How to Glue Plexiglass to Glass
In this guide on how to glue plexiglass to glass you will learn which steps to take first and how to make sure the bond is secure before testing its strength.
The top three adhesives that are used for gluing plexiglass to glass include silicone and polyurethane adhesive, followed by epoxy resin. These adhesives each have excellent bonding to these surfaces
There is not much preparation to bond these materials together but do need to be lightly prepped beforehand. Because plexiglass and glass do not flex too much, the bonding will be perfect for select uses. Acrylic to Glass glue is perfect because it is clear and won’t be too obvious.
Curing times for each of these adhesives will need warm conditions to help speed up the curing time. Depending on the type of adhesive, this may influence the need for faster or slower curing adhesive.
What Glue Can You Use for Plexiglass to Glass?
Here are some of the best glues to use on both plexiglass and glass to bond them together:
Silicone Adhesive
The advantage of using silicone adhesive to glue plexiglass to glass is all due to the ability for silicone to readily bond to smooth glass-like surfaces. As long as silicone is 100% pure, it does not need to be specifically a dedicated adhesive. Clear silicone caulking such as GE 100% silicone or fish tank silicone is perfectly acceptable. There is very little preparation needed to help silicone stick to smooth surfaces.
Since silicone also is very transparent, this makes adhesion ideal for plexiglass and glass pieces that need to remain see-thru. Very little silicone is needed to sandwich between these two surfaces to achieve high-strength bonding.
Polyurethane Adhesive
Another great option for gluing plexiglass to glass is using a polyurethane adhesive that works similar to silicone adhesive. Most of the polyurethane adhesive is also semi-flexible which allows two smooth pieces to have excellent vibration absorbing capabilities. A good example includes the original Gorilla Glue formula and E-6000. Both of these adhesives can be found at hobby stores and hardware outlets.
Polyurethane glue is moisture sensitive which will make curing conditions ideal for faster adhesion requirements. Polyurethane adhesive will not need much preparation between plexiglass and glass surfaces to work effectively.
Epoxy Resin
Another good reason to use epoxy resin to attach plexiglass to glass will be beneficial when there is plenty of time allowed for curing. Epoxy resin is also excellent for achieving excellent clarity when transparency is required between two clear pieces. There will be clamping requirements to ensure that plexiglass and glass are not migrating too much during the curing process.
Many of these 2-part epoxy kits come in small amounts for hobby usage and offer 5-minute quick set products. It would be better to have a slower setting epoxy adhesive which will offer better and longer-lasting adhesion.
How to Prepare Plexiglass and Glass Before Gluing
Because plexiglass and glass are typically smooth as glass, this will allow adhesives to bond much easier. This will be optimal for polyurethane, silicone, and epoxy depending on the need for allowing enough getting enough clarity. If the transparency is not so much of a concern, these surfaces can be sanded using 700-grit sandpaper to rough up a glass or plexiglass surface a bit more.
Both surfaces need to be free from oil or any kind of dust that is sticking to them. Using some 99% alcohol to clean their surface and drying them before adding adhesive is highly advised.
How to Apply Glue for Plexiglass to Glass
Silicone adhesive is thick like paste and should be applied using the applicator tip that comes with squeeze tubes. Silicone can also be spread using a spatula to spread easier. Polyurethane glue is runnier so it will be easy to add this adhesive in thin strips and then press two flat pieces together. This adhesive can also be spread with a spatula for better coverage.
Epoxy resin is syrup-like and needs to be spread using a spatula spreader similar to a spackle spreader. When plexiglass and glass are attached together, clamping needs to be strategic using spring-loaded clamps or sticky tape.
How to Cure Plexiglass and Glass Glue
Silicone and polyurethane will take less time than epoxy resin takes to cure. It will take more than 12-15 hours to cure with a total of 24 hours for a complete cure. Silicone takes less time with 5 to 10 hours for a total cure but 24 hours is best for a complete cure. Polyurethane can be sped-up by spraying a fine mist of water on a glass surface before adding the plexiglass piece coated with adhesive.
Polyurethane needs a couple minutes to start curing with a total of 5 to 10 hours for a post-cure. Being placed into a warm room will seep up the curing process if this room is at least 75 degrees Fahrenheit or higher.
Which Is the Best Glue to Use?
The best glue for plexiglass to glass is silicone adhesive but it does need time to cure. When there is a need to glue these two pieces together in the shortest amount of time will use polyurethane glue. Epoxy resin is an excellent bond that is best when visual clarity is needed the most. All of these adhesives are easily available and are easy to use without much safety equipment such as rubber gloves and safety glasses.
