Based on the grit count you are using your sandpaper can make the surface smooth or rough. Each time you advance to a higher grit size you eliminate the scratch marks from previous sanding.
It will allow you to cut out old body filler or shape new filler if you have some extremely high areas in your bodywork.
Repair what sandpaper grit should i use before priming. You can actually go even more coarser if you re doing a single stage enamel. Like if you want to prep the surface for exterior painting where you want that the primer and paint stick firmly it would be better to use a lower count coarser sandpaper to make the surface rough. However first the paint edge around the damages are will need to be smoothed or tapered.
Some people even paint over 280 grit sanded surfaces. After some time with the 400 grit you can move to a 600 grit paper to give yourself a nice smooth surface to work with when you are painting the car. 320 grit at this point along the wet sandpaper grit chart the options are ideal for smooth buffering as well as the removal of thick paint.
You need to choose the sandpaper grit size according to the material you re preparing to prime. Block sanding primer and final sanding paint. Then primer coatings can be applied.
Dry sand using 180 grit sandpaper to remove rust or surface damage before moving. Deeper the scratch more shrinkage you will get later down the road people load up primer to fill in 80 scratches less is best. A little experimentation will help.
That is an excellent grit to paint your base coat and clear coat over including enamels or anything else that you re doing. This is called feather edging and is normally done using a da sander and 220 grit sandpaper. 32 and 40 grit sandpaper can also be used for sanding heavy rusted areas and cleaning them down to shiny metal.
32 and 40 grit sandpaper can be used for sanding and grinding paint down to metal. When people ask what grit of sandpaper is suitable for a wet sanding primer 240 grit is a popular answer because a wet folded 240 will generally offer durability during a sanding job. When sanding wood for example start with coarse sandpaper such as 80 grit gradually increasing in fineness.
Less the depth of scratch less primer is needed. As a starting point if you are sanding a coat of rough primer you can start with a 400 grit sandpaper to knock down all of those little bumps. Its best finishing of your bondo before priming with 180.
Sand the paint either to the bare metal the original primer or at least sufficiently for the new paint to adhere. So i ll say it like i ve said it before you should paint over 400 grit. When sanding a softer surface such as plastic you may need to start with a higher grit size such as 120 to avoid excessive scratching.
Once the body filler is block sanded with 150 to 220 it is ready for primer.