A hole in a fibreglass bathtub or shower doesn't necessarily mean you have to replace the unit. Although the process is a bit complicated, there are some ways to fix the hole. You will be using solvents and adhesives, so take the time to learn about the compounds you are using. A little patience, maybe a little practice cutting and glueing the glass cloth, you can fix the hole yourself. Wear breathing masks, goggles, ear guards and gloves. Then use the disc sander attachment on the power drill bit to grind shallow slopes or slopes along the edge of the hole. Use 40-grit sandpaper. The bevel creates a larger surface area for epoxy. The length of the inclined plane should be 12 times the thickness of the laminate. For example, 1/8-The inch thick laminate should have 1 1/2Width of inches. Polish the bevel area with 80-against the sanding tool of your choice to polish the sandpaper. Clean the dust with a tack cloth. Tape a plastic drop cloth around the hole. Cut the glass cloth and create a larger layer to fill the inclined area. Set the fibreglass layer to the original thickness of the housing.Before placing the first layer of fibreglass, moisten the inclined area with epoxy resin mixed with the hardening agent. Repeat the process with the remaining fibreglass, moisten and place each layer at a time. There are several combinations of epoxy resin and hardening agent on the market, so please follow the manufacturer's advice on mixing ratio.
For holes greater than 1/4, apply a layer of glass cloth and dry before applying the rest of the glass cloth. Let the repair solidify overnight and wash the surface with water and sand. Clean up the dust with a sticky cloth. An adhesive filler is added to the epoxy resin to produce a thickened white mixture. This can be used as a colour-matched filler. Sand will be hard. If you have to use sand, use 320Waterproof sandpaper and wet sandpaper and the area by hand. Attach the sandpaper to a block, or immerse it in a bucket of water, or spray wet areas with a spray bottle. Paint the shell with fibreglass paint to achieve the most consistent colour matching. There are other, more complex methods to cover the patch to match the rest of the shell, but these methods require a mix of various epoxy and adhesive products. It is difficult to get perfect results in this process.