Some weeks he might do 30 hours and other weeks five hours, depending on what was going on, he said. "Whatever comes up, I do, or I twist someone's arm."
Mr Harnett was one of the nominees for the Eves Realty Volunteer Excellence Awards run by Volunteer Western Bay.
The finalists were introduced to an appreciative cross-section of community and business leaders at the awards ceremony at Classic Flyers which, appropriately, relied heavily on the work of volunteers.
Tauranga city councillor Catherine Stewart told the finalists: "You are the life force of our community, without you it would be a far poorer place to live, thanks for enriching our lives."
Cr Stewart described Mr Harnett as an amazing and humble person who could think outside the square and fix anything.
She recalled the time Mr Harnett and another volunteer rigged up an ingenious contraption to shift a garden shed, thereafter earning the nicknames Barney and Fred after the Flintstones characters.
Homes of Hope said Mr Harnett brought practical much-needed help, great fellowship and yummy sustenance. "A man of many talents and humble to a fault."
His nomination said he repaired, recycled and created things from virtually nothing, solved many practical challenges around the homes and, to top it off, baked amazing apple shortcakes and choko pies.
"He is truly one-in-a-million. Quietly buzzing in and out getting the odd and very necessary jobs done for us, all the while with a smile on his dial and very much wanting to stay under the radar."
You are the life force of our community, without you it would be a far poorer place to live, thanks for enriching our lives.
Winner of the Trustee of the Year award was Ann Kerewaro, 79, who has been a member of Multicultural Tauranga since 2006.
The award was presented by Envirohub general manager Marielle Haringa who said juggling family and work commitments alongside her voluntary work, while finding time to serve the migrant community, was truly laudable.
Multicultural Tauranga said the committee member had previously held executive roles as secretary from 2006 to 2010 and treasurer from 2011 to July this year. "Typical for Ann is that she always puts her hand up to help others."
The Youth Volunteer of the Year was Karleigh Jones from the House of Science. Award presenter, The Incubator director Simone Anderson, praised Karleigh for her work which included helping to prepare food and activities for the 40 kids who go through the programmes every day.
"She assists with kids' programmes and also volunteers on Fridays for four hours to help with cleaning, counting and sorting. The event was organised by a Volunteer Western Bay volunteer Kara Herbert.