Finishing of wooden floors with waterbased finishes
Waterbased top coats (1- & 2-component) give the floor final look and physical properties. The finishes are available in different gloss levels extra matt, matt, semi-gloss and gloss. We recommend to apply max 2 coats per day (sealer and/or finish).
- Use an applicator with mohair felt 300-500mm with pile high ca. 6mm or a roller ca. 300mm with 6-8mm pile high
- Suitable products for top coat: BASIC, PRO, TOP, TOP 5, NovaBEST, STAR
Finishing a wooden floor is not an assembly line job. Each floor is unique when it comes to appearance, condition, type of wood, etc. Each environment in which a floor is situated is also unique in respect to wear and the effects of everyday chemicals. Temperature and humidity are other factors that can vary a great deal from one job to another. The choice of products and handling of the products must vary according to the situation. The following advice can be seen as a guide for success in using waterbased finishes.
1. FULL RENOVATION OF FINISHED WOODEN FLOORS
2. FINISHING OF FACTORY-FINISHED FLOORS
3. RE-FINISH OF PREVIOUSLY FINISHED FLOORS
1. FULL RENOVATION OF FINISHED FLOORS
Before beginning, the floor must be checked to see that its condition permits re-sanding. If it is of laminated (engineered) parquet, ensure that the wear layer is still well-glued to the underlying layer. Tap with your fingernail in a few locations and listen for indications that the wear layer is no longer firmly secured to the sub-layer. If it is not, you can be certain that the wear layer will buckle because of the stress changes involved in sanding and finishing. In the wood is a living material, humidity shifts cause the wood to move. Solid board flooring is often dried too quickly and far too little. If such a floor is installed and is immediately sanded and finished, the risk of substantial contraction crevices is very high. Occasionally, the finish can function as glue in the tongues and grooves, and the risk of major cracks upon contraction is large. This phenomenon is known as side-bonding or panalising. In these cases, where the final results are less than what the consumer expected, it is important to inform the consumer that the condition of the wood floor construction can jeopardise the final results.
NOTE: TARKETT DIAMANTFURU, BJÖRK DIAMANT, BRUNBOK, BOK MAHOGNY, KÄHRS DONAUEK AND JUNKERS HOMOGENEOUS WOODEN FLOORING MAY NOT BE FINISHED WITH WATERBORNE FLOOR FINISHES.
A good base is a fundamental requirement for a good surface finish. This is an old truth that still applies, especially when working with waterborne floor finishes. Keep machines in good order and use high-quality sandpaper. Rough sanding is performed with coarse paper and high roller pressure. It is important to sand so that the floor is levelled as much as possible. Floor finishes are developed to flow easily, and if the floor is uneven, the finish will be thicker in depressions. If there are deep impressions where spot sanding is necessary, the sanded areas should be smoothed to the sides as much as possible. Never omit more than one coarseness grade while sanding. The norm is 50 and up. Fine 120-grit paper should be used in finish sanding and with the least possible roller pressure. If the roller pressure is too high during finish sanding, soft spring wood will compress. If moisture from the lacquer later begins to affect the wood, the spring wood will swell back to its original volume, which results in noticeable heightening. During finish sanding, it is also important that the sandpaper be of good quality and not excessively worn. The abrasive material should cut off the wood fibres without pressing them down into the wood. This is very important in keeping grain raise to a minimum.
- BEFORE FINISHING
Vacuuming prior to finishing is very important. Be sure to also remove dust from skirting, heating units, window recesses and similar objects and areas. All finishes should be shaken before use. Do this before vacuuming so that air mixed into the finish during shaking has a few minutes to escape before use. The finish should be at room temperature when applied. If the finish is too cold, it flows much less freely and also releases air poorly, which can result in brush stroke marks and air bubbles remaining after drying. It takes about seven hours to warm the lacquer from 0°C to 20°C. This period can be hastened by placing the lacquer container in a bathtub and rinsing with water at 40°C. Never use hot water alone: hot water can cause clumps to form in the finish. If possible, there should be good ventilation when the initial coat is applied. This permits the lacquer to dry faster, which naturally saves time, but also results in less grain raise. On sunny summer days, direct sunlight should be blocked if possible. The finish sets very quickly if the floor is warm and the risk of visible overlaps and bubble formation increases significantly.
- START FINISHING
All waterborne finishes contain small amounts of basic amines that chiefly affect oak. It is therefore important to apply the finish in an even coat. If drying conditions are poor (high relative humidity because of the weather or because the room has recently been wallpapered, for example), you must apply the finish somewhat more thinly to avoid discolouration.
- FIRST COAT – APPLICATION WITH APPLICATOR OR ROLLER
- MIXING of HARDENER 1648
With Synteko 2-component finishes the hardener should be added shortly before finishing. Be careful to add the correct amount. Affix the strainer and lid, and shake the container immediately for at least 30 seconds. Let the mixture stand 5 minutes before use, allowing air bubbles to surface. Finish mixed with hardener must be used within 2 hours. The container must be kept open after addition of hardener. Shake well before use! If the hardener is syrupy (high viscosity), it will not mix properly and must not be used. Be careful when handling the hardener: all hardener are reactive substances that even react to skin. If you should get hardener on your hands, immediately wash them with soap and warm water. Ensure that the finish is not stored at temperatures above room temperature. This can lead to the formation of clumps in the finish.
