Gymnasium floors refinishing by re sanding the Maple hardwood floors back to bare wood

Large area resurfacing refinishing restoration, floor sanding of all kinds game court markings and hardwood floor finishing with all types of finishes.

The Re Sanding of a standard MFMA Maple 2nd & better High school Gymnasium

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screening or burnishing the bare floor

INSTRUCTIONS on SANDING A NEW STRIP OR PLANK FLOOR

Load the drum sander with a coarse grit to medium

grit sandpaper ( #3 or #4). Place the machine

along the right hand wall (unless making an angle

pass as described in TIPS #5 through #7), with about

two-thirds of the length of the floor in front of you.

Start the motor with the drum raised off the floor,

walk slowly forward at an even pace and ease the

drum to the floor. As you near the wall at the end of

the pass, gradually raise the drum off the floor.

Practice before turning on the machine.

Cover the same path you made on the forward cut

by pulling the machine backward and easing the drum

to the floor as you begin the backward pass.

When you reach your original starting point ease

the drum from the floor. Move the machine to the left

side approximately three to four inches. Then repeat

the forward and backward passes and move to the

left after completing each set of passes. You will only

sand a 3” to 4” wide strip of un-sanded area with each

set of passes. When the two-thirds area of the room

is sanded, turn the machine in the opposite direction

and sand the remaining third in the same manner.

Be sure the sanding passes made in the one-third

area overlap the first passes by two to three feet. This

blends the two areas together.

After completing the first sanding operation, or

“cut”, with the drum sander, use the edger to sand

along the baseboards, up to corners, in closets, and

other areas the drum sander did not reach. With new

flooring, which is relatively smooth, use the next grit

Fig. 2. To load the drum sander, thread sandpaper into the

loading slot, turn the drum a full revolution and

slip the other end of the sheet into the slot. Tighten

by turning the nuts at both ends of the drum. Don’t

over tighten and over-compress the drum rubber,

which stresses sanding paper, widens slot, and

increases chatter. Some sanders may take sanding

sleeves or belts. Others may have a clamp to hold

paper on the drum. ALWAYS UNPLUG sander when

changing paper.

sandpaper that will be used on the drum sander. With

old flooring it may be necessary to use the same grit

paper as the first drum cut to remove old finish or

level abused areas. (See TIPS #9)

If a medium grit cleans and sands the floor completely,

use it for the first cuts. If extra passes are required

to clean and level the strips go to a more coarse

grit paper. The first cut with drum sander and edger

should produce a level, completely sanded floor (with

corners and obstructions to be scraped later). All following

sanding procedures merely remove the sanding

scratches produced by the first cut. (See TIPS #10)

When using the edger move in an easy quarter-

Fig 3. Never let the sanding drum touch the floor unless

you are moving the machine forward or backward. If that

happens you will cut a hollow in the floor that is difficult

to remove. (See TIPS #8)

circle pattern at end walls overlapping into the drum

sanded area 4”-6”, and following the direction of the

grain, to some extent. (See Figure 5.) Do not try to

make the edger cut more aggressively by putting extra

pressure to the front. This merely makes ridges and

grooves which are hard to remove. Along walls parallel

to flooring direction, move back and forth with the

direction of the flooring, also overlapping into the

drum sanded area. The edger typically cleans a 1” to

2” strip on each pass.

After drum sanding the floor with a coarse grit

sandpaper, repeat drum sanding with a medium grit

sandpaper. For the edger, use fine grit sandpaper. If

coarse was used on the first cut use medium grit and

follow with fine grit on the edger. Complete the sanding

operation using the fine grit sandpaper on the

drum sander.

Generally, filling of nail holes, blemishes, cracks,

etc., should be done before the fine sanding cut. Use a

commercially prepared wood flooring filler. Some

fillers may need coloring or may not take a bleaching

operation; check with the supplier or manufacturer.

Also, it may be necessary to trowel fill the entire

floor, particularly an old floor, due to the extent of

cracks between strips. Multiple character marks found

in #1 and #2 COMMON Grades which are fill able

grades may also require trowel filling. Trowel filling

should be done before the medium or final sanding

cuts. Let the filler dry thoroughly before proceeding

with the sanding. (Overnight is best.)

When drum sanding and edging are completed

proceed to hand scrape and then hand sand corners

and around doors and other cased openings. Also hand

sand the perimeter edges. Use the same grit as the

last cut. Using a sanding block or electric oscillating

sander can facilitate the hand sanding process. If

staining the floor a dark color, the electric oscillator

may leave egg shaped marks which will show in the

stain. Hand sand these out or do not use the oscillator.

When using a hand scraper apply even pressure,

scraping in the direction of the grain. Avoid gouging

the wood with the scraper. A brick with a piece of old

blanket glued around it makes a good sanding block.

Sand about 6” into drum sanded area. Always sand

and scrape in the direction of the grain along the

length of boards.

Fig. 6. A hand scraper is used where the edger does not

reach, and to remove old finish in tight spots.

Always scrape in the direction of the flooring grain.

Then hand sand or oscillate scraped area. Stripper

(See TIPS #9) may be used where scraping is difficult,

such as under radiators or between stair

balusters.

