Wood Flooring Finishing
Sanding of Wood Flooring
The key to a good sanding job is to create a preparation of machines and the job sites itself.
The homeowner should remove all wall hangings including wall arts, photographs, decorative items, mirrors, and book shelves. You may also need to consider removal of the window curtains especially drapes and blinds if they are into closer proximity to the floor. We understand that we are not just providing sanding and buffing services but we are creating a fresh new surface to ensure a beauty and durability of the wooden floor. We will ensure a stable aggrieve finishing on newly installed wood floors and remove all old stains and finish on re-sand jobs. We also use edger a compact machine which use to sand the edge of the wooden floor in ensuring consistent finishing across the wooden surface.
Trim work on the job site is either removed or replaced or left up and protected. If the trim work is left in place then we cover them with baseboard with tapes and protect them from scratches. All contact points of the equipment are being protected to avoid any scratches with the contact points. Nails and staples must be removed from the previous carpets as they may badly damage the floor and sanding equipment.
Always wear safety glasses and ear plugs while using sanding equipment’s and vacuums finishing wooden floors. Whenever possible unplug machines before adjusting to prevent accidental damages. Keep hands and loose clothing away from all moving parts. Sanding and finishing of wooden floors can create an explosive environment, hence always keep our area ventilated. We avoid hitting metal objects while sanding. Sparks can create an explosion in sanding bags or vacuums. Properly dispose all dust on daily basis. Most fires do not occur immediately.
The goal of the first cut on floor sanding is –
– To remove all over/under wood from new install job
– To remove all old finish, sealer, and stain from re-sand jobs
The belt sanders are being used in the main area of the floor for its speed and aggressiveness. As much as possible we always try to keep all the wheels of the Sanders on the smooth freshly cut surface. Hence the direction and starting point of sanding is utmost important in sanding wooden floors. If we start from right to left the leading left-hand wheel of sanding machine will always be rolling an uncut surface causing irregularity in the floor transferring it back onto the floor. Hence, we always prefer to move left to right while sanding any wooden flooring surfaces. This will help to keep our belt machine and sanding as smooth as possible. The vertical direction of sanding machine is also an important aspect, sanding in forwarding direction removes some finish from the floor. But the backward pass on the same path as that of forwarding path creates a lot more cutting power since the machine is pulling against itself. The backward pass helps us in clearing remaining finish as well as any loose wood fliers. On a first cut, we usually cut slight across the grain of the wood as it helps us to select right abrasives more aggressively. This will help us in sanding as straight pass will transfer the unevenness in wood joining when there is an over and under wood. Sanding in a slight angle of 7 to 15 degree to the wood grains will shape those areas down evenly. Cutting beyond 15 degrees is considered very aggressive and must and should be used only if we have a highly damaged wooden floor. Usually, 45 degrees is the maximum angle that we may use in repairing the highly damaged wooden floor. The cross-grain scratches left from cutting at 45 degree needs to be removed by following up with a straight on cut using same greet. Occasionally we may need to cut across 90 degrees in an area such as hallways or other tight areas where flooring runs across space. For these areas, a finer grade abrasives will be used by lowering the drum pressure. The repetitive cuts in these areas will be followed by an edger or a multi disc buffer.
For each sanding pass moves forward and backward in the same path, this is called as overlapping pass. Then move over half the width of a drum and repeat. Overlapping the passes in this way blend the board and typography of the floor which in turn creates a flat smoother result overall.
Another useful sanding technique that we use is, we always start with the full length of the starting wall over the right side of the machine to the wall. This creates a fresh starting point to work on. Turn the machine around and work across the room sanding 2/3 of the floor working towards the far wall. Then sand the full length of the far wall, the post which turns and sand the remaining 1/3 of the floor overlapping the mid flow transition area.
The edger is being used along the wall edges and the areas that are not accessible by the drum sander. Working around the room in the clockwise direction will allow us to cut with the leading edge where we have more pressure and feather with the following edge where we have less pressure. This will help us get an aggressive cut without leaving any deep edge swirls which take a lot of time to remove in subsequent steps. We always start with a grit which is aggressive enough without being overly aggressive. Cloaking refers to how we turn our edger during use. Whether edging along open walls or along butt – end walls we know where and how an edger is cutting. The aggressiveness of the edger will be judged through its cut points against the grains of the wood which in turn helps us to clock the edger accordingly. Though edger is useful to reach out the smallest areas on the floor, it is not recommended to grind edger in the corner of the floor area. This may create an uneven sloppy area which is very difficult to remove. Instead feather it straight back from the corner from one side of the wall to another side. It is important to know that the edger must be moved side to side in wide sweeping motion by moving towards the wall. If the section is too big to sand first cover up the left side of the section following which right section of the area will be sanded using the same method. For butt-end wall, we use J-turn method where for first cut we work side grain moving side by side to flatten and remove all stain and finish then clock the edger to align in line with grain and moving slowly clockwise oval motions. If done correctly this method will leave much fewer scratches to clean up later.
The floor must always be vacuumed in between sanding cuts to remove any stray grits. While vacuuming work on a path like a belt sander i.e. move back and forth on the same path then overlap about 25% on each pass always working towards the wall.
