Choosing the Right Glue

The glue you choose to use on your model bridge (or model airplane) can make or break it. I’d venture to say that glue choice is just as important as your wood choice, which makes it pretty important.

This article compares and contrasts different types of glues, showing the strengths and weaknesses of each so that you can make an informed choice for what glue to use on your bridge.

All These Glues I’ve Personally Used

All the glues on this page are ones that I have used extensively, both in model bridge building and other wood working creations. While some might be better in specific situations than others, all of these are solid choices. The links below are Amazon affiliate links, which allow me to help support this site when you make a purchase.

What you want to look for in glue:

Generally speaking, these are the factors that you need to consider when choosing a glue. You will need to strike a balance, since there is no such thing as a perfect glue. Or is there? Let me know in the comments.

  • Drying time
  • Price
  • Weight
  • Strength
  • Ease of Use

CA Glue (cyanoacrylate) aka Super Glue
This is a very common glue used for a variety of projects. It generally dries in seconds. It is also widely available. You’ll find it in virtually all big box stores, online, and most hobby stores. However, it is not cheap and doesn’t have a super long shelf life.

CA glue can be bought in three types: thin, medium, and thick. The thin stuff is very light, but not especially strong. The thicker stuff is heavier, but stronger. I have known people to build extremely efficient bridges using CA glue. It is also handy to have around the house for other things as well.

Lately I’ve been trying out the Gorilla Glue Gel CA, and it has proven useful in a number of cases.

CA Glue Pros:

  • Dries quickly
  • Strong when used correctly
  • Good strength to weight
  • Bonds to most materials, especially wood

CA Glue Cons:

  • Dries quickly (see what I did there)
  • Very easy to glue fingers together
  • Bottles can get clogged and dry out completely in a relatively short amount of time
  • Relatively expensive

Purchase Pro CA Glue 1/2 oz Thin

Official Wood glue, such as Elmer’s or Titebond
Wood glue, just like it sounds, is great for wooden model bridges. Also known as PVA glue. I’ve used both Elmer’s and Titebond, both for model bridges and other wood working projects and to be honest, I can’t tell a difference. (Titebond does make a waterproof version). Both seem excellent at what they do.

For model bridges, the main downside to standard wood glues is that they are relatively heavy. However, you can reduce weight by thinning the glue with a bit of water. In some cases, this allows the glue to seep into the wood, creating a stronger joint.

Wood Glue Pros:

  • Strong
  • Gives time to work before setting up
  • Readily available

Wood Glue Cons

  • Takes time to dry (sometimes this can feel like forever)
  • Heavy

Buy Carpenters Wood Glue by Elmers from Amazon

White Elmer’s glue
Not to be mixed up with the brown wood glue version, this glue is perhaps the most common glue on the planet. Well, I’m not 100% sure about that, but I do know it is used everywhere from schools, arts and crafts, to general use around the house. It usually dries in 30 minutes or less, depending on the amount used.

It is, like the marketing says, an all purpose glue. It is a good enough adhesive for a lot of materials. However, it isn’t what I would call a performance glue.

White Glue Pros:

  • Cheap
  • Good enough for a lot of things
  • Dries fairly quickly

White Glue Cons

  • It wasn’t made to be a performance glue

Buy Elmer’s White Glue

Epoxy

The first glue I ever used in building model bridges was 30-minute epoxy. I liked it because it was very strong and could be bought at many stores. Epoxy comes in several different “setting times”. You can get 90 second, 5 minute, 15 minute, 30 minute, and up to 4 hour epoxy. Generally speaking, the slower the drying time, the stronger the bond.

The trouble with epoxy is that you have to mix it. While I had great success with it for my early bridges, I stopped using it due to one bridge breaking because I didn’t mix it correctly once. I discovered that it was hard to mix it correctly in small amounts, and I ended up wasting a lot of glue because I never knew exactly how much I would need.

Epoxy Pros:

  • Very strong when mixed correctly

Epoxy Cons

  • Can be hard to mix correctly
  • Feels wasteful when you mix too much

Purchase PermaPoxy 5 Minute General Purpose Epoxy

Special Glues:

Probond / Gorilla Glue
This is polyurethane based glue and is super strong. I think Probond came out first, but I’m not completely sure about that. Since then, Gorilla Glue has taken over in popularity. It is not light, but you don’t have to use very much of it. It is also somewhat expensive.

It takes at least 4 hours to set, and your pieces have to be clamped together while drying. I still keep a bottle of it on hand, because it works for about anything.

Gorilla Glue Pros:

  • Super strong

Gorilla Glue Cons

  • Requires clamping
  • Takes forever to cure

Elmer’s Probond Wood Glue 16-Ounce

Weldbond
Weldbond is in a similar class as wood glues, but has some unique properties. Namely, unlike the typical PVA wood glues, Weldbond is white and dries completely clear (wood glue dries yellow). I really like this feature because I think it looks nicer.

