You only need to drill into the surface of the crack if the damage doesn’t run all the way through the hull. If you can see clean through the crack to the other side, drill all the way through the kayak’s hull. You do not need to drill gouges, punctures, scratches, or thru holes, which are holes in the hull that are deep enough where you can see through to the other side.
You can use soap and water if you don’t have any rubbing alcohol. The main goal here is just to clean the area.
The goal here is to oxidize the polyethylene, not to melt it. Oxidizing the surface ensures that whatever filling material you use will bond permanently to the kayak. If you don’t do this, your patch job is much more likely to come undone.
This process is ideal for gouges, deep scratches, and small holes that don’t go all the way through the hull. If you have a fancy fiberglass kayak, this is the only way to repair damage.
You can buy a 2-part epoxy resin from a hardware, construction supply, or automotive store. It’s often used to fill in damaged pipes or plastic surfaces. Any 2-part epoxy resin will work for this.
It looks pretty thick in the cup, but the epoxy pours smoothly. You shouldn’t need to move it around in the damaged area. If you do need to spread it around, feel free to use your gloved finger to do this.
Most kayak enthusiasts don’t bother painting over repairs on the bottom of the hull since you can’t see it anyway. If you do want to paint over it, use standard acrylic spray paint.
This repair is ideal for nasty hull damage that can’t easily be repaired with resin. If the shape of the hole or scratch is malformed and you need to move the repair material around, this is the way to go. If the plastic isn’t clean, wash it with soap and water and dry it off before doing this. If possible, use a plastic that matches the color of your kayak. This will make the repair less noticeable. You’re going to destroy this object for your repair, so don’t grab something you may need one day!
If you don’t have tin snips and you’re using thinner plastic, you can carve it out of the object with a utility knife.
You can use a butane torch instead of a heat gun. Just make sure you don’t let the flame directly touch the plastic and move the torch around to melt each piece evenly.
If the plastic patch begins dripping or bubbling, stop heating it and wait 10-20 seconds before proceeding.
You can repeat this process any number of times if you run out of patching plastic. Use the tip of the putty knife or screwdriver to scrape up any excess plastic. Wipe the plastic off on a piece of paper or cloth.
Most people don’t bother sanding or painting the damage if it isn’t really noticeable or it’s on the bottom of the hull.
If you bought the kayak recently, the manufacturer may cover the damage with your warranty. They may just send you a brand new kayak if you ask. Patching a thru hole is pretty hard. It can certainly be done, but the finished product may not look the best.
If possible, get a plastic bucket that is roughly the same color as your kayak.
This is pretty hard to do in 2-3 cuts. You may need to cut small portions off one at a time until you can shape the plastic to match your kayak.
If the middle of the patch starts drooping down in the center, carefully prop it up from underneath with your gloved finger. If your finger starts to get hot, grab a piece of scrap wood to hold it up from underneath.
You can cover the seam between the patch and the kayak with a plastic weld rod or Lexel caulk to seal it if you’d like a cleaner finish.
