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Written by Terry Dunn
A builder’s guide to common adhesives
How-to
As seen in the October 2013 issue of
Model Aviation.


There’s a television commercial that reminds us to shop around for car insurance every six months, lest we miss out on a better deal. Maybe we should apply similar logic toward the glues we use. If you haven’t scanned your hobby shop’s glue shelf in a while, you may be unaware of some contemporary offerings.

As new materials have been ushered into the modeling realm, so have new adhesives. Likewise, new modelers are often unfamiliar with some of the classic hobby glues that have stuck around.

This article is not intended to be a comprehensive catalog of modeling glues, but is meant to serve as a broad overview of what’s available. This article also avoids the technical aspects of how and why glues work and behave the way they do. Chemistry never was my best subject, so I’ll stick to the basic properties and practical applications for each of the listed glues.




Polyurethane glues expand as they dry and fill gaps. This is useful when repairing damaged models.


In no particular order, the glues I’ve chosen to discuss are:

• Cyanoacrylate (CA): This is the most popular type of glue in all of modeling. I’m comfortable making that assumption. Thick, thin, foam-safe—at least one type can be found on nearly every modeler’s workbench.

Yet, CA is also one of the most hazardous glues on the list. Who among us has not glued his or her fingers together, ruined a pair of jeans, or cried from the fumes? Most of us are willing to accept and manage that risk for the reward of strong and immediate glue joints.

• Polyvinyl acetate (PVA): Most of us have been using (and perhaps eating) PVA glue since grammar school. Whether you call it Elmer’s Glue or white glue, you already know that it is ideal for attaching raw macaroni to construction paper. It is also useful for gluing balsa airframes together.

Yellow Carpenter’s Glue is also a PVA glue. It tends to be a tackier than white glue when wet, which is often useful.

• Canopy glue: Although canopy glue looks similar to common white glue, it performs differently. Canopy glue bonds well to nonporous materials and remains flexible when dry. These properties are what make canopy glue well suited for attaching plastic parts (such as a canopy) to the skin of a finished model.

• Goop: This household glue has a strong odor until it dries into a rubbery consistency. It sticks to nearly anything, but it will dissolve some foams (always test first). It works great on vibration-prone joints.

• Cellulose glue: Modelers have been using cellulose glues such as Ambroid for decades. It is still a favorite adhesive for weight-conscious and/or nostalgic builders. Cellulose glues can be thinned with acetone to the desired consistency and applied with a syringe for extra precision. When dried, the glue is lightweight and easily sands.

• Contact cement: There are many types of contact cement but they work in the same basic way. Glue is separately applied to each of the mating parts and allowed to dry, then the parts are combined for a quick bond. This is a popular adhesive for sheeting foam wings and building foamies.

• Epoxy: A longtime favorite for high-stress joints, two-part epoxy is hard to beat when strength is the main objective. It requires careful mixing to ensure proper curing and deliberate application to avoid excess weight.

Epoxy is available in versions with various working times (5-minute, 30-minute, 1-hour, etc.). There is an art to dispensing each part in equal amounts and also sizing the batch to have the right amount of epoxy for the job.

• Hot glue: Hot glue is applied using a gun-like, heated applicator. The low-temperature versions of hot glue can be applied directly to sheet foam without melting it. The quick drying (cooling) time of hot glue makes it ideal for assembly of flat foam models. Keep in mind that hot glue joints can get brittle in freezing weather.




Hot glue is handy for quickly assembling sheet-foam models. This fancy glue gun has a variety of applicator tips. Even inexpensive glue guns are effective.


• Polyurethane glue: This glue expands as it dries, making it ideal for repairing crashed models. Bond strength can be improved by poking holes in the mating surfaces. It can also be used for initial builds. Water (including humidity) is the catalyst that kicks off the curing process. Care must be taken to keep the bottle airtight between each use to prevent curing.

• Water-based polyurethane: This easily applied, brush-on liquid can be found in the household paint section at your local hardware store. It provides a lightweight method for adhering fiberglass cloth to balsa or foam models, although it does not provide the same degree of structural rigidity of an epoxy-based finish. It can also be used to laminate foam sheets together.

You may have a favorite glue or two that isn’t on this list. Be sure to share that secret adhesive with your flying buddies. More importantly, watch for new glues. It appears that there is always something new, and this week’s release might be what you’ve been looking for!

Learn more about building!

[Editor’s note: Because there are so many types and brands of adhesives, we don’t have the space to list websites for them all. A search of the Internet or a visit to your local hobby shop or home improvement store should provide any additional information you might need.]

—Terry Dunn
terrydunn74@gmail.com






7 comments

For those of us that are allergic to Epoxy, especially during the curing stage, what glue is recommended that is nearly as "robust"..?

Do you know what glue is used to send credit cards or attach paper to non-porous surfaces? It looks like its put on with a tube and then the card or paper is flatten down on the glue. It's very sticky but doesn't stick to itself very well. This stuf would be great for mounting servos to anything. I've tried to find it via Google, but no luck. Thanks.

Beginning in 1967 I built my first rc plane.
I used a bonner rc radio system. I have always
used Titebond Glue. Buy it by the gallon.

Thanks

Why can't they fix CA so it doesn't attack your respiratory system.
One whiff and I can't breath through my nose for days.

Good basic knowledge .................... thanks

I sure wish Ambroid was still available.

Very informative. Any way to get a line card of all these products??

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