The Little Gadgets That Mean a Lot
This month Bill Perry’s article is in part about using a small, inexpensive, yet indispensable finishing tool, the mil gauge. A mil gauge simply measures wet film thickness, or the depth of the coating being applied. You might not realize how important this is, but Bill Perry’s article gives you all the details and the correct method for using a mil-gauge and also explains the importance of a viscosity cup.
All the talk these past few days about mil gauges reminded me of the importance of being precise, not only in woodworking but in other activities. My mom was a great cook, but she could never tell you what she did. It was a bunch of this or a shake of that and toss in some of that. Not exactly precise, never the same thing twice. What worked for my mom certainly didn’t work for me and I learned it the hard way.
When I approached developing film for the first time, I arrogantly thought I could just read the directions and who cares whether I’m precise or not, it will still come out ok. My flip attitude didn’t work. I created cloudy tones and unusable negatives. Lots of good photos were lost forever. As soon as I followed precise instructions for temperature, timing and mixture formulas, my balances, tones and eventually prints were excellent because I learned the virtue of being precise. Flying by the seat of your pants might be okay in some instances but it doesn’t work in developing film or in woodworking. Another place I needed to be absolutely precise was when regulating the action of a grand piano. The pianist strikes a key or several keys at once. It must take exactly the same amount of pressure to make each key hit the string at the same time or it is maddening to the pianist. The piano technician works hard to reach this precise point. This is done with precision tools and fine adjustments.
Successful woodworkers achieve great results when they are able to use their eyes, hands and precision tools. Precision tools comprise two components. To begin with they must be precisely made. There can’t be burrs on a blade or loose hairs on a brush, or a router table that wobbles. The metal must be the highest grade and machined to high tolerances. Then the tool must do its job consistently without breakdowns and constant starts and stops.
We certainly have come a long way since the first HVLP sprayers to the Apollo 835VR, and 1050VR Precision system. The amazing thing is that there are still some very happy customers out there using some of our earliest machines and getting results that please them. If they were to try our new machines they’d be ecstatic!
Finally, I want to leave you with some masterful inspiration. Here are two beautiful pieces by TheFinishingStore.com writers who are also master woodworkers. The glorious table is by Bill Perry.
Perhaps you remember Charles Neil’s Bombe Box which was auctioned off on EBay with the proceeds going to Wounded Warriors. Charles very generously gave one to my wife. It is exquisite and both she and I are very proud to have it in our house.
Sr. Vice President and COO
Apollo Sprayers International, Inc.
Finishing Feature Article by William Perry: Viscosity, Finish Thickness, and the Magic of the Wet Mil Gauge
Pro finishing shops maintain tight controls. Temperature, humidity, finish viscosity, air pressure, fluid volume, spray patterns – it’s a lot of factors that have to work together to produce the perfect finish, and measurement and control are the only ways to ensure a top quality result.
We tend to be a little more loosey-goosey in home shops. Controlling temperature can be a challenge in itself; as for humidity, we’re pretty much at the mercy of the elements. And while we may have to accept what Nature does, there are many elements of spray finishing that we can – and should – control if we’re looking for professional results.
Some are so basic that they shouldn’t need a mention, but they seem to just the same. One of these is proper lighting. Flat, featureless light veils all the details of the finish as it’s being applied. It’s a recipe for runs and sags. To see how the finish is behaving as you spray (or brush) it, you need low raking light across the surface of your workpiece, just like the lights they use at automotive paint shops. READ MORE
Product of the Month: Apollo Filter Stand
The Apollo Filter Stand is something that no spray finisher should be without. It is an extremely handy and simple device that will save you hours of clean up and keep your workbench clean and free from spills whenever you need to fill your spray gun coating containers. The Apollo Filter Stand makes filling your spraygun as precise as using the gun itself. You just place a filter cone into the filter holder, place a 1 quart or a 2 quart coating container underneath the filter cone and easily pour your favorite coating through the filter cone. The cone traps any unwanted particles, dirt or lumps. It not only prevents wasted hours of clean up from spills, but also filtering your material before filling your containers ensures that nothing will ever clog your favorite spray gun again.
Finishing Tip by Bob Flexner: Understanding the Resistance of Dyes to Fading
All dyes fade much faster than pigment when exposed to bright light—sunlight and fluorescent light being the worst culprits. But some types of dyes fade faster than others.
The worst for fading are the natural vegetable dyes, such as walnut husks and berries. These were sometimes used centuries ago, but they were replaced in the late nineteenth century by “aniline” dyes.
These are usually acid or basic dyes derived from various chemicals. They quickly replaced natural dyes in the textile industry and then entered the woodworking industry. They are available to woodworkers today in powder form to be dissolved in a solvent, usually water.
In the middle twentieth century a new class of chemical dyes, called “metalized” or “metal complex” was developed. These dyes are usually packaged in liquid form and are more fade resistant than the powder dyes, but the range and richness of colors is somewhat inferior. These dyes are often marketed as fade resistant.
The left dye in the photo is Transtint metalized dye. The right dye is Lockwood analine dye. Both are water-soluble. I covered the top half of the panel and put it in a west-facing window for six months. You can see that both dyes faded (on the lower areas) but the analine dye faded more than the metalized dye.
Finishing Tip by Bob Flexner: When Polyurethane Won’t Dry
If you experience oil-based polyurethane not drying well, it’s not likely that it’s bad polyurethane. It’s more likely that the wood you’re finishing contains a natural oil or you have applied an oil to the wood and the oil hasn’t dried.
In both cases we’re talking only about the first coat of polyurethane. After the first coat has dried, there shouldn’t be any further drying problems.
Most exotic woods (woods from jungle areas), with the exception of mahogany, contain a natural resin that is very oily. You can feel the oiliness. The mineral-spirits solvent in the polyurethane is also the solvent for the resin. So when you apply the polyurethane to the bare wood, the oily resin and the polyurethane mix and the oily resin retards the drying of the polyurethane.
The same explanation applies to the situation of applying polyurethane over linseed or other oil until that oil has totally dried.
If you have already applied the polyurethane and it isn’t drying, you can try applying heat—for example, from a heat lamp or blow dryer. It will speed the drying, just not very much. You may have to strip off the polyurethane with a strong solvent such as lacquer thinner or acetone, or with paint stripper, and start over.
Before applying polyurethane to an oily exotic wood, wipe over the surface with naphtha, lacquer thinner or acetone to remove the oiliness. Then apply the polyurethane right after the solvent dries.
Alternatively, apply a first coat of shellac to “seal in” the oily resin. Shellac will usually dry well on exotic woods.
If you have applied an oil to the wood, let it dry completely before applying the polyurethane. This may take a week or so in a warm room.