- BEFORE FINAL FINISHING
If the initial coat was applied with an applicator or roller, the floor should first be sanded with 150-grade sandpaper. If an oscillating sander is used, it should be used in quick passes, back and forth and with the least possible pressure so that the sandpaper does not become clogged, which would otherwise result in ineffective sanding. If a buffer is used the buffer should be moved faster the heavier the buffer is to avoid clogging the paper or screen. After the surface has been sanded, it should be carefully vacuumed. If the initial coat has been applied with an spatula, check to see if intermediate sanding is necessary. Before final finishing, ventilation should be checked to ensure that there is no draft over the finish surface during final finishing. Bear in mind that if a door to a stairwell is open, there will often be a draft over the floor even far into the flat. In cases where powerful mechanical ventilation systems are presenting use, such as in sport halls, these should be turned off. After finishing the application the ventilation may be turned on depending on how the finish dries. Large areas must be completed within app. 2 hours. In large areas an applicator-based application is preferred.
- FINAL FINISHING – TOP COATS
Final finishing provides body for the surface and forms a wear layer that will withstand years of wear and tear. Final finishing is therefore more abundant than the initial coat. If the floor is uneven along the walls, for example, it is important to apply the finish a little more thinly in these locations so that the finish does not flow into depressions and form an excessively thick layer. If humidity is high, you must also apply the finish more thinly so that it does not remain wet too long. If the finish remains wet for too long. If it does, discolouration may occur, especially on oak. There are also risks of flow problems and renewed grain raise. In the worst case scenario curing can also be affected resulting in a soft surface. Just as with the initial coat, final finishing should be performed so that application is parallel to the shortest wall to permit overlaps to be made as quickly as possible. With larger surfaces, an application edge can sometimes begin to set before the overlap is made. If this occurs, the edge will be visible after drying. To avoid this, periodically return to the application edge and make an overlapping pass to keep the edge wet. Pour the finish off to the side and pick up a little with each stroke. If you are using a roller, the finish should first be roughly distributed over a surface of about 2 m². The finish is then evened out by rolling at a right angle to the first rolling. Use rollers with an app. 8 mm pile. Mohair rollers transport more air to the lacquer when rolled in one direction than the other. You should therefore roll in the direction that produces the fewest air bubbles. Close to walls and corners, and other areas that are difficult to access, a smaller brush must be used. When the finish application is complete, never fully close all doors. While there should not be a draft across the finish surface, normal ventilation in the area is favourable for the drying process.
NOTE: IN THE DAYS IMMEDIATELY FOLLOWING FINISHING, THE SURFACE MUST NOT BE COVERED WITH ANY MATERIAL THAT DOES NOT ALLOW EVAPORATION. NOTE: NEVER APPLY TAPE TO THE FINISHED SURFACE.
2. FINISHING OF FACTORY-FINISHED FLOORS
In premises and spaces where especially hard wear can be expected, it is advisable to apply an additional coat of finish after laying the floor. This can be appropriate in (for example) halls, kitchens, stairways, public environments and commercial areas.
Only use finishes that are recommended for these high wear areas. Note that the application of a supplementary finish on site cannot be performed under the same favourable conditions as per factory finishing; there is a greater risk of the presence of dust burs and similar objects.
NOTE: SYNTEKO DOES NOT RECOMMEND THE SUPPLEMENTARY FINISHING OF LAMINATED FLOORS.
- PRELIMINARY TREATMENT
A factory-finished surface should always be sanded with very fine sandpaper to avoid the appearance of sanding scratches through the finish coat. It is also easiest to flatten the surface gloss with fine sandpaper. Use 180-grade sandpaper and after that a maroon pad to an even sheen level. After sanding, the surface should be carefully vacuumed and thereafter dried with a damp, clean cloth so that the surface is entirely free of dust.
Always check that the finish you plan to used has been approved for use on the material to be finished. Finish mixing and finishing are performed in the same manner as described under the respective headings in the first section.
3. RE-FINISH OF PREVIOUSLY FINISHED FLOORS
An absolute requirement for re-finish or touching up a previously finished surface is that it is free of grease, polish or similar substances. If the floor has been waxed, it should be sanded down to bare wood prior to finishing. If the floor has been treated with polish, an adhesion test must be carried out.
Begin by carefully cleaning the floor. Finish a few dm² in one corner; let the finish dry and harden for a few days. Next, test adhesion by scraping with a coin or similar object. If the new finish comes free from the old, adhesion is poor and sanding to bare wood will be necessary.
For all re-finishing, the floor must be clean and free of grease. Wash the floor with a strong cleaning agent. Rinse the floor with a mixture of vinegar essence and water (3 dl of 24% vinegar essence to 8 litres of water). Sand with 180-grit paper and use a maroon pad to an even sheen level.
If there are scratches or spot-wear where the old surface is worn-through, you can attempt a touch up by scraping or sanding these surfaces. Apply 1–2 coats of finish in these locations and thereafter finish the entire floor once or twice.
Finish mixing and finishing are performed in the same manner as described under the respective headings in the first section.
NB! Detailed information and instructions are provided on the Product Information sheet and MSDS (Material Safety Data Sheet). This document only presents a selection of key information.
Last but not least the skills of the contractor/user of the products are of greatest importance in successful work. In situations where you are unsure of how to handle products or think you do not have enough experience to handle difficult jobs, do not hesitate to contact a Synteko representative. The above recommendations are based on many years of experience. The conditions of the job site are out of our control. So the responsibility always lies with the user of the products.