White Glue - The Classic in Workshop Applications
Already applied white glue today?
White glues are a classic in workshop applications. Still, there are a few things to bear in mind. Did you know that contact with iron can lead to blue discolouration in the wood? Or that the open time of the glue depends on the surrounding temperature? A reoccurring, contentious issue is the content of formaldehyde in the products. Therefore, we also have in our range variants low in formaldehyde.
OSTERMANN‘s white glues are used for bonding soft and hard woods, for HPL surface bonding, for gluing board gaps, for block-bonding and carcass and assembly bonding applications. The addition of hardeners boosts the adhesive properties of white glues. OSTERMANN supplies glues and hardeners from different manufacturers to cover various applications.
White glues are thermoplastic dispersion adhesives based on PVAc as binder. The latter is delivered as a ready-to-use dispersion in water. These water-based systems harden physically by drying out. The water evaporates from the glue line and/or is absorbed by the workpieces. White glues are needed for different purposes in the workshop, as for example HPL surface bonding, solid wood, block or assembly gluing. High final bond strengths are achieved. Our REDOCOL Kombicoll Super-N white glue is now available in an improved bucket. The new outlet makes both work and handling easier.
From D1 to D4
One of the most important classifications for white glues is the durability class as per EN 204. It gives information on the water resistance of the adhesive and allows conclusions on when it might be adviseable to change to other adhesive systems (e.g. PUR).
Interior doors, furniture and coverings
Interior use, wood moisture level max. 15 %.
Kitchens and bathroom furniture
Influence of running water or condensation and/or occasional high air humidity and an increase of the wood moisture level up to 18%.
Exterior doors, windows and stairs
Interior with frequent short-term exposure to running or condensed water and/or occasional high level of humidity. Exterior not exposed to weather.
Furniture for indoor swimming pools, windows, exterior doors, stairs and ladders in the exterior area
Exposure to running or condensed water and/or occasional high level of humidity. Exterior exposed to weather, but with adequate protection by an adequate surface coating.
Many carpenters know bleed-through all too well - particularly when veneering. How may this phenomenon be avoided or at least reduced?
There are several possibilities. Firstly, it helps to reduce the pressure and make the glue mixture a little thicker. The amount applied is of importance. Normally, 90 to 100 g per m² suffice. For highly absorbent surfaces, 120 g per m² may be used.
You can draw conclusions from a simple finger test: if you are able to draw finger tracks into the glue, too much adhesive has been applied. Should the glue bleed through despite all caution, clean the surface immediately with warm water, a cloth or a scrubbing brush. The faster you react after the pressing, the better it will work.
White glues normally have a pH value between 3 and 5. They are thus graded as acidic, aqueous solutions. Due to the acidic pH value, discolourations of the wood may occur with certain wood types (e.g. oak), when processing white glues.
Therefore, it is advisable to execute test bonds beforehand. An alternative is the use of pH-neutral white glues. This will considerably reduce the risk of wood discolouring.
The greater the viscosity, the thicker (low flow rate) is the fluid, the lower the viscosity, the thinner (high flow rate) is the fluid.
High viscosity – low ﬂow rate – thick – e.g. honey
Low viscosity – high ﬂow rate – thin – e.g. water
Video: White glue
Click on the play button to watch our video tutorial on REDOCOL Kombicoll Super-N PVAc glues!