Plexiglas (polymethylmethacrylate or PMMA) is a material that is widely used in shipbuilding. Composed of transparent thermoplastic, it is distinguished by its numerous advantages.
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The advantages of plexiglass
First, it is a material that looks like glass and offers better light transmission and sound insulation characteristics while being lighter.
In addition, it is resistant to shocks, atmospheric agents, and UV rays. It is clear, smooth, shiny, and recyclable. Its life is almost unlimited, provided of course to be well maintained.
All these features make Plexiglas the ideal material for making portholes, hoods, insulation panels, and even windshields!
The disadvantages of plexiglass
That said, plexiglass has some disadvantages. First, it is more sensitive to scratches compared to glass, which may make it dull.
As a result, its aesthetic appearance deteriorates over time. In addition, it has the risk of being able to dissolve in many organic solvents.
In this article, we will mainly talk about the best tips for repairing broken or cracked plexiglass on your boat.
Repair the broken plexiglass
Virtually all organic glazing used in shipbuilding belongs to the plexiglass category, which is known by several trade names such as Perspex, Lucite, Nudec, and Crystalite.
Despite its high rigidity, plexiglass can eventually break. On sensitive parts such as the windshield, the porthole, or the bonnet, broken plexiglass may bring seawater or rain into the boat, which can eventually damage electronic equipment and devices.
There are usually several tips for repairing broken plexiglass. The easiest and simplest method is to use an organic solvent to dissolve the plexiglass and repair the breakage. To do this, put about 50 to 100 cm 3 of acetone or chloroform in a container and add Plexiglas debris. Mix well with a small spatula or wooden mixer.
The plexiglass pieces will gradually dissolve in the solvent. If you notice that the mixture is not consistent enough, add more pieces of plexiglass until you get the right consistency. You will be able to glue pieces of plexiglass.
For breaks that do not show complete breaks, do not bother calling Jerome from Carglass 🙂 it is advisable to prepare a more fluid mixture that you can pour on the plexiglass using a syringe to have an assembly more precise.
In any case, clean the entire broken area thoroughly with a neutral detergent. Then apply the mixture of plexiglass and solvent already prepared and press lightly to assemble the edges of the break.
The mixture will play the role of glue and will repair the broken plexiglass effectively. The only drawback of this technique is that the glued portions of plexiglass are not transparent but rather translucent. To improve the appearance of your plexiglass, you can sand the bonded area with a suitable paper and polishing paste for plexiglass. After doing this you will be proud of your work and your wallet too!
As an outboard motor owner, you may like to read our how to repair a damaged base fin of an outboard motor article.
Repair cracked plexiglass
To repair large cracks, you can use the same technique as for broken plexiglass. On the other hand, for small cracks, you can apply pure acetone or chloroform directly on the damaged part. You can also use a methyl cyanoacrylate glue ( super-glue actually) to repair cracks on plexiglass.
To eliminate scratches on plexiglass, simply polish with a suitable foam pad. That is VERY flexible and a polishing paste also made for this. If you use a machine, be careful not to heat the plexiglass
Repair plexiglass: what to remember
Despite its rigidity and impact resistance, plexiglass can break or crack. It is usually easy to repair broken or cracked plexiglass with certain chemicals such as acetone or chloroform.
To avoid the risk of scratches and cracks, you must clean and maintain the plexiglass elements in your boat. Above all, never use abrasives, organic solvents. And especially not products containing ammonia because they may dissolve the Plexiglas. However, always clean the plexiglass with fresh water and neutral soap before using a suitable cleaning or renovation product.
Shopping list :
- Polish for plexiglass
And what are your tips and tricks when you have to repair the plexiglass on your boat? Tell me in the comments. You may like our boat fairing tips.