I have been experimenting on cleaning and removing old varnish from dials where the varnish has discoloured and then applying new varnish to protect the raw surface.
The dial before treatment.I heat up water to boiling pointI then soak the dial.The varnish is partly dissolved after soaking. I now use a soft sponge to wipe of the remaining varnish. It is very important to be careful over the lettering. I blow-dry the dial and inspect it. The dial still has some old varnish around the markers that I clean off with wet pegwood. I use quick drying water based varnish that I dilute to the consistency of milk.Airbrush kit for models is perfect for this jobEverything ready for spraying.I now have a dial ready for varnishing and I spray the dial with as little varnish as possible so not to make it run. Too little varnish gives a bad, uneven result.And the finished result with new luminous compound applied. This looks too good to be true! Problems that can occur are loss of print. Below are some before and after picturesDial looks very dirty with lots of dust that has melted in to the varnish somehow.The C and V are lost and so are parts of swiss made, but no markers are damaged. The dial besides the letters looks great with some patina of the good kind still showing.Before brown varnish that really is beyond your usual patina.Some of the lettering is damaged from a mistake of cleaning off dust with rodiko – something I won’t do again! Besides that the watch looks much better than before. The dial looks terrible with brown rust pitting all over from water damageThe letters where printed on the varnish and unfortunately fell off with no effort during cleaning. The pitting did not go away in water but after being soaked in vinegar was cleaned off. All is not lost since the dial can still be sent to be restored with a dial specialist.Not a nice finish at all where the watch looks dirty and cracked.No damage to print and looking very fresh and nice.Very dirty looking dial that otherwise would be restored.No damage to print and a nice feel of age.
My conclusion is if you have a dial with gunk beyond what you can tolerate as patina then it is worth trying this rather than a full restoration. The finished result is very nice and is much more authentic than full restoration. If you are already planning on restoring the dial you might as well try and clean first as you have everything to gain and nothing to loose;)