Repairing a plastic shower tray with polyester or epoxy

Plastic shower trays sometimes become damaged through use, renovations or age. In this article we discuss the most common damages and show you how you can easily repair them yourself.

Repairing a scratch or dent in an acrylic shower tray or plastic bath

Acrylic shower trays are mostly found in homes. They are plastic trays or baths reinforced on the back with polyester and fibreglass. These shower trays and baths are relatively durable, but prone to scratches and damage. Especially if hard objects fall into them, these baths are vulnerable.

Damage such as scratches and dents are easy to repair with a sanitary repair kit. With this kit you can repair damage to your acrylic bath or shower tray in 15 minutes. To do so, follow these steps:

• Clean the damaged part. 
• Mix the A and B component together and let it rest for 5 minutes with the cap on. 
• Remove the contents from the bottle using the syringe and fill the damage. 
• Apply enough, during curing it can shrink up to 20%. 
• After curing, sand the repair with sandpaper and water. 
• To make the repair shine, you can use the supplied polishing paste and rub it out with a cloth.

Repairing a cracked shower tray

Plastic shower trays without fibre reinforcement are mainly used in motorhomes, caravans, boats and mobile homes. Due to ageing, these trays may crack, causing leakage. The leakage often occurs at the drain or in the corners. Replacing the tray is often not an easy job because sometimes even walls have to be removed.

It is, however, often possible to repair the shower tray with epoxy or polyester.

Should I use epoxy or polyester?

Both materials produce a watertight result. Epoxy and polyester just cannot be used interchangeably. So a choice has to be made. Below are the advantages of epoxy and of polyester.

Working with polyester

Polyester gives off a pungent odour during application. If the caravan, boat or motorhome is still being lived in while the repair is being carried out, we recommend using epoxy, as it is odourless and can therefore easily be used indoors.

Requirements (per square meter):

• G4 Adhesion primer: 250 gr/m2
• Fibreglass chopped strand mat 450 gr/m2: 1 m2 to 3 m2 
• 1 kg polyester resin (when using 1m2 fibreglass chopped strand mat 450 gr/m2) up to 3 kg polyester resin (when using 3m2 fibreglass chopped strand mat 450 gr/m2) 
• Sandpaper on a roll 
• Polyester topcoat in colour (300 gr/m2)

Step 1: Stabilising the surface

If the shower tray bounces because a support on the underside has broken or rotted away, this does need to be addressed. Clean the shower tray very well, with water and ammonia, for example. Remove the shower drain and clean well here too. Sand the shower tray with 120 grit sandpaper.

First apply a coat of G4 adhesion primer. After a minimum of 30 minutes and a maximum of 12 hours, you can apply a layer of polyester resin and fibreglass mat. For small, well-supported trays, 1m2 fibreglass chopped strand mat 450 g/m2 will suffice. For larger and less well-supported shower trays, up to 3 times 450 g/m2 fibreglass chopped strand mat can be used.

Then finish with fibreglass chopped strand mat 225 gr/m2. This gives a slightly finer texture to the surface.

Step 2: Finishing the polyester topcoat 

Finishing with topcoat is quick and efficient. It produces a surface with a light texture that is easy to keep clean. Polyester topcoat is available in almost all RAL colours. You can optionally add an anti-slip grit to the topcoat to make the floor less slippery.

Besides finishing with topcoat, you can also finish the shower tray with DD Paint. As polyester has more structure than epoxy, it does require more putty to make it tight. DD Paint is the first choice when it comes to paint. This paint is available in high gloss and silk gloss and in almost all RAL colours. An anti-slip powder is also available for this paint.

Using epoxy

Epoxy is almost completely odour-free and can therefore be used even when living in the caravan, camper or boat. It also has better adhesion to materials such as metals, wood, etc.

Requirements (per square metre):

• 3 m2 glass fabric 300 gr/m2
• 1 kg universal epoxy
• Epoxy filler
• DD Paint in RAL colour
• Sandpaper on a roll (grit 120)

Step 1: Stabilising the substrate

If the shower tray bounces because a support on the underside has broken or rotted away, this does need to be addressed. Clean the shower tray very well, with water and ammonia, for example. Remove the shower drain and clean well here too. Sand the shower tray with 120 grit sandpaper.

Then you can apply three layers of epoxy and glass fabric 300 gr/m2. You may want to leave this about 10 cm up against the walls. If the floor is large and poorly supported, you will need to apply more layers.

Step 2: Finishing epoxy

Glass fabric 300 gr/m2 leaves a fine texture. If this structure is not desired, you can roll a layer of epoxy over the fabric. This will fill the structure almost completely. It can then be sanded and, where necessary, touched up with epoxy filler. Then DD Paint can be used to finish the tray. This paint is available in high gloss and silk gloss and in all RAL colours.