What are some maintenance Tips for Wildco Core Samplers?

Cleaning Wildco® corer valves:
Keep valves and seats in corer heads free of dirt, grease and oil to maintain a good air seal. It’s best to clean valve and seat after each sample with 70% ethyl alcohol.
Chemical removal of rust stains from stainless steel:
Stainless steel parts may show a rust stain, indicating an active corrosion cell area which should be deactivated. These are often caused by scratching or marring the surface.
Soak the stained area in concentrated HNO3 for a few hours or make a paste to spread over the stain using Vaseline, corn starch or other thickener. Repeat as needed.
Sand blasting with clean silica sand will remove rust but must be rinsed with strong HNO3 to prevent future damage.
If left in salt water, stainless steel corrodes quickly. All stainless steel should be rinsed at once with fresh water after removal from salt water.

What are Core Samplers?

A core, in marine research, is a cylindrical section taken from sediments underlying a water body.

Core samplers, the instruments used to obtain cores, range from the simple to the complex. The variety of corer types reflect the breadth and variety of marine research.

For example, the simplest corers are hand-operated types used in shallow waters to collect sediment cores containing fauna. For biological studies, a core 20-25 cm (8-10”) in length is usually sufficient.

The most complex core samplers are those used in oceanographic research. These are generally large and require winches, power sources and other gear. In extreme cases they can take cores as long as 25 m (80’). Such cores have provided geological and climatic information through study of the stratified sediments and their contained fossils.

If done properly, core sampling is a reliable method for obtaining basic data for many types of studies pertaining to the water-and-bottom interface of marine bodies. It is often the only practical way – and therefore the best way – to sample underwater strata satisfactorily.

Wildco® core sampling equipment offers dependability, versatility and quality. It ranges from light, hand-operated corers used in shallow water from boats to gravity corers relying on weight such as the K-B™ corer. Interchangeable parts serve as “building blocks” to construct the equipment you need for your particular project. For example, the heads can attach to more than one type of core tube.

The “building block” concept relies on a simple design feature: the uniform use of coarse pipe thread. This thread provides an extremely reliable way to connect core tubes to sampling heads at a low mass-market cost. Because we use straight pipe threads threaded all the way into the head assembly, no pipe wrenches are required – a bonus in the field. While by the very nature of the equipment these threads can become dirty and jam, they can be washed in water to remove debris and easily reattached.

Wildco® hand and Ogeechee™ corers are designed to be lowered on a taut line or cable into the substrate. They are not designed to be dropped because they are top heavy and can easily tip over. While some customers tell us they obtain a good sample by a free drop on a loose line up to 20-30” (7-10 m), to accomplish this you must keep the sampler entirely in water, still and vertical when dropped. This cannot be attempted using bricks or cement blocks as weights due to the need to keep the core tube balanced and vertical.

What are Characteristics of good core samplers?

Perpendicular placement: The core sampler must make a vertical or straight entry into sediments to secure a reliably representative cross-section sample.
Penetration: It must penetrate the sediments you expect to find and adaptable for many field situations.
Core retention: There should be minimal loss of any part of the sample during return to the surface.
Maximum sample validity: This means:
a. Samplers intended for layered sediments should obtain cores showing minimum disturbance of layers by compression or by displacement around the circumference.
b. Samplers intended to obtain bottom sediments and their resident fauna need a design which causes minimum displacement or escape of fauna during sampling.
Simplicity: Purchase the simplest instrument capable of producing the type of samples you require.

Maintenance Tips for Wildco Core Samplers

Cleaning Wildco® corer valves:

Keep valves and seats in corer heads free of dirt, grease and oil to maintain a good air seal. It’s best to clean valve and seat after each sample with 70% ethyl alcohol.

Chemical removal of rust stains from stainless steel:

Stainless steel parts may show a rust stain, indicating an active corrosion cell area which should be deactivated. These are often caused by scratching or marring the surface.
Soak the stained area in concentrated HNO3 for a few hours or make a paste to spread over the stain using Vaseline, corn starch or other thickener. Repeat as needed.
Sand blasting with clean silica sand will remove rust but must be rinsed with strong HNO3 to prevent future damage.
If left in salt water, stainless steel corrodes quickly. All stainless steel should be rinsed at once with fresh water after removal from salt water.

How does the K-B corer work?

Aircraft cable fits into a closing trip mechanism at the stop of the head assembly. When a messenger strikes the trip lever, a neoprene valve drops and seals the core tube under the head assembly. A suction, formed between the top valve and the core sample, creates a partial vacuum inside the core tube as the sampler is raised. This partial vacuum helps hold the sample in the core or liner tube, thus allowing collection of all but the soupiest samples.

Can I use my sounding line with a Kemmerer bottle?

Caution! Sounding line will not thread through center tubes of 1200 Kemmerer bottles. If you wish to use with Kemmerers, simply attach 50-L10 Kemmerer adaptor kit to the bottom link and thread through the center shaft of the Kemmerer bottle. Be sure to secure the end of the adaptor kit with the supplied cable clamps!

Can I hammer my corer into the ground?

Warning! Hammering or pounding corers into sediments may damage them. When entering or exiting the bottom, do not tilt. This may cause the head assembly posts and tube to bend. The PVC core tube may break if bent too much.

Are Wildco corer parts interchangeable?

Head assemblies, core tubes, liner tubes, core catchers and nosepieces may be used interchangeably between:

  • 2” Hand corers
  • (2424-A20 and similar)
  • 2” Ballchek
  • (2416-B25)
  • 2” K-B Corer
  • (2400-B20 and similar)
  • 2” Ogeechee
  • (2427-B20)

 

A sample checklist for using the Ballchek™ Corer:

The purpose of this equipment is to obtain a core sample from a lake or ocean bottom. Because the equipment is heavy, take care.

1. Attach cable from winch to corer head
2. Loop cable over end of pulley wheel on boom of crane. Use winch to gently lift corer vertically until suspended by the cable.
3. Swivel boom with corer off boat, slowly lower corer into the water with the winch. Stop just beneath the surface to let air escape from the liner.
4. Lower until it is about 5 m above the bottom. Verify depth, position.
5. Release the ratchet brake on the winch and allow the corer to free fall to the bottom. Keep hands and clothing away from cable during free fall. The cable will slacken once the corer has penetrated the bottom.
6. Wait about 2 minutes before attempting to reel in the corer.
7. Lock ratchet brake into place and reel in slack line. Do not overtighten.
8. Reel in cable until corer reaches the surface. Lay corer horizontally on deck. Place end cap on plastic liner.
6. Remove plastic liner and attach an end cap to the other end. Use a marking pen to label top and bottom of the core and its ID number.
7. Inspect sediment inside of liner. Measure and record the recovered length of core and its condition. Describe contents. Place core horizontally in a storage box. Wash off deck and corer of any loose sediment.
8. Record: Sample #________ Location__________ Date_______
Time______ Latitude____ Longitude____Depth_________
Recovered length _____________ Condition ___________
Description of core: ________________________________

Perform lab analysis of core
1. Stratigraphic description (describe on cm scale the record of sediment layers in terms of composition, particle size, color etc.
2. Chemical and/or organic analyses performed (list type and results)