Chemical bath to save waka

MAARTEN HOLL/ The Dominion Post

RARE FIND: Dilys Johns says the pre-European waka prow is delicate and care is needed to stop it cracking.

A delicate process is under way to preserve an ancient waka prow found in the Hutt River three years ago.

A three-metre long end of the totara canoe was found by Hutt City Council contractors in July 2006. It is believed to be from pre-European times.

The waterlogged prow was unearthed from under five metres of silt and gravel at the building site of Opahu Stream pumping station near Ava railway bridge in Lower Hutt.

The curved and hollowed out timber has been kept in a shipping container in Lower Hutt for three years and regularly hosed down and checked. Because it was wet for so long, it will need to be dried out slowly and carefully to avoid any damage.

University of Auckland senior research fellow Dilys Johns has been discussing the best way to dry out the waka with the Culture and Heritage Ministry.

Ms Johns said the timber would be lowered into a tank of polyethylene glycol, or PEG, next week after she had taken some wood samples.

"We are going to clean it and then impregnate it with PEG. The chemical will slowly replace the water in the wood and allow it to keep its shape. After all the water is drawn off, it will be dried."

PEG is an expensive chemical and two 233-litre drums of it will be used. Each drum costs $2000. The tank itself, which the waka will be lowered into, holds 3000 litres and the PEG will be diluted.

Ms Johns said the waka was a rare find and it was important to take care with it.

"It is very delicate and if we didn't do this [conservation], it would crack."

Kaumatua Sam Jackson said the size of the waka prow was an indication of how big trees had grown in New Zealand.

"It is a wondrous find and it was a wonderful tree. If you have a look at how it was made, it was made with ancient tools. We want to keep it forever so this process will help. We don't want it to deteriorate anymore."

Heritage operations senior adviser Liz Cotton said the Crown would maintain ownership of the waka prow till the process was complete and its rightful owners were identified.

"We have had a response, but the ownership has not yet been resolved."