Mobile techniques for leisure boat hull cleaning
Well known and not appreciated is the rapid development of fouling communities self-establishing on hulls and reaching in short time substantial adherence, volume and durability. This inevitable natural process increases friction, weight and reduces speed. Biocidal antifouling coatings are state of the art and widely in use which shall eliminate the fouling organisms just after settlement. The use of biocides in open and shallow enclosed water bodies may cause several problems and may impair water quality.
In this project, a variety of mobile celaning techniques will be tested with respect to "easy to handle for boat owners", or professional use only. The projects focusses on the efficacy of the cleaning methods under consideration on the impact on water quality. Several techniques designed to collect the removed fouling organisms will be tested and evaluated. These aspects are important with regard to future approvals and permissions for inwater cleaning in marinas. During the cleaning trials, time and costs will be recorded to identify effective, environmental friendly and inexpensive techniques. The aim is to present alternatives to the use of biocidal antifouling coating in sensitive water bodies, and to favour their introduction on the market.
In the first year, the cleaning trials will be performed on non-toxic, non-eroding coatings like on polyurea of PANADUR and on epoxy coatings filled with a hydrophobic additive. During the project the following methods and techniques will be applied:
- Big Easy Cleaner, a hand-operated cleaning pad equped with a device to collect the removed fouling organisms
- Scrubmarine, a hand-operated cleaning tool with rotating brush and integrated collecting system for removed fouling particles
- a rotating brush in combination with a net to collect the removed fouling organisms
- a rotating brush order jet in combination with a high-pressure pump including a collection system
- the Caviblaster which remove the fouling community with shock-like waves in combination with a variety of collection systems.
Negative impact like corrosion or osmosis in the underlaying material (steel, glass-enforced polymers, wood) will be tested in separate trials. In the first year, the efficacy of each cleaning technique will be tested in freshwater (Nordener Tief, Eas Frisian main land) and in marine water (Norderney island, North Sea) on statically exposed plates. In these trials the maximal cleaning intervall shall be determined in which the fouling community can totally be removed without damaging the coating. To reduce the impact of cleaning to the water quality, the most appropriate methods to collect the fouling debris shall be identified. Fouling residues which cannot be collected will be checked on their biological and chemical oxygen demand. In addition, the viability of the removed fouling organisms will be recorded to evaluate the risk of introduction of alien species by cleaning.
The project is funded by the German Bundesstiftung Umwelt for a duration of 2 years.