What’s The Best Glue For Polystyrene / Stryofoam

Just a quick post on the what is the best glue for Polystyrene and Styrofoam expanded foam sheets, both hugely popular for making landscapes, hills and inclines.

Styrofoam and Polystyrene are some of my favourite building materials for landscapes, especially on small layouts or those in a spare room where I might not want or be able to build more elaborate hills, cliffs, and inclines from other heavier more permanent materials.

With a bit of shaping (see Where Next below for a suitable tool) and a top coat of plaster cloth very credible landscapes can be quickly constructed.

Before going further, there is a lot of confusion around these materials so it’s worth clarifying exactly what material I’m referring to here.

Is it Polystyrene, Styrofoam or Expanded Polystyrene foam?

Although often used interchangeably these terms shouldn’t be confused.

The material I’m glueing here is expanded Polystyrene expanded foam or Expanded Polystyrene (EPS).

It’s available in sheet and block format and is most often used for packaging but is great for railway, diorama and war game landscape modelling.

Typically white in colour, the expanded foam variant is made of small beads giving a lightweight, soft corky, texture. It’s easy — although messy — to work with and can be cut with a knife or hot blade (the fumes from the heating foam board are highly poisonous. This should absolutely only be done in well-ventilated areas — I do it in my shed with the extractor fan running.

If you’re interested, it’s made by expanding Polystyrene beads under heat and bonding them together.

Styrofoam meanwhile is blue in colour and most often used in building construction — for pipe insulation etc — and while it’s is often mistakenly used as a generic name for extruded Polystyrene foam it is actually the brand name for the product from Dow Chemical Company. The same glue I suggest below will work for this as well.

Injection-moulded styrene has completely different properties to the expanded foam variety. It’s a hard plastic, often in sheet form, and used as the construction material for many of the model kit buildings on layouts. I won’t dwell further on the glue for that, instead, I’ve covered it in my guide to glues.

What glue not to use with polystyrene foam (EPS) sheet

Before getting to the best glue for polystyrene I want to touch on some glues you shouldn’t use and why because many people will likely have these around at home and might be tempted to use them but doing so can be problematic, to put it mildly.

Firstly, hot glue. I use this for various projects (my miniature bird nests for example), it’s low cost and many people have hot glue guns lying around. But the heat from them will melt the foam. Both the tip of the glue gun and even the warmth of the glue as it emerges before cooling is more than enough to dissolve the foam.

Another glue, probably even more common than hot glue, is super glue. Cyanoacrylate (CA) glue to use its correct name, is tremendously strong and long-lasting so might seem like a good choice, particularly for small projects but don’t go near polystyrene (EPS) foam with it. Super glues type adhesives which will melt the foam boards like the acid blood of the predators in Aliens.

So, what is the best glue for polystyrene foam

glueHaving experimented with different glues over the years, I’ve found this to be the best glue for fixing Polystyrene foam board and Styrofoam to baseboards and to each other — for building up layers on hills etc.

It’s easy to apply, and work with (spillages can just be wiped away), it’s cheap and forms a strong bond when set.

Another reason I like this glue, in particular, is that it’s still easy to cut through for later detailing and shaping, even once dry.

While other glues hold the foam together (No More nails and epoxy substances in particular) they can produce a very hard barrier that’s difficult to cut through later.

It’s also a good all-around glue that can be used for many other jobs around the layout (track laying, scenery fixing, water modelling etc.). I get through a lot of it so buy it in bulk using the above link.

Where next?

 


> A final, personal, note: I spend a huge amount of time testing, photographing, writing and researching techniques for these articles and pay for all the running costs of MRE out of my own pocket. If you found this article useful you can support me by making a donation on my fund-raising page. Thanks and happy modelling, Andy.

 

 

 

Founder of ModelRailwayEngineer, Andy Leaning

Andy is a lifelong modeler, writer, and founder of modelrailwayengineer.com. He has been building model railways, dioramas, and miniatures for over 20 years. His passion for model making and railways began when he was a child, building his first layout at the age of seven.
Andy’s particular passion is making scenery and structures in 4mm scale, which he sells commercially. He is particularly interested in modelling the railways of South West England during the late Victorian/early Edwardian era, although he also enjoys making sci-fi and fantasy figures and dioramas. His website has won several awards, and he is a member of MERG (Model Railway Electronics Group) and the 009 Society.
When not making models, Andy lives in Surrey with his wife and teenage son. Other interests include history, science fiction, photography, and programming. Read more about Andy.

Afflliate disclosure:The links on this page may take you to carefully selected businesses, such as Hornby, Amazon, eBay and Scale Model Scenery, where you can purchase the product under affiliate programmes. This means I receive a small commission on any orders placed although the price you pay does not change. You can read my full affiliate policy here. I also sell my my own ready to use, pre-made and painted buildings and terrain features. browse the range.
8 comments
  1. Hi, having done trials, PVA adhesive does NOT stick polystyrene sheets together. They just peel apart.
    Article is good, except author gets glue completely wrong!!
    Jk

    • Hi Jonathan, are you referring to the hard type of styrene – eg the type used for model buildings etc? PVA won’t fix this and as said in the article requires a different type of glue. This article refers to expanded foam, often used for packaging which definitely DOES work with PVA. I have a ton of it in my shed, use it all the time for scenic sections and it works perfectly with PVA. Andy

  2. Just to clarify, Andy – Styrofoam is EXTRUDED polystyrene foam, also known as XPS, whereas the cheap white packing material is EXPANDED polystyrene foam.

    I have built my baseboards using 25mm Styrofoam, and it is a brilliant material to work with, unlike expanded polystyrene, which crumbles easily into tiny balls.

    Also, it is very easy to cut straight lines through it with a fine-toothed (25tpi) tenon saw, or a razor saw for short lengths.

    • Hi Roger, cheers and agreed. Styrofoam (the extruded stuff) is much better for large baseboard areas for the reasons you mention lthough I have used expanded Polystyrene foam sheet for bases if the layout is small and for landscape elements. Yes, it crumbles into little balls easily and is a pig to clear up but I just like working with the stuff. I also usually top off scenic elements constructed from it with fine plaster or plaster cloth. Thanks, Andy

  3. Silicone sealant for bathrooms or kitchens, sticks like the proverbial to a blanket. Just a smear will do. Completely inert, will not melt anything. I’ve been using it for years to stick all sorts.

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