There are many ways to clear coat your project but if you have the time and plenty of elbow grease, a tung oil finish is hard to beat for achieving a deep clear luster, durability, repair-ability and ease of application. Follow these simple steps and I’m confident you will be happy with the results.
Sand, sand, then sand some more. Remember I mentioned elbow grease, you will need it now. I sand up to 320 grit with a random orbital sander then begin sanding by hand, finishing with 400.
Make sure all swirls and scratches have been removed by using a magnifier, I wear a Bausch and Lomb visor throughout the entire sanding process looking for hiding scratches. If you don’t get those scratches now, they will haunt you and become accentuated as you apply successive coats of oil and will be difficult to remove, you do not want to go backwards at this point. Once the sanding is finished, clean, buff and polish all surfaces with a soft, clean rag free of buttons, stitching or any other hard foreign matter that would scratch.
One could begin to apply tung oil at this point, I prefer applying a coat of wax free shellac prior to the oil to seal the wood. The first coat of oil over shellac looks like the third coat of oil over bare, raw wood, it’s a bit of a head start. Be very careful not to over apply the shellac, put it down and move on. Over applied areas can be carefully sanded level before applying the oil or stain. Apply in small areas and have a plan before you start the application. Once dry, sand lightly with 320 grit followed by very fine steel wool, then buff and polish.
Often times, there is color variation within the wood so at this point, I apply two coats of wiping stain to make the piece much more uniform in color. A shellacked surface is a wonderful sub surface for stain because it controls variation of stain absorption, making for a much more uniform finish. When completely dry, buff and polish.
Apply the first coat of tung oil with a soft clean rag, working in small areas. Wipe immediately, tung oil dries fast and will become sticky, remove all oil and allow to dry 24 hours before the next coat. Never put your project in the direct sun to dry, the oil will heat and expand, oozing out of the grain only to dry as little pimply bubbles. After every 3 coats or applications, stop and lightly sand with 400 grit and very fine steel wool to keep the surface smooth and level, then buff and polish with a smooth rag before the next coat. Don’t rush the applications, It’s very important to allow the oil to dry for 24 hours between coats to harden. The way the finish develops it’s wonderful deep sheen is by vigorous buffing and polishing between coats and the oil must be hard and dry, otherwise, it will scratch. By now, you should be using plenty of elbow grease and clean, soft rags.
The beauty of the tung oil finish is you can put down several coats and it will never cloud but only become deeper, 10 or more coats and a couple of weeks is not uncommon.
Once you have achieved the desired depth and sheen, allow to cure for several days before applying two coats of wax. The main ingredients for a great tung oil finish is plenty of time and elbow grease.
It’s very important that you soften all machined or hand-planed wood edges before applying any film-building finish. The finish will peel away from sharp edges (as is shown in the example) if they aren’t rounded over a little.
It’s also a good idea to soften edges when using non-film-building oil finishes. Sharp edges dent easier than softened edges.
You can easily remove the sharpness from edges with several light passes using medium-grit sandpaper.
Recently, I was involved in a “Woodworking Throw-Down” on the Lumberjocks.com forums. In just a few days, I needed to create a table-top box to store remote controls and ‘stuff’ in.
So I pondered on it a bit, then settled on a “Bombe” style, with a contemporary flair, and maybe a little Asian influence. Not what most would expect from me, I do a lot of period work, but I also do a lot of contemporary, so this should be fun. I used 6/4 Tiger Maple and a piece of Curly Claro Walnut.
Now, the rest of the story. I had to get a “killer” finish on it. One of the things I have learned, while bold contrast can be very nice, sometimes something as simple as a “Blending Tone” of color that actually subdues the “stark” contrast can add a lot of elegance. I have Tiger Maple and Dark Curly Walnut, white and dark brown, a little more contrast that I wanted. Now, to tone things down a bit, I got some AquaTone “Golden Oak” stain (#100-02-04) as I know Golden Oak brings a softer and beautiful color to walnut, especially steamed walnut. The golden color helps to kill the purple tones and adds a nice amber tone. Walnut lightens as it ages, so the Golden Oak brings some of the “aged” colors in as well. It’s one of my favorite colors on walnut.
