story). I've become a big fan of overkill.

zenda
02-16-2007, 12:23 PM
Hey guys,
In the above discussion of adhesives, Titebond III didn't come up, as I hoped it would. According to the manufacturer, it passes ANSI/HPVA Type I tests, is water soluble until cured, and stronger than the wood being glued. I am seriously considering using it to strip-plank my boat; haven't made the final call yet.

mariner2k
02-16-2007, 01:32 PM
http://www.titebond.com/ProductLineTB.asp?prodline=94&prodcat=1

"not for use below the waterline"

Thorne
02-16-2007, 01:43 PM
As long as the boat stays out of the water, TitebondIII should be fine!

;0 )

(in other words, don't go there...)

Bob Smalser
02-16-2007, 02:45 PM
Hey guys,
In the above discussion of adhesives, Titebond III didn't come up, as I hoped it would. According to the manufacturer, it passes ANSI/HPVA Type I tests, is water soluble until cured, and stronger than the wood being glued. I am seriously considering using it to strip-plank my boat; haven't made the final call yet.


Not a good choice. Not because it doesn't stick or isn't waterproof, but it's not repairable...you can't glue over its residue to repair damage....nothing useful sticks well to it.

Picture feathering in a hole repair in a Titebond stripper using epoxy, and you can see the several feathered gluelines that will make the repair unsound because the epoxy won't stick to the gluelines.

I did finally get PL Premium Poly Construction Adhesive to stick to Titebond residue, but I didn't test its strength and I wouldn't bet anybody's safety on it. You can be sure if you sell or give away a Titebond boat, someone will use epoxy to repair it when it's damaged, and may not have a problem until the boat is a mile offshore in a blow.

http://www.woodenboatvb.com/vbulletin/upload/showthread.php?t=6799

mariner2k
02-16-2007, 02:54 PM
Thank God someone (Bob) does there homework. Of all of the research and testimonials I have found so far, I haven't found anything that will make me comfortable with any of the poly glues for this application.

Paul Kessinger
02-16-2007, 04:38 PM
I just laminated up some deckhouse beams and engine bearers using the new Balcotan Super Fibre, a special formulation that has fibers added for strength and to give it modest "gap-filling" properties, which is one of the weaknesses of PU vs. epoxy. The beams were doug fir and the engine bearers fir with a white oak cap . The bearers are also mechanically fastened so I don't have to be superworried about delamination.

Anyway, the Balcotan was amazingly easy to work with since it is a "low foaming" formulation that really minimizes cleanup. With any kind of laminating you get squeezeout. I would have been sanding and grinding and ruining planer blades for hours with epoxy. With Balcotan I knocked off the big globs with a chisel, hit the rest with a block plane and that was it.

I live in Connecticut and was stumped as how to lay hands on some Balcotan, since Melco Bodning wouldn't answer my emails. Then I contacted Robbins Timbers in the UK and they were extremely cooperative and even contacted the British Post Office to see if it could legally be mailed using a cheap overseas parcel rate (it could).

The cost turned out to be about $30 per kilogram, which is, I guess about a liter bottle. Expensive initially compared to epoxy, but if time is money, much less expensive over the long haul.

I'll try to look at the bottle tonight and check the legaleze, but I think this formulation has passed a very high standard in the UK for boatbuilding applications. I've been seeing stripped-planking projects using Balcotan for years in Watercraft magazine, and haven't seen any "oh my God, what a mistake messages" in the letters column.

I guess where I'm coming out is below the waterline and in high-strength applications, I'll stick with epoxy. For general marine glue-up I'm a Balcotan man unless the dollar goes to hell against the pound even worse than it has been.

mariner2k
02-16-2007, 08:07 PM
I read about Balcotan but didn't see anything about it being submersible. I emailed the company and haven't heard back yet. In my predicament I'd like to use resorcinol, but I'm not comfortable with the application environment. So it may be one of the epoxies.

