How to repair a crack in a fiberglass

Always wear a face mask when working with GRP so as not to breathe in any glass particles. It's also advisable to wear gloves, so the glass strands don't cut your fingers [source: New York City]. You may want to apply colored gel-coat enamel over the repaired area, so the repair won't be so noticeable. You may be able to obtain a small amount from an auto body shop.

Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Home Improvement. Home DIY. Home Repairs. How to Repair a Crack in Fiberglass. Drill a tiny hole at each end of the crack. This will stop the crack from extending any further.

Examine the crack. This will open up the damaged area so that your epoxy can get inside and bond. Wipe done the area with acetone. Cover a rag with acetone and wipe down the surface and the inside of the holes. Acetone is the cleaner of choice when dealing with fiberglass.

It gets rid of all dirt and grime, as well as fiberglass dust, without leaving a residue. When using acetone, remember that it is highly flammable and needs to be used away from an open flame. The rag you use should be disposed of in a double bag in your garbage can. You can also get it at pharmacies and big box stores in their nail care section, as it's most common use is as nail polish remover. Cover the back of the hole with masking tape, if necessary.

If you are repairing an area that you can get to the back of, block it off with tape so that the epoxy doesn't run right through it. Use any type of masking tape that you have on hand, as it just needs to hold for a small amount of time.

In some situations, such as when you are repairing a bathtub, you won't be able to get to the back and that is fine. The epoxy will go down into the damaged area and you will need to use more to fill up the void but it will firm up quickly enough to fill the hole.

Mix epoxy resin, hardener, and filler together. In order to fill a small hole, you need a mixture of these three components. Consult the instructions that came with your epoxy resin to determine how much of each material you need. It is very important to get your proportions right, so follow the directions closely. Once the epoxy sets, the container and the stirrer will be coated with it permanently. The epoxy is the bulk of the material, the hardener causes the epoxy resin to firm up, and the filler makes the mixture thicker so that it doesn't drip right out of the repair area.

These products are available from online retailers, marine supply companies, and some specialty hardware stores. Pour the mixed epoxy into the hole until it is filled. How much epoxy you have to pour in depends on the hole and what is below it. If you have a solid surface underneath, it won't take much epoxy.

However, if you have a hollow area, it may take quite a bit of epoxy. Try to keep the stream of epoxy small and slow so that you don't create a mess. You can mix more and add onto the top as long as the previous batch is still tacky. If you overfill the hole or spill some epoxy outside of the hole, wipe it up with a rag right away. Then smooth out the surface.

Wait 5 minutes and make sure the top of the epoxy stays level and doesn't slump. If it does slump, simply add more epoxy mix. Sand the surface smooth once the epoxy has cured. Consult the curing directions on the epoxy packaging. Once the designated amount of time has passed, start smoothing out the patch area. Start with 80 grit sandpaper to get large areas of excess epoxy off. Then switch to grit sandpaper to smooth out the surface. Method 2.

This should include gloves, eye protection, and a dust mask or respirator. When repairing a large crack or hole you will be creating fiberglass dust, which shouldn't get into your lungs or eyes. You should also try to keep it off your skin as much as possible, as it can be irritating.

Determine how much of the area is damaged. Tap a coin around the area that is visibly damaged. You should be able to hear a difference in the sound made in areas that are damaged and areas that are not. This will help you keep track of what needs to be fixed. Clean out any damaged material.

Open up the area that is damaged in order to understand the extent of the cracking and to prepare the area for repair. Remove loose areas with your fingers and pick off broken chunks with a utility knife or another pointed tool. This will allow the epoxy to get into the crack and adhere to it. Sand down the area around the damage.

Clean off any surface treatment on the damaged area and out beyond it at least 2 inches 5. Use sandpaper or a sanding bit to take off the surface. This will ensure that all damaged material is removed and that there is plenty of surface area for your patch to adhere to. When sanding, you want to sand to the bottom of the damaged area and then taper up your sanding less and less as you move away from it.

If you angle your sanding down towards the cracks, it will make your repair stronger and will allow you to make a smoother patch. Clean the surface with acetone. After the surface is sanded down, you need to get everything off the surface so that the epoxy and fiberglass patch will stick. Use a rag or paper towel soaked in acetone to wipe down the entire area, including all of the internal edges of the fiberglass that you opened up. Clean 1 to 2 inches 2. Be careful when using acetone.

It is highly flammable, so don't use it around an open flame. It can also be purchased at pharmacies and big box stores in the nail care section, as it's commonly used for removing nail polish.

Fill any holes with resin combined with filler. In order to create a base for your sheets of fiberglass to sit on, you need to fill any large holes or cracks with a base of epoxy. Mix your epoxy resin, hardener, and filler at the ratio suggested on the packaging. For filling gaps, the mix will have enough filler to create a product that is the consistency of peanut butter. How much epoxy you mix depends on the size of the crack you are filling. It's fine to make a guess and then if you don't mix enough, you can always make more while the first batch is setting.

These supplies are typically available from online retailers, marine supply stores, and specialty hardware stores. Tear out several pieces of fiberglass sheeting. Rip out the pieces of fiberglass sheeting in the shape of the area you are covering. Don't cut the pieces out with scissors. Ripping them will make a more subtle edge on the patch, which will make it easier to create a smooth transition. Ripping it can create glass dust that could be inhaled if you don't have on personal protective equipment.

Fiberglass sheeting is available from online suppliers and at many large home improvement stores.