Efficient Sanding for Collision Repair
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Abrasives from 3M provide the perfect basis for best painting results. The portfolio includes grinding wheels and stripes, hand abrasive and wet abrasive. The right abrasives play a key role for a perfect result in vehicle refinishing. Whether in the preparation, in dry primer or fine sanding: Our quality abrasives and a further range of accessories are designed to help you safely and efficiently exercise your processes, especially...
- Body Filler preparation and sanding - preparation for primer application
- Fine sanding for Painting - Surface Preparation of the primer, ready for Base coat application
- E-coat Sanding for new part preparation
- Always select appropriate Personal Protective Equipment - Eyewear, gloves, hearing and respiratory protection for your job and workplace!
Body Filler sanding - preparation for primer application
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Step 1 - Clean the area
In preparation for filler application, clean the repair area and remove all loose paint particles or rust. Sand down to bare, clean metal using Cubitron™ II 150+ on a DA sanding machine - to achieve the surface that you want to apply body filler onto.
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Step 2 - Apply Dry Guide Coat and key the featheredge
Apply 3M Dry Guide Coat to highlight any 150+ scratches, then key the feather edge around the bare metal with Cubitron™ II 220+ to prevent that any solvents from the filler can penetrate the edges and lead to subsequent swelling.
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Step 3 - Apply Body Filler
Apply 3M Body Filler by the method of your choice - either using the innovative 3M Dynamic Mixing System or standard Filler application processes.
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Step 4 - Apply Dry Guide Coat onto cured filler
Once the filler is cured, apply 3M Dry Guide Coat to show the filler structure and allow a controlled fast sanding. Dry Guide Coat also helps to reduce clogging and extends the live of the abrasive.
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Step 5 - Filler sanding
Use 3M Cubitron™ II 150+ by machine or with the right Handblock and dust extraction for a fast shaping of the filler area.
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Step 6 - Re-apply Dry Guide Coat to highlight fine scratches
Re-apply 3M Dry Guide Coat to highlight any deeper scratches and surface imperfections to be removed with finer abrasives.
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Step 7 - Reduce any scratches
In order to prepare the surface for the primer application, reduce any scratches of 150+ by using grade 220+. To achieve optimal flattened results, use abrasive with a hand block.
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Step 8 - Final sanding before Primer
Following the manual sanding, use a DA machine (Festool Automotive Systems LEX 150 / 5 or Festool Automotive Systems ETS / EC 150 / 15) and Cubitron™ II 220+, followed by P400 / P500 to featheredge and improve the adhesion of the primer.
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Step 9 - Blending area
Interim protect any surrounding edges with a strip of masking tape, before you prepare the blending area.
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9a : Using 3M™ Flexible Abrasive Sheets P1000 - P1200 to prepare the edges and styling lines of the area that the base coat needs to be blended in.
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9b : To prepare the whole blending area, use 3M P1000 abrasive (e.g. 260L+, Flexible Disc or Trizact™) with an interface pad on a DA machine. -
9c : Using Scotch-Brite™ Disc Grey on a DA with dust extraction, clean the surface in preparation for a clean base coat application, wipe the surface clean with a 3M Panel Wipe and suitable degreaser, then mask the primer area as required.
Apply and cure the primer of your choice, following your paint manufacturers recommendations.
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To improve the adhesion of the primer, it is recommended to key the surrounding edge area with P400/P500.
Apply and cure the primer of your choice, following your paint manufacturers recommendations.
Any machine used for preparation should have a throw of 5 mm or more - anything for fine sanding should have a throw of 5 mm or less!
Fine sanding for Painting - Surface Preparation of the primer, ready for Base coat application
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Step 1 - Apply Dry Guide Coat
Apply Dry Guide Coat to the primer area to allow control of work progress.
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Step 2 a - Flatten the surface
The first step in primer sanding is done with P320 / P400 using 3M abrasive sheets on a hand block in central repair area above the filler to flatten the surface.
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Step 2 b - Re-apply Dry Guide Coat
Re-apply Dry Guide Coat to the sanded area to to highlight scratches to be removed.
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Step 3 - Manual Sanding of styling lines
To avoid burn through with latter DA sanding, any edges and styling lines within the repair area are sanded by hand first, using Hookit™ Flexible Abrasive Sheets P1000.
Tip: Key is not to sand through the primer and open up bare metal again. If it has happened, please make sure you cover this area with the required thickness (paint manufacturer recommendation!). A badly treated area will show up with a darker coloured base coat and ultimately lead to contact corrosion.
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Step 4 - Remove structure of primer application
Sand the surface now using Festool Automotive Systems LEX3 150 / 3 or Festool Automotive Systems EETS / EC 150 / 3, equipped with a soft back-up pad. Abrasive grade to be used is now P400 / P500 to remove the structure of the previous primer application and leave the perfect surface for the base coat to be applied to.
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Step 5
Using a Scotch-Brite™ Disc Grey on Festool Automotive System DA machine with dust extraction, clean the surface in preparation for a clean base coat application. Wipe the surface clean with a 3M Panel Wipe and suitable waterbased degreaser.
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Step 6 - Final cleaning
As a final step before base coat application, when the car is already in the paint booth, wipe the surface clean with 3M™ Tack Cloth Aqua.
E-coat Sanding for new part preparation
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Step 1 - Key the area
Inspect the replacement part - clean and degrease in accordance with paint company recommendations.
Working from the interior to the outside, use a Scotch Brite Grey (from Roll or as Hand Pad) to key the inner area of the part and around corners, edges and rims.
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Step 2 - Sanding
Sand the surface now using a DA machine with 3 mm throw, equipped with a soft back-up pad and an interface pad for additional buffering. The ideal abrasive for this process to be used is the special E-coat Disc 3M™ Hookit™ Abrasive Disc 337U, grade P320.
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Step 3 - Dust Removal
Using a Scotch-Brite™ Disc Grey on a DA with dust extraction, clean the surface in preparation for a clean primer application.
Final clean in accordance with paint company recommendations and apply the primer.
- 3M and Festool Automotive Systems have formed a global strategic collaboration to best serve the automotive collision repair industry. 3M’s best-in-class abrasives innovation, including 3M™ Cubitron™ II Abrasives, are now available in conjunction with premium Festool Automotive Systems surface prep tools, including pneumatic and electric sanders, polishers and backup pads, vacuums and surface-prep workstations, dust extraction capabilities and service.
