About Feather Prime Block

  • Great paint jobs don’t happen by accident. Preparation is crucial – and it starts with proper masking. Like any part of the collision repair process, masking requires the best products used in the best ways. Featuring products and techniques from the company that set the standard for automotive masking, these 3M standard operating procedures provide you clear and simple steps to help you ensure that your finished work will look sharp and clean before you even pick up your spray gun.

    Download English Feather Block Primer Standard Operating Procedure (PDF, 315.75 KB)


Feather Prime Block Steps

  • Feather Edge

    Step 1: Featheredge

    Blow off repair area with clean, dry air. Featheredge the surrounding repair area using a P180 abrasive.


  • final sand & inspect paint

    Step 2: Final Sand and Inspect

    Final sand the surrounding area using a P320 abrasive disc on a DA sander. Blow off with clean, dry compressed air. Clean with wax and grease remover. Inspect the repair for quality.

    Blow off the entire repair area again with clean, dry compressed air. Feather-edge the area surrounding the filler and glaze using a P180 grit abrasive. Be sure to remove the remaining straight-line scratches from the repair area and abrade the outer perimeter for primer. Inspect the repair area and the surrounding panel for quality.


  • mask for primer paint

    Step 3: Mask for Primer

    Mask the repair area as necessary. Refer to our Primer Masking SOP for specific 3M masking recommendations.


  • apply primer paint

    Step 4: Apply Primer

    Apply primer to the repair area following manufacturers’ recommendations. Allow the primer to cure.


  • apply dry guide coat paint

    Step 5: Apply Dry Guide Coat

    Apply 3M™ Dry Guide Coat over cured primer.


  • hand block repair paint

    Step 6: Hand Block Repair

    Hand sand or “check block” sand the repair area using a P320 abrasive sheet on an appropriately sized hand block. Look for imperfections in the repair area highlighted by the dry guide coat. If necessary, re-apply dry guide coat and continue block sanding to repair any defects as required.


  • reapply dry guide coat paint

    Step 7: Re-Apply Dry Guide Coat

    Re-apply 3M™ Dry Guide Coat over the entire repair area.


  • da sand primer paint

    Step 8: DA Sand Primer

    DA sand the repair area using a P400 disc and a soft interface pad until all 3M™ Dry Guide Coat is removed.

    Note: Use a 3M™ Flexible Abrasive Disc to reduce burning through the primer surface.


  • clean damanged area paint

    Step 9: Clean the Damaged Area

    Clean the repair area with a VOC compliant surface cleaner.


Request a Feather-Prime-Block Product Demonstration

Our sales team is happy to show you how any of our products can help your feather-prime-block paint preparation processes. Whether you feel a certain part of your paint prep needs improvement or you just need a quick refresher, we’re here to help. To request your demo, simply click to the right.


  • Important Note
    There are of course many factors and variables that can affect an individual repair, so the technician and repair facility need to evaluate each specific application and repair process, including relevant vehicle, part and OEM guidelines, and determine what is appropriate for that repair.