Lucky Luke
02-16-2007, 11:51 PM
http://www.imagestation.com/picture/sraid224/p05042236bddfb60299452e2d61c29ba2/eaa4b289.jpg
These 4 x 4 in. broken frames were repaired (not sistered: plain ugly!) using laminated white oak and resorcinol. Although this was a temporary repair (she now has been re-framed) she sailed hard for about ten years with this. You can see some being already repaired, some waiting for the repair: I did not want to de-frame the whole boat all at once!

Since it was a long process, the lamimation was done with five layers of 5mm. veneer at a time , in order to avoid the glue setting before pressure was applied. Pressure was applied using 8mm. dia. threaded rods in lieu of the (10mm dia) copper clenches that were put in after, and the result was good.

One problem though was the gluing of the new oak to the old one wich was black, hard like rock, and had been iompreganted over the years with...gee knows what! I staggered the lamination in order to do a sort of scarf (with a short ratio: 1/3), but felt I should better rely on mechanical fastenings. So, besides the (few) clenches that take both the old and new parts, had plentyof monel grip-nails to help.

http://www.imagestation.com/picture/sraid93/pe135bf236e6c4165592e9276891bb9a1/fa3e4c3c.jpg
http://www.imagestation.com/picture/sraid93/pd55a8cbb853e4e50622797b6a365dd59/fa3e4c42.jpg

mariner2k
02-17-2007, 09:40 AM
After the ten years was there any problem? My old ribs are pretty much black also.

mariner2k
02-17-2007, 09:49 AM
Since I have time....any info on scarfing vs. sistering? Scarfing methods?
thanks, kevin

Spissgatter W-9
02-17-2007, 01:58 PM
Nearly all of Trine's frames were damaged below the waterline by failure of the original fasteners (galvenized). The previous owner constructed new frames of white oak on individual molds. These were attached to the undamaged, upper portion of the original frames by a scarph joint. The laminations and attachment were made of epoxy with a layer of Reme (landscape cloth) in between.

This was at direction/supervision of an shipwright who used this technique over his long career without failure. He said that without the cloth layer the joint would fail as described above. I'm struggling to remember what kind of material the cloth was made of. It's not fiberglass. I will be talking to him next week and find out if you were interested. Here are some pics

http://homepage.mac.com/george_boggs/.Pictures/Photo%20Album%20Pictures/2007-02-17%2010.51.51%20-0800/Image-77FAC092BEB711DB.jpg

http://homepage.mac.com/george_boggs/.Pictures/Photo%20Album%20Pictures/2007-02-17%2010.51.51%20-0800/Image-77FADC3ABEB711DB.jpg

http://homepage.mac.com/george_boggs/.Pictures/Photo%20Album%20Pictures/2007-02-17%2010.51.51%20-0800/Image-77FB02CABEB711DB.jpg

zenda
02-17-2007, 03:24 PM
Bob,
I just read your glue experiment thread; you exhibited great thoroughness and patience. Thanks for the invaluable information; all the glues out there are bewildering for an amateur. One question: is Balcotan significantly better than the "locally" available one-part poly glues (Gorilla, Elmers, etc)? I am planning a strip/diagonal hull which I will encapsulate in epoxy, and want a one-part adhesive for the wood-wood joints.

zenda
02-17-2007, 03:25 PM
I found this link interesting.
http://www.holdich.demon.co.uk/chemical/balcotan.html

Lucky Luke
02-18-2007, 12:39 AM
Spissgatter: That isa lovely racing double ender, indeed! And thees scarfs a really neat! Thanks for the pics.

Mariner K:
1- scarfing vs. sistering: besides the real problem caused by adding extra holes in your planking, and although sistering (when possible: too many bits in the way sometimes!) is very strong, it is aesthetically unacceptable onn many yachts. Cannot imagine the boat shown by Spissgatter hereabove with sistered frames!!

2: How was that repair after 10 years: just perfect. I could not say the same about the repair of the (broken) stem, though: the lamination was difficult, glue settiing too fast, and it caused some problems.

