Although Incralac is designed for protecting Copper & Alloys, it appears people use it for gold (military) medals and sports medals etc..... (is gold considered in the alloy family?, dunno).
Wattyl Incralac (at most hardware shop) seems to be the most popular one to use.
Make sure the item is VERY clean, polished and then cleaned with alcohol or something to eliminate all finger acids & blemishes.
Typically you dip the item into a bowl of incralac, then hang the item to drain off & dry over 24 hours.
You don't need to 'thin' the lacquer, but if you do 'thin it' you may see rainbows appear on the surface if it's thinned too much.
Rainbows also appear if the room temp is too low. Incralac doesnt like a cold room.
( if rainbows occur, acetone will remove the lacquer and try again ).
On the other side of the coin, dont hang your item near a heater, it'll either combust (incrac is VERY flammable) and/or your coating may distort & bubble due to the harsh heat........
You might consider (now in this colder weather) to make sure the heater is on the opposite side of the room from where your item is hanging.
There's plenty of Incralac data sheets out there, well worth a read.
MM.