Happy New Year!
To start off 2014, we are pleased to introduce you to an exciting new book on finishing by Charles Neil of Charles Neil Woodworking. I know that Charles is no stranger to you as he has been writing for us for over a year in his direct and distinct style. Having met Charles personally and shared thoughts and ideas on finishing I can tell you that he is knowledgeable, full of good information with many years of experience and a great style of communicating his skills.
In this issue we are happy to present an excerpt from Charles’ new book Finishing, Simply Put – No Chemistry Degree Required. We are providing a link to Charles’ website before the article, if you are interested in reading more. I must admit that I have learned a few things that I didn’t know after reading this new offering. You’ll learn about preparation, sanding, blotch control, bleaches, wood coloring, application techniques, types of finish and more.
At the end of 2013 I was answering some frequently asked questions about HVLP technology and promised to continue in the New Year. First as a refresher I’m providing the text from two previous newsletters (#141 and #142) and will then continue on to answer some additional frequently asked questions. This way, you have some of the most vital information about spray finishing in one feature length article.
If you have more questions that you would like me to write about, please feel free to contact me.
Again best wishes for a HAPPY NEW YEAR and all of us at Apollo Sprayers and TheFinishingStore.com wish you HAPPY FINISHING in 2014!
Stay tuned for many new things from APOLLO SPRAYERS HVLP throughout 2014.
Sr. Vice President, Sales & Marketing
Apollo Sprayers International, Inc.
Product of the Month: Apollo Blow-Off Tool
This simple device is getting more and more positive reviews from woodworkers. This genuine Apollo device directs turbine air to blow your work area clean. This handy tool can replace the air blow off tool that you use with your air compressor. The only difference is that this Air Tool runs from your turbine system so you will be assured of always having warm, dry air that is free from contamination like oil and water, typically found in many air compressor lines. Plus, you save on electricity by running a turbine instead of your air compressor. Great for blowing off parts when machining or dust during the finishing process as this picture demonstrates. An autobody repair specialist is using it to clean the panel he’s about to spray.
Frequently Asked Questions About Spray Finishing
by Bill Boxer
What I realize from the many conversations that I have been having are the common questions and the frequency with which the same questions come up. One in particular that occurred again yesterday was “how do you clean the spray gun?” While I can be funny and reply “with your hands,” I realize that most people perceive the task of cleaning a spray gun as ominous and as a barrier to buying this tremendously useful tool.
Let me assure those of you reading this who have had the same thoughts that cleaning your spray gun is far from the complexity that you perceive. You probably imagine disassembling and re-assembling a multitude of parts, flushing and cleaning all and taking a sizeable amount of time. Not so! Today’s HVLP spray guns, especially Apollo, are far simpler than conventional spray guns of the past. There are fewer parts, larger passageways, and overall they are easier to clean and manage.
In the case of Apollo, stainless steel is extensively used internally which makes cleanup even easier – especially with waterbase coatings. I would venture to guess that if you normally clean your paintbrushes properly, that the time consumed in cleaning a spray gun is no different, if not less than the time it takes to clean a paintbrush.
Another frequent question that comes up is “how do you adjust the viscosity of a coating for spray finishing?” Again there are many preconceived ideas that one must be a chemist to mix and adjust viscosity. Far from correct. Today, many products, especially waterbase coatings are formulated and ready to spray straight from the can. It couldn’t be easier than that. Simply stir, strain and pour into the spray gun cup and you’re ready to go.READ MORE
Finishing Feature Article by Charles Neil: Sanders Can Make a Difference
An excerpt from Charles Neil’s new book:Finishing, Simply Put – No Chemistry Degree Required which is available at: http://bit.ly/19nMZrK
Back in my autobody days we had what we referred to as a D. A. Sander. This stood for dual action. Today in the woodworking world we know them as random orbit sanders. I knew these worked extremely well on wood and used one in my workshop. I was glad to see them evolve into the woodworking industry. The random orbit sander has probably done more to cure sanding issues than any other single item I know of including increasing the speed of getting a sanding job done.
There are many sanders in various configurations and today they almost all use the random orbit technology. This is where the pad semi-oscillates in a random scratch pattern that is not discernible to the eye. How much scratch is seen depends on the grit and the stroke length, meaning sanders that have more of a vibrating action than a true oscillating action can leave visible scratches. READ MORE
Finishing Tip by Bob Flexner: Thin Coats vs. Thick, Which Is Better and Why?
It’s common to hear the instruction that it’s better to apply several thin coats than one thick one. Why is this so? Or is it?
What’s involved is drying time, nothing more. Thinner coats of all finishes dry faster than thicker coats. The difference is great enough that you can build the same thickness with several thin coats in less time than you can get that thickness with a thick coat. But the thick coat will eventually dry just as hard and perform just as well as many thin coats.
Shellac and lacquer dry entirely by solvent evaporation. The solvent evaporates much quicker from a thinly applied coat than from a thick coat because it takes much more time for the solvent at the bottom of the thick coat to work its way up through the finish and out into the air.
Varnish, including polyurethane varnish, dries by the crosslinking of the molecules in the presence of oxygen. It takes much longer for oxygen to work its way to the bottom of a thickly applied varnish than a thin varnish coat.
Water-based finish dries by both solvent evaporation and some crosslinking, so the result is the same. It takes much more time for a thick coat to dry than several thin coats.
Of course, oil finishes don’t dry hard at all, so coats must always be as thin as possible, accomplished by wiping off all the excess.
Finishing Tip by Bob Flexner: Correcting Stains from Rain Water Spots
If you transport unfinished wood or an unfinished wooden object through rain or sprinkling, the water drops will raise the grain, and wood stains will show up darker over these spots. The cause is the rough raised grain retaining more of the stain. The accompanying picture shows an example of what can happen.
There are two ways to avoid the spotty staining, both involving sanding (even if the wood has already been sanded). The first is to sand the wood thoroughly to remove the raised grain over the spots. The second is to wipe over all the wood with a wet cloth to wet it everywhere, then sand it smooth.
Because it’s hard to know how much sanding is necessary to cut deep enough to remove all the raised grain over the spots, the second method is actually the safer one because it creates an equal amount of raised grain everywhere. So even if you don’t sand enough to cut through all the water-damaged wood, the staining will still be even, maybe just a little darker.
Finishing Tip by Bob Flexner: How to Repair Dents and Gouges
Dents and gouges are both flaws in the wood. But they are not the same thing, so they should be repaired differently.
Dents are compressed wood. The wood fibers are still intact, just pressed down or indented. Gouges are also indentations, but the wood fibers have been torn and usually some of the wood has been removed.
Dents can usually be steamed level. Gouges have to be filled with wood putty or some other filling material. Sometimes the indentation is not clearly a dent or gouge, so you can try steaming before resorting to filling.
To steam out a dent, drip some water into the depression using an eyedropper or syringe. If the dent is shallow, the water may swell the wood enough to bring it level with the rest of the surface. If the water doesn’t work, drip some more water into the dent and cover the surface with a dry cloth. Then apply a medium hot iron to the cloth. The hot iron causes the water to turn to steam, which enters the wood and swells it. You can do this several times.
Whether using water or steam, sand the wood well after the moisture has dried out to eliminate any raised grain.
Because water raises the grain of wood, it’s best not to lay a wet cloth on a wide area of the wood, as is often recommended, before heating with the iron, because this will increase the amount of sanding necessary. It’s best to keep the wetted area as small as possible.