This blog is a “how to” or “informational page” on the different products used to seal/finish fine art. It is written in part (ok, mostly) by Todd as he’s the expert in our household on this subject. Todd also creates and preps most of the boards that I burn on (yes, I’m a very lucky person), so not only will he discuss sealing the wood, but he’ll mention prepping the wood for optimal burning. Without further ado…
Last updated July 2019
Considerations on Finishing Wood
When I say finish the wood, by that I mean to seal it. You are attempting to protect it against water (spilled or just humidity), oils (from your fingers or anyone else’s fingers who picks it up to look at it), and dirt that can accumulate and then get ground in when touched; giving it a dingy look.
Also, sealant provide a barrier to keep moisture levels constant in the wood. This prevents moisture loss/addition which can cause the wood to contract/expand. This can cause wood buckling, warping, or cracking.
Even though you seal the wood, remember that this is not bullet proof armor you will be putting on, so you must still treat it with respect. You can still scratch it, dent it, break it, etc.
Next warning: there is no “best” finish. The finish is dependent on the project. For example, I finish a cutting board very different than I do wall art.
TIPS ON PREPPING THE WOOD BEFORE BURNING:
Before we get started on finishing the wood, I’d better throw in a quick word about prepping the wood before you burn. I always sand my blanks down to at least 220 (grit sandpaper). I then take a bowl of water and a rag and wet down the wood thoroughly and let it dry. I do this to raise the nap of the wood. I then sand it down again to 220. Depending on the wood, I might do this twice. Woods like Basswood, Poplar, and Maple need a single wetting and sanding. Others, like Oak, Hickory, or Cedar, I would probably do twice. The reason you’re doing this is because, when you put your finish on, it’s wet and that will raise the nap, so you will then have to sand it to get it smooth. I find it objectionable to sand over finished artwork, therefore I try to get that all done before the wood is burned on in the first place.
So, here are a few of the most commonly used and available finishing products today – without having to mix your own. I will cover each one and give its advantages and disadvantages as I see them. I’ve used them all, including doing nothing to the wood and can give a firsthand account of how that worked out over time.
FOREWORD – a quick word about ALL finishes/sealants.
1) Never dip your brush directly into the can of sealant/finish because you can contaminate the product. Some woods, like padauk, will leach color, so the brush will pick up that color. You don’t want your finish/sealant to be tinted red, so always put a small amount of sealant into a bowl, mason jar, etc for use. Another common source of contamination is stained or dyed wood.
2) Also, all of these – excepting oil finishes and doing nothing to the wood, will require that you have a space that is warm enough to apply the finish to the wood. Read the container, but essentially, if should be about 70 degrees Fahrenheit (21.1 celsius). If it is not at least that warm the finish will either not set right or will set so slowly, glaciers will be passing it by.
Also, if you take a cold can of finish out and start to use it in a warm room, you will most likely get bubbles in the finish as it warms up. There were bubbles in there you couldn’t see and when they warm they expand and poof – there they are ruining your nice finish. Warm up your can of finish first and warm up your wood too!
3) Apply the finishes in a well ventilated area. Some of them are very strong smelling and the fumes can be irritating on the lungs.
4) Always apply at least 3 thin coats of finish. You will get much better results than trying to apply 1 thick coat.
5) NEVER mix your finishes! The chemical properties of the different finish are not always compatible with each other, so mixing finishes can ruin the finish or prevent it from curing properly. If you start out with a lacquer, you finish with a lacquer. If you start with a polyurethane, then you finish with polyurethane.
SPRAY ON VS BRUSH ON
Should you spray on or brush on the finish? It really doesn’t matter unless you have applied color to your work.
If you have applied color, then use spray on finish for the first couple of layers. You can follow up with a brush on, but make sure it’s the same type of finish.
Spray on is a lot more convenient, but a bottle of spray cost more than a jar of brush on finish. Between the wood working I do and Brenda’s pyrography, we go through a lot of finish, so purchasing jars of finish is more economical for us. A standard 12 oz can of Lacquer costs around $10 and will cover approximately 3-4 art projects. Whereas a gallon can of lacquer costs a little under $30 and will easily cover 20 projects.
If you use a spray on finish, make sure to spray in uniform passes. Keep your pace steady as you move across the board. Start spraying just BEFORE reaching the board and continue to spray just after passing the edge of the board. This ensures you don’t get pools of finish along the borders of the wood, or, put another way, the layer of finish is uniform across the entire board.
