The good old days of club manufacture

Before technology took over and the driver became the monstrous feat of engineering and design that it is these days the persimmon wood ruled the tees and fairways.
Other imposters tried to supplant the material of the golfing gods but failed. It would eventually take over ten years for the 'johnny come lately' metal woods to take the place of persimmon on the PGA and European tours.
So what is persimmon, the holy grail of club manufacture and what is the history of the processes that gave the likes of Nicklaus the weapons that drove him to glory?
FANCY A BIG CHUNK OF GOLF HISTORY?
What is a Persimmon Tree
The Persimmon is a member of the Ebony family but though rich cream in colour, it does have a black heart which explains the occasional but non-detrimental faint black traces or spots in a persimmon club head.

The tree grows in several countries - China, Japan, Iran and possibly Russia. but the most suitable and main commercial supply was from the USA and in particular near the rivers of the Southern States of Arkansas, Mississippi and Louisiana. 
The bark of the tree is very distinctive with vertical and horizontal fissures creating a mosaic or “alligator skin” pattern. The fruit of the Persimmon - a type of plum, when fully ripe provides a delicious ingredient for a pie, pudding or jam. The trees can grow to a height in excess of 60 feet with a maximum diameter of 2 feet.

The reasons why persimmon was the perfect raw material for golf woods is quite simply because it was; so hard, smooth wearing, tough, dense, heavy and shock-resistant.

All trees at the time they are felled contain a very high percentage of water and sap. A block of persimmon, sufficient to make one golf head contained several ounces of liquid most of which had to be removed artificially but under controlled conditions to avoid impairing, the natural properties of the wood. 
In the 18th century, persimmon was left to dry, as naturally as possible, in large sheds. This was a lengthy two year process and unless the temperature was strictly controlled, the strength of the wood could be permanently weakened.

During the first half of the 19th century, kiln drying was used, which reduced the drying process to 12 months. It was during this period that oil impregnation was introduced in an endeavour to conserve or increase the hardness of the wood, particularly lightweight Persimmon, and also to provide an artificial moisture barrier.

New technology in the 1960s led to Radio Frequency Drying (the same principle as in microwave ovens) which dried the wood in less than one hour! This process also shrunk the blocks and so increased their weights, but unfortunately, the excessive stress on the wood was inclined to create a brittleness.
This accounted for many of the complaints in the ’60s and early ’70s and is a classic example of the way in which a perfect raw material can be impaired by a manufacturing process.

In the late 70s a new ‘power dry’ technique, using radio frequency waves but in a vacuum, was introduced and, although a longer process of approximately 40 hours, it produced a block that retained all the natural properties of persimmon (including colour) and equal to those of naturally dried persimmon.
The benefits of oil impregnation were dubious as although it may have improved the moisture barrier it did not increase the strength of the wood only the weight. It allowed mass producers of golf woods to use low grade, low weight and low-cost inferior Persimmon in the knowledge that the oil additive would artificially increase the weight!

A raw block of Persimmon, sufficient to make one golf wood contains after drying, approximately 10% of water. If the finished golf (head) club was stored near water, or in a moisture-laden atmosphere or left wet after use, then the head gradually absorbed the atmospheric water or the water which has been left on the head.

As the water was absorbed, so the head swelled and the lacquer began to crack increasing the water moisture penetration - a vicious circle!
The reverse situation to swelling was shrinkage with results as equally disastrous. If golf woods were stored in or near excessive heat, e.g. adjacent to radiators, then the required water content in the club heads started to evaporate with the resultant shrinkage distortion and drying of the heads, followed by the cracking of the lacquer and even the head itself.

So here are the rules that most of us of an age now realise we all broke.

Not all clubs were as good as they looked
Although clubs looked pretty much identical coming off the production line this was not the case for many persimmon woods manufactured some fifty-odd years ago.
If the purchaser could have lifted the soleplate, in the way he might lift a car bonnet and peer at the engine, he would in many instances have been horrified. What he assumed essentially to be a solid piece of hard, dense,  heavy wood or laminate, would often be revealed as a miniature cavern, or caverns, containing a surprising quantity of lead,  and a mass of thick dried glue surrounded by a collection of ill-fitting angled screws.

The very heart of the club head was often ravaged and weakened to house the artificial weighting of lead. Sometimes the hole that was drilled to accommodate the lead was so deep that it is dangerously near the top surface of the clubhead and so creating a weak stress point. Similarly, screws driven too far into the wood contributed to the overall weakness of the head.
Frequently shafts were not inserted to a sufficient depth resulting in a weakening of the neck and eventual cracking. These faulty clubs, which included clubs in the premium price range were, without exception, visually appealing with gleaming sole plates, attractively designed graphic inserts and often carrying the name of a well advertised manufacturers name.
It is almost inevitable that a clubhead that had been ravaged and weakened during manufacture, and so possessing many weak stress points, could not be expected to withstand the tremendous impact when it struck the ball or exposed to conditions which caused it to shrink or swell.  Something had got to give and it did! The head cracked or split and the insert or sole plate became likely to loosen or move.
This article was produced with the help of Andrew Simpson of Dreamgreens in Wakefield who has a collection which comprises an astonishing 1,150 Classic MacGregor persimmon woods dating back to the 1950s through to the 1970s.
Andrew sent GolfPunk a pamphlet produced by the late Paul Gibson of PROGOLFF a famous club builder of yesteryears who provided clubs to top pros of the 70s and 80s.