The use of glue reaches back to the dawn of human history. One can imagine the exciting moment when early humans recognized the cementing powers of things like tree sap, egg white, and beeswax. From that moment on, we’ve been dreaming up every kind of adhesive and adhesive application we can think of. Makers should never underestimate the usefulness of glue (with a glue gun, we will join the world!) or the benefits of gluing and fastening.

The 3 Cs of Good Gluing

From Dmitri Monk comes this tip, first included in “Eyeglass Frame Repair” in Make:.

Cleaning Surfaces should be clean and dry with a matte texture. The glue needs a solid, clean surface with a little “toothiness” to bond well.

Clamping Hold the parts steady while the glue sets, or the bond will be weakened.

Curing Give the glue time to set. Straining the bond before it has fully set will weaken it.

Breaking Glue with Canned Air

Canned air allows you to freeze and “break” certain types of glue joints, like those made with hot glue, epoxy, and white glue. You can also use canned air to make hot glue dry faster. Just apply the glue, and then hit it with a quick squirt. [JD]

Using Cyanoacrylate Glue and Baking Soda as Gap Filler

Cyanoacrylate (CA), aka Super Glue, can be mixed with baking soda (you can also use baking powder) to create a strong material that can be sanded, carved, and used for repair, gap filling, and more. Baby powder also works. [DH]

Baking Soda as CA Glue Kicker

You can also use baking soda as a “kicker” to make CA glue set faster. Of course, it adds material to the bond, but in many cases that may not be such a bad thing.

Getting Rid of Glue Strings

If you use a hot glue gun and end up with a lot of unsightly glue strings, you can use a portable hair dryer to zap the strings away. Just be careful not to re-melt your glue deposit or overcook any heat-sensitive parts.

Debonding Hot Glue with Alcohol

You can debond dried hot glue with isopropyl alcohol and cotton swabs.

Keeping Squeeze Tube Caps Lubricated

After using Shoe Goo or contact cement in those toothpaste-type tubes, first wipe the threaded neck after use, and then apply a thin coat of petroleum jelly on the threads only. You’ll be able to twist the cap off with ease every time. [MG2]

Lubricating CA Glue Caps

Super Glue caps always end up getting glued on. To prevent this, spray some WD-40 inside the cap and it will never stick. [JD]

Spreading Glue with a Threaded Rod

To spread glue effectively over a surface, especially a fairly large surface, use a threaded rod as a “serrated” squeegee. First, apply your glue in a zig-zag pattern along the entire surface to be bonded. Then, drag and twirl the length of the rod along the surface to smear out perfect rows of glue. You can also use an old credit card with a zig-zag pattern cut along one edge with pinking shears.

Use Wax Paper When Gluing around Metal

When doing glue-ups using bar clamps, the wood glue can sometimes chemically interact with the metal of the bar and stain your wood black. To prevent this, and to make cleanup easier, place wax paper over the bar clamps beneath the project before clamping. [IS]

Salt Your Glue to Prevent Board Traveling

If you’re gluing pieces of wood that might move during the gluing and clamping process, sprinkle a very small amount of table salt over the glue. It will create just enough friction to prevent the boards from traveling. You can also help prevent unwanted travel by tacking the pieces being glued in a few strategic places before gluing. [IS]

Consider Prefinishing

Prefinishing some projects can be a good idea, because it allows you to finish each component before it’s assembled. If you do this, first tape up all of the areas to be joined so that you will get a good wood-to-wood bond during assembly.

Shaving Glue at the “Gel” Stage

There is often debate about the best time to remove excess glue from a glue-up. Some builders wipe it away immediately with a damp cloth, whereas others wait for the glue beads to be completely dry before shaving away the rest with a chisel. One other recommended method is to wait for the glue to gel, about 15–30 minutes, and then shave it off with a very sharp chisel.

Create an Impromptu Clamping Jig on Your Workbench

If you want to glue something and you don’t have suitable clamps, fasten two pieces of scrap lumber down to a work surface so that they’re parallel and slightly wider than the workpiece to be glued. Place your glued-up project between these wedges. Now, use shims between the wedges. The shims are there to hold the glued workpiece firmly in place. [IS]

Using Hot Glue as an Impromptu Clamp

If you don’t need a high degree of clamping pressure (e.g., when you’re using a router), consider hot-gluing the workpiece right onto your bench. By gluing instead of clamping, you have the entire surface of the workpiece free for the router to travel over. When you’re done, it’s easy to whack or pry the piece free from your table. [JD]

How Not to Test if Hot Glue Has Set

Never use your finger to check to see if the hot glue has dried. It hasn’t.

