We have been sanding and sealing , staining and restoring floors for over 10 years, although we would recommend that you use a professional to sand and seal your floor, if you can follow it simple guide:
It is the key to every job we do, if your prep is bad the finished job will be terrible, if prep is excellent the finished job 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 is what we aim to do).
Firstly you need to prepare your floor for sanding, you need to remove all nails from any gripper rods that were in-situe before, also any bits of carpet underlay that have become stuck to the floor. Once you have fully cleaned the area you need to check for any loose boards, if you find any lift them up fully to check for pipes underneath, then, using cut nails 1 to to 2 inch, nail them back down carefully. Then set all the nails in by at least 3mm using a center punch and hammer, this will increase the life of the sanding belt, and limit and damage to the drum.
You are now ready to start sanding; you should start with a 36 grit belt or 40 Grit (depending on the state of the boards). Sand in the direction of the boards, never work diagonally or across them as this will put scores marks in that will take forever to remove. If you are using a Hiretech HT8 then you will need to be very careful, as these machines are really light and they tend to jump and skip over the boards rather than sand them. When sanding never leave the machine in one place for more than 2 seconds as it will create burn marks in the board that are impossible to remove. Rather keep the sander moving at all times and let the roller gently coast on the floor.
We use (and hire out) a Bona Flexidrum, this has a continuous belt on a rubber drum, the belt just slides on, no need for metal bars and screws as on the HT8. It weighs around 60kg (very heavy) and has a 2.2kw motor, it is incredibly fast at removing material and is 98% dust free; it always leaves a beautiful finish.
The 36 or 40 grit should be used until all of the boards are sanded back to bare wood, if the boards are particularly curved you could use a small sander to get the very edges of the boards cleaned up. Once you are back to bare wood you can start working through the other grades, do not be tempted to skip grades you must work through them all – 60, 80, 100, 120 grit. Once you have sanded to 100 grit you should start sanding the edges, again keep the sander moving at all times, start with the most coarse disc and work to the finest (80 grit). After the edges are done, do the corners and around any pipes with a detail sander 40 to 60 grit (no need to go any finer it's a very small area). After all this is done its time to do the final pass with the 120 grit belt, before running a random orbital sander around the edges (60 working to 100 grit). The final pass should be no more than twice in each direction, you're not trying to remove material but just giving a final light sand. With this part done now your on the final stage (at last) …. go around the whole room with a random orbital sander, sand out any score marks or swirls that are in the boards, start at 60 grit, then 80 and finish with 100 or 120.
I know this all sounds very long winded, but trust me if you put the preparation in you will be rewarded when it comes to applying the finish.
If you are going to stain the floor you obviously need to do it before the seal is applied. We recommend the use of a solvent based stain that can be lacquered over. We use Bona Décor. We apply this stain with a rag in a circular motion, working the stain into the boards; you must make sure that all the stain is fully rubbed in with no 'wet looking patches'. Once you have done this the stain needs to dry for 24-48hrs before applying your primer coat.
Most stains that are oil based can not be lacquered over; instead a top coat of oil is applied after the stain. We have in the past used spirit based stains; however these can be notoriously difficult to apply evenly, especially on woods that are porous like beech. If you are using a spirit based stain you have to work very quickly and always keep a 'wet edge', on porous woods the stain should be diluted with white spirit so that it can be applied more evenly.
You're now ready to seal the floor, so firstly fully vacuum it off ensuring that there is no dust of any kind on the floor. We always recommend the use of a base coat primer such as Bona Prime Intense or Prime Classic. A primer stops any side bonding, this is when the floor expends and rather than each block moving individually, they more as a section creating a shear line in the pattern (herringbone block). A primer enables the floor to move under the lacquer (the primer has elastic type qualities) avoiding any cracks from side bonding. This is obviously very important on any parcel or herringbone floors, not so important for floor boards but it is still good practice, as it is an extra layer of protection and aids adhesion of the top coat.
Firstly shake the bottle of lacquer well for one minute, then using the filter provided, decant it into your roller tray. Brush all the edges of the floor first using a fine bristled paint brush, making sure to cover all corners and come about 4 inches of the wall. There is no need to wait for this to dry you can carry straight on with covering the rest of the floor.
We apply the lacquer with a roller, again from Bona, do not be tempted to use a paint roller, the lacquer roller that Bona make is guaranteed to give an orange peel free finish without dropping any pile.
When you have covered the entire floor, and checked that you have not over applied in any areas (this can be seen by a blue looking film on the surface) leave it to dry for 2 to 3 hours. You have a choice now, you can either nib the lacquer back with a buffing machine or not, if you do not you will get a rougher grippier finish than if you nibbed it back.
If you go down the buffing route then you need to use the buffer on the slowest speed with a maroon pad and a scrad wing (a small sanding sheet that sticks to the maroon pad). Work over the floor quickly keeping the sander moving all the time, if you stay in one place to long you will rip through the primer.
After this, vacuum the floor again to ensures a dust free surface, then apply the lacquer in exactly the same way as you applied the primer, leave to dry for 3-4 hours then repeat for the final coat. The floor will need two top coats, making three in total, if you buffed the primer the first time round then you need to do the same with the first coat of lacquer. Do not buff the top coat; it should be pretty smooth if you stuffed the two previous coats.
So that's it! All done!
NB – Make sure you put felt pads on any furniture in the room as this will stop any scratches when moving furniture about.
Need to rent a floor sander in Farnborough ?