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Glue for laminating outdoor lumber

Pattnmaker

Stainless
Joined
Nov 2, 2007
Location
Hamilton, Ontario
Anyone have experience laminating fir in an outdoor application? I am currently quoting a job where I will need 12"x3" (dressed not nom.) douglas fir or WRC planks. I am looking at buying 4"x6" and 4'x8" and gluing them together as I have not had luck finding 4x14" planks. Some of the planks have to be cedar and I plan on epoxy for them as I have had issues in the past with gluing cedar. But I am wondering if I can use titebond 3. for the gluing or maybe a polyurethane glue even though I hated the polyurethane glue when I used it in the past.

These parts are not highly stressed and will be stained, but will be out fully exposed to the weather. Epoxy is the safest bet but there are a lot of these and the added expense of both the extra cost of the epoxy and the extra time to epoxy them will be significant as there a lot of these pieces we are looking at about 10 000BF. On the other hand I don't want to take any chances.
 
I used to buy redwood & cedar that size (12 x 4) from Industrial Wholesale Lumber co, in Cleveland, but apparently they are out of business. (WATTS # reaches a medical facility). They had stuff as big as 16 x 24 probably 40' long in the yard, and resawed whatever you wanted out of it. Not dried, though.

More rencently (past 5 -7 years) I bought big cedar from Canada wholesaler at pretty decent pricing. Would have to look up source. But again, pretty much any size you wanted.

If you intend to glue, be sure the material is dry in the middle, under 12%.

I used to use (35-40 years ago) Phenol Resorcinal, but WEST epoxy is so much easier and more forgiving/reliable.

I would never use Titebond for an exposed exterior app. If it is covered, it may work ok. But if by exterior you mean it routinely gets wet, even from rain spray, I would stay away from it. Go on the Titebond website and read the technical specs. It's strength falls off incredibly, even extrapolating to 100°F which is another factor in exterior exposure. I know Epoxy is not very good at temps over 140 or so, but on the aggregate of features, WEST epoxy mixed correctly with the correct fillers (cotton flocking for bonding) & applied on the appropriate schedule (observe absorption characteristics of the substrate) is multiples better than anything but P-R, and easier and more reliable to use.

If you are gluing up anyway, can you laminate 2 x 4's on edge? They might be easier to be had dry though a lot more lumber is lost to face jointing and planing for flatness.

I used to glue a lot of exterior woodwork, especially bent stuff. This job is more recent, hadn't really done as much landscape stuff for a while since moving to upstate NY from MD in the early 90's.

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smt
 
Back in the '35 Packard wood days, I left a drop from a White Oak laminated member out in the rain for a bit. Glued with T88 Epoxy, it literally fell apart. I always assumed the swelling and then shrinking in the sun did the trick
 
Where are you finding failure above 100 degrees F. I just looked at their website And I get this brochure Titebond III: Ultimate Wood Glue Which talks about it being boiled in water at 145 degrees F to pass the ANSI standard.

These are going to be just flat panels. At this point I am quoting based on epoxy, but would really like to avoid it.

Looks like we cannot get the 16/4 in C select and it will not be fully kiln dried. Even getting surfaced dried is an extra 4 weeks delivery. Looks like we are going to laminate this up out of 4/8 lumber or maybe 8/4 and 6/4.
 
I can't seem to link directly to the page and I don't know how to take a screen shot.

Go here:

Titebond - Product

Then click on physical properties.

At the rated 4,000PSI room temp, only 57% of the failure is in the wood. (43% of joints are not as strong as the wood, in a simple shear test)

at 150°F Overnight the strength drops to 800 psi, & 0% failure is in the wood.

Good luck with it, maybe it will work for you. I'd be happy if someone else runs the test on this product.
Call Franklin/Titebond, you are probably going to need enough to interest them, and see if they will warranty your product.

The limitations guidelines & application guidelines are worth reading. Few have the ability to attain the PSI necessary for ultimate bonding within the assembly time frame. Open times can be a factor on large laminates without automated clamping. Epoxy is nice because it is a strong gap filler, surface prep and contamination is less of a factor, and it does not require much pressure. Sanded surfaces bond best with epoxy. Titbond and other glues need near perfect knife finishes for best bond.

I'd call both WEST, and Titebond, and see which one made me feel better about their product. If the product will be submerged, maybe even call a phenol resorcinal supplier. That takes perfect joints & hellacious PSI clamping, too, though.

smt
 
I'm sure that size cedar is out there.

If you have to glue up, neither titebond nor epoxy would work very reliably with wet lumber (over about 12% mc in the center) Epoxy would rather bond with water than wood, so despite its huge affinity for dry wood, moisture is something of a poison to the reaction.

About the only glue that might work up past 15% could be phenol resorcinol. But I would research that thoroughly. I used to use it with pressure treated lumber after machining the glue surfaces flat. (which also removed the surface Wolman salts and some of the densest chemical layer)

Anything over about 15% still has free water as well as unbound water in the cell walls and will stress any joint immensely when it does dry.

smt
 
I concur with Thomas about Phenol Resorcinal, I made a outdoor swing for my dad 35 years ago using resorcinal and red oak. Joints are just as good today as they were when I made them.

Tom
 
Plan right now is laminate from dry lumber using epoxy. Specs are quarter sawn lumber which makes getting the timbers cut to 14" wide hard to find. As well that big they will be green or surface dried only. I don't want to risk major cracking 6 months down the road, as these parts will be out in the open subject to full sun wind and rain. I would rather not get the job because I am too expensive than risk major cracking due to green lumber.

Thanks for the link. I will be discussing this job with Titebond and probably gluing up small sample blocks and put them in the yard here for future reference. 100 degrees f is rare where these are going maybe 1-2 days a year in a typical year. Even in full sun with a medium colour stain I cannot see these getting anywhere near 120f let alone 150. That being said when I make samples I will paint one of them black and make sure it has good sun exposure.

i will look into Resorcinal but I am not sure I can get it in Canada because of toxicity.
 
Polyurethane glue from Richelieu, it is a German brand and very good.

I glued up some 2" x 8" x 12' long boards (they weren't even jointed very well) and put them on top of a concrete wall cap to cover up the brick wall. (cedar shingled the ugly wall) Full exposure the the elements and west facing sun, to my knowledge they are still there 20+ years later.
I was waiting for them to grenade in the first few years but nothing happened and the glue joints held very well, perfect.

I would not hesitate to use Poly for this application, a reasonably good jointed edge and good clamping pressure will result in a very strong joint.

Of course sourcing the correct size will save you a lot of time and hassle.

Lots of that wood out here on the wet coast.

Good luck,
Michael
 
Sorry to resurrect this old thread. I was looking around for this exact information and found it very informative - thank you. Stephen, Those arches are very cool. Just to clarify, you laminated those with the West Epoxy System? Any further words of wisdom you could impart? Ive got a job that includes some laminating and Ive not done it to this degree before.

Already I have more info than I started with so thanks for that.

Andyboy
 
West System epoxy is used successfully in wooden boat applications. I have used it myself with fir with good results. Resincol is also used and as previously mentioned, requires extra attention to joint prep (little gap filling properties).

Two additional observations. Some epoxy formulations are subject to creep. So engineering the joint (potentially backing it up with screws or mechanical joints) might be required. Also, epoxy has a harder time with oily woods. So while gluing fir is straightforward (no particular concerns about adhesion or gap filling) other oily woods (like Teak) require an acetone wipe-down immediately prior to applying the glue to strip the oil from the surface and from the pores on the surface.

Jamestown Distributors in RI has a great catalogue and technical service department that can help with specific applications.
 








 
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