This one is kind of technical, sorry. Skip if you're not in the trade.
The core of our racket — the inner layer — is poplar plywood. Faces are beech, sometimes okoume on the budget line. For the poplar to laminate properly and stay flat after the hot-press, the moisture content has to sit around 8 to 10 percent. Above 12% you get warping, below 6% it gets brittle and the silk-screen ink doesn't bond as well.
The traditional way to get there is a kiln. Takes 3 to 5 days depending on the season. Slow, costs energy, takes floor space.
In 2019 a sales guy from a vendor in Shandong came down and pitched us on RF (radio-frequency) drying. Much faster — like, hours instead of days. We bought a small unit, ran it through summer 2019 into early 2020.
It works. The moisture readings come out right. But.
The wood that came out of the RF dryer felt different. Hard to describe. Drier on the surface than the core sometimes — you'd hot-press a sheet and it'd look fine, then a week later you'd see a tiny cup. Not always. Maybe 1 in 30 sheets. Thats a 3% reject rate which sounds small but for us that's like 60 paddles a month going to the seconds bin.
Also — and this is the part I can't really prove with data, just feel — the rackets that came out of those press runs didn't sound right. Frescobol players will know what I mean. You hit the ball and the racket should have a kind of warm tock, not a sharp click. The RF-dried ones tended toward the click. Two of our long-term Brazilian buyers actually called this out without us telling them anything had changed.
So we sold the RF unit. Went back to the kiln. The Brazilian buyers stopped complaining. We lost some speed on the front end but the seconds rate is back under 1%.
I think the lesson is: faster isn't always better, and the old guys in the workshop sometimes know things they can't put into a spec sheet.
