Epoxy, fiber boat repair, boat construction and repair is a wonderful substance that does a lot of work. Its use is not limited to boats and can be used in general woodworking, even in domestic repairs, provided that it is of course slightly salty. If I remember correctly, technically it is a material called "thermoset plastic". The two syrups coming from separate cups consist of a mixture of "resin" and "hardener". Depending on the manufacturer of the epoxy system you are confusing these two at varying rates. When you mix it properly, it is exothermic, that is, a reaction starts giving out heat and the epoxy gradually hardens. First, the gel (or jelly) phase passes through a given phase, that is, it comes to the jelly consistency, then this jelly gradually becomes hardened by being hardened. If you want to say "freezing" to it, though the freezing is the actual cold connotation, the epoxy will freeze up, but whatever. Frozen epoxy is a very strong adhesive with excellent waterproofing properties. I have read from multiple sources that a well made plywood-epoxy connection is stronger than the plywood itself. You can work on the epoxy until you come to the jelly stage. How many times this will take depends on several factors, which are explained later. Mixed resin and hardener are not thickened (or thin) epoxy if no other ingredients are added. With fine epoxy you can isolate your material against our water (plywood and wood for us). It can also be used as an adhesive, but the latter is preferred because it can be obtained by thickening a bond epoxide to the same strength. Thickening both the epoxy is more economical and difficult to keep at the fine epoxidation point of the syrupy consistency. Filling materials called "fillers" are being used to thicken epoxies. Almost every epoxy producer produces a variety of fillers. Each of the filler material bond strength, color, ease of sanding and so on. have different characteristics. Generally, powdery fillings are much cheaper than epoxy itself. Thus, while it is possible to substitute other things as filling material, it is a more guaranteed way for amateurs to buy directly from the epoxy producer. Pour the resin and hardener into a bowl and mix thoroughly to obtain fine epoxies. This blend, then, on the one hand constantly stirring until you get the consistency you want add up the filling. A terminology based on the consistency of the thickened epoxy is developed.
Where and how is it used?
If you want to insulate wood or plywood against water, you use thin epoxy. You can use a brush for this job, but you need to throw a brush at the end of the brush because the hardwood epoxies can not solve anything. So use the cheapest brush you can find. If you are insulating large surfaces like a carina, there are better ways than brushing. You can pour some epoxies on the surface and spread it with a sponge. According to my experience, the best way is to spread the epoxies again by making circular movements with smooth semi-hard plastic (English squegee). It is even better if you do this as if there is a narrow angle between the surface and the plastic. You will minimize the formation of unwanted air bubbles. The more you penetrate the epoxy surface, the better your insulation will be, so it is better to sand the surface first. This will allow both epoxy to penetrate better, as well as allowing you to escape from foreign materials (such as oil) that may be present on the surface. Of course you need to clean the sandpaper. More than one coat insulation for the boat is usually recommended.
Although thin epoxy can be used directly as an adhesive, it is stated that thickened epoxy is preferred for this work. Just as it is in the insulation, the bond strength of the bond is tightly linked to the extent to which the epoxy penetrates the surfaces to be bonded. If the thickened epoxy is applied directly to the bonding point, the material will become slightly epoxidized from this mixture and the bond will weaken as the amount of epoxy remaining in the mixture decreases. Therefore, both surfaces must be wetted with thin epoxy before the thickened epoxy is applied to the bonding point. Since the edges of the plywood, especially the plywood, absorb a lot of epoxy, it is good not to forget this process. The most economical application is to wet the surfaces after preparing the thin epoxy in the door, then to add the thin epoxy filler remaining in the door and to thicken the adhesive. If you do not do this, be sure to apply thickened epoxies before the epoxy freezes in the wetted parts.
When applying fibers, you use thin epoxy. Foil publication, pour a little epoxy onto it and roll it out or with plastic. Take care not to leave air bubbles between the fiber and the plywood. If you notice a bubble, run it to the edge and get rid of it. Only use enough epoxy to make the fiber translucent, and more if it hurts. After you arrive at the jelly stage, but before it's fully frozen, apply the next coat in the same way. Since the fiber tape is usually coated on the paste, the application is a bit different. First, place it nicely on the fresh paste with a tape spring and a roller brush or with your fingers. We do not want air bubbles, but do not break the shape of the paste, which is still soft when doing this. I suggest you wait 5-10 minutes later. The tape will take some epoxy from the following machine and the parts that suck up enough epoxy will be transparent. Apply thin epoxy to the non-transparent parts until they are transparent. You can use a normal or roller brush. Again pay attention to not pushing the Mac too much and distorting its shape. Finally, look again for the air bubble and remove if you can find it.