3- Scarfs: I do not mean it is THE way to do, but it worked onto black, hard and sometimes oily old oak. I cut the staggered scarf joint with circular saw, as shown, finishing with chisel. Easy!

I do not think that anything would have really been able to glue this old wood. I cleaned it with trichlo, and tried the best surface I could for the best gluing, but still relied on mechanical fastening as well: not only the few copper clenches which were in the scarf, but monel ringnails also, as shown on hereafter sketch.

One important thing is to stagger the scarfs. I admit it remains a weak point, excepted those that were below the 20 x 80mm stainless steel floors that had replaced the old iron ones: the *sandwich* was really strong there!

In two places where the break was far away enough from the big stringer you can see on the pictures, I simply replaced a section of frame by a solid oak one, with two classic scarfs, but replaced the copper clenches by countersunk head stainless steel bolts.

I am not able to enter the discussion about the various glues you can find in the US, but I have often used PU glue in old boat reapirs. It might not be the best bonding , but it accepts many old surfaces, and its *foaming* helps filling voids that would be prejudiciable to the wood, causing rot. I have also used this type of glue for some laminations on very resinous larch for making long handrails for a *chalet*(swiss type mountain house), exposed round the year scorching sun, rain, snow, and freezing: no problem at all after five years. Quite good, I would say!
http://www.imagestation.com/picture/sraid224/p7375a3fd12fb32bba089138bc7e2d2eb/eaa23d67.jpg

boylesboats
02-18-2007, 01:54 AM
The US Forest Products Lab has made an extensive series of tests on Polyurathane Glue. The results can be found at:
http://www.fpl.fs.fed.us/documnts/pdf1998/vick98b.pdf
I many cases, polyurathane out performed rescourcinol bonded joints.
According to the report, commercial grades of the new adhesive have been modified to make the product even more effective.
My personal opinion is that this glue may be what we in the boat building industry have been seeking for many years, a glue that will work well when dealing with woods that are historicly nearly impossible to glue with the adhesives that we have depended on in the past.
Jay

By the way, I have seen polyureathane failed where rescourcinol didn't... So, it is a gamble... I still wouldn't recommend polyureathane on boat's stucture...

boylesboats
02-18-2007, 01:58 AM
Hey guys,
In the above discussion of adhesives, Titebond III didn't come up, as I hoped it would. According to the manufacturer, it passes ANSI/HPVA Type I tests, is water soluble until cured, and stronger than the wood being glued. I am seriously considering using it to strip-plank my boat; haven't made the final call yet.

We all have a thread in the past on this subject...
Titebond III is a joke to use in boat building.. I wouldn't use it, if it the last glue on earth...

mariner2k
02-19-2007, 07:50 AM
For what it's worth. I emailed for info on Balcotan and received this reply:


Kevin,

Thanks for the email. Balcotan, once cured, is non-soluble in water and therefore ok below the waterline. It will work well with White Oak as long as it has been seasoned - Green Oak would be a problem as Balcotan would react with the very acidic tannins in unseasoned Oak.
I have attached a fact sheet for your information.
N.B. The thinner the glue line under cramping, the stronger the joint.

Please get in touch if you have any further queries.

Regards,

Andy Vowles


Robbins Timber
8-18 Brookgate
Ashton Vale Trading Estate
Bristol, BS3 2UN, UK
Tel: +44 (0)117 963 3136
Fax: +44 (0)117 963 7927
Email: timber@robbins.co.uk
Web: www.robbins.co.uk

emichaels
02-19-2007, 08:42 AM
FWIW. Aerodux 500 is the resorcinol glue of choice for boat builders laminating white oak. It is no longer being sold in the US due to high the "haz mat" shipping charges.

http://custompak.com/shop.htm (this site is the same as priduct listing below, but search for the resorcinol and you will get more info )

http://www.custompak.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=cp1&Product_Code=046-G1131A-050


This company is however selling the equivalent in the US. This is the company that was selling the Aerodux 500.