Sanding Second Cut –
The reason we perform multiple cuts is to remove the scratches from the previous cut creating a smoother and finer surface for finishing system. Sanding paper selection in the second cut is the most important aspect of the second cut. The important aspect to remember is “Never skip more than one level of grit”. For example, if you use 40 grits on your first cut, skip 50 and go to 60 for the second then skip 80 and move up to 100 for the third cut.
Just like in the first cut, sand the first cut along the starting wall to create a fresh path. Turn the machine around to begin sanding across the room. This time working in a straight line as supposed to be on a slight angle as in the first cut. Work 1/3 of the room moving towards the far wall, sand the full length of the far wall, turn back around, and complete the remaining 2/3 area of the floor by overlapping the transition areas. By switching the transition area between first and second cut will be able to blend the two cuts together smoothly. Many time we usually use three cuts of drum sander for the floor but we usually settle with two cuts of the edger. This is because the scratches from edger are much easier to see than those from the sanders. So, we can easily see if our final sanding git was able to remove the scratches from previous sanding grit. Again, the floor should be thoroughly vacuumed between the cuts to ensure that any stray grits are been removed.
A professional wood floor craftsman knows when to fill and when not to fill open cracks and joints in the wooden floor. As prescribed in the characteristics of wood, wood typically expands in spring and summer and contrast in the winter. Seasonal gaps that are occurred during dry or winter heating season should be left alone to give room to move back when the humidity levels increase in the warmer months. Filling seasonal crack in winter may lead to that same filler being pushed back out in the summer as the flooring expands leaving raise grip in the fillers along the affected board. Another potential issue in filling seasonal cracks is called edge crush. Because the filler tends to dry harder than the wood as the flooring expands against it, the wood grain at the edges of the board may be permanently compressed. This causes an even bigger crack the following winter when the wood contracts and the filler crumble into the large seem.
Different colors of fillers may be needed to match different wooden species. Occasionally several different colors may be needed for the same species. To fill large knot hole which are very large defects extra color may be added to the filler. Wood filler is used to fill slight (hairline) cracks and gaps in the floor. Also filling close of the grain and open pore species. Larger gaps (cracks) should be repaired using splinter technique.
First, steer the filler to ensure all the components are mixed well. Use a putty knife to apply the small amount of filler only where it’s needed. Usually, end joints, nut holes, and other minor defects are filled up using the filling material. We need to ensure to add the right amount of water into filler mixture. Too much of water may cause sagging and cracking which then must be filled again. The filler is filled into the ends and grains with the 45-degree angle of putty knives to the flooring. This will prevent the filler from following the trail back out of the floor. Sanding off an excess filler can be very messy and difficult; hence it is important to apply the right amount of filler on the wooden surfaces. Make several passes over the same area to work the filler into the floor. After filling the entire floor including the edges, any skip spots will be visible in the final finish of the final product. As we progress in filling up the flooring area the filler starts to become thick as it mixes with the wood dust. We should not use this thick product by putting it back into the mixture, rather this should be thrown away to start with the fresh mixture from the bucket.
With sufficient air flow, the filler should be allowed to dry overnight. Although the surface may feel dry after a few hours, the filler in deeper cracks underneath may still be wet. Sanding the wet filler will often pull it out of the floor leaving it to fill it again.
Sanding Final – cut
For final cut, we ensure to use the same type of abrasive on both the sander and the edger. Grit selection depends on what we used in the previous cut. If we used a 60 grit we will skip 80 and use 100 grits. We never skip more than one level of grit. The drum pressure for final cut must be set for fine settings. Few professionals prefer to use edger first over the sander where they will ensure to finish the edges of the floor area first over the main area. Both ways are useful and are depends on an individual’s preference and choice. As in first cut, first sand the full length of the starting wall with the right side of the machine towards the wall. Turn the machine around and work half the length of the room working across the room towards the far wall. Sand the full length of the far wall, then turn and sand the remaining half of the room using overlapping pattern i.e. overlapping your transition area.Moving transition area from 1/3 in the first cut to 2/3 to the second cut and then finally by keeping to the half of the floor area helps us to avoid any unevenness showing through in our final product. The good edging technique is most important for the final pass. Any edge remark left after this point will need to removed manually later on which can cost us valuable time on the job.
Prior to final buffing finishing, the scraper will be used to remove any remaining finish, stain and extra wood from corners and other areas where edger can’t be reached. The scraper is used to remove edge remarks along the wall as well. Scraper must be used with the grain of the wood whenever possible. If we must scrap across the grain, we do it carefully or very lightly to avoid ripping out of soft grains. The short scraper is a key in detailed work. We ensure to re-sharp the scrapers during the use. To remove edger and scraper marks use solid or dual density hand sanding block. Two grits of abrasive can be used on a dual density block. Heavier grit on the hard side to remove edger/scraper marks followed by a finer grit on the soft side for final detailing. We also use to prefer small random orbit sander to cover the uncovered corner and edge areas.
For the rounded price of flooring such as stir cases standard scraper is been used to carefully remove the old stain and finish. Rounded bullnose scraper can also be used for this task. For final sanding of these edgy areas use the soft side of the sanding block to remove scraper marks and to smooth out the surfaces. We also ensure to vacuum all the detailed area post manual sanding and cleaning.