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04.04.14

TOP TIPS: Maintaining BCDs and drysuits

If a regulator fails underwater it tends to lead to one of the following situations: inhaling water, an air leak reducing your air endurance, or a freeflow causing catastrophic air loss. With good training, self control and an alternative air source, all of those events are easily survived. The nightmare scenario of the regulator actually failing to supply air is fortunately extremely rare. The vast majority of divers understand that to avoid these risks their regulators need to be regularly serviced.

Compare that to a BCD. Failures that I have witnessed over the years include: shoulder buckles failing; bladders leaking air and losing buoyancy, direct feed inflation units stuck causing rapid ascent, dump valves failing causing unexpected descents, and cinch bands failing (on one occasion causing the cylinder to be jettisoned down the stone steps of a harbour wall. How we dived for cover that day!). BCDs, and for that matter, drysuits are not maintenance-free devices. When you consider the consequences of these failures, it is clear that BCDs and drysuits are as much a part of your life support system as your regulator.

So why is it that for every ten or so customers that bring a regulator to my workshop for a service, only one brings their BCD as well? Here's a list of things to cast a critical eye over:

BCDs:

• Shoulder and waist buckles - check these for cracks and replace as necessary, although this may mean renewing the stitching. If your local dive shop can't help directly they may well know someone with a heavy-duty sewing machine - a sail maker, for example.

• Inspect straps and stitching - especially at the shoulder anchor points as well as the webbing where it is pulled through buckles. This is particularly important on BCDs that spend a lot of their life in swimming pools, as pool chemicals have a very detrimental long-term effect on BCD fabrics.

• Cinch band buckles - look for cracks in the plastic as well as failures of stitching.

• Integrated weight pockets - check the weight-release system to make sure that the weights are secured properly and not prone to accidental jettison because of damaged buckles or Velcro.

Check the integrity of weight pouches

• Leak check the BCD by inflating it - if it deflates but you still can't find the leak then it's time to fill the bath and look for bubbles. A small hole can sometimes be repaired with polyurethane adhesive, but this may not be possible if the hole is close to or at the seam. If your BCD is quite old and it appears to have a few pin holes, then the material is probably porous, in which case it's time to consider a new one. With your BCD in the bath, now is a good time to wash the inside of the BCD with a sterilising solution (same stuff used for baby bottles). Oral inflation of BCDs is a required training skill so it makes sense to ensure that your gear is hygienic.

• Hoses - stretch the corrugated hose and look for cracks due to perishing and stress. Direct feed hoses eventually perish and crack so inspect the entire length of the hose, especially underneath the hose protector.

• Dump valves can leak because of debris underneath the diaphragm - most BCD dump valve assemblies simply unscrew; so as long as they are not too tight or require special tools/procedures, it’s easy to remove and clean them. Operate each dump valve to make sure that they seal properly and don't leak.

• Direct feed inflation units - they frequently look fine on the outside but can hide corrosion and debris inside. Submerge the direct feed unit with it connected to an air supply and check for leaks. Check that the button works easily and reliably with no tendency to stick. Also check that there is a good fill rate. A slow rate of inflation is usually caused by a filter blocked by salt and corrosion.

• Emergency inflation cylinder - if your BCD has one fitted then it must be tested on the same basis as your main diving cylinder, every two-and-a-half years. The trouble is that because it’s only you that has to fill it and not a compressor operator, it is easy to forget this. Potentially this is very hazardous, because these cylinders do not have an easy life. They tend to get filled and emptied rapidly and have been known to be flooded with sea water from the BCD.

Drysuits:

• Neck and wrist seals - carefully stretch these and look for tiny cracks or holes. Also check that there is still plenty of elasticity in the seal. Dust the seals with unscented talc to help preserve them in storage.

Stretching a wrist seal reveals that it is perished and close to failing

• Use a toothbrush to clean sand from the teeth of the zip - as the zip starts to wear look out for loose threads and trim them with sharp scissors before they unravel any further. Wax the zip with beeswax or a proprietary wax every time. There is not much change, if any, from £100 to replace a drysuit zip.

• Boots - check these for cracks and holes. Minor damage can be repaired with polyurethane repair adhesive. Check the insides for small stones or grit.

• Leak check - one way of leak testing the suit is to block off the seals with suitable objects such as bottles or balls. With the zip closed and dump valve blocked off, inflate the suit fully and then systematically spray soapy water all over the suit until you find bubbles. Small holes can be patched with polyurethane adhesive. First clean the area with a cloth dampened with thinners and then create a patch by brushing a thin layer of adhesive over the hole. If you’re concerned with aesthetics then you can make the patch on the inside of the suit.

• The inflation valve should operate smoothly - if it’s stiff to operate get it serviced without delay. The consequences of it seizing underwater and causing uncontrolled inflation of the suit could be lethal.

• Inspect the dump valve carefully - if you’re getting wet on most dives then it’s quite possible that there is sand or debris under the valve seat. Resist the temptation to service inflation and auto dump valves yourself. They usually require special tools and procedures that require careful attention to ensure that they work properly afterwards. That said, the simple cuff dump valves are very straightforward to open up and clean out.

You can now turn your attention to basic kit - delayed SMBs and reels, weight belts, masks, fin straps and buckles. There surely is no bigger frustration than being fully kitted, only to break a fin strap seconds before going in the water!

Martin is a PADI MSDT and BSAC National Instructor with 30 years of diving experience, much of it spent running PADI 5-star Anglesey Divers. For more information on Martin and his dive centre, visit www.diveanglesey.co.uk.

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