I really like using this glue.

Weldbond Universal Glue 8 oz Bottle

As I mentioned at the top, these are the glues I’m familiar with. If the type of glue you use is not listed, leave a comment below and let us know about it.

Chart Comparing Glues (obviously biased by my experience)

 Wood GluesCA GlueProbondWeldbondEpoxyWhite Elmer’s
Strength3/54/55/54/54/52.5/5
Price3/52/52/54/53/55/5
Weight3/55/52/54/52/53/5
Drying Time3/55/52/54/52/53/5
Ease of Use4/53/53/55/52/55/5
Average3.2/53.8/52.8/54.2/52.6/53.6/5

Conclusion

I’ll summarize with a few scenarios. If I was…

  • Building a high efficiency bridge: I’d probably use one or both of CA and Weldbond
  • Building a for fun bridge, or building one with my kids: Elmer’s White Glue
  • Building for speed: CA Glue hands down

Additional Resources:

56 thoughts on “Choosing the Right Glue”

    • Shawn, I haven’t used Gorilla glue much, especially not the variations of it. My initial impressions were that it seemed very similar to Probond, which is mentioned here.

      EDIT in 2021: I’ve since used a lot of Gorilla glues and have added some notes to the article.

      Reply
  1. Garrett,

    I have an upcoming balsa bridge competition that has a time limit and is judged on efficiency according to its maximum load. From this page I would assume CA glue is my best bet. What is your opinion?

    Reply
  2. I have seen some people use hot glue on their pop-sickle stick bridges online. In my experience, it snaps really easy. What sound appealing is drying time and cost. If everyone in the class is required to use hot glue would it still be a good learning experience or the lack of bond would make the project a bit of a waste of time?

    Reply
    • To be honest, I’ve kind of avoided hot glue on principle. However, others have told me that they’ve used it and it’s turned out ok. It will be much more flexible than these other glues, but I think you’ve highlighted that it has two significant advantages: cost and drying time.

      Reply
  3. I am repairing my grandmothers 50 yr old popsicle stick lamp. Your information has helped me. I wish i knew the glue she used because it is so stronge. Just a few areas have come loose and the rest are still very tight. I plan to try some of these. I started off using the carpenters wood glue. if this doesn’t work I’ll try one of these others. Thank you

    Reply
  4. Hello,

    I was searching for glues in my area but I wanted to find weldbond but when i was searching the staff suggested me to use JB weld I searched for it but there are many types which should I use?

    Thank you

    Reply
    • I am Geometry teacher. Each year my students build bridges and we have used many different types of glue. I have found that Locktite professional super glue works the fastest and best. It drys within seconds and the sticks will break before the glue joint. Students have tried Gorilla glue and its OK but not as good as Locktite.

      Reply
  5. Garret,

    I am doing a project where we are trying to do the most efficent maximum load/weight of bridge. Out of the glues that you listed above, which one do you think would be best for strength/weight of glue?

    Thanks in advance for your help!!

    Alex

    Reply
  6. Garrett,
    I’m planning a Pratt pin-truss bridge for an S-scale model railroad module for our club layout. It wil be 30″ long and approx. 6″ x 6″ cross section with 6 5″ bridge segments. It has to support as much as 50 lb. Assuming one heavy articulated locomotive on each of the two tracks. These locomotive cost over $1000 each, so my bridge has to be strong enough. My plan is to hide 4 ea. 30″ by 1/2″ x 1/8″ steel strips in the horizontal stringers under the rails and use 1/8″ marine plywood for the main uprights at the ends and first vertical sections. All of my diagonal and lower center horizontal tension members will be 1/16″ x 1/4″ aluminum strips. My pins will be steel 1/8″ diameter. Can I get away with basswood and plastic for the rest of the compression members? I really like the light weight appearance of the pin-truss design but I’m not an engineer and i don’t want to risk a failure. Fortunately the load will be distributed, but also dynamic. Thanks in advance for your advice. Steve

    Reply
    • Steve,

      This sounds like a really fun project.

      I think I get the picture of most of your design, except for the “first vertical sections” being 1/8″ plywood.

      Are you going with a Pony truss (open top)? What about your top chords, what material/dimensions are they?

      Why not just use aluminum strips for all the compression members? I am a little concerned if you had a 1/4″ square basswood strip for the compression member, but drilled a 1/8″ pin through it.

      Have you tried plugging your design into the Johns Hopkins designer? I’d be curious exactly what the load on your compression truss members is based on your max load. 50lbs isn’t all that much over a 30″ span, so you are probably going to be safe with Basswood. As far as using plastic, I don’t have experience with it, and it probably depends on the type of plastic.

      When you’re done, send in some photos!

      Reply
  7. i have to do an outline for science about making wooden bridges. this really helped and will help making the glue decision easier! thanks

    Reply

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