Take note of the usable teperature range for the Aerodux 500. 50 degrees F not 70. I have an old can of Aerodux 500 sitting in the shop. It too says 50 degrees. I believe the weldwood brand is 70 degrees though. Now the replacement of demostic Aerodux 500 says 70 degrees at the glue line.

Note: It is possible to get the Aerodux 500 you will just have to pay for a shipper that will do the appropriate arrangements to ship it into the US. via the point of sale in the UK.

Eric

mariner2k
02-19-2007, 10:41 AM
Regarding the temperature range needed for resorcinol glues...
Is a heat lamp appropriate for acquiring a desired temperature?

Bob Smalser
02-19-2007, 11:23 AM
Buy an old heat blanket or two from Goodwill and achieving 70 degrees won't be a problem.

Wax paper, the heat blanket, some insulation like an ensolilte foam sleeping pad or a fiberglass batt, all covered by a tarp will cure domestic resorcinol reliably in 20-degree weather.

mariner2k
02-19-2007, 01:50 PM
Thanks Bob.
Another question. Seeing that green oak is readily available, I was wondering how long it takes to dry (season) when ripped into 1/4" x2 inch strips, stored inside? Flexibility is also an issue. I need to make an S-shaped bend, and sneak it behind a stringer.

Bob Smalser
02-19-2007, 01:58 PM
Thanks Bob.
Another question. Seeing that green oak is readily available, I was wondering how long it takes to dry (season) when ripped into 1/4" x2 inch strips, stored inside? Flexibility is also an issue. I need to make an S-shaped bend, and sneak it behind a stringer.


Depends on how dry the "green" oak is, green being another word for airdried but not yet in equilibrium. Anywhere from a couple months to 6.

For tough lamination bends, you can steam the strips, clamp them into shape, then let them dry to the 15% resorcinol requires.

Also remember that wood at 20-25% EMC steam bends just as well as wet wood fresh from the mill. As keeping fresh green oak fresh and bug-free in large quantities is impossible, oak furniture manufacturers prefer 20-25% stock.

mariner2k
02-21-2007, 10:14 AM
Bob, I'm planning in ripping the strips to 1/4" then laminating them. The problem is time and wood type. I have plenty of access to some nice green oak, which I could rip and allow to dry indoors in a heated environment. I suppose I could rip it dry it and check it with a meter, but if it wasn't ready by the beginning of april, I would have wasted my time. Not to sure on the availability of dry oak. Next question would be...a different type of wood? Any suggestions either on drying or different woods (bearing in mind I'm east coast)?

Sawcutmill, if your watching.....

mariner2k
02-21-2007, 10:21 AM
Bob, a couple of threads ago you mentioned "domestic" resorcinol.
Why do you specify "domestic", and what type is recomended?

Bob Smalser
02-21-2007, 06:44 PM
http://pic20.picturetrail.com/VOL12/1104763/3075040/214182916.jpg

You can buy a basic moisture meter like the one in the center that'll read up to 30% EMC fairly cheaply, and it'll be a small investment compared to lams that don't remain lammed. It's the sawyer's meters on the right that read up to 80% that are spendy.

But if you don't, and you're worried about your oak still being too wet when it's time to build , then try PL Premium construction adhesive, which will work up to 25% EMC, which is fairly wet.

Otherwise, buy oak that's already dry and if you don't want to spring for glue shipped from the UK, use any "domestic" resorcinol sold by Jamestown Distributors or one of the other boatbuilding suppliers.

mariner2k
02-21-2007, 09:07 PM
I thought PL wasn't up to the task? Especially considering the lower ends may sit in the bilge whichis certainly subject to constant moisture? Wouldn't I be better springing for dry wood?

zenda
02-23-2007, 05:02 PM
Have any of you had any experience with the new Titebond HiPURformer? It's a hot glue system.
http://www.titebond.com/ProductLineTB.asp?prodline=80&prodcat=5

mariner2k
02-23-2007, 10:24 PM
http://www.simplicityboats.com/pl_premium.htm

they claim the pl premium for concrete is better. Apparently doesn't swell as much.