Until recently, I had a rather elementary understanding of adhesives. (Elementary in the sense that, like a third grader, I was overly fond of peeling dried Elmer’s off my fingertips.) But woodworkers aren’t into children's school supplies, opting instead for serious-sounding, grown-up glues like aliphatic resin emulsion.
Selecting an appropriate adhesive may seem nonessential, but it can actually make or (literally) break a project. Furniture makers take their glue seriously, and rightfully so — without it, most joinery simply wouldn’t handle the pressures of everyday life. Good wood glues are designed to be even stronger than the woods they are applied to — meaning if a joint were to break, the wood, not the adhesive, would be to blame.
And while glue might turn a cursory mistake into a more permanent position, that's no reason to shy away from it. If you are prepared with some decent clamps (Bessey and Wetzler make the best) and a handy assistant when necessary, you'll be just fine. Once you’ve identified the best adhesive for the job, you can usually just stick to the directions on the bottle — that's if you don’t get stuck to the directions on the bottle.
• Yellow glue – Whatever you call it (polyvinyl acetate, aliphatic resin emulsion or simply, yellow carpenter's glue), this stuff is the closest thing there is to the perfect wood adhesive. It's cheap, non-toxic, easy to find in hardware stores and works without fail. It's used in everything from case construction to veneering — however it does dry lightening fast, leaving you with very little wiggle room. Try Titebond I or Titebond III if your piece will be exposed to moisture.
• Epoxy – Epoxy is usually sold as a two-part solution. Add equal parts resin and hardener and you're left with a smelly, toxic goo that's great at filling loose joints and killing your sensory system. On one hand, it's waterproof and has a long set time, allowing you to adjust your glue joints until they are perfectly flush and square. On the other, it's mighty expensive and dangerous to touch and inhale. Your sense of smell is kinda swell, so wear a mask and gloves!
• Polyurethane glue - Polyurethane glue is relatively new to these shores, having been introduced in the U.S. less than ten years ago under the Gorilla Glue brand. Everyone makes the stuff now and for good reason: it's very strong, water-resistant and takes stains fairly well. But despite what they advertise, nothing fills gaps like epoxy.
• Hide glue - Made by boiling the connective tissue of animals, hide glue dates back to Ancient Egypt. With the advent of the adhesives above, it has become a specialty glue primarily used by instrument makers. Applying heat will loosen the joint, allowing for delicate repairs to be made. Most hide glues must be applied hot and smell like burning hair.
Best of luck with all your glue-ups!
(Images: 1 Sandal Woods , 2 Titebond , 3 West Systems, 4 Gorilla Glue, 5 W Patrick Edwards Inc)
Johnny is currently blogging his experience as a student and amateur woodworker. You can keep track of his projects on his blog, Woodlearner.
© 2009 Apartment Therapy
another excellent & informative post! keep it up; this is great stuff!
view timmy jr.'s profile
I agree with timmy jr. Johnny Williams' posts are among the best on AT. They're always very informative and not just repetitive drivel.
view Daily Nuance's profile
Epoxy can also heat up and catch fire during the curing process, depending on how much you use. I had to pour it into the bow of a kayak I made several years ago, and fire was our biggest concern while it set up.
You also really, really need to use a good respirator when using epoxy - those little paper masks are worthless.
view asinner's profile
I can't believe you posted this- I was JUST looking for a decent woodglue for a home project. Great summary!
view saeras's profile
don't forget (CA) cyanoacrylate (aka "super") glue... great for the right application and there's sooo many more formulas that your dime-store crazy glue. hobby shops often have a good selection: http://tinyurl.com/ycel7j6
view redneckmodern's profile
It's like an introduction that misses half of the useful information, and an excellent example of why -- if you prefer to have pieces like these written by beginners (perhaps because you like the beginner-talking-to-beginner element), I'd suggest you at least have someone review who is not a beginner. Seeing information gaps here makes me wonder what's been missed in other attempts at being informative.
