“You’d take them off the line and put them through here to iron them,” he says.
Soon thousands will get to see Mr Donaldson’s mangle, and a host of other machinery – much of it rare – the retired Ashburton farmer has collected over a lifetime.
He will take it to the world ploughing event in Methven in April, and he has an inkling he might even be in with a chance to win a certificate for having the oldest piece of New Zealand-made machinery.
The item is a set of harrows made at Woodend by James Little in 1876.
Little’s name is stamped on the harrows, and they have been used by four generations of Donaldsons.
And because they have not been used on hard country, they are in good condition, carefully restored by Mr Donaldson.
Nearby is a hoop made by James Little for a daughter.
It, like the harrows, is hand-crafted and so good is the work that Mr Donaldson cannot find the point at which the steel was joined, and the hoop was hammered on an anvil.
The Donaldson collection also boasts a single-furrow plough made by James Little, unique rotary harrows made by Raes of Christchurch, and rare Lanz binders.
The rotary harrows are unusual in that the direction of the circular harrows can be changed, clockwise or counter-clockwise, by shifting a steel weight.
Mr Donaldson has restored for a friend at Lagmhor.
They have been used by Mr Donaldson, and work well.
He believes there may be only three such sets in existence.
But there is much more in the Donaldson collection: a Massey-Harris horse plough, a tin-bath and associated chip heater from Surrey Hills, a fine collection of milk separators, and the Lanz implements.
They were on display new at the Christchurch Show in 1952, with one binder found in Oamaru and another at Seadown.
“You have to keep your eye out,” says Mr Donaldson.
Brother Reg, a retired carpenter and joiner, helps with the restoration projects.
Some, much of the collection will make its way to Methven for the New Zealand and World ploughing events in late April.
The event will attract many thousands of visitors, and many overseas visitors will not have seen some of the implements and machines Mr Donaldson will have on show.
New Zealand, he says, is lucky to have much of what it has, thanks to early importers.
And it is thanks to people like Gilbert Donaldson, 74 and still playing tennis three days a week, that the machines have been preserved for this and generations yet to come.