Apologies for resurrecting an almost decade-old thread, but I thought I'd share the contents of a related article I've just been translating from Russian into English. At the very least, this posting will show what I've been up to lately during lockdown!
The article, whose title goes into English along the lines of "STORAGE AND REPAIR OF RUBBER EQUIPMENT", appeared in a 1980 issue of
Sportsmen-Podvodnik, the Soviet equivalent of
Skin Diver magazine. If you want to read the original issue, you can retrieve the scan at
Sportsmen-Podvodnik-58. The translation may be of interest to anyone concerned about rubber diving equipment parts perishing. Diving gear was in such short supply in Soviet-era Russia that it had to be maintained, stored and repaired with enormous care. I'd be grateful for any feedback about what is recommended in the article, particularly the following advice for partial restoration of any perished article: "Place it first for 15 minutes in a warm 5% ammonia solution and then for 15 minutes in warm water with 5% glycerine added to it." My first reaction was "don't try this at home", but I could be wrong.
DRW
G. MOKSHIN, A. PODZINSKY: STORAGE AND REPAIR OF RUBBER EQUIPMENTMany important diving equipment parts are made from different types of rubber. These are mask flanges, fins, mouthpieces, membranes, dry and wet diving suits, etc. (Neoprene used for manufacturing wet diving suits is a rubber-like substance with air bubbles distributed throughout its volume.) Compliance with the rules of operation, storage and repair of rubber products prolongs their service life, preventing their failure in an emergency.
Diving equipment is used in a variety of conditions: in hot weather and at negative temperatures, in salt and fresh water. All of these influences affect the quality of the rubber and its service life. Heat and direct sunlight tarnish and soften rubber. At negative temperatures, rubber becomes brittle, sharp temperature changes "age" it. When operating and storing rubber products, therefore, they must be:
1) protected from sunlight;
2) dried thoroughly before storage (dry diving suits — both outside and inside);
3) stored flat and dusted with talcum powder;
4) stored in a room with constant temperature (15-20°C) and humidity (50-70%), away from heating devices;
5) The storage room must be unventilated.
While operating equipment, leakage often occurs due to abrasions, cuts, and ruptures. Damaged wet and dry diving suits can be repaired. Rubber glue, which is a solution of natural rubber in petrol, is used to repair dry diving suits. The rubber adhesive is available in two grades: A and B. Both adhesives are suitable for repairing diving suits. The rubber adhesive must meet the following requirements:
• Light grey or light beige colour;
• Uniform consistency;
• No lumps or impurities.
To restore the leaktightness of diving suits with through cuts and tears, cut out a patch overlapping the edges of the hole to be sealed by 8-10 mm. The surfaces to be glued are cleaned with coarse-grained sandpaper; dust is removed with a cloth soaked in petrol. The glue is applied in an even layer to the edges of the tear and patch. After the first layer has dried, the second is applied. The edges to be glued are pressed tightly against each other and tapped with a wooden mallet.
To restore abrasions of the rubberised fabric of GK series diving suits, rubber glue is diluted with petrol to the consistency of liquid sour cream. The damaged area is thoroughly washed with warm water and soap, dried and treated with coarse sandpaper. The prepared surface is thoroughly degreased with petrol. To match the colour of the restored area to the colour of the base material, use a powder dye diluted in a glue solution. The maximum ratio of the filler to the mass of the glue solution is 1:10. The resulting mixture is applied in a thin layer to the prepared surface. After drying is complete, apply the next layer. To ensure the leaktightness of the restored area, there should be at least three layers. After these have dried, the repaired area is dusted with talcum powder to prevent stickiness.
To improve the mechanical properties of the adhesive seam, vulcanisation accelerators are used. These include thiuram, captax and some other compounds. Vulcanisation accelerators are introduced into the rubber adhesive in small quantities. To glue wet diving suits manufactured here or abroad, in addition to the adhesives included in the repair kit, you can use "Krokus" nairite quick-setting glue used in the shoe industry. "Krokus" nairite glue is a solution of synthetic polychloroprene rubber in a mixture of ethyl acetate and petrol with vulcanising agents and resins added to increase the setting speed and heat resistance of the coats of adhesive. A "Krokus"-glued seam has a tensile strength of 30-35 N/cm².
When repairing wet diving suits, a joint is usually a butt joint. The surfaces to be glued are washed in warm water and degreased with petrol. A thin layer of nairite glue is applied to the prepared surface. After the first layer has dried, the second is applied and after 30-40 seconds' exposure, the surfaces to be glued are pressed against each other. When the glue is completely dry, the strength of such connections often exceeds the strength of the base material.
Note. For testing, we used "Risopren-u" glue, which is made in Yugoslavia.
Sportsmen often decorate their suits by gluing rubber strips in a variety of colours over the seams. Based on experience, this is not an ideal solution, since water gets under the glued tape and the diving suit material will perish and deteriorate.
Rubber products are subject to aging during operation and storage. There are no effective measures to prevent or delay this process. You can partially restore the product as follows. Place it first for 15 minutes in a warm 5% ammonia solution and then for 15 minutes in warm water with 5% glycerine added to it.
Rubber diving equipment parts require disinfecting from time to time. Many types of bacteria, often pathogenic, live and multiply on a rubber surface and can cause a variety of infections of the oral cavity, skin, etc. The most affordable disinfection method is treatment with 96° ethyl alcohol. Treat the surfaces of parts that come into contact with mucous membranes, skin, and air exhaled from the lungs. Before each descent, the scuba or snorkel mouthpiece and mask flange should be disinfected. AVM-1, AVM-3 scuba tank inhalation and exhalation tubes and other similar structures are supposed to be disinfected twice a year, Sadko and GK-SVU diving suit helmets at least once a year. New, unused equipment is also disinfected.
Correct operation and storage of rubber diving equipment parts and timely repairs significantly extend their service life.
