xswqaazz
13.05.2021 10:58:48
For smaller objects, like aluminum wheels, rims, or parts, a more efficient method now exists. more
See full version: Sandblasting Aluminum Wheels (and other Surfaces)
For smaller objects, like aluminum wheels, rims, or parts, a more efficient method now exists. more
By using a vapor blast cabinet, or a slurry blasting cabinet, the blasting time is greatly reduced, and the polishing step is eliminated completely. The advantage of wet blasting is that it produces no dust. With a slurry blast cabinet, the media and water are mixed, then blasted at the surface. With our Vapor King, we’ve combined the force of direct pressure blasting with wet blasting. Both options make stripping a surface much quicker than the old dry blast and polish methodology. more
The larger the blast nozzle, the more air pressure you will need to effectively blast. You can find a handy reference chart of recommended CFM here.
Start by testing a portion of the blasted surface. If the air pressure and results look good, feel free to blast the rest of the surface suing the same conditions.
In order to achieve a quality painted finish on bare aluminum, you must first clean the metal with PRE Painting Prep or some type of solvent. This will remove dirt and contaminants from the surface of the metal. more
Next, go over the aluminum with 320 Grit Sand Paper on a DA Sander. This step can be done by hand but for the best results a DA Sander should be used. After sanding, use a blow gun to remove any dust and then wipe down the aluminum again with PRE. more
If you are going for a more finished look you can apply High Build Urethane Primer and level with 320 Grit Sandpaper on a Sanding Block. Scuff the piece with a Gray Scuff Pad and wipe down with PRE. With the surface now level it is ready for paint and primer.
Depending on the goal of your project you have a few options after the epoxy primer is sprayed. If you are happy with the the primer looks all that needs to be done is a quick scuff the panel with a Gray Scuff Pad or 400 grit sandpaper and you are ready to paint and clear.
Will a wire wheel work for texturing the metal-No they mostly provide a polished or burnished surface, they do work well for rust removal though. [links]
Some common mistakes I've seen people make is not prepping bare metal properly for good primer adhesion. Keep in mind epoxy and DTM type primers need the metal to have some texture and it also needs to be perfectly clean. The perfect texture is achieved by sandblasting or sanding with 80 grit on a DA, some fiber discs like 3M's Clean-n-strip discs also work well. Failure to texture the metal and clean it well can lead to less than adequate adhesion. Blasting jambs and similar areas is usually no problem but outer sheetmetal should be left to a professional to avoid warpage-(Shine should do a thread on blasting techniques). Hand held gravity fed spot blasters are an economical way for anyone to clean small areas-they work well. When sanding change your paper often so it produces a sharp scratch pattern and not a shiny polished surface.
Clean the bare metal with solvent based wax and grease remover then follow that with waterborne wax and grease remover-spray the cleaner on and wipe it off while it's wet, or you can pour the cleaner on one towel then wipe it on and wipe it off with a clean towel. Why two cleaners?-they each offer their own benefits. (Update: New SPI guidelines call for waterborne to be used first, then solvent base.) Should sandblasted metal be cleaned-definitely and especially if you recycled your sand. I've seen primer fall off of sandblasted steel when the person didn't clean it before priming. You'll end up with some towel fuzzies on a blasted surface as the texture grabs the fibers-no big deal just give it a light scuff with a red scotchbrite and a blast with the blow gun and they are gone and they need to be gone!
Simple Green, 409, Dawn dish soap, Ajax, Fast Orange, Engine Degreaser. -- these can all be handy during the precleaning stages of a job but you shouldn't be cleaning your bare metal with them for the final clean before primer. more
Will an acid etched surface provide enough adhesion? No, if you use acid make sure to neutralize it well and then mechanically texture the surface with sanding or blasting. Acid works great for rust removal but needs to be completely removed for any primer application.
The sand that can be used in a sandblaster comes in many grades, which differ in thickness and abrasiveness. Sand should be picked according to how much work needs to be done and how damaged the aluminum is. Sandblasting aluminum with fine sand is best for small imperfections, while medium is better for larger imperfections. Large-grain sand is rarely needed and may be too harsh for even very damaged aluminum. [links]
Sandblasting aluminum to remove the imperfect parts is one way of fixing rust or other damage to the metal. Before sandblasting aluminum, it generally is a good idea to clean it to ensure all the imperfections are visible. There are many different sand grades, and picking the right grade will ensure the aluminum is not further damaged by the sandblasting. As someone sandblasts, he should keep moving and not remain on one spot, which could dig a hole in the aluminum. The aluminum also should be checked frequently — every few seconds — to ensure only the correct amount of sandblasting is done.
While it is possible to start sandblasting aluminum before cleaning it, this generally is not the best idea. If there is dirt or grime on the aluminum, it may hide further imperfections or create an optical illusion that makes the damage look worse. To get a proper idea of how damaged the aluminum really is, it should be cleaned beforehand with simple soap and water.
During sandblasting, it normally is best if the person moves back and forth and does not stay on one spot, even if there is only one spot that needs to be repaired. If someone sandblasting aluminum focuses on one area, then it will cause that section to wear away very quickly and may take away too much aluminum. Going back and forth also makes the sandblasting blend better and look more natural. more
Keeping a sandblaster trained on a piece of aluminum for an extended period of time can make it difficult for the operator to know how well the sand is working, and it may cause him to sandblast too much away. This normally makes it best to turn off the sandblaster every few seconds — or minutes, depending on the size of the area being sandblasted. This allows the operator to see exactly how much work still is needed. As soon as the damaged sections are sandblasted away, the operator should stop, because further sandblasting at this point can lead to permanent damage.