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Capillary Bunkers - Maintenance Program and Best Practices

Capillary Bunkers - Maintenance Program and Best Practices

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The World’s Leading Bunker Liner

Capillary Bunkers is recognized as the World’s Leading Bunker Liner, and the most durable bunker construction method. Over 800 courses around the world have built or renovated their bunkers with Capillary Bunkers, including many of golf’s top 100 courses. Even though you now have the best and longest-lasting bunker on the market, there are some best practices and maintenance procedures that need to be followed.

Sand Depths

The sand depth in your bunkers should be based on the Water Release Curve of your sand, and the preference of compaction levels as measured by the TrueMeter from the USGA. Different players require different compaction levels, and it is important that a general TrueMeter value desired is established for all the bunkers, taking into account the specific rakes to be used and methods of raking. This value is in direct relation to the moisture levels of the sand, which in turn is decided by the Water Release Curve. Your sand supplier should be able to provide this Water Release Curve.

However, the USGA recommends an average sand depth of 4-6 inches at the base of the bunker and 2-4 inches on bunker faces, giving you some indication of where you should be. As a general rule, faces should never have the same sand depth as the bases, and the firmer the faces are the better as it promotes faster play and less maintenance problems. Sand depth should be spot checked monthly and thoroughly quarterly, with a maximum spacing of measurement points of 10 ft (3 m) in a grid pattern across the whole floor of each bunker. It is recommended to equip each bunker maintenance team with one probe each (broken steel golf shaft for instance) with two clear markers on (tape or similar) for floor depths and face depths respectively. It is important to monitor player feedback on the bunkers and sand, and to remember that the less sand in a bunker the more moisture it will hold and the firmer it will play. It is also important to wash the sand with the Capillary Wash Box on a regular basis depending on your location and contamination levels.

Sand compaction

If you are looking for a 4” sand depth in your bunkers, we recommend installing 5” that will compact down to 4” over time. A light plate compactor on wet sand is necessary to get the sand to compact, but most likely it will take several months for the sand to get to its final compaction level depending on your sand choice.

Maintenance of completed bunkers

Bunkers can be raked as you wish and on a frequency of your choice. Mechanical trap rakes are okay to use as well, but require more attention to sand depths, see above. With the added stability of the sand on the faces due to the Capillary Bunker installation, some clubs have gone to the “Aussie” method of bunker raking. They will use the rounded back of the rake to smooth the slopes of the bunker and rake the interior as usual. Regularly raking and mixing up of sand is important to avoid algae and weed growth (weeds do not grow through the Capillary Bunker but can germinate in the sand layer).

Sand Maintenance with the Capillary Wash Box

All bunker sand will get contaminated over time, by grass clippings, algae or merely by regular use and sand particles grinding into smaller shapes. With the Capillary Wash-Box, the sand can be washed instead of replaced, and this can have a significant economic and time-saving impact. It is recommended to wash your bunker sand every 1 – 4 years, depending on your site-specific circumstances.

Washing Instructions

The Capillary Wash Box and this system is designed to only remove organic material (algae, clippings, leafs etc.) and
particles smaller than 0.05 mm, which will float in water for some time. These are the particles that usually contaminate
bunkers and change infiltration rates, and they can be effectively removed by following the below instructions.

  1. Locate the Vault with the Wash Box and remove the bunker sand to expose the lid.
  2. Remove the lid and place enough Extensions (the middle part of the Wash Box) to where the top of the last Extension is above the top of the sand surrounding the Vault.
  3. Connect a hose with nozzle to the irrigation system and start by washing the immediate area surrounding the Wash Box to make sure the sand layer is never above the top edge of the Wash Box Extension. This must be done from time to time while washing not to have larger sand particles enter the drainage pipe.
  4. Now start as far away from the Wash Box as possible and wash the sand with a water beam from the nozzle that is at least 2 ft wide.
  5. Work the water beam so that the sand does not displace too much, merely gets turned around and washed in its place. You may have to push the dirty water along to reach the Wash Box from time to time.
  6. Be sure to wash all the way to the edge of the bunker as there is often an excess of sand located there and we seek to re-establish the original sand depth and edge.
  7. On steeper faces, be careful not to wash too deep if not necessary as the sand will have to be pushed back up the face after washing.
  8. From time to time, check the drainage pipe in the Wash Box to make sure larger sand particles do not wash into the pipe and clog it. Some particles will inevitably reach the pipe, and the pipe must be washed clean by directing the water beam into the pipe, but this should not have to be done more than once or twice and after completing the entire bunker when the pipe must be cleaned at least for 5 minutes.
  9. After completion, the sand must be pushed back to ensure a uniform sand layer in the bunker, and often times new, clean sand must be added to reach the desired sand depths throughout the bunker.

Bunker Edge Maintenance

Depending on your choice of edge construction, various techniques to edge the bunkers should be used. If your bunkers have artificial turf edges or stacked sod edges, great care should be taken not to damage the edge and not to use any other tools than string trimmers or hand scissors. It is always important to remember that a bunker shape tends to change over time due to edging, and eventually all bunkers will end up oval shaped. Therefore, it is very important to locate the original edge before commencing the edging procedure. Flagging or spraying the original edge after locating it with a probe before edging is very important. Remember that edging without properly locating the original edge will result in oval shaped bunkers where noses have been edged back and other areas of bunker have grown over with grass.

Drainage Maintenance

A locator wire is recommended in the trench with your drain tile. This will help locate the pipe if you ever need to inspect it or repair it. The locator wire should follow the pipe up to the cleanouts on the outside of the bunker. The cleanout should be installed inside a 10” round valve box with a lid to allow for inspection. It is recommended to install the outfall pipe of the bunker with sufficient fall to allow the pipe to be self-cleaning to avoid clogging. Recommended slope is 1.25% for 4” pipe and 0.85% for 6” pipe. It is a good practice to daylight the drain into a 12” catch basin to protect the pipe end from becoming crushed or clogged. If the pipe daylights into a pond that the water level rises above the bunker, a flapper style check valve is recommended to be installed in the pipe to prevent the line from allowing water to back feed into the bunker and possibly cause damage.

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