Home Improvement

Thoughts & Stuff I Like When We Redid Our House

Grits Sanding

Floor Sanding

ADVICE FOR DIY - FLOOR SANDING
Our honest advice would be to let the professionals do it for you!

FLOOR SANDING COMPANY - LONDON

However, if you are a confident and competent DIYer you might find these instructions of use to supplement any information provided by your equipment hire company.

Equipment you will need:
1. Drum or Belt Floor Sander
2. Edger Disc Sander
3. Rotary Floor Buffer/Maintainer
4. Vacuum cleaner
5. Sandpaper (fine, medium, coarse grades)
6. Grade 120 Mesh Screen Disc with Pad
7. Hammer and nail punch
8. Crow bar
9. Hand Scraper
10. Dust Mask, Safety Glasses, Ear Plugs

Preparing the Floor
1. Remove any quadrant molding from the edges of the floor. Use a small
wooden wedge between the skirting board and the crow bar to prevent damaging the
skirting board.
2. Repair or replace loose boards by gluing and/or nailing.
3. Counter-sink all protruding nail heads with nail punch.
4. Vacuum the floor of any debris regularly.

Sanding the Floor
NEW FLOORS (Recently installed or slightly worn)
FIRST SANDING: (Medium Abrasive, Grit 36-2)
Afix the sanding pad/sheet to the sander in accordance with the machine manufacturer's instructions; ensure it’s neither too tight nor too loose. Position the drum sander alongside the wall in the direction of the wood grain, with approximately two-thirds of the length of the floor in front of you.
(1). Start the machine and gently ease the drum down onto the floor. Walk slowly forward at an even pace. As you near the wall, gradually raise the drum off the floor. Start pulling the machine backwards as you ease the drum back down to the floor. Cover the same path previously sanded, raising the drum upon completion of this pass. The next pass should be done in the same manner, but move the machine approximately four inches into the unsanded floor area. After a few passes, you will notice your sander's dust bag will start filling up. Stop sanding and empty the dust bag frequently for optimal performance.

(2). Once this two-thirds area of the room is fully sanded, turn the machine around by 180 degrees and sand the remaining one third in the exact same manner, allow a two to three foot overlap over the already-sanded area. If you start to notice the sanding rate is dropping, your sanding sheet or pad is probably clogged or worn out. Stop sanding and replace with a new one. If you continue operating with a worn out or clogged sanding sheet or pad, you will eventually burn or damage your floor!

(3). Once sanding of the main floor area is complete use the edging sander machine to sand up to walls or skirting boards and into areas which the drum sander can’t access. Move the edging sander in a brisk left-to-right, semi-circular motion. (Use same grit abrasive as used on drum sander). Hand sand or scrape corners and areas inaccessible by your machines. Vacuum the entire floor. Apply wood putty to any exposed cracks or holes in wood. Allow to dry before proceeding to the next sanding step.

SECOND SANDING: (Fine Abrasive, Grit 80-0)
Upon completing both drum and edging sanding operations with a medium abrasive sheet or pad, repeat the process outlined above with the fine abrasive - grit 80.

OLD FLOORS
Those requiring a generous amount of old finish to be removed, and /or uneven floor contours to be corrected.

FIRST SANDING: (Coarse Abrasive, Grit 20-3 1/2). Afix the sanding pad/sheet to the sander in accordance with the machine manufacturer's instructions; ensure it’s neither too tight nor too loose.

(1). Visually divide the room into thirds, position the drum sander alongside the wall in the direction of the wood grain, with approximately two-thirds of the length of the floor in front of you. Start the machine and gently ease the drum down onto the floor. Walk slowly forward at an even pace. As you near the wall, gradually raise the drum off the floor. Start pulling the machine backwards as you ease the drum back down to the floor. Cover the same path previously sanded, raising the drum upon completion of this pass. The next pass should be done in the same manner, but move the machine approximately four inches into the unsanded floor area.

If your floor is severely cupped or curled you may need to sand this first pass at a 45-degree angle to the direction of the wood grain. Otherwise, sanding should always be done with the direction of the wood grain.

(2). Once this two-thirds area of the room is fully sanded, turn the machine around by 180 degrees and sand the remaining one third in the exact same manner, allow a two to three foot overlap over the already-sanded area. If you start to notice the sanding rate is dropping, your sanding sheet or pad is probably clogged or worn out. Stop sanding and replace with a new one. If you continue operating with a worn out or clogged sanding sheet or pad, you will eventually burn or damage your floor!

(3). Once sanding of the main floor area is complete use the edging sander machine to sand up to walls or skirting boards and into areas which the drum sander can’t access. Move the edging sander in a brisk left-to-right, semi-circular motion. (Use same grit abrasive as used on drum sander). Hand sand or scrape corners and areas inaccessible by your machines. Vacuum the entire floor.

IMPORTANT: Do not attempt to remove 100% of the old finish during this operation. Residual amounts will be removed during subsequent sanding operations. Vacuum the entire floor.

SECOND SANDING
Repeat the process outlined above but with a medium abrasive - 36 grit. Apply wood putty to exposed cracks and allow to dry.

THIRD SANDING
Upon completing both drum and edging sanding operations with a medium abrasive sheet or pad, repeat the process outline above with the fine abrasive - grit 80.

Final Preparation
Screening the floor
This step is optional, but will add a professional touch to your floor.
Slowly lower the floor buffer with either a tan or green nylon pad attached over a 120 grit sanding screen. Keeping the buffer balanced, sand the entire floor in the direction of the wood grain, overlapping your passes by four inches, as you work your way to the wall behind you. Remove the screen and shake out sawdust as it will have a tendency to become clogged.

Hand scrape and fine sand areas the power sander was not able to reach. Vacuum the entire room thoroughly, especially around windows, sills, doors and door frames. Inspect the floor. Hand sand any remaining imperfections and swirl marks.

Follow the manufacturer's recommendations and guidelines for applying your chosen floor finish.

Helpful Hints
1. Check your fuse supply as heavy-duty sanding machines may overload your circuit.
2. Remove furniture, rugs, curtains, pictures and any other dust-accumulating items.
3. Complete any wall covering and painting projects prior to refinishing floors.
4. Always ensure adequate ventilation during sanding and refinishing.
5. If the room has a large doorway, cover it with a fabric or plastic dust sheet. Insert towels or cloths alongside and under bottoms of doors and cover all air vents.
6. NEVER stop the sander with the drum in contact with the floor.
7. Wear clean, soft footwear or socks to avoid dirt marks and scratching freshly-sanding floors.

Warning!
1. Sanding dust is extremely combustible.
2. Never smoke or have open flames present while sanding or applying finish.
3. Empty sander dust bags frequently into container and place out of doors if possible.
4. Unplug sanding equipment when not in use or when changing sanding pads or disks.

About the Author

I am building a motorcycle, Prepping for paint what grits of sandpaper should I use ? What about wet sanding?

use 80 to 120 grit to remove all paint. prep the bare metal with metal prep/conditioner to clean the surface. prime with a good primer such as dp401 from ppg. do any body filling now. prime with a high build primer and let dry/cure. begin sanding with 300 grit and a block. working up to 600 grit wet. always use a block or pad to maintain the flatness of the panel.

apply a sealer then your topcoat. i would use two part urethane in a basecoat clearcoat system. apply your graphics before the top clear coat. clear coat and allow to dry/cure.

you can wet sand with 1000 or 1200 grit and then buff out the finish.

the above is for the tank, fenders and side covers. for the frame sand, prime and topcoat with urethane single stage.

How to Use a Power Sander : How to Use Sandpaper Grits With a Power Sander