Do-it-yourself boat repair

This is not so much an article as knowledge gained in practice in the form of notes.

I started repairing plastic back in sports times. When, at the moments of the master's binges, the entire base brought oars to me for repairs, and then boats. Since the boats were hit often, I had a good opportunity to gain a lot of useful knowledge empirically. Which were then actively used in the repair of hulls of motor boats, boats and yachts.

The main materials in the repair of plastic cases are epoxy resins and various fiberglass.

Epoxy resins in the world there is a great variety. Basically, they are all very resistant to external influences after curing. But as always, you won't find the best. Or it stands like a cast-iron bridge. Experiments have shown that for ordinary household compounds EDP and EKF, as well as automotive epoxy putty (the essence is also some kind of EKF) are quite suitable for repairing hulls. The main thing is to have the appropriate hardener. ECF after curing gives a more plastic layer. Any industrial compounds, from the category “two buckets of epoxy and a bucket of hardener” are also suitable, but for repairs they are usually not needed in such quantities as they are usually supplied from factories. And they are highly toxic. You can get an allergy, or you can get poisoning by the type of BOV of a skin-blistering action, smoothly turning into eczema.

Epoxy is best handled outdoors or in a well-ventilated area and wearing medical gloves.

Ideally, epoxy is diluted with a hardener according to the instructions. But experiments have shown that if it is well stirred, then the compound will seize even with a small amount of hardener. It just takes a long time to catch up. And the layer will be more plastic. Accordingly, and vice versa. However, the more hardener, the harder and more brittle the layer.

Video (click to play).

Sometimes for work you need a compound with a filler. At worst, even dry fine sand can be used in the field. But it is better to buy or otherwise have ground mica or silver. Don't blow into the silver. You will be worse off.

If you pour a hardener not from it into the resin, you can get a lot of problems. Usually the resin warms up slightly when the hardener is added. But in my practice there was also the release of some kind of smelly smoke and fire and just stink.

Some grades of epoxy melt well after curing at

150 degrees. This can be used if you need to remove the compound from non-combustible material.

If the compound is heated during polymerization, then it sets faster. We remember the hair dryer.

If it is necessary to press down the surface covered with the compound, then it is enough to put a sheet of cellophane, polyethylene, and preferably fluoroplastic on top.

Fiberglass is different. I am not a brand specialist. Therefore, I will explain “by eye”. When repairing, you mainly need a fabric with an average thread size. Preferably with "oblique" or satin weave. But the usual one, with “homespun” weave, will also work. In rare cases, glass sack or glass wool is needed. The thickness of the threads they are the same. They differ in weave. For those cases when you need a thick fiberglass weave do not care.

The fiberglass that we need should be from twisted filaments. From solid fibers will not go. If you shake it, then a cloud of pieces of glass should not fly out of it. Such an operation as shaking a large piece of fiberglass is best done where there are no people. By the wind And holding my breath. God forbid this muck to inhale or shake yourself or anyone else in the eye.

Fiberglass comes in sheets, rolls and tapes.In the sheets, this is a big deficit. That is, each piece is sealed from all sides. The roll is sealed on both sides. In principle, the tape is the same roll, but narrow. Usually comes with the most convenient slant binding, but rarely comes across wider than 5 cm.

Currently, fiberglass of various brands is quite often sold in ordinary building materials stores. You can also buy fiberglass in various construction organizations, for example, those involved in laying heating mains. Well, or agree with those men who wrap this heating main.

To work, fiberglass must be dry and free of grease. In the field, you can quickly dry fiberglass by calcining it well on a sheet or in a bucket. She will not burn. It is better not to dry over a fire. God forbid it gets dirty. Fiberglass is degreased by rinsing it in any solvent.

Fiberglass must be impregnated before being molded somewhere. It is necessary to impregnate by repeated immersion of the workpiece in the diluted compound. After each immersion or “kneading” in the compound, the workpiece must be squeezed out. For example, stretching it between two tightly compressed sticks, pipes, fingers, etc.

The housing must be clean, dry and free of grease before repair. In places of repair, of course. in some cases long drying is required. Better than a technical hair dryer. But the hair dryer of your beloved wife and an ordinary home fan heater will also work.

