What waterproof outdoor glue?

[Randall J Cox]

I'm getting ready to build two 52" dia octagon back yard (non covered) picnic tables, one for me and one for my daughter. I bought approx $600 of white oak for the project (should have some left over for other smaller projects). I am replacing one I built for myself over 20 years ago out of redwood as its falling apart (used Penofin oil on it for years). I have titebond 3 (advertises as waterproof) or maybe I should buy some epoxy. I live in central Calif, mild winters (lows of 24 sometimes) and hot summers, low humidity. My question is what type of glue would you use, Titebond 3 or epoxy? I have designed to take into account a little expansion and contraction. And also, would you oil it or leave it be and just let it weather? If oil, what have you used that you would recommend? Thanks. Randy

[Chris Padilla]

Well, let me tell you my experience thus far and I don't live too far from you. I built a bench/pergola out of ipe. I decided to use (poly) Gorilla Glue (GG). It is supposed to be good for waterproof and good for oily'ish woods. Well, some of the decorative pieces I glued together (to make corbels to hide hardware) failed right at the joints. I did NOT wipe the ipe prior to gluing the boards together. Other sections that I glued and screwed, are fine...likely due to the screws. So I'm not so sure I'd recommend GG.

TB-III is supposed to handle such situations fine so I'd go for that one and see how it does. Epoxy, for sure, would do fine but it is kinda spendy. One trick I heard is to flood the wood with epoxy wherever it meets the ground. Likely, it'll be end-grain that meets the ground and for sure, it soaks up any moisture it comes into contact with. The epoxy will seal it and prevent that. You could just as easily flood it with TB-III.

As to what finish you want, natural weathering or semi-yearly oiling, is entirely up to you. I oiled my ipe and used a product specifically designed for ipe (it is called, you guessed it, Ipe Oil).

[Brian Williamson]

I used TBIII on some frame and panel WRC gates a few years ago. The glue is holding up just fine. I'm on the central coast of CA so my weather is a bit different, so YMMV.

[Chris Fournier]

Plastic resin glue hands down. Pre-catalyzed powder version is relatively inexpensive and has never let me down. Make sure your glue up is in a 70 degree F environment!

[John TenEyck]

TB III if your joinery is good and you are cheap, PRG if you are less cheap, and epoxy if your joinery is not that good, you don't mind spending a little more, and you hate taking risks.

And just to show you I have nothing against TB III, I built a little bird feeder about 15 years ago. I glued up the top out of three pieces of 3" wide redwood, using TB III for the butt joints. It sits outside year round in western NY, with no love at all on my part. The top is curled, but those joints are still tight!


John

[Randall J Cox]

TB III if your joinery is good and you are cheap, PRG if you are less cheap, and epoxy if your joinery is not that good, you don't mind spending a little more, and you hate taking risks.

And just to show you I have nothing against TB III, I built a little bird feeder about 15 years ago. I glued up the top out of three pieces of 3" wide redwood, using TB III for the butt joints. It sits outside year round in western NY, with no love at all on my part. The top is curled, but those joints are still tight!

John

Good answers, thanks! Interesting as I just built a birdhouse out of redwood and edge glued the joints with TBIII and its out in our garden (wifey wanted). However, only been out there a couple of months. Depending on what others say, might just use TBIII. Just hate to take risks, as you put it, with $600 worth of white oak and all the work I'm putting into these two tables. Its between that and the plastic resin that our Canadian friend recommended. Randy

[Mel Fulks]

Titebond can be really slow setting on redwood. For that reason I prefer to avoid it. Once cured it's fine. I found this out after having to call one of their reps about a glue up that was not setting .

[Wayne Lomman]

Epoxy. Not worth using anything less. Cheers

[Paul K. Johnson]

I would go with epoxy as well. For something like this I would not use anything I hadn't tested personally in similar conditions.

[Michael Dye]

If your joints are tight, I would take a shot at using PL Construction Adhesive. This stuff is amazing. Any outdoor project I build has this stuff in it and I have yet to see a failure. And I am a huge fan of TBIII, as well.

[Randall J Cox]

As I have not used epoxy in woodworking before, what brand do you use? And whats open and cure times normally? Randy

[Paul K. Johnson]

Slower cure epoxy is better than fast cure. It's stronger and less brittle. Any major brand will work. I'm currently using West Systems (as of last year) but for nearly 40 years I just picked up whatever was in the store I went to - usually Devcon.

I never use anything faster than 30 minute. If you order online be sure you're getting Adhesive and not epoxy for composites (sometimes called "Laminating Epoxy). Stuff for composites has a very low viscosity to easily penetrate the various cloths used (fiberglass, kevlar, carbon fiber, etc.)