Now, what to do with the white Tiger Maple box. I didn‘t want to dye the curl. I want subtle. I opted to do a single coat of amber shellac which gave the curl a little boost and “pop”. Next was a light coat of Acrylacq, scuffed lightly with 600 grit (I didn’t want to risk cutting through the finish), then I used the Golden Oak as a glaze over the finish just to add some matching tone and subdue the stark white of the maple. I sealed the glaze with another coat of finish. When it dried, I wanted a little more so I glazed it again and I got exactly what I wanted. I stained the walnut in raw wood as would be normal, I then applied two more coats of finish. Scuffed with a 320 grit light sand in between and I had gotten the finish I was after. I sprayed the finish with the Apollo Atomizer and was able to lay out a “silk slick” finish.
In the contemporary world a lot of contrasting woods are used, I hope you can see and understand how a little toning and working with the finish can help you soothe the contrast to make a beautiful piece.
Paint and varnish removers sold in plastic containers contain the solvent n-methyl pyrrolidone (NMP) as the active ingredient. This solvent is relatively expensive, so manufacturers often mix in other solvents to reduce the cost. But it’s the NMP that does the majority of the work.
NMP has less solvent strength than the methylene chloride and the other solvents used in strippers sold in cans. Just the packaging, plastic vs. metal, tells you this. The reason NMP is still effective is that it evaporates extremely slowly, so it can remain wet on the paint or finish for days if necessary.
I find this paint stripper very easy to use when I’m not in a hurry. I just brush a thick layer of the stripper onto the surface and walk away for an afternoon, overnight, or longer if necessary, until I can take off all layers of the paint or finish at once.
The problem with this stripper is that some of the solvent remains in the wood for many days, and the solvent can affect the drying of the finish you apply. So, if you want to begin finishing within several days of the stripping, you need to dry out the NMP.
You could do this with heat, of course, but it is usually easier to simply wipe with denatured alcohol or lacquer thinner. Alcohol is less expensive and less toxic. Wipe several times with a damp cloth to dry off the surface. You can feel if you have succeeded; the wood will feel dry. You can also tell you haven’t succeeded if your sandpaper clogs up.
I spend a lot of my time as a professional painter fixing paint problems that were caused by people.
Sometimes their choice of paint was a problem. More often, the way they painted was the bigger problem.
If you paint at any kind of level, you likely understand that the proof is in the pudding when it comes to creating nice results. When you get really skilled at painting, it doesn’t matter whether you are spraying, rolling, brushing, or any combination thereof, the application method is just the medium – the thing standing between you and the result you seek. The goal is to be able to use whatever means at hand to get there.
Renaissance men in literature were revered for being “skilled in all ways of contending”, and the romantic in me
holds the art of finishing to that same standard.I am lucky to be able to work on all types of interior/exterior finishes and see how paint problems happen, and which ones cause failure. I enjoy the challenge of figuring out how to fix finish issues.
Working on exterior surfaces in the summer gives me the “bulldozer” perspective on painting. Exterior paints have to hold up to the elements, which is no small feat. While interior finishes are more Porsche than bulldozer. The sequencing of prep and painting for exterior trim is not all that different from interior, just different products. But, of course, product drives process. So while similar, everything is different.
Professionally, I am either taking finish off or putting it on most of the time. Each process comes with a sequence of steps requiring consistent habits to eliminate paint problems.
Overuse of caulking is a common paint problem.
What are paint problems?
On exterior surfaces, paint problems are those technical things that happen during application that prevent paint from remaining intact on the surface over time. Think flaking or peeling paint as obvious examples.
Interior finishes fail in different ways, and it is usually not the fault of the product, but rather the application process. Dramatic interior failures are rare, and more subjective.
If you take finishing seriously enough to continue chasing the dragon of perfection, then you might at times feel like anything short of perfection was a failure. And perfection is elusive.
Scott on an exterior paint removal project in 2014.
Number One Cause of Finish Failure…
Without doubt, the biggest way that people create paint problems that lead to finish failure is by over applying paint: putting too much on at once. It is counter intuitive, I know, and almost like some stubborn vestige of good old fashioned common sense. More paint will hold up better, right? In the old days of old products, sure. And again, regardless of your particular finishing discipline or interest, the same basic truths seem to hold.