Typical plastic damage: 1. damage to the decorative layer 2. cracks in the body 3. “half-holes” 4. holes 5. parted “corners” 6. shells 7. all this together

Damage to the decorative layer - minor damage. A scratch that does not damage the layer through and through is simply primed with GF primer or epoxy without filler. Sanded and painted over. Through scratch, even if the body itself is not deeply affected, it is puttied with a compound with a filler. It is sanded and painted over. If the decorative layer lags behind, then it must be peeled off to the place where it is firmly attached to the body.

The inside of the case is usually just painted. This is true. On a note.

Never grind the edges of holes. Let them get better. It will be stronger.

Where we have fiberglass, the body should be cleaned along the first native layer of fiberglass from this side so that this layer is slightly tangled. Even if it is torn in places. This is best done with a large sandpaper wound on a block of wood, cork or finely porous foam.

The fiberglass sheet must be glued so that the edges are smooth and do not fall on the paint or decorative layer.

When working, it is better not to rush. And figure out in advance how to put the body in the right position. Bo is most convenient to do anything if the working area is horizontal. And if there is a need to glue a large piece of fiberglass, then the only way to lay it properly is to place the surface horizontally or close to horizontal.

A half-hole is vile damage. This is a break in the case where a piece of plastic remains mostly attached to the case. Not a patch, but for the most part. In general, an abomination. We clean on both sides. Then we figure out whether it will be possible to put the piece in place. This usually works for small breaks. If there are no chances, then it is better to remove the piece. Get a normal hole and repair as described below. If the piece itself is damaged, then it must also be removed. But you can try to straighten it. We coat all surfaces with the compound. From the side of the direction of impact, we put a good emphasis on the break. Preferably with a thick rubber gasket. On the other hand, gently put the piece in place with a mallet. It will never work out exactly in place, but you have to try. As a result, we get a dent on one side, and a bulge on the other. We immediately put a soaked piece of fiberglass on the bulge. And fix with a spacer or load.When everything polymerizes, we begin to process the dent. Putty with resin with filler. After hardening, grind. We glue the impregnated sheet. We grind. cover with a thin layer. We sand and paint.

For a good sealing of the hole, a punch must be made. For example, foam. This is necessary in order not to disturb the contours. It is better if it is a punch along the outer contours. This is just the case when thick fiberglass is needed. We process the edges. That is, we remove the paint and lightly shake the native fiberglass. We cut out several patches from glass sack, with a minimum (3-5mm) overlap covering the hole. The number of layers is chosen by eye on the basis that the thickness of the package should correspond to the thickness of the body. We put a punch. Paste patches in layers. Each layer is dried until the resin is semi-polymerized. And no bubbles. After that, from the inside of the body: sanding, gluing another layer, sanding, second layer, sanding, covering with a layer of pure resin, sanding, painting. Outside, we put one layer and process it in the same way.

The divergent corners are glued similarly to sealing cracks. But it is best to use tape for them. It is advisable to put the corners in the transom on the knees. Knits are made of plywood or tank plywood. Carefully adjusted to the mating angle. First, the knitsa itself is glued. Then it is covered with fiberglass. For example: on the transom of Ladoga-2, two knees with a side of 100 mm were placed at the joints with the sides. At the junction of the bottom, three on each side. Of course, all the places where the fiberglass fits are carefully cleaned to the first native layer.

No one has come up with anything uglier than shells. The sink in laminated plastic is either a factory defect. Or is it the result of water getting between the layers of the body. This usually results from damage to the outer layers. After a couple of winterings, freezing water bursts the layers. If this shell is closer to the inner side, then it can be assumed that the entrance to it is from the inside. It is better to score on such damage. If it is closer to the outside, then it must be repaired. The main problem is that the sink is very difficult to dry. therefore, in order not to wait a month in the sun, the shell must be opened. From the side where water enters it, we drill a hole

8-10 mm. Depth before entering the cavity. With a wire or any other thin and flexible object, we determine the true dimensions of the sink. Open the shell with a knife or “claw” from a hacksaw blade. We make it wide enough, up to 5 mm. incision along the largest size of the shell. Several parallel cuts are possible. If the width of the sink is more than 100-120mm Dry it with a hair dryer through the cut. Then we drive as much compound as possible inside with a syringe. Most importantly, the sink must then be clamped over its entire area in some kind of press. Or brace and brace. Or a clamp with a large coverage. Or cargo. Well, the favorite process of puttying, grinding and painting after polymerization.