Heal the Burn

Hot glue can stick to your skin and cause painful burns, and it’s nearly impossible to remove until after it solidifies. It’s a good idea to keep a bowl of cold water nearby so you can dip your hand in it and cool the glue faster to minimize the burn.

Using Cheap Paint Stripper as Solvent Cement

Unless your application is critical, cheap, liquid paint stripper from the hardware store (not the gel, paste, or color-changing varieties) is a fine substitute for commercial acrylic solvent cement. Comparing one material safety data sheet (MSDS) to another, we see that each product is about 75 percent dichloromethane (aka, methylene chloride), which is the “active ingredient” that softens the plastic and allows it to weld. Purpose-made acrylic solvent is a bit thinner, evaporates a little faster, and contains trace amounts of acrylic monomer that may result in a slightly stronger bond, but for most practical purposes, these qualities don’t justify paying twice as much for it. [SMR]

Combining Hot and PVA Glues

If you need the long-term bonding power of say, PVA wood glue, with the immediate hold of hot glue, you can have the best of both worlds! Apply the wood glue all around the outside of the surface you wish to glue, but leave a place in the center dry. Now, apply hot glue to that area and join the piece. The hot glue will bond immediately, and the PVA glue will dry more slowly, leaving you with a piece that is immediately workable, but still bonded for the long term. [IS]

Prototyping with Hot Glue

Don’t forget to think about using hot glue as a prototyping adhesive. You can quickly glue up the test parts for a build. This will make them strong enough to hold together to see if everything works, but weak enough to be taken apart again to make changes and before final assembly.

Bond Sticks of Hot Glue as You Feed Them

If you’re feeding a new stick of glue into most glue guns, and it hasn’t been grabbed by the feeder mechanism yet, it will fall out while you’re gluing at certain angles. To prevent this, dab a bit of hot glue on the end of the new stick before you feed it in, and join it to the stick currently being fed through the gun.

Hot Glue as a Sealant

You can use hot glue to form a reasonably strong watertight and airtight seal.

Use Hot Glue as an Electronics Insulator

Wireheads have known about this trick for a long time. You can use hot glue to hold wires in headers, insulate wires and components on a PCB, and otherwise encase your electronics in plastic. If you decide you want to remove the glue, a small amount of denatured alcohol along the edges of the glue blob will break its bond.

Use Hot Glue to Create a Mold

If you want to create a quick and dirty mold for a crude casting of a small part, just lay down a healthy deposit of hot glue, and before it dries, press the object you want to cast into it to create a mold. You can also use hot glue as a casting medium. For instance, silicone ice trays work really well for casting hot melt adhesive.

Use Hot Glue to Seal the Edges of Foamcore

If you’re working on a prototype, craft, or modeling project where you want the edges of your foamcore to be sealed, one easy way to do this is with hot glue. First, you have to make a little tool out of scrap foamcore that spans the width of the foamboard you wish to seal. Then, you simply run a bead of glue down the edge of your workpiece and use your tool to scrape off all the excess and ensure a complete seal.

Use a Straw to Scoop up Squeeze-out

There are many techniques for, and much debate over, how to deal with squeeze-out, the excess glue that squishes out from two bonded workpieces. Trying to remove squeeze-out from an inside corner can be especially challenging. This tip from WoodSmithTips shows a clever way of using a plastic drinking straw to scoop up squeeze-out from inside corners.

Create a Water-Resistant Mixture with PVA and . . . Water

You can create a water-resistant solution, for treating things like a fabric shower curtain, by soaking the fabric in a mix of PVA glue and water. PVA is not waterproof, but it will add water resistance. Carpenter’s glue is waterproof, so I guess you could mix that with water for true waterproofing? [AL]

Needle Bottles and Capillary Action

You can buy 10-packs of 30 ml, needle-tip glue bottles online for under US$10. If you put your CA glue in one bottle and the CA accelerator (aka a “kicker”) in another, you can use capillary action and a kicker to very quickly glue up plastic, wood, and other materials. You simply hold or clamp your pieces together, run a bead of glue along the joining edge, followed by a swipe of the kicker—done. If you watch YouTube videos of seasoned plastic scale model builders, you’ll see most of them very quickly assembling a model using a needle-tip bottle, a kicker, and capillary action.