Using a sanding disc (one grit finer) or screen disc (same

grit as fine cut) on the buffer over the entire floor can

also improve blending of edged and drum sanded

areas. (See TIPS #11) Move buffing machine back and

forth with the direction of flooring boards.

If the floor is to be stained a light to medium color,

the fine sanding cut with 80 grit sandpaper leaves

the wood fibers open and enables more stain to penetrate,

producing a deeper shade and more uniform

appearance. An option is to screen with an 80 grit

after the fine sanding cut, particularly if the fine cut

was 100 grit. Use of the buffer and screen increase

the risk that circular scratches will show if a dark

stain is applied.

Fig. 7. Parquet, block, herringbone and similar floors.

Three sanding cuts followed by screening or disking

is the recommended procedure and will provide a uniform

surface for most all standard finishes. Two cuts

followed by the screening or disking operation may be

sufficient but may produce a more coarse surface and

is considered a minimal sanding procedure.

SANDING PARQUET, BLOCK AND SIMILAR

PATTERNED FLOORING - Use the drum sander

and edger for two sanding cuts. With the first cut do

not sand directly across or with the pattern but always

on an angle. Start the first sanding cut diagonal to

the grain using a medium grit sandpaper. Then use

fine grit sandpaper for the second cut on the opposite

diagonal. Use the buffer and screen or disc to make

a final fine cut with the room’s longest dimension.

(See Figure 7.) (A coarse first cut is usually not

necessary.)

REFINISHING AN EXISTING FLOOR - Most

solid wood flooring is 3/4” thick and can be sanded and

refinished a number of times. Thinner wood floors,

solid or engineered - 1/2” or 3/8” thicknesses - should be

refinished with caution because repeated sanding

can wear down the groove edge, causing breakage or

wear through to reveal nails. With laminated flooring,

professional sanding is recommended.

To determine the floor thickness remove a floor

heating register or the shoe mold and baseboard so

that an edge of the flooring can be measured.

When refinishing floors, remove as little of the

surface as is absolutely necessary. This is particularly

true with veneered and thinner floors. On square edge

strip flooring that is face-nailed, all nails must be

driven slightly below the surface of the wood to permit

sanding.

The following instructions apply to standard 3/4”

strip, plank and block floors and, with the cautions

just mentioned, to the thinner materials.

Sanding. It may be necessary to use a very coarse

“open coat” paper to remove the old finish. The heat

and abrasion of the sanding operation make the old

finish gummy and may quickly clog normal sanding

paper. First try regular paper (particularly on a

diagonal). If 90% of the finish is removed and the floor

is generally flattened, coarser grits are not necessary.

(See TIPS #3) When you get down to new wood use

the same procedures and grits as previously described

under “Sanding a New Strip or Plank Floor”. If the

old floor has been painted several times it may be necessary

to use paint remover to uncover the wood

surface. (See TIPS #12)

The number of sanding passes required for

“Refinishing” will be largely determined by the condition

of the old floor and the thickness of the finish

being removed. If the surface is in very good shape,

with only light scratches and few dents, and has no

build-up of old finish and wax, one pass with the disc

sander and fine paper may be sufficient. Be sure all

the old finish is removed.

If the floor has been abused, scarred or dished, use

as many cuts as are necessary to get a smooth,

unblemished surface. If badly scarred and abused

boards have not been repaired, it may be advisable

to leave some blemishes in the floor or too much

sanding may be required. (See TIPS #2 #5 #8)

With a floor that is in fair condition, make the first

cut at a 45°± angle to the flooring direction with

medium grit paper to level the floor and remove 90%

of the finish. Then follow the instructions given for

sanding a new floor on the succeeding cuts. Use the

same grit paper as was used on the 45° cut for the

first cut parallel to the flooring strips.

PREPARATIONS FOR FINISHING

IMPORTANT: Allow ample time with the sanding

procedure to apply the first coat of stain

or other finish the same day that sanding is

completed. This prevents a raised grain condition

which creates a rough surface.

When machine and hand sanding are completed

sweep and vacuum the floor. Wipe up and/or vacuum

all dust on windows, sills, doors, door frames, and

baseboards.

Inspect the floor carefully. Spot-fill missed cracks

and nail holes with a commercial flooring filler, applied

sparingly with a putty knife. When dry, hand sand

with fine sandpaper, same grit as final sanding.

IMPORTANT: Check with finish manufacturer or

supplier to make sure fillers are compatible with

finish materials.

For future re-finishing, it is essential to know the

brand names and color of the stain and other finishing

products used, or if the floors were prefinished at the

flooring manufacturing plant.

FINISHING

Immediately after sanding is completed the

finishing process should begin. This process involves

applying a protective coating and a color, if desired,

to the flooring. Finishing produces a uniformly

enhanced surface and seals the wood to make it less

absorbent to moisture and foreign materials.

GENERAL TYPES OF

FINISH MATERIALS

IMPORTANT: Read entire label before applying

finish and use only compatible products.

Compatibility questions between different

materials should be referred to the finish manufacturers.

Always follow ALL of the manufacturer’s safety

precautions, especially for skin contact,

ventilation, breathing apparatus, fire hazards

and disposal.

Overlaid Game court Markings VS Standard Game lines Lay out

KEN MOERSCH 604-603-7317