For instance, with yellow glue, "however it does dry lightening fast, leaving you with very little wiggle room" by whose standards? I use this for the vast majority of projects, and while it doesn't have as much open room as epoxy, it does have a more-than-reasonable amount, usually five to six minutes. Furthermore, it can be cleaned up with soap and water (another very important detail you omitted), so if you realize you've messed up, you can undo the piece, wash off the glue, wipe down the wood and start over. What you drip while clamping, you can clean up with a damp sponge.
With gorilla glue, you say "despite what they advertise, nothing fills gaps like epoxy" -- except that epoxy is cruel and unusual punishment for 90% of any gluing projects. With a few notable exceptions (most of which a beginner might not run into, anyway), you can get by with yellow glue, gorilla glue, or a construction adhesive like liquid nails. And gorilla glue's ability to expand and fill all the holes and gaps between two pieces is just as good, or better, than advertised, without epoxy's complex prep and use.
However, gorilla glue, like epoxy, should only be used with gloves. When gorilla glue gets on your skin, it's like the old kind of super-glue: it will not be coming off, not unless you really like taking off the top three layers of skin. Not making that up. It's some nasty, nasty stuff. On the plus side, not nearly half the fire hazard of epoxy, and on the negative side, it's got half the set-up time of yellow glue.
Hide glue is right up there with epoxy glue when it comes to advanced uses. Only times I've ever seen it used or used it myself is for fine woodworking. Adding it here -- as a basic 'intro' for folks otherwise not very sure -- is possibly confusing more than it's really helping.
In a nutshell: if you are gluing, do the two pieces fit together perfectly, pressed up against each other without gaps? Yellow glue will probably do the job just fine. Are there gaps between the two pieces, or just not a perfect match? Use gorilla glue, so the glue can expand into every crevice to make the glued-joint solid.
Failing the willingness to at least be more specific (est. time for "short set up time", solubility & clean-up, etc) perhaps consider linking to additional/more in-depth articles either for each major point or for the article as a whole. Taunton's Fine Woodworking does have free articles on these topics, and they're one of the best storehouses of information for beginners, if you don't want to get into a dissertation here. But at least, then, you wouldn't be giving the impression that this is the most basic need-to-know information when it's barely close.
view k02's profile
I recently bought Gorilla Glue's Wood glue and I a a big fan of it. I am using it to put together a small ikea drawer thing, the one with the 9 little drawers. They provide nails, which suck, so I switched to wood glue. It sets in the perfect amount of time. I used my hands as clamps and held each piece for a few minutes. After it set, they are rock solid.
It also dries more clear instead of yellowish. Very nice.
view jmorey's profile
@k02
this is a good dose of follow up information, but there's no need to lash out at the writer. most of us who have been following this column are invested because it speaks well to beginners and is inspirational to watch someone learning and maturing with their craft. that said, thanks for the info...just be nicer to your fellow woodworker.
view cbauch's profile
A correction does not always constitute a lashing-out, nor would I characterize my reply as such. If that had been my intention, I simply would've said, "this sucked!" and not actually provided the missing information nor suggested ways to improve.
I understand the value of beginners speaking to beginners, but at minimum it wouldn't hurt to run DIY posts past an expert to catch any misleading or confusing gaps.
view k02's profile
(To clarify, my example of negative response is an example only and not meant to imply my reaction to this particular column. Badly worded, above, for which I apologize. Sometimes an edit function would really come in handy.)
view k02's profile
@johnny, I love your descriptions. LOL!
view quiltmaster's profile
As Lloyd Bridges famously said in one of my favorite movies of all time, Airplane!: "Looks like I picked the wrong day to stop sniffing glue!"
I'm glad my article has spurred some debate and appreciate it when readers chime in with additional advice. Keep it coming ; )
view woodlearner's profile
I've had some comedic episodes with Gorilla Glue that rival Lucille Ball's routine at the candy factory conveyor belt. The first time I used it, I was unaware that it swells up into foam and lost the battle as big puffs of it bloomed all along the edges and hardened. The second time I thought I was prepared, applied less glue, and again lost the battle as it dripped and marshmallowed in unforeseen places. Removing the excess required a chisel. Gorilla Glue turns me into a klutz.
Nevertheless, I read an article about its being stronger at joints than the wood itself, and I have two Gorilla-Glued shelves I can hang on without their breaking loose!
view Aulaire's profile