Checking and repairing cracks in diesel engine blocks and cylinder heads
2024-11-29 12:03:45
First lightly tapping with a metal object, such as the sound is not crisp and husky, there are cracks. Then take a closer look and find the extent of the crack. If you cannot find a hydraulic pressure test that can be performed using specialized equipment, the location of the water seepage after pressurization is the location of the crack. If no special equipment is available, apply 75% of engine oil and 25% of kerosene mixture to the area to be inspected. Then wipe off the mixture with dry cotton wool and immediately apply a layer of zinc oxide and methanol solution. The solution changes color. The place is where the crack is. This method can also use kerosene or diesel oil instead of a mixture of engine oil and kerosene, with white chalk powder, white lime powder instead of zinc oxide methanol solution. The white powder should be evenly coated and not coated too thick. The place where the white powder turns black is where the crack is.
If the crack location is not affected by the impact force, it can be repaired by adhesive; if the working temperature of the crack is below 300°C, it can be filled with epoxy resin; when the operating temperature of the crack is high, the copper oxide monophosphate inorganic can be used. Adhesive sticking. When replenishing, it is necessary to dust, degrease, remove rust, dry, and roughen the replenished parts, then apply the prepared adhesive and reapply the glass cloth or metal patch as needed.
If the cracks occur in the interior and where the strength requirements are high, the welding method can be used, and the current cold welding method is often used. First use a wire brush to clean the cracks, preferably by gas welding, and then drill a hole in each end of the crack; use a tweezers to open a “V†shaped groove with a depth no more than 75/85 of the workpiece 2/3. The size of the cast iron electrode is selected to use a welding current of 130-250 amps. Generally each time welding 10 ~ 15 mm long section, welding a light tapping hammer with a hand hammer, when the workpiece temperature dropped to 30 ~ 40 °C, then welding a section until all welding is completed, and the site of the rake Thorn hair.
If the crack is wider and more concentrated, it can be repaired by patch plate method. First crack the wire with a wire brush and drill a hole at each end of the crack. According to the crack range, about 18 mm from the edge of the crack was cut to a thickness of 2 to 3 mm steel or copper plate as a patch. Use a drill with a diameter of about 4 mm to drill holes along the edge of the plate, each hole being 15 to 18 mm apart. The patch is placed in the crack and the patch is used as a template to drill a hole in the part to be machined into a screw hole. Apply red lead oil to the side of the patch that is close to the part to be repaired, then install it on the part to be repaired and tighten it with bolts.
Repairing small cracks can take nails. Using a drill with a diameter of 5 mm, drill holes along the gap between the cracks and tap the threads. Then use screws made of copper rods to screw into the holes. The depth is the same as the thickness of the cylinder head gasket. Saw 2 to 3 mm away from the surface of the body. In the same way, screw the red copper screw between the copper screws so that the whole crack is full of screws to form a screw chain. Finally, tap the surface exposed screws with a hammer to completely cover the cracks.
Whichever method is used, it should be finally checked whether it has been completely repaired. If it is not completely repaired, it should be repaired again.
If the crack location is not affected by the impact force, it can be repaired by adhesive; if the working temperature of the crack is below 300°C, it can be filled with epoxy resin; when the operating temperature of the crack is high, the copper oxide monophosphate inorganic can be used. Adhesive sticking. When replenishing, it is necessary to dust, degrease, remove rust, dry, and roughen the replenished parts, then apply the prepared adhesive and reapply the glass cloth or metal patch as needed.
If the cracks occur in the interior and where the strength requirements are high, the welding method can be used, and the current cold welding method is often used. First use a wire brush to clean the cracks, preferably by gas welding, and then drill a hole in each end of the crack; use a tweezers to open a “V†shaped groove with a depth no more than 75/85 of the workpiece 2/3. The size of the cast iron electrode is selected to use a welding current of 130-250 amps. Generally each time welding 10 ~ 15 mm long section, welding a light tapping hammer with a hand hammer, when the workpiece temperature dropped to 30 ~ 40 °C, then welding a section until all welding is completed, and the site of the rake Thorn hair.
If the crack is wider and more concentrated, it can be repaired by patch plate method. First crack the wire with a wire brush and drill a hole at each end of the crack. According to the crack range, about 18 mm from the edge of the crack was cut to a thickness of 2 to 3 mm steel or copper plate as a patch. Use a drill with a diameter of about 4 mm to drill holes along the edge of the plate, each hole being 15 to 18 mm apart. The patch is placed in the crack and the patch is used as a template to drill a hole in the part to be machined into a screw hole. Apply red lead oil to the side of the patch that is close to the part to be repaired, then install it on the part to be repaired and tighten it with bolts.
Repairing small cracks can take nails. Using a drill with a diameter of 5 mm, drill holes along the gap between the cracks and tap the threads. Then use screws made of copper rods to screw into the holes. The depth is the same as the thickness of the cylinder head gasket. Saw 2 to 3 mm away from the surface of the body. In the same way, screw the red copper screw between the copper screws so that the whole crack is full of screws to form a screw chain. Finally, tap the surface exposed screws with a hammer to completely cover the cracks.
Whichever method is used, it should be finally checked whether it has been completely repaired. If it is not completely repaired, it should be repaired again.
Fresh Half Shell Mussel Meat,Half Shell Mussel Meat,Frozen Cooked Mussel Meat,Frozen Mussel
Shengsi Xiangyuan Aquatic Products Co.,Ltd., , https://www.xiangyuan-aquatic.com