Outdoor adhesive with increased moisture resistance

An adhesive that provides a highly moisture-resistant bond to wooden elements is very necessary because high humidity can be both inside and outside. Pieces of furniture in bathrooms or kitchens, everything that is fitted with wood in these areas, must be able to withstand higher humidity than in other rooms. Likewise doors, windows or garden furniture need items to stay glued together even if they get rained on. An adhesive with such resistance is a D4 adhesive. It falls into this category because of its qualities. I intend to tell you more about this type of adhesive below.

What is a D4 adhesive and how is it different from a D3 adhesive

I recently told you about a improved D3 adhesive for use in winter conditions. The area code D3means, according to European standard DIN EN 204, that it can be used for interior construction exposed to short-term moisture or damp environments, for exterior construction in mild climates, for joining steps, doors or windows installed in weather-protected areas.

Unlike D3, D4 adhesiveis used for joints that need much greater moisture resistance. It can be used both indoors (bathroom, kitchen) and outdoors (garden furniture). It is a very suitable adhesive for making solid wood panels, laminated wood, windows and doors used on the outside. One such adhesive is Tiszabond 1kD4-D cod 4133 of the Szolvegy Târgu Mureș.

Main features of Tiszabond 1kD4-D 4133 adhesive

The adhesive is a one-component, aqueous dispersion of polyvinyl acetate (aracite). It has improved adhesion to the substrate, which results in a much higher bonding quality.

The film formed after curing the adhesive is transparent and very elastic which is a great advantage for manufacturers of joined panels. What is this advantage? Apart from the fact that the adhesive film is not visible at the joints, it substantially increases the average tooling time, planing machines).

The hard films formed when using inelastic adhesives aggress the tools and shorten their life. When the film is elastic the hardness is lower and the tools suffer less. The elasticity of the Tiszabond adhesive film is due to the fact that the adhesive does not contain fillers (chalk in general).

But the main feature is moisture resistance. The adhesive film formed has a very good impermeability and is, according to DIN EN 204, a D4 adhesive. The moisture resistance is comparable to a D4 adhesive with hardener. Despite being one-component it cures after a short pressing time, resulting in a solid, firm bond.

Where Tiszabond 1kD4-D 4133 adhesive can be used and where not

⊕ The adhesive can and should be used for gluing wooden elements that are used indoors, in environments with very high humidity (bathrooms, kitchens). Increased temperatures in these areas amplify the effects of humidity.

⊕ It is very suitable for gluing wood panelling, wooden steps or laminate flooring.

⊕ It is recommended for obtaining solid wood panels and for gluing veneer to wood or chipboard panels.

⊕ Being resistant to external conditions, it can be used to glue laminated wood for windows, to make wooden door panels for exterior use. It is also recommended for gluing garden furniture.

⊗ However, there is one area where polyvinyl acetate adhesives are not recommended. These are obtaining support beams.Builders need to differentiate support beams from other beams, and manufacturers must NOT use aracite adhesives in their manufacture. Szolvegy recommends D4 (1kD4 PU) one-component polyurethane adhesives certified for this purpose for bonding these support beams.

What you need to know when using this adhesive

I used to say that any product, no matter how good, never works wonders. That's why, in order to have a perfect moisture-resistant bond, several parameters must be taken into account:

• soldering surfacesmust be smooth and free of impurities or greasy substances;
• ambient, adhesive and wood temperaturemust not be less than 10°C
• relative air humidity must be 60-70% at an ambient temperature of 20-22°C or 45-55% at a temperature of 23-25°C
• wood moistureshall be 8-10% when the interlocking elements are used indoors and 11-15% for elements used outdoors;
• quantity applieddepends on the absorbency of the wood and should be between 120 and 180 g/m².

Variation in these parameters influences the reaction times of the adhesive.

In terms of pressing, increasing the temperature accelerates the curing process of the adhesive. For example, the gluing of hardwood elements (oak, ash) takes 17 min. at 20°C, but decreases to 9 min. at 50°C, reaching 6 min. at 70°C.

Tests with very good results, even beyond expectations, convinced the manufacturers that they were on the right track

Szolvegy wants to establish long-term partnerships with customers. That is why they are always concerned to offer the best service (permanent stock, rhythmic transport with heated machines, technical support) and the best products. That's why they usually test their products before putting them on the market under conditions much tougher than those required by the standards.

I told you a while ago that a one-component adhesive with properties similar to bicomponents, was tested at boiling for 8 hours instead of 2. In the case of 1kD4-D 4133 adhesive they pushed the limits again. They manufactured, by finger jointing and laminating, a 4 m long beam with a 40×30 cm section, which was heat treated (boiled) in an autoclave 3 days after bonding and not 7 days as recommended. It was then left outside in the open air for 2 years. The beam held up very well, which was a surprise even to the poducers.

I forget to tell you a very important advantage. The adhesive is also available in small packs of 10, 5 and even 0.750 kg. That doesn't mean that if you need 32 kg, 130 kg or even 1100 kg, you can't find that too. All you have to do is decide.