The inner wall of the sandblasting barrel parts that have been used for a long time is prone to rust, which not only affects the performance of the equipment, but may also shorten its service life. Repairing the rust on the inner wall of the sandblasting barrel parts needs to be handled step by step to ensure the repair effect and equipment safety.
First, a comprehensive assessment of the rust on the inner wall of the sandblasting barrel parts should be conducted. Carefully observe the inner wall to determine whether the rust is slight floating rust or pits or even perforations have appeared. The thickness of the barrel wall can be measured with a thickness gauge to mark the areas with severe rust. At the same time, analyzing the causes of rust, such as whether it is caused by moisture in the sandblasting medium or corrosive gases in the environment, will help to take targeted protective measures after repair to prevent rust again.
After completing the assessment, the inner wall of the sandblasting barrel parts needs to be thoroughly pretreated for rust removal. First, clean up the remaining sand in the barrel, remove the removable parts, and blow away the floating dust on the inner wall with high-pressure air. For large-area rust, electric wire wheels or angle grinders with sandpaper discs can be used for grinding. Grind in the circumferential direction until the metallic luster is exposed. Pay attention to the strength when grinding to avoid excessive grinding and thinning the wall thickness. For gaps, pits and other parts that are difficult to grind, acidic rust remover can be applied. After waiting for a few minutes, use a hard brush to remove the rust residue, then rinse with clean water and dry thoroughly to ensure that the inner wall roughness meets the appropriate standard and enhance the adhesion of subsequent coatings.
If there are perforations or deep pits on the inner wall of sandblasting barrel parts, structural damage repair is required. For sandblasting barrel parts made of low-carbon steel, E4303 welding rods can be used for arc welding. First clean the rust and oil around the weld, open a suitable groove, and weld in multiple layers to reduce stress concentration. After welding, use an angle grinder to grind the weld flat and check for defects such as pores and cracks. If the sandblasting barrel parts are made of aluminum alloy, argon arc welding should be used, preheating before welding, annealing after welding, and the wall thickness should be measured again after repair to ensure that the thickness of key parts meets the requirements.
After rust removal and structural damage repair, a suitable anti-corrosion coating should be selected for the inner wall of the sandblasting barrel parts. If the sandblasting barrel parts are used in a neutral sand material and humid environment, epoxy resin coating is a good choice. Apply primer first, scrape putty to fill the pits after drying, and then spray topcoat. In a high-impact environment, polyurethane coating has better wear resistance and can be applied by airless spraying. For large sandblasting barrel parts with severe corrosion, thermal spraying metal coating combined with sealant can provide long-term protection. Pay attention to the ambient temperature and humidity during construction, use the correct spraying method, and avoid problems such as sagging and missing coating.
For the parts of the sandblasting barrel parts where the sand particles are severely impacted, such as below the feed port and the slope surface of the barrel bottom, it is also necessary to strengthen protection. Wear-resistant rubber plates or polyurethane linings can be pasted, fixed with high-strength structural adhesive, overlapped at the joints and reinforced with beading; tungsten carbide welding rods can also be used to locally weld the wear-resistant layer and grind it after welding; or removable stainless steel protective plates can be installed to facilitate regular inspection and replacement.
After completing the above repair steps, the sandblasting barrel parts should be tested for sealing and performance. Inject compressed air into the barrel to the working pressure, apply soapy water to the welds, interfaces and coating surfaces, check for bubbles, and re-coat or re-weld in time if leakage is found. After the sealing test is qualified, load standard sand material, adjust the pressure for sandblasting performance test, observe the sandblasting flow rate and sand flow form, detect the cleanliness of the sprayed sand particles, and ensure that the coating does not fall off or powder.
To prevent the inner wall of the sandblasting barrel parts from rusting again, preventive maintenance is also required. After each use, use compressed air to blow away the residual sand and water vapor in the barrel. In humid areas, place desiccant and seal the barrel cover; use dry and clean sandblasting media, install air dryers and oil-water separators, and regularly discharge condensed water; disassemble sandblasting barrel parts for inspection every year, measure the coating thickness, and re-coat in time; store sandblasting barrel parts in a dry and ventilated place, and apply anti-rust oil and seal them when they are idle for a long time. Through these measures, the service life of sandblasting barrel parts can be effectively extended and their normal operation can be guaranteed.
