Plastic Repair – Ultimate Guide

Plastic Repair

Any plastic material can be repaired in various ways. In this article, we explain to you how to repair plastic boats using different methods for Plastic Repair.

There are methods to repair cracks, holes, and large missing parts, to restore canoes, boats, and kayaks.

Depending on the size to be repaired you can choose different options, using plastic or fiberglass.

plastic repair patch holes

How To Fix Cracks In Plastic

How To Patch A Hole In Plastic

Material Needed To Fix Cracks In Plastic and Patch A Hole In Plastic

– Pliers

– Knife or cutter

– Heat gun

– A wire mesh from an insufflated or rotomolded

How to Repair Insufflated Or Rotomolded Plastic

The first thing to know is that, although all kayaks are made of the same type of plastic, the density of the plastic itself is not the same.

A rotomolded kayak has a lower density and therefore is a little more fragile than an insufflated kayak. On the other hand, a rotomolded kayak has more elaborate models than an insufflated kayak, due to the ability to modify the mold at a low cost.

During the manufacture of blown kayaks, the cooling process of the plastic takes place at high pressure, thus achieving a higher density.

However, during the repair, it is necessary to heat the plastic, and this must be done in an environment with atmospheric pressure, and therefore the heated area will lose the high-density properties generated under pressure during blowing.

Why Do They Break?

The exposure to the sun, the wear, and tear with the stones, forcing it against the bars of the car, is something that weakens our kayak day after day. Especially the part of the bottom of what we call the hull is deformed little by little until the plastic weakens. Of the little we can do, I would emphasize the care during transport, do not drag it, do not leave it long periods in the sun, and if possible, navigate with water to avoid scratching the bottom.

hoe to repair plastic patch holes scratch

Preparation And Sanitation

The first thing to analyze is the type of repair. A crack, a crease, a hole? Sanitize means removing the organic remains and dirt that may be on the surface to be repaired.

In my case, I had some moss or algae that had remained in the crack. It is necessary to clean well with a knife and remove the damaged part making bevel cuts to leave a wedge-shaped indentation.

In the edges, we will make 2 drills to stop the advance of the crack. This can be done with a fine drill bit or simply with a pointed knife. The objective is to delimit the advance of the crack.

Depending on the place of the repair, we may be interested in disassembling the seat to work better.

As I said before, most of the cracks are usually in the hull itself, often under the kayak seat.

To disassemble it will depend on each brand and model, but normally except for the Jackson, loosening the side screws and loosening the thigh straps usually come out.

With the seat out we can work better. If we can support the hull of the kayak on a surface where it fits well, when we heat the plastic, we can apply pressure and get a better repair.

How to Repair Plastic

 It is very important to clean the crack and prepare it for repair. Next, we must reinforce the crack. We are going to do that with a small metal mesh that we can take out of a kitchen strainer.

Cutting the mesh and placing it on top of the plastic, we can introduce it inside, and give it the necessary rigidity. If we heat it with the heat gun, the mesh will melt the plastic by introducing it into the internal layer.

To push the mesh we recommend doing it with the edge of a knife since it will hardly leave a trace.

Once we have the mesh inside we can incorporate a piece of plastic. If we don’t have it, we can take it from the edge of our kayak, the lack of a piece of plastic on the back will not give us problems.

Plastic Welding

To prepare the plastic strip and make it stick easily we must file the tip or remove the tip with a knife.

plastic welding
Photos: Jounjip Plastic Welding Repair Kit

A thinner tip will heat up faster by welding it to the plastic of the kayak. Be careful not to overheat the kayak as the crack may open. Before gluing plastic to plastic it is advisable to clean both surfaces well, any kind of grease or dirt will prevent it from sticking properly.

Make sure that the temperature of the plastic is not exceeded, heat both parts so that they are welded together. (Order plastic welding here).

how to plastic welding
Photos: Jounjip Plastic Welding Repair Kit

The plastic becomes shinier when heated and when heated excessively the color changes. Be careful because if we heat excessively, the plastic loses the elastic properties.

Once welded, if we manage to exert pressure it will be much better.

how to plastic welding repair
Photos: Jounjip Plastic Welding Repair Kit

As soon as it has stuck correctly, we let it cool and remove with the help of a sharp knife the edges that can make jump the patch. A thick file is not recommended, since it makes vibrates the plastic.

If we see that some patch has stuck badly, we must remove it and put again another layer of plastic in the same way that I have explained previously. This time it is not necessary to introduce the mesh.

JOUNJIP Standard Plastic Welding Kit- UL Certified Plastic Welder 80W- Professional Grade Plastic Repair Kit for Automotive Car Bumper, Kayak, Tank Repair
  • UL CERTIFIED - Our Plastic Welder, the factory, and the process have been tested, approved, and Certified by Underwriters Laboratories (UL). Safety is our number one priority
  • Specially Engineered- PolyPlaz plastic welding rods(included) work on many types of plastic repair: Bumper, Kayak, Canoe, Plastic Tanks, Car Headlights, Auto Parts, Dashboard, Plastic Tab Repair, Kids Riding Toys, and Recycling Bins
  • 80W Plastic Welding Iron- Heats to 525°F in just a few minutes(120V, 60Hz max). Standard Kit Includes: 1 plastic welder, 2 triangle welder tips, 2 wire mesh, 5pc HD aluminum tape, 20 PolyPlaz black welding rods, and sandpaper

Polyethylene Welding Kit

A polyethylene welding kit is a good option to help in the repairing and restoration of boats, canoes, and plastic kayaks without using fiberglass.

Plastic Kayak Repair With Fiberglass

When the damage is large, the most recommended is to repair using fiberglass. Learn about how to repair plastic kayaks with fiberglass.

canoa repair