Plastic repair on the example of the gas tank
My lawn mower had a serious problem - there was a hole in the gas tank. Having learned the price of a new tank (about 200 bucks), I decided to repair the old one, especially since I have been repairing plastic parts of medical devices for several years and I am good at it.
In fact, most plastic products are very easy to repair, but it requires patience, accuracy and knowledge of the process technology. The main problem is the limited time of fixation of plastic elements, therefore, in addition to theoretical knowledge, a certain skill is needed.
Thinking that my experience could be useful to other amateur craftsmen, I decided to share this method, which can be useful for repairing various plastic parts and products.
To repair plastic products do not need a lot of tools:
1. Heat gun - the main working tool with which the softening of plastics.Hairdryer or other heating equipment will not work, as they have insufficient power and temperature of the heat flow.
2. Construction knife for cutting plastics and trim edges.
3. Steel trowel. Used to press down plastic and smooth edges.
4. A flathead screwdriver is used for the same purposes as the trowel. The screwdriver allows you to press small areas as needed.
Important! No need to use a soldering iron or any other hot object to heat the plastic.
Preparation for repair
First of all, you need to clean the product, which is subject to repair. I removed the gas tank and washed it with plenty of running water inside and out. I also used dishwashing detergent, rags and a stiff brush to remove all dirt. Inside polished until the smell of gasoline disappeared.
For final cleaning and degreasing of the working surface, I used isopropyl alcohol. Particularly successful was the fact that the alcohol bottle was made of the same plastic as my gas tank. Therefore, in order to use the bottle for making latok, it was necessary to pour the remaining alcohol into another container.
Preparation of patches for repairs
In my case, the repair was complicated by the fact that the damage was on the corner, so the patch should go around the hole on both sides. For this, I cut out a corner element from the bottle so that there is a good overlap on all sides of the hole.
You also need to remove all plastic burrs and other roughness around the damaged area so that the patch fits as tightly as possible.
The most crucial moment is the uniform and proper heating of the working area and the patch. The goal is to soften the plastic and make it quite soft and elastic, but keep the shape and not let it spread. Here it is important to observe the following rules:
- Keep the gun away from the heated part.
- To drive a heat jet over the surface of the part so that it warms evenly over the entire area.
- Plastic should not melt and flow, and moreover, to smoke or burn.
Having softened part of the patch so that the plastic began to look wet, I applied it to the repair site and began to warm it further, at the same time smoothing and pressing a part attached to the gas tank with a spatula.As the plastic patch warms up and softens, he presses it with a spatula so that it sticks tightly to the surface of the tank.
Tip! When smoothing the patch, it is important not to overdo it with effort, as you can push the softened plastic and make it worse than it was.
When the patch is completely glued, the parts should be allowed to cool down by themselves, without putting additional effort on it (do not immerse in water).
After cooling down, I poured water into the tank to check for leakage — everything was fine, even if pressing in the patch area.
Finally, I want to give a few simple rules for carrying out a successful repair of plastic products:
- For such a "soldering" of plastics it is impossible to use hot tools (soldering iron, etc.), since this will lead to the melting of plastics and the violation of the elasticity of the material.
- The work surface and the patch must be completely clean and free of grease.
- The product to be repaired and the patch must be made of the same type of plastic. This will ensure maximum repair efficiency, since various plastics have their own temperature limit of softening and fluidity.
- It is necessary to heat gradually so that the material does not melt.If you see smoke, then you are doing something wrong!
Note! Be prepared that the first time may not work and will have to impose another patch of a larger size so that it overlaps the previous one. This may also be necessary if the plastic chosen for the patch is too thin.