High quality in bonding and sealing leads to cost savings

Adhesives and sealants are widely used in the RV industry. When one manufacturer likes to bond more, the other still prefers traditional construction methods using screws or other mechanical fastenings. Both methods require their own specific products. We would like to highlight 2 products of DEKALIN product portfolio which can be used for the different construction methods: the classic sealant DEKASEAL 8936 and the latest developed elastic sealant and adhesive DEKASYL MS-6

In the early days of RV construction mechanical fasteners, like screws, have been used. Every screw or hole inside an RV is a potential risk of water ingress. Therefore plastic-elastic sealants (and tapes) based on mainly Polyisobutene (PIB) or butyl, are in use since the beginning of RV construction and are still largely used in the RV OEM market and the repair market.

“DEKALIN is already more than 40 years active in the RV market”, says Roland Oldenburger, Business Manager Deka- lin RV, “and our most used and important plastic-elastic sealing product is our high professional product DEKASEAL 8936. This product is based on PIB and has some great features and advantages compared to other chemis tries. Important to mention is that DEKASEAL 8936 can not be used as a gener al sealer, but should always be used in combination with mechanical fastening, like screws. It doesn’t hard en and remains permanent ly sticky and flexible and keeps it’s initial properties over time.”

The most important fea ture of DEKASEAL 8936 is that it has the lowest water vapor permeability of all available chemistries in the market, due to its high content of PIB. This means that it provides the best barrier against water and moisture, so preventing leakages. From an application point of view the most important feature of DEKASEAL 8936 is that it can be dabbed off with itself. This means that when e.g. a service hatch or plug socket, sealed with (enough) DEKASEAL 8936, is screwed onto the side panel, excess material which is pressed out can be cleaned (dabbed off) with a piece of DEKASEAL 8936 where the solvent already has been evaporated. So no cleaning agents (solvents) are needed. This leads to time (and cost) savings and less emission of solvents in the air. Another feature of DEKASEAL 8936 is that it can be removed very easily in case of a repair. Company says that even after more than 30 years the product can still be dabbed off easily without leaving residues and without damaging the surface and/ or service part. The repairability is an important reason why some manufacturers still choose for screwed connections in combination with DEKASEAL 8936 or similar products above bonded parts which cannot be dismantled as fast and as easy without damaging some parts. However, there are manufacturers who use screwed connections in combination with (curing) elastic adhesives or sealants (e.g. when installing a service hatch). In this case, one of the main properties of an elastic adhesive/sealant doesn’t come to its right, which is the compensation of movement due to thermal expansion, as there is almost no layer thickness. Secondly as just mentioned, repairability of a bonded part is much more difficult. The use of DEKASEAL 8936 is therefore a solution also considering the very low water vapor permeability compared to other products.

Elastic bonding and sealing

As mentioned earlier in this article, there are 2 different methods in RV construction. When it comes to elastic bonding and sealing, DEKASYL product range offers a wide variety in solutions. DEKASYL adhesives and sealants are based on MS-Polymer technology (Modified Silane) and are free of isocyanates, solvents and silicones, have a wide adhesion spectrum and show a good UV- and weather resistance. Bonded constructions offer a uniform stress distribution,