The life of a floor
Alec Stacey, technical manager at Bona, looks at a solution for every stage of the floor’s life
FOR a year or so, Bona has been promoting a Floor Care Programme to our Bona certified contractors as part of their ongoing training. The programme consists of three well-defined processes intended to offer the commercial floor-owner the most appropriate treatment for their floor.
For the contractor, it provides a scale of treatments available for the floor, varying in cost, intensity and the degree of downtime required. This allows an expansion of the services that a contractor can offer, as well as developing and retaining a useful relationship with the floor owner, facilities manager, caretaker etc.
The benefit for the floor owner is that they have the ongoing services of an expert who can ensure the floor is always in the best possible condition and any high ‘surprise’ costs are replaced with a predictable regime of floor maintenance.
The three maintenance alternatives offered to the commercial floor owner are:
Gold: Full renovation, where the floor is sanded back to bare wood and re-finished.
Silver: The surface preparation and application of a further lacquer coat to a floor showing wear, but which has not progressed to bare wood.
Bronze: A deep cleaning of the surface followed by the application of a suitable maintainer.
To render these maintenance alternatives attractive, it was important to develop a simple approach utilising elements of the Bona system.
In particular, developments made by Bona with our abrasive range has been central to the effectiveness of each process.
The Gold Floor Treatment Programme: This is the most intensive treatment involving a full re-sand back to bare wood. For the initial sand to remove any previous treatments, Bona Ceramic abrasives are used.
Their performance stems from the extreme hardness and sharpness of the ceramic grit particles, which cuts through tough finishes, including the fortified, scratch resistant pre-finishes used on many wood floors.
Available in 36 and 50 grit sizes, the ceramic abrasives would only be used to strip the surface back to bare wood or to remove stubborn contaminants from the surface like dried adhesive from a previous installation. Once bare timber is reached the remaining sanding steps are made with zirconia mix abrasives.
Our zirconia mix abrasives are developed to produce the most even surface possible, in terms of texture and also remain sharper for longer.
Owing to the uniform grit size the texture of the sanded timber is much more uniform, this allows greater scratch removal with each successive grit size.
During lab testing we found that with our zirconia mix abrasives far less tearing of the wood fibres occurred and a powdery dust was produced compared to the more fibrous dust produced from the use of abrasives with a less uniform grit distribution.
The impact from the abrasives of differing quality is dramatic.
The surface sanded with the Bona 8300 displays more moderate fibre ripping with fewer deep scratches in the surface. As the grit particles are near identical in size, scratches are of an even depth. This means it is easier for the scratches to be removed with the following sanding pass.
The Bona sanding dust is like a powder whereas dust from other abrasives, many of which are produced for sheet metal work is more fibrous - indicating ‘tearing’ rather than sanding.
For additional life and for superb dust extraction, the zirconia mix abrasives also have an antistatic coating which reduces clogging and helps maintain a dust-free environment for improved working conditions and final quality of applied treatments.
Bona Diamond Abrasives: Our Diamond abrasives were developed in response to problems experienced when abrading an existing finish on sports floors prior to the application of a coat of lacquer.
The common process used for this scenario would be to clean the surface and then abrade using a fine sanding screen fitted to a rotary buffing machine. After this the dust would be removed and a new lacquer coat applied. This worked well until sports floor manufacturers started to adopt reinforced, anti-scratch finishes.
These are so tough that when a standard abrasive is used it rapidly becomes blunt and, after as little as 10-15m, the pre-finished surface is no longer being sanded and the preparation is wasted.
When the surface is over-coated, the new finish will adhere where the surface is abraded but elsewhere peeling of the lacquer can occur. We’ve tested a floor where this has happened using a simple coin test.
Where the abrasion using the screen began, adhesion is excellent, but further away from the starting point a significant reduction of adhesion becomes apparent, with it being possible to peel the applied lacquer from the surface.
Our diamond abrasive 240 grit was developed to prevent this. Having a much longer life, abrasion is more uniform and, with a finer yet sharper grit, the surface is effectively ‘keyed’ without visible scratches - a much more reliable approach.
Diamond abrasives have now been integrated into our programme for bare timber sanding and are now available in two more grit sizes - 80 and 120.
Following sanding with zirconia mix abrasives the final sanding of the bare wood is made using diamond grit 120. This leaves the surface perfectly even and smooth and, if used as part of the correct sequence, can produce a surface without visible scratches.
Using these abrasives in conjunction with our Bona Flexisander fitted with Powerdrive and Quattro Heads, Bona recommends has defined and recommends three sanding methods to prepare the surface according to the treatment it will receive. These are ‘Speed’, ‘Standard’ and ‘Colour’.
