This is part two of the article; please read part #1 before you continue. Thanks.
Under Coat Problems
If the oil base stain and the paste wood-fillers are not completely dry before the lacquer goes on, it may look at first as if you are getting away with it. All will be well, but then a day, or a week, or a month, or a year later, you may notice a distinct greying of the lacquer which gets worse and worse and worse as time passes. This is called blooming.
Blooming takes place through the whole thickness of the finish coat. It can only be corrected by complete stripping and refinishing. Earl Stebbens, a finisher I used to know, told me that it happens because the oils are able to slowly penetrate the molecular matrix of the lacquer, turning it grey. Leave plenty of drying time for your stains and fillers.
The worst thing that ever happened to a good finish was lemon pledge. This and other spray polishes containing silicone make the furniture shiny and not smudgy. They make it glow and radiate warmth. Unfortunately, they also turn the lacquer to jelly within ten to fifteen years of regular use. They cut the life of a good finish in half, or even to a third of normal. They are the scourge and torment of every good re-finisher, because they settle into the wood. Stripper won’t touch them, sanding won’t remove them, they cause fisheeye. This is a situation where the lacquer simply flows away from spots on the wood surface like water off a duck’s back and will not stick there no matter how many coats of finish are sprayed. The result is a miniature moonscape of craters – a ruined finish.
There is a product called ‘Smoothie’ which can be added to a lacquer mix to make the lacquer flow and stick to a silicone surface. It must be added to every coat of finish, or the trouble recurs. If you see fisheye forming as you spray, you can race across the shop, pump a double shot of ‘Smoothie’ into a cup, race back and shoot an extra heavy coat of lacquer over the offensive spot, and if you have moved quickly enough, often the problem will go away. But not always. Then it’s back to stripping and starting over.
When I receive for refinishing a piece of furniture with a gummy, sticky finish, I say to myself “Ah, the dreaded Silicone Syndrome” and I plan to use ‘Smoothie’ in every cup of the new finish.
‘Smoothie’ does have one drawback. It weakens the lacquer somewhat, and the finish won’t last as long as one without it. But at least a finish can be done.
I go forth preaching the gospel of silicone free polish to my clients. I recommend lemon oil to most; lemon oil is simply mineral oil with lemon scent. It does no damage to the wood or finish. For some things where more gloss is desired, paste wax can be used. Just see to it that all of the old wax is cleaned off with mineral spirits or naphta before new wax is applied, so that dirt, smoke and acids, etc. will not be trapped next to the finish where they can do damage.
A sound lacquer finish is impervious to water, alcohol, turpentine, paint thinner, naphta, oil, baby food, and warm dinner plates. Many times I have come into the home of a client whose table has white rings on the finish caused by a wet cup or a warm plate on an otherwise sound finish. In these instances I put on my most professional attitude and ask for a tube of toothpaste and a damp paper towel. These opaque white rings are almost always in the surface layer of wax or polish only, and the mild abrasive in the toothpaste will clean them right off. The client is thrilled at saving the cost of a refinishing table top. Modestly I accept the praise I get for being so clever, and usually I get a lot more work from the client through the years.
Be careful, though. An old finish, cracked lacquer, schellac, old varnish and the like are impervious to nothing. Alcohol, water, turpentine, etc. can do damage to the wood, so test first on a hidden spot before you try to clean wax off with anything, just to be safe.
In an upcoming article, I will talk about different kinds of lacquers and how to mix them. Thank you for reading.