Zoo Hannover: Corrosion prevention for a seawater basin

Synopsis:
Corrosion prevention for a seawater basin at a zoo

Task:
Cavity protection for extremely corroded cavities with rust scale.

Special Challenge:
The rust scale could only be partially removed. A lot of the peeled-off rust scales remained inside the cavity.

Solution:
We use our corrosion protection grease. To boost the capability to creep so it can penetrate the lose corrosion we modified the corrosion protection grease. We added our solvent-free penetration oil TimeMAX Speed Lotion.

Advantage:
The modified grease even penetrates thick layers of corrosion. Despite extreme pitting the facility did not have to be closed down.

One of the most important attractions in the Hannover Zoo is “Yukon Bay”. With a lot of effort a small piece of Alaska was built here. The basin for salt water shown in the picture below has walls made of steel. It is home not only to the rather harmless penguins but also to dangerous polar bears.

A photographed section of a placard: This is what the facility looks like when the basin is full.

For maintenance and repairs the water has to be drained.

Penguins and polar bears need “real” seawater to be comfortable. The aggressive salt water regularly causes corrosion damage, thus the maintenance effort for Yukon Bay is quite high.

The location of our works: The steel walls next to the green crane.

The old crane was built by MAN and is well-preserved despite the salt water stress.

Our place of work is located to its left: The red box stabilises the four-metres-high sheeting wall made of steel.

The box has a length of approximately 7 metres. Its outside has just been freshly painted. But, as often is the case, the problem comes from inside.

The old MAN crane, from a different angle. Normally the polar bears bathe at the spot from which this picture was taken!

Openings show what the salt water has done inside the cavities. It is just like with sea-going ships and old cars: The really dangerous corrosion occurs not on the outside but inside the cavities!

“Normal corrosion protection” will not be enough here: It takes a lot of experience and extremely performant products to get a grip on damage of this kind.

We were awarded this job in Hannover with good cause. We were hired because our corrosion protection greases have special qualities: First, they have a high capability of creep and penetrate into the corrosion fast and deeply. And our material stays right where it belongs. Even in the heat of summer it does not flow off in large amounts as other greases often do.

As much rust scale as possible was tapped off and removed from the cavity. Our wet vacuum cleaner came in handy here.

Hours of tapping and vacuuming: Rust removal alone took more than a day.

To remove the remaining dampness we carefully heated up the cavity.

On the second workday the actual corrosion protection treatment began: A whole 70 litres of corrosion protection grease and an additional five litres of penetration oil were used! The oil is called TimeMAX Speed Lotion No.1 and was used first. Its task was to penetrate deeply into the thick layer of corrosion.

First oil, then a lot of grease: This is what the cavity looks like after treatment. We play it safe: Due to the deep craters in the steel the thickness of the applied layer of grease measures several millimetres.

Wherever our materials were applied water and oxygen cannot reach the steel any more. And as we know from chemistry lessons at school there is no corrosion when there is no oxygen!

As usual at TimeMAX every step of work was extensively documented. To check the layer thickness we took more than 100 pictures of all areas inside the cavity.

The quick work pays off for the penguins and polar bears as well. Only a few days after the TimeMAX treatment the seawater basin was flooded again. Finally they could go swimming again.

Zoo Hannover: Corrosion prevention for a seawater basin

Werkstatt & Ausstellungsräume

Lager & Shop

Anfahrt zur TimeMAX-Werkstatt