Lamination offers an elegant solution for many problems encountered in boat making. For example, D4 may require a thicker plywood, such as a rudder or roll, which may not be in your case. Or you may need to bend a thick wooden for example. If it is not possible to give the desired shape to the thickness of the piece, the shortest solution for amateurs is lamination, that is, the method of obtaining the desired thickness with many thin pieces pasted on top. For lamination, first clean the parts, sand, dust and wipe both surfaces thoroughly with thin epoxy. Then cover one of the surfaces with thickened epoxy in ketchup or mayonnaise consistency. Torture, weight, you can use what you find. There are a few things you need to be aware of. Laminar parts are small or thin, and if thicker, you can use thicker epoxy (mayonnaise). On the other hand, if you are sticking pieces with large surfaces to each other, you may want to choose a finer consistency (ketchup). That's why it reduces the likelihood of air bubbles occasionally. As this is a major problem for large surfaces, drill a hole in the top surface (I drill a hole in every 10cm x 10cm) to escape the trapped air. Then gently hold the pieces together and feel comfortable if the epoxy mix leaks out of the holes. Last but not least: The strength of the connection is not proportional to the holding pressure. Actually the opposite is true. If the tiredness gets too tight and the remaining epoxies get out completely, you get a weak bond. It is necessary to fix the parts in the adhesive with epoxy so that they do not move. As a result, do not apply too much pressure!
Same as described for lamination that needs to be done. You clean the areas to be adhered and you are sanded and wet with thin epoxy. Then you thicken the epoxies as much as you want. Mayonnaise, even ketchup if you are not working against gravity. If you're working against gravity, it's a good idea to make the epoxin a little thicker and shark-like to keep it from flowing. Then you stick to the epoxidation zone so that the particles do not move. Be careful not to overtighten.
Filling, gap filling and surface smoothing
When you tighten the pieces that you stick with thickened epoxy, some of the epoxy will overflow. If you take this overflowing part, you will say it with your fingertip or something shaped like a curved sealant (English fillet) that will come out if you scatter it along the area of adhesion. Our goal is to leave a putty layer as if it were on the same glass edges. The paste distributes the load over a larger area, making the connection stronger. You can use your fingers to apply the paste properly (do not forget to wear gloves). Spoons for this job, or flat wooden bars that doctors use to push the language when people look at their throats are recommended. Of course you can also cut out scrap pieces according to the radius you want and use the things you will prepare.
For best results, the thickness of the paste must be close to the thickness of the glued-on control at its thickest spot (ie, 45 degrees above the connection point). The length of the paste towards the sides, that is, the length from the connection point to the edge of the gum region must be greater than the thickness of the glued control (1.5 times a good choice so that the total paste thickness is 3 times as large as the counterpart). If the overflowing epoxy does not provide these dimensions, you need to add it. The next picture is called "fillet" and the yellow color is the epoxy, the paste we are talking about. "Filling gaps" is epoxy, which is there for filling voids.
I do not need to explain what is filling the gap. You start again by wetting the next areas of thickened epoxy on the job. Then you apply the thickened epoxies and shape them according to your hand. Surface leveling (English fairing) is technically actually filling the gap. But here the gaps are not deep and the surfaces are very wide. The small dents that are formed in your car are actually the job of the bodyworker to straighten it up with putty instead of hammering it. Of course there is a hammering option in the car, but you can not hammer a wooden carousel. As a result, we are talking about filling the remains of lightweight dents on a large surface to obtain a flat surface. Again, you start by soaking the surface with thin epoxy. It is useful to wait until it becomes jelly before applying thickened epoxies. It is easiest to apply the thickened epoxy with the previously mentioned plastic part. When your epoxide is completely frozen you are thoroughly sanded. There is no need to use a filler with very strong bond properties for surface leveling. So, choose the one that you use to thicken epoxies easily sandable. Generally, the bonding strength of the easy sanding fillers is low and the bonding strength of hard sanders is high.