The Speed method involves just three sanding steps and is perfect for when the floor is to be finished using a very matt or ‘natural’ lacquer treatment. These treatments are the most forgiving in terms of expressing slight imperfections which may have occurred during preparation.
The ceramic abrasive grit 50, used to sand back to bare wood is followed by an 80-grit zirconia mix. Both are used with the Powerdrive base plate, the gear-driven base-plate which has 4x150mm heads.
As the plate turns the individual heads are powered at 800 rpm for fast and effective sanding. For the final sand using the diamond abrasive grit 120 the Quattro Plate is fitted. The four heads in this case are not powered, providing a less aggressive sand which is perfect for taking out the fine scratches and rendering the surface smooth and uniform.
The Standard method is intended for use when floors are to be treated with finishes which are slightly more critical of the preparation process, such as gloss lacquers and unpigmented oils/hardwax oils. In this sequence a further intermediate sand is added before the final sand with 120 grit diamond abrasives.
For more critical treatments a 60 grit and 100 grit sanding after the coarse 50 grit greatly reduces scratch depth and their visual impact. This used to be an issue with floors present in areas with dominant light sources such as large windows or down lighters but not anymore!
The most critical treatments that can be made to wood flooring are coloured (penetrating) oils and stains.
These will highlight every scratch and any variation in texture can produce significant colour variation. Using Bona’s defined ‘Colour’ method, again with an additional intermediate sand, using 120 grit zirconia abrasives on the Powerdrive plate, and following with the diamond grit 120, all scratches are removed producing a quality only previously seen with factory produced pre-finished products.
Bona Diamond abrasives are pivotal to the effectiveness of these sanding methods but especially when colouring floors. During finishing sanding using standard abrasives, wear occurs to the grit particles which reduces their sharpness.
This reduces the cut into the timber and consequently the penetration of stain into the floor, producing a lighter colour compared to the area of floor sanded when the abrasive was sharp and un-worn.
This can result in ‘colour drift’ where the intensity of the stain fades as one progresses across the floor. This does not occur when using diamond abrasives which remain sharper for much longer. When the floor is complete the colour should be uniform in intensity with no ugly scratches.
The Silver Floor Treatment Programme: In many situations, a full-scale refurbishment of the floor may be undesirable, perhaps due to costs or the level of disruption that a full re-sand involves.
Using the Silver treatment, the floor is cleaned, using the Bona Deep Clean System, abraded, using diamond abrasives and then one coat of Bona Traffic HD lacquer is applied.
The beauty of this approach is that no harsh chemicals are used to remove contamination from maintenance products or similar. Instead, the floor is given a thorough clean using a deep clean solution and power scrubber fitted with red (coarse) brushes.
Using a diamond abrasive, grit 80, all surface contamination, waxes, polish etc. is removed. This is then followed with diamond abrasive, grit 240, which serves to remove the scratches that the 80 grit leaves behind. The result is a surface which is perfectly ‘keyed’ and clean, ready to accept a new coat of lacquer.
This represents a radical departure from past situations where polish was present on a wooden floor, when our advice would have been to sand the floor back to bare wood. Providing the surface is not textured or brushed, this Silver treatment delivers a much faster refurbishment with the floor ready for use the following day. When it’s easy to add a further layer of lacquer to the floor like this, its life can be extended greatly.
Also, in sports environments, the new layer offers the best surface for slip resistance and sheen. The Bronze Floor Treatment Programme: Our third option for wood floor treatment is the Bronze programme. This is a fast, non-disruptive and low cost process for restoring the appearance of any wooden floor (lacquered or oiled).
The surface is given a thorough clean using our deep clean system.
As the dirty cleaning fluid is sucked from the surface, the floor is practically dry following this process and can then be treated with a suitable maintenance product.
For lacquered floors, an application of refresher or polish and for oiled floors, depending on the specific treatment, either more treatment oil can be added to the floor or a wax oil refresher applied. This is a very quick way to dramatically improve the quality of the surface without the need for sanding.
The floor in our picture was taken in a busy restaurant where the floor had originally been treated with a water based lacquer.
The owner agreed for his floor to be used in a trial where half was treated (the right side in our picture) using the Bronze programme. Following deep cleaning, a coat of matt polish was applied.
As soon as this had dried (in 1-2 hours), the surface was ready for full use and was photographed before the contractor treated the other half (see image).
Using the appropriate treatment from the Bronze, Silver or Gold programme means that it should be possible to greatly extend the life of the floor. Of course, it is important that these procedures are scheduled at the correct frequency, depending on the environment and the level of use the floor receives.
Our certified contractors use their expertise and experience to produce a schedule of treatments for the floor owner that is retained by both parties, so each knows when the next inspection or treatment is due.
Knowing that the long-term maintenance of their valuable wood floor is in safe hands means one less thing for the floor owner to worry about!
Alec Stacey is technical manager, Bona