Author: M.D. Emelyanov
Abstract
The purpose of this work is to restore the strength and ensure the durability of the outer shell plating when receiving damage caused by osmosis. To achieve this goal, the article considers the process of development of osmotic changes in the plating, the degree of damage and selection of possible repair methods. At the first degree of osmotic damage consisting in the presence of high humidity, the repair consists in drying the plating and applying barrier coating. At the second degree, characterized by the presence of moisture not removed when drying, the repair consists in removing the gelcoat, drying the plating, restoring the gelcoat and applying barrier coating. At the third degree when there are bubbles formed under the gelcoat and delamination of the fiberglass plating is present, repair consists in the removal of bubbles and delaminated sections with subsequent drying, restoration of the covering, gelcoat and application of barrier coating. The article also describes the methods of evaluating the plating moisture content and detecting the delamination of fiberglass surface. In the repair of fiberglass ships preference is given to epoxy compositions, which outperform polyester ones by all major physical and mechanical parameters, including their superior watertightness. In addition, they are less sensitive to high humidity and low temperature environment, allowing to perform repairs in the open air and to use reinforcing materials without special treatment with coupling compounds. Technologies of cleaning of the plating from fouling, vacuum drying, repair of gelcoat bubbles and fiberglass delamination and restoration of the worn-out plating are also presented.
Keywords: polyester fiberglass repair, gelcoat bubbles, fiberglass delamination, plating wear, barrier coating.
References
1. Nigel Clegg. At my yacht osmosis? Waterway. (Available at: https://www.amariner.net/article26_osmos_ru.html).
2. Emelyanov M.D. Ustroystvo udaleniya vlagi iz povrezhdennykh mnogosloynykh paneley. Zayavka na poleznuyu model' № 2017121728/03(037604) ot 20.06.2017, reshenie o vydachi patenta ot 15.12.2017 [The device for moisture elimination from the damaged multilayer panels. The application for useful model No.2017121728/03(037604) from 6/20/2017, the decision about issues of the patent from 12/15/2017].
3. Gelcoat Blisters - Repair, Diagnosis & Prevention. Book by Gougeon Brothers of WEST System. Catalog number 002-650, 9th Edition Printed 6/07. (Available at: https://www.westsystem.com/wp-content/uploads/Gelcoat-Blisters-Diagnosis-Repair-and-Prevention.pdf)
About author:
Emelyanov Mikhail - PhD, Central Marine Research and Design Institute, 6, lit. A, Kavalergardskay str., 191015, St. Petersburg, Russia, e-mail: emelyanov@cniimf.ru
Issue: 50/51 (2018)
For citation: M.D. Emelyanov. Repair of osmotic damage to the fiberglass outer shellplating. Research Bulletin by Russian Maritime Register of Shipping. 2018, No. 50/51, pp. 14-21.* * *
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