As products continue to move toward EPA compliance, less is definitely more in the application of finish. Creating thinner layers can help with adhesion, but can make smooth lay down of product more difficult. In spraying, we refer to the thin coat build technique as “tack coats”. It is easier to get a thin coat of finish to adhere (hold) to a thin layer of itself than to get a heavy coat of the same finish to hang on the substrate. READ MORE in Newsletter
Here’s a frequently asked question. Do you really need to clean your spray gun every single time you use it? Do you need to clean it when you go to lunch? What if you are putting it away for a week? Which coatings mean clean “right away?” Here’s the scoop: always clean your gun immediately if you are spraying a quick set up coating such as a two part urethane or epoxy paint.
Clean it even if you are going to lunch. If you are using a pigmented coating and are finished with that color, clean the spray gun. If you are going from a water based coating to a solvent based, or the other way round, clean the spray gun. Other coatings can wait until you are finished for the day. Some finishers keep 2 or more spray guns and dedicate each one to a particular coating, such as water based or solvent, pigmented or clear, 2 part or simple.
Bill Boxer: This week I am going to go over all my spray guns to make sure everything is in order. Here’s what I do:
Here’s how I prepare my spray guns on a regular basis:
- First, I test the spray guns for pattern accuracy to make sure the spray pattern is even from top to bottom.
- If it is heavier on one side or another, I rotate the air cap. If the problem moves to the opposite side, the first thing I do is thoroughly clean the air cap with spray gun cleaner and my cleaning kit brushes. Generally the problem is solved.
- If the problem persists, I look at the nozzle and needle assembly. Again, I clean with my spray gun cleaner and brushes. If that’s not the solution, it’s time to replace the nozzle and needle.
- Next, I lubricate all the threads with Spray Gun Lubricant.
- I check the gaskets and replace if necessary. Then my spray gun is good to go.
- At this time I also make sure I have a supply of cup gaskets, and non return valves.
Nothing is as frustrating as being shut down for such a simple problems.
The vast majority of hobbyist woodworkers, and quite a few professional woodworkers – who might only complete a project or two a month – do their finishing with brush or rag. However, as you begin to undertake more projects, or you move to larger carcass work, it’s natural to start thinking about spray finishing.
There are at least three good reasons for considering a switch to spray finishing. First, it’s surprisingly easy to achieve a near perfect finish with spraying. With practice, you’ll be able to apply the finish evenly and uniformly in a lot less time than you would by brush. Second, because a spray finish goes on thinner than a brushed finish, it dries fairly quickly. Dust doesn’t have much time to contaminate the surface, and you can apply any follow-up coats that much sooner. Third, because spray finishes are fast and easy to apply, you can spend more time building projects rather than finishing them.
A spray finishing system consists of two devices that work in tandem – a continuous source of pressurized air, and a gun that atomizes the finish and delivers it in a controlled pattern onto the work surface. Since the advent of spray finishing, air compressors have provided the necessary source of pressurized air. The compressor forces air at high pressure into the spray gun, which atomizes the finish and projects it at high pressure (upwards of 60 or 70 PSI) onto the work surface. The drawback is that, because of the high pressure, only about 30 percent of the finish lands on the work surface. Most of the finish either bounces back from the surface or ends up sprayed around the work surface. Quite a bit of that wasted finish material ends up vented into the atmosphere.
High Volume Low Pressure (HVLP) systems significantly reduce the problem of over spray and bounce back. They rely on a high volume of air at a low pressure (a maximum of 10 PSI) to transfer upwards of 80 percent of the finish onto the work surface, which is better for your pocket book, and the environment. And, because the air is travelling at a low velocity it’s a lot easier to control the spray.
There are two types of HVLP systems. If you have an air compressor you can purchase an HVLP spray gun that runs off the compressor (these are referred to as ‘conversion spray guns’). Because these spray guns require a lot of air you’ll want to use a compressor in the 5 HP, 60-gallon range, and with an 80 percent or higher duty cycle, otherwise the compressor is going to by constantly cycling on and off.
