How to sand and seal floorboards

We have been sanding Y sealing, staining Y restoring flooring for more than 10 years, although we recommend that you use a professional to sand and seal your floor, you can do it yourself, if you follow this simple guide:

Preparation

It is the key to every job we do, if your preparation is bad, the finished work will be terrible, if the preparation is excellent, the finished work will be outstanding.

The whole point of sanding and sealing is that you should be able to recreate a factory applied finish on site (at least that’s what we intend to do).

First of all, you need to prepare your floor for sanding, you need to remove all the nails from the grapple rods that were in place before, as well as any pieces of carpet backing that may have stuck to the floor. Once you have completely cleaned the area, you should check for loose boards, if you find any, lift them all the way up to check for pipes underneath, then with nails cut 1 ½ to 2 inches carefully re-nail them. Then drive all nails at least 3mm with a center punch and hammer, this will increase the life of the sanding belt and limit and damage the drum.

Sanding

Now you are ready to start sanding; You should start with a 36-grit or 40-grit belt (depending on the condition of the boards). Sand in the direction of the boards, never work diagonally or across the boards as this will put marks that will take forever to remove. If you are using a Hiretech HT8 you will need to be very careful as these machines are really lightweight and tend to jump and jump on boards rather than sanding them. When sanding never leave the machine in one place for more than 2 seconds as it will create burn marks on the board that are impossible to remove. Instead, keep the sander in motion at all times and let the roller glide smoothly over the floor.

We use (and rent) a Bona Flexidrum, this one has a continuous strap on a rubber drum, the strap just slides off, no need for metal bars and screws like on the HT8. It weighs around 60 kg (very heavy) and has a 2.2 kW motor, is incredibly fast in material removal and is 98% dust free; always leaves a beautiful ending.

36 or 40 grit should be used until all boards are sanded to bare wood; If the boards are particularly curved, you can use a small sander to clean the edges of the boards. Once you get back to bare wood you can start working with the other grades, don’t be tempted to skip the grades, you should work with all of them – 60, 80, 100, 120 grit. Once you’ve sanded to 100 grit, you should start sanding the edges, again keep the sander moving at all times, start with the thickest disc and work your way to the finest (80 grit). Once you have finished the edges, make the corners and around the tubes with a 40-60 grit detail sander (no finer needed, very small area). With all of this done, it’s time to make the final pass with the 120-grit tape, before running a random orbital sander around the edges (60-100). The final pass should not be more than twice in each direction, you are not trying to remove material, but simply giving a final fine sand. With this part done now you’re in the final stage (at last) … go around the room with a random orbital sander, sand any scoring marks or swirls on the boards, start with 60 grit then 80 and finish with 100 or 120.

I know this all sounds very long, but trust me, if you put in the preparation, you will be rewarded when it comes to applying the finish.

Staining

If you are going to stain the floor, obviously you must do it before applying the stamp. We recommend using a solvent-based stain that can be lacquered. We use Bona Décor. We apply this stain with a cloth in a circular motion, working the stain on the boards; you need to make sure the entire stain is fully rubbed in with no “wet-looking stains”. Once you’ve done this, the stain should dry for 24-48 hours before applying the primer coat.

Most oil-based stains cannot be varnished; instead, a top coat of oil is applied after the stain. In the past, we used alcohol-based dyes; however, these can be notoriously difficult to apply evenly, especially on woods that are porous like beech. If you are using an alcohol based stain it should work very fast and always maintain a ‘wet edge’, on porous woods the stain should be diluted with white spirit so that it can be applied more evenly.

Sealing

You are now ready to seal the floor, so first vacuum it completely making sure there is no dust of any kind on the floor. We always recommend using a base coat primer like Bona Prime Intense or Prime Classic. A primer stops any lateral seams, this is when the floor expands and instead of each block moving individually, more like a section they create a cut line in the pattern (herringbone block). A primer allows the floor to move under the lacquer (the primer has elastic-like qualities) avoiding side joint cracks. Obviously this is very important on any parquet or herringbone floor, not so important for floorboards, but still good practice as it is an extra layer of protection and helps top coat adhesion.

First shake the bottle of hairspray well for one minute, then, using the filter provided, decant into your roller tray. Brush all edges of the floor first with a fine bristle brush, making sure to cover all corners and to be about 4 inches from the wall. No need to wait for it to dry, you can continue to cover the rest of the floor.

We apply the lacquer with a roller, again from Bona, don’t be tempted to use a paint roller, the lacquer rollers that Bona manufactures are guaranteed to give an orange peel-free finish without dropping any hair.

When you have covered the entire floor and you have verified that it has not been over-applied in any area (this can be seen by a blue looking film on the surface) let it dry for 2 to 3 hours. Now you have a choice, you can cut the back of the lacquer with a polishing machine or not, if you don’t, you will get a rougher grip finish than if you cut it back.

If you go the buffing route, you should use the buff at the slowest speed with a maroon pad and a scraped brim (a small sanding sheet that sticks to the maroon pad). Work on the floor quickly keeping the sander moving all the time, if it stays in one place for too long it will tear the primer.

After this, vacuum the floor again to ensure a dust-free surface, then apply the lacquer in exactly the same way you applied the primer, allow it to dry for 3-4 hours, and then repeat for the final coat. The floor will need two top coats, making three in total, if you polished the primer the first time, you should do the same with the first coat of lacquer. Do not polish the top coat; It should be quite smooth if you buffed the previous two coats.

That’s it! All ready!

NB: Make sure to put felt pads on the furniture in the room, as this will prevent scratches when moving the furniture.

Do you need to rent a floor sander in Farnborough?