Also I see tons of guys on youtube mix epoxy on a porous surface and then they just swirly it a few times. It needs to be mixed thoroughly and it's a good idea to let it set for a few minutes and then stir again.

I use plastic cups - usually one ounce medicine cups (I bought a case of 5,000 of them). But cleaned out yogurt cups or whatever you have that's plastic, metal or glass will work even though I think glass is a very bad idea in the workshop.

In the past few years I've started weighing epoxy when that's how it's supposed to be mixer per the instructions. Before that I used the graduations on the cup to measure. Some epoxies are by volume so that would be the right way to go but some are by weight.

So I put my cup on an accurate postal scale, press the Tare function (to zero out the weight of the cup) and then add both parts of epoxy. If I'm mixing a large batch then I dispense into separate cups. I put one part in a cup more than large enough for both parts. Then pour the other part in, mix well, wait a few minutes, mix again and apply.

I don't do anything special to prepare the wood. But you do want it to grab so having some texture is good. In other words, don't sand to 15,000 grit. 80-220 is a good stopping point, then wipe off the dust and tac rag.

[Brad Shipton]

For this type of project I would use West 610 epoxy. That product is thicker and has a mixing tube so you can use a standard caulking gun. You can find it at boat repair shops. It was about $20 per tube here in Canada, but due to the mixing head in the tube you do not get the same volume of adhesive out of tube that you do with a tube of caulking.

PL Premium from the local hardware shop is another good option. It is a structural adhesive, easily applied, and also easy to find. It is a polyurethane, so cleanup is not nearly as nice as TBII or even an epoxy. I have glued down concrete cap stones for a retaining wall with this and it works very well. I did some testing with different adhesives when I made some flooring borders as well. The borders were made of 1/2" baltic birch with a 5mm thick wear layer of tigerwood. I submerged the wear layer into water, but made sure the baltic birch substrate was not submerged. After three days being submerged the bond between the two did not fail.

I know where Chris was coming from with his project, but I would not fully discount gorilla glue either. IPE and some of the other tropical hardwoods are unique when it comes to adhesives. They are far denser than your Oak and these woods are far more likely to win the war when it comes to the fight between wood shrinkage and glue bond. I completed a deck project in Cumaru that was comprised of many many glue ups. For some parts I resorted to veneering 1/16" Cumaru to a stable substrate after I found that the adhesives would not hold up over the hot summer/cold winter months. In other areas that are more exposed to the weather I opted to replace parts with a different wood that looked similar. Unless this wood is dried perfectly it will break virtually any bond if it twists or dries. IPE/Cumaru and others like it belong in tropical climates where the wood is happiest. At the end of that project my conclusion was the only option to connect parts made with these woods is to use screws if the finished product is outdoors. You can read about a guys disaster project on the woodweb where he tried to use an IPE floor indoors.

[Mike Cutler]

Randall

Here's an old thread, that should be an article, to make it easier to find, on the subject of glue/adhesives. There is a lot of info in it.
I don't know if Bob is still about these days, but he's a fabulous resource.

http://www.sawmillcreek.org/showthread.php?21822-Are-Your-Glue-Joints-Repairable

[Larry Edgerton]

I have a two story round Victorian gazebo out there for over thirty years now that is all CGV redwood bent laminated over forms on such things as the railings and facias. It is still in perfect shape except where the landscapers decided that the sprinklers should water the railings. I used resorcinal [spelling?]. Its cheap, easy to work with, and lasts a long time.

I get rid of Titebond 3 on my cloths by soaking for a day before washing. I do not believe it is good enough for outside, at least not in my climate.

Epoxy would be second choice. West System is my epoxy of choice.

Just thought I would confuse the issue............

[Mel Fulks]

Would love to see photos of the gazebo,Larry. Interesting point about the soak removing the Titebond 3. But I suspect that the stuff needs a certain full cure time. Lot of testing has to go in to legally saying "waterproof". But since tannin can slow down full cure of Titebond the rescorcinal was a great tried and proven choice.

[andy bessette]

For this type of project I would use West 610 epoxy...

I wouldn't use six10 by itself. You really need to prime the wood with neat resin/hardener first.

[John Piwaron]

My experience is this - years ago I built the NYW outdoor planters and benches. To do that, I bought cedar 2x4s and x6s from HD. I did what I had to do with laminating them and otherwise cutting them to size to get the dimensions needed for the project. I used gorilla glue for about 1/2 of the parts and joints and titebond 2 for the other 1/2. After many years of living outdoors they didn't fail through any fault of the adhesives used. Eventually the cedar in the planters began to rot. Initially I used a Sikkens Cetol product to finish the benches and latex paint for the planters. I've rebuilt the planters with my own modification of Norm's design to allow assembly using Dominoes. At that time I chose to use the Rot Doctor product to try to seal the cedar, especially on the ends against water. Following that, I used latex primer and paint on the planters. The benches are the same ones I started with. Except now I stripped and refinished them with Epifanes clear gloss varnish. I think the Epifanes holds up better than the Sikkens Cetol.

