Prestocure High Pressure Sap Displacement HPSD

The business known as Sisson Kayaks, Sisson Kayaks Ltd or Sisson Industries Ltd actually started in 1972 – producing light engineered components for George Mason (the kind man), also known as C.G.W. Mason (the scientist). George held patents for Perfusion Brand ‘Improved Apparatus’ High Pressure Sap Displacement (HPSD) equipment.

Wherever George took his plans the apprentice was given the job. George knew what he wanted but he never received much engineering assistance. Nothing worked. I owned some light engineering equipment and set out to assist George to commercialise his dream. My main day job was Service Manager for M S Motors, Ford Dealers in Nelson. My work for George was a hobby.

Only now in 2018 – using Google search – do I (at last) understand George’s plan For at least twenty five years he had been searching for ways that would enable farmers to extend the life of their own timber thinning – to make their own posts and poles. I wish I had better understood George in 1974.

In early 1974 I resigned my job at M S (Meager Salary) Motors and decided to catch up with George’s back-log of work (two weeks), before looking for a new job. I never found the time to look for that job!

Perfusion HPSD was commercialised within 12 months with quite a few plants exported. However, the pressure cap construction included many small parts – that were expensive to manufacture and assemble. In the forest these same parts broke.

What to do. HPSD certainly worked. How to make a more durable – and cheaper pressure cap? I had a light-bulb (literally) inspiration and loosely discussed my invention with George. We agreed that I should develop the prototype myself – patent it – demonstrate it to George – and he would write me a sizeable cheque to purchase the patent. My chosen name was Prestocure HPSD.

Nine months later, just one week before the patent became valid, my customer, mentor and friend George died.

I became the owner of a venture that required capital to succeed. Newman Export a division of the TNL Group came alongside and Prestocure HPSD was subjected to the scrutiny of the Timber Preservation Authority. The process worked. All of the scientific testing proved positive. Approval to treat timber to H3 Standard was granted.

Meanwhile Sisson Industries sold Prestocure HPSD laboratory sets to Dow Chemicals and the Forest Research Institute. Many farmers purchased Prestocure HPSD equipment. Zero failures. No small parts to break. The fibreglass pressure caps were tested to three times the possible pressure that a log would sustain.

OK – time to come clean – Sisson Industries Ltd started a fibreglassing section to manufacture Perfusion HPSD caps – not kayaks. The kayaks happened later – by accident.

Why is this story relevant in 2018? Simple – in parts of Asia there is renewed interest in HPSD (as there should be) but they seem to lack access to decent reliable pressure caps. I have a huge (dead) stock of Prestocure caps.

Over the next few weeks I will add some photos to this page. Plus a lot of links to George and his lonely mission. And who knows – someone in Asia may Google HPSD and find my Prestocure page – and make a offer for my dead Prestocure HPSD stock.


Contact Grahame

For all enquiries and orders please contact me directly:

Phone: 027 2755 499


Phone: 027 2755 499Email:

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