Powder Coating of Hoops
Many clubs are now turning to powder coating
for refurbishing of hoops. The following
is drawn (with permission) from a letter to the Croquet Gazette 2001 from
Bob Sharman of the East Dorset L.T. & Croquet Club. The advice
will be extended as more information becomes available. Please send
comments and contributions to the Equipment Committee.
After careful examination and comparison of our 24 older, spray-painted hoops
with 6 new powder-coated hoops, the current conclusions are that much depends on
the treatment process prior to painting and very little, it seems, on the type
of top-coat.
The condition of the hoops when presented for
re-furbishing is obviously critical - old, battered hoops eventually come to a
stage when they are not worth further expenditure. It is suggested that a
minimum of three quotations should be obtained from local metal-finishing
companies, each quote being based on exactly the following specification.
- Check and straighten each wire using a jig etc. (Cast
iron hoops may succumb to this treatment).
- Thoroughly clean off all the old paint and any rust
by blasting. This may be soda, sand, grit, shot or bead-blasting or a
combination or succession of these types, depending on the condition of the
hoops. The resulting surface should be finer rather than coarser.
- 'Plate' the bare metal with zinc by a hot chemical
process or by spraying with a zinc-rich primer. (This provides a porous and
flexible foundation for the subsequent paint layers).
- Immediately after 'plating', apply a yellow,
acid-etch primer coat, preferably a two-component pack. (Subsequent coats of
paint will not adhere to the zinc without the acid etch).
- Apply the
white finishing coat. This may be either sprayed or powder-coated;
both seem to be satisfactory, but it is not yet clear which is to be preferred.
Powder-coating should be of the polyester or acrylic type, but NOT epoxy
because that has less resistance to UV light.
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