Bottom line - I think gorilla glue or ordinary Titebond 2 are completely up to the task of outdoor use. My qualifier is this - in the woods I've used those adhesives in. Cedar & redwood. There's a little bit of redwood in the replacement planter boxes.

[Randall J Cox]

Well, after reading all these replies (and learning a lot), although I tempted to use my existing TB3, with $600 worth of wood I ordered West 610 epoxy. Thanks for all the insight, looks like a couple of options in reality. Randy

[Randall J Cox]

OK, one more Q. I'm end butting the 8 perimeter pieces and going to join with epoxied splines. The oak perimeter pieces are 13/16" thick. How thick should I make my splines? I was thinking 3/8" or is 1/4" better? 1/4" seems a little too weak to me, the splines will be 1 1/2" wide. Randy

[Larry Edgerton]

You already may know this Randall, but make your splines with the grain running across the joint, not with it. 3/8" does not leave much on either side, I would opt for 1/4" myself.

[John Piwaron]

OK, one more Q. I'm end butting the 8 perimeter pieces and going to join with epoxied splines. The oak perimeter pieces are 13/16" thick. How thick should I make my splines? I was thinking 3/8" or is 1/4" better? 1/4" seems a little too weak to me, the splines will be 1 1/2" wide. Randy

1/4"

But just for fun and because I have the bit for doing it, I might try making a finger joint. But that's just me. :)

[Randall J Cox]

After doing some test cuts, settled on 5/16" (more than 1/4 and less than 3/8). Took lots of tweaking to get it exactly centered...as I will have to turn over each piece to cut in from the pointed end to have no tearout on the outside part that will be seen. Randy

[Randall J Cox]

Ok, one more question to those who recommended West Systems 610 epoxy. I bought two tubes of the stuff. I see that it mixes in the nozzle so its premixed when it comes out the end. This also tells me the mixing nozzle is a one time shot as the mixed epoxy will harden in the nozzle. So I'm guessing that you don't use the nozzle and just dispense a little bit at a time and mix and use? Randy

[Bob Michaels]

Ok, one more question to those who recommended West Systems 610 epoxy. I bought two tubes of the stuff. I see that it mixes in the nozzle so its premixed when it comes out the end. This also tells me the mixing nozzle is a one time shot as the mixed epoxy will harden in the nozzle. So I'm guessing that you don't use the nozzle and just dispense a little bit at a time and mix and use? Randy
Randy, the nozzles are not reusable from session to session for the reason that you stated. I remove and discard the used nozzle at the end of a session and replace the small divided plug into the end of the cartridge and then replace the threaded "nut" that holds it secure. Make sure the plug goes into the correct 1/2 of the cartridge tip so you don't mix hardener with resin. One nozzle comes with each tube and i buy extra bags of nozzles for multiple session use of the same cartridge. Without cross contaminating hardener and resin, the cartridge will have an indefinite shelf life. The 610 product is spendy but i like it. I'm a big fan of West System products and have used it for years. I also believe in wetting out the surfaces with conventional West System epoxy before applying 610.

[Brad Shipton]

Buy extra mixing tips and be careful not to get hardener on the resin where it exits the tube. You can re-install the end cover after using and then install a new tip whenever you need to mix more. The epoxy does cyrstallize somewhat after many many months, so do not buy a ton extra.

[andy bessette]

I have used WEST system epoxy professionally for ~40 years and have never once seen the need to use six10. It is extremely expensive and does an inferior job, by itself.

[Paul K. Johnson]

I didn't think the price of the mixing tips was worth it. I just weigh the epoxy on a pretty decent postal scale. I also have the metered pumps for West epoxies which pump out way more epoxy than I ever use. I think they're accurate but I just pump out what I need which is 1/4th-ish of a full pump stroke.

Edit: If you really wanted to you could soak the tips in lacquer thinner and use pipe cleaners to clean them out. That would be a good option if your time is worthless. :)

[Randall J Cox]

Ok, one last Q on epoxy. I have started to use the two tubes I bought. I don't use the mixing tip, just squirt into a cleaned out yogurt cup and mix and spread. I have tried to find the answer on u tube and all over the place, no luck. So my Q is, am I supposed to brush the epoxy on both pieces of wood before bonding or will just one do if he layer is thick enough? (I did learn not to over clamp in my research.)

[andy bessette]

You are supposed to saturate both surfaces, first, with WEST epoxy resin/hardener mix, and then apply the thickened epoxy glue, in this case six10.