"It was something I had to do myself, personally, not representing the port or business or writing out a cheque," Mr Cairns said.
"Everyone's touched by cancer but to me, having a healthy child, you take that for granted."
Mr Cairns said he also had a friend going through radiotherapy for prostate cancer.
After the funeral, Mr Cairns sent out a humorous but self-deprecating email last week asking for sponsors.
"I'll be shaving my lid ... come down and watch the ugly bugger made even uglier!" he wrote.
The "fun-razor" would take place this Saturday, March 17, at Mount Maunganui's main beach. The original $10,000 goal was adjusted to $30,000.
Mr Cairns said he was overwhelmed with the generosity already shown.
Shipping line Sofrana, port stakeholder Devon Funds and law firm Holland Beckett had each donated $1000 while port staff had contributed personal donations of $100.
Mr Cairns would join Dame Susan Devoy and the father who originally asked for his help, Morris (Moss) Carlin, in shaving their heads.
A couple of weeks later, Mr Cairns said he would travel to Europe for business.
"I have to wonder what my customers will be thinking."
Mr Carlin said he did not have to do much asking before Mr Cairns "jumped in with both feet".
Mr Carlin's 14-year-old daughter, Victoria Rhodes-Carlin, had been ill but "was now well". Having the support of the port and his boss through those rough times was "everything", Mr Carlin said.
Annual appeal:
This is the month for the Child Cancer Foundation's annual appeal. During a Beads of Courage Day on March 23, volunteers will be out on streets collecting money to help the cause.
More than three children on average per week in New Zealand are diagnosed with cancer. Each year New Zealand children with cancer collectively undergo 100,000 treatments and procedures throughout their journey.
For each one they receive a Bead of Courage.
Email: news@bayofplentytimes.co.nz