What method of sanding before applying base?

G

Garrett1984

Promoted Users
Finally got my hood laser straight using acrylic blocks. Finished sanding with 220 grit and sprayed 2 coats of SPI epoxy yesterday. I will be spraying 3 coats of base from the manufacture, Motobase. The colors will be solid. Colors will be tan and white.

I have a few questions:

1. I am told I should wet sand by hand with 400 grit wrapped around a flexible rubber block. I am also told I should sand in straight lines parallel to the airflow over the vehicle. Is this true?

2. I am also told it is better to dry sand the hood with 400 grit on a DA sander with a soft interface pad. A friend of mine told me this was better because of all the little swirl marks created by the DA helps hide 400 grit sand scratches under the base and clearcoat. Is this true.

I am told both methods will not screw up my already perfect straight body work. However, I can’t help but think I should listen to my gut instinct and go ahead and wet sand with 400 grit on an acrylic block in an “X” pattern.

Thoughts?
 

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My humble opinon is listen to your gut. Keep reading here and keep doing what got you this far. The hood looks great man !!
 
Chris_Hamilton said:
320 dry with a block then 600 wet with flexible hand type block or soft block. You could finish with 400 wet as well.

Keep a DA far away from finish work.
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I will do this. Thank you for your help. Let me ask you this:
Should I wet sand parallel with the length of the hood or use an “X” pattern? Also, I will be using SPI Universal clear. Would it be safe to say, in my situation, the SPI Universal clear will definitely bury the 400 grit sand scratches by using this high solids clearcoat from SPI? I have been told a high solids clear coat will bury 400 grit scratches, but would like to confirm from a known professional if it is true. I am aware 600 is a must for metallics.
 
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BB70 said:
My humble opinon is listen to your gut. Keep reading here and keep doing what got you this far. The hood looks great man !!
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Thank you! I appreciate it! As you know it is hard work. Have to say though, the end results are so very satisfying! I am a DIYer restoring my grandfather’s old Chevrolet. I inherited it. I used to restore antique aircraft, but this type of work is obviously different than dope and fabric. Been reading and asking questions to build more confidence.
 
Garrett1984 said:
I will do this. Thank you for your help. Let me ask you this:
Should I wet sand parallel with the length of the hood or use an “X” pattern? Also, I will be using SPI Universal clear. Would it be safe to say, in my situation, the SPI Universal clear will definitely bury the 400 grit sand scratches by using this high solids clearcoat from SPI? I have been told a high solids clear coat will bury 400 grit scratches, but would like to confirm from a known professional if it is true. I am aware 600 is a must for metallics.
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Your base will cover 400 sand scratches imo. Don’t overthink this. Sand it anyway you want for a solid base.
 
Garrett1984 said:
I will do this. Thank you for your help. Let me ask you this:
Should I wet sand parallel with the length of the hood or use an “X” pattern? Also, I will be using SPI Universal clear. Would it be safe to say, in my situation, the SPI Universal clear will definitely bury the 400 grit sand scratches by using this high solids clearcoat from SPI? I have been told a high solids clear coat will bury 400 grit scratches, but would like to confirm from a known professional if it is true. I am aware 600 is a must for metallics.
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You can cross hatch with 320 but for your final wet sand be it 400 or 600 ( doesn't matter which) I will just go in straight lines. Usually horizontal. Just my preference and what I was taught. I don't like seeing scratches going any which way on the last sand. JMO.
 
I don’t know about you pros but I cover my haphazard hack 400 scratches in short order long before my OCD has any opportunity to kick in… :p
 
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