If you don’t have a compressor, consider purchasing a turbine HVLP. The turbine is somewhat like a mini compressor, except that it delivers a consistent high volume of air at low pressure to the spray gun. Turbines also warm and dry the pressurized air, which helps the applied finish cure more quickly. As well, turbines are very small, so they can be easily stored or moved from one location to another. You’ll find that turbines are rated by the number of fans (called ‘stages’) they contain. The more stages, the greater the volume of air and pressure the turbine can deliver, and the wider the viscosity range of the finish you can use without having to thin the finish.
Ready-to-spray water based finishes are ideal for use with HVLP systems in small shops because, unlike solvent based finishes, they are non-flammable and non-combustible, and they contain fewer environmentally hazardous materials. As well, they’re practically odourless. These finishes have great clarity as they don’t have the typical amber cast that you get with solvent based finishes. And, cleaning up your gear at the end of the finishing session is relatively easy. You do, though, need to pay somewhat more attention to temperature and humidity with water based finishes than you would with solvent based finishes.
Even though water based finishes might be considered ‘friendly’ finishes, you’ll still need to use some kind of spray booth, provide adequate ventilation, and wear an appropriate respirator rated for organic compounds. For small shops, a free-standing knock-down booth is a good choice for spraying large projects. Duct tape pieces of heavy cardboard (appliance boxes work well) or coreplast together for the body of the booth. This makes it easy to quickly set up the booth when needed, and then fold it up and store it between uses. A small, bench top booth is handy when you want to spray smaller pieces. As an alternative to cardboard you could also use plastic sheeting. Set up the booth the night before so that dust has time to settle down before you being spraying. And, for the best results it’s important to illuminate what you’re spraying, so that you can differentiate between wet and dry areas. Instead of overhead lights, use free-standing lights that you can raise, lower, or angle to better illuminate the work. A simple shop made turntable is also invaluable for rotating your work so that you can spray all sides.
If you’re at the point where finishing your projects with a brush is beginning to take too much shop time, then you really should think about spray finishing. A good place to start is one of the better books on the topic, such as “Spray Finishing Made Simple” by Jeff Jewitt, or “Spray Finishing” by Andy Charron. Once you’ve made the plunge, spend the time to get acquainted with the spray system, and practice until you’re satisfied with your results before you commit to a first project. The time you invest in learning about the equipment and practicing with it, will pay huge dividends in the long term.
IWF 2016 is the largest showcase of machinery, supplies and services in the Western Hemisphere for woodworking. There are thousands of products and innovations displayed and demonstrated live. It’s by far the most exciting event for woodworkers. August 25th we are hosting a special guest in our booth #5453.
Master woodworker and television star, Chip Wade will meet and greet, sign autographs, and be photographed with our woodworkers from 10-12pm. Chip has appeared on HGTV’s Curb Appeal, The Block, HGTV’s Showdown, HGTV’s Design Star, HGTV’s Elbow Room, Ellen’s Design Challenge, Oprah, and CNN. Attendees who come to our booth and wish us “Happy Birthday” will receive a free Blow Off Tool.
Directions on cans of paint-and-varnish remover instruct to “neutralize” the stripper as a final step. This is misleading and often leads to finishing problems.
The instruction is misleading because there is nothing in paint strippers that needs to be neutralized. “Neutralizing” refers to acids and bases, not solvents.
What needs to be done with all paint strippers sold in metal cans is remove the wax they contain. Manufacturers add wax to these products to retard evaporation so the stripper remains in contact with the paint or finish longer. This wax will retard the drying and weaken the bonding of most finishes. You should wash off the wax before applying a finish.
Washing is different from neutralizing. Washing means thoroughly wetting and drying off the surface several times. Neutralizing means just wiping over the surface with a damp cloth that is acidic or alkaline.
You can use any number of solvents to wash off the wax residue, but mineral spirits (paint thinner) is the least expensive, stays wet on the surface longer and is just as effective, or even more so, than naphtha, denatured alcohol or lacquer thinner.
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.
Essentials for Every Woodworker, Novice or Master Woodworker
ECO5 ECO-LOGICAL, ECO-NOMICAL TURBINE SYSTEM Efficient 5 stage turbine
Blow Off Tool In Action
Zhan Viscosity Cup