hi guys..
the above members said every things and did not left anything for me to say

anyway...
dry sanding
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1. dry sanding will create dust in your workshop
2. dry sanding is not healthy becuase of the dust flying in the air
3. dry sanding will create a heat
4. dry sanding will not let your sand paper last long
5. dry sanding will create a deeper scraches in your car surface
6. the good things in dry sanding are:
a. will not create rust
b. will not spoil the papers which covered your car window
wet sanding
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1. wet sanding will not create dust... but the dust go with the water
2. wet sanding is more healthy..
3. wet sanding will create cool sanding
4. wet sanding will let your sand paper last longer
5. wet sanding will give you smooth finish without scraches
6. the bad things in wet sanding are:
a. will create rust when you reach the steel surface
b. will spoil the paper and masking tape
c. will let the water hide under your masking tape
I like both above ways :thumbup:
wish u all the best