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 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 topcoat.
The condition of the hoops when presented for refurbishing 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.