DIFFERENT FINISHES TESTED
- Nothing – raw wood
- Lacquer – Brush On, Spray On; with Lacquer Thinner
- Mod Podge (hard coat) – brush on
- Oil only – Mineral Oil, Tung Oil, Walnut Oil, etc.
- Polycrylic – Brush on
- Polyurethane – Brush On, Spray On
- Shellac – Brush On, Spray On
- Spar Urethane – Brush On, Spray On
- Tru Oil – brush on
I will start the discussion with nothing, because nothing is the easiest thing to do. Once you’re done burning the wood, you simply hang it on the wall, or prop it up on a table if you like; whatever works for you.
When to use: I don’t recommend doing nothing!
- Time saved; which can be several hours of work depending on size, type of finish/sealant, and the number of coats you need/want to put on.
- If anyone picks it up to look at it, the oils and anything else (like hand lotion) on that person’s fingers/hands will transfer to the wood and penetrate it which means that you can’t just wipe it off.
- It is more prone to moisture loss/addition which can cause the wood to contract/expand. This can cause wood buckling, warping, or cracking. Sealing the wood provides a barrier to keep its moisture levels more constant to help prevent the aforementioned problems.
Lacquer offers a tough, durable finish. It can age over time, but is fairly easy to repair without sanding down the wood. Lacquer can be sprayed or brushed on. It can be thinned down with Lacquer Thinner to the consistency you desire. It comes in satin, gloss, or high gloss.
When to use: This is a great finish for musical instruments and artwork. Note that it is not good in high moisture situations like a coasters.
To Apply: I recommend thinning the lacquer with lacquer thinner for the first coat; about 50/50. It flows better and dries faster. Then go to full strength. As with all sealants, use in a well ventilated area. Allow to dry a minimum of 30 minutes between coats. When applying additional coats, do not pour on and then brush out. Any lacquer that sits in a pool will soften/dissolve the previous layer and make your finish pitted and uneven.
Note that as of March 2019 Lacquer continues to be our favorite finish for Brenda’s pyrography.
- Tough finish.
- You can polish this finish after it hardens.
- It requires no sanding between coats.
- It does not discolor the wood as much as other products like shellac or polyurethane do.
- Has the fastest dry time.
- Does not have hardeners in the mix, so cans and jars of lacquer will never dry out or become a solid mass like other finishes will.
- If you thin the lacquer, it flows better and the coats dry more quickly.
- It will not stand up to thinner being spilled on it even after it’s dried.
- Lacquer has quite a strong smell and requires a space with good ventilation. (Brenda here – to me lacquer is nowhere as stinky as polyurethane and for some reason the smell reminds me of dill pickles).
- It will take three or more coats to get a good solid finish.
- When thinned it is very wet and if you haven’t raised the nap of the wood and then sanded it back down, you’ll wish you had.
MOD PODGE (hard coat)
When to use: In crafting situations where you want to decoupage a photo onto the wood.
To Apply: Brush on a thin coat and let dry 15-20 minutes. Sand with 400 grit sandpaper between coats. Apply 3-5 coats total. Fully cured in 4 weeks.
- Tough finish.
- Cleans up with water
- Doesn’t have a strong odor (Brenda here – it reminds me of Elmer’s glue mixed with acrylic paint)
- Need to lightly sand between coats.
- Unsure about how well the finish will age, but we are testing it.
- Takes 4 weeks to fully cure. That’s a long time!
By oil only, I am referring to products like tung oil, mineral oil, lemon oil, walnut oil, etc. These are mostly for things like cutting boards to keep the wood moisturized and to prevent water from penetrating the wood that would causing it to warp, swell, or crack (this is mostly on end grain cutting boards, but you get the idea).
WHEN TO USE: Cutting boards and other items that are in contact with food and/or items that be will exposed to extremely high heats. Food grade mineral oil is what I use to treat cutting boards and trivets with. Mineral oil doesn’t get rancid and won’t react with food. Plus it can withstand very high heat without damage. I’ve taken a pan out of a 450 degree oven and placed it on a oil coated trivet with no problems.
To Apply: pour a generous amount onto the wood and rub it it. Let it sit for several hours and then apply another coat. Continue until the wood quits absorbing the oil. Once or twice a year re-apply to keep the wood protected.
- Easy to apply
- Easy to reapply when you need a touch up
- Minimal smell
- The wood isn’t really sealed as additional oils can and will penetrate given the opportunity. Again this oil can be from an unintentional source like greasy hands.
- Dirt and dust will accumulate on it and because the oil is a “wet” finish it will stick.
- Oils don’t quickly dry out, but they do need to be reapplied to keep up the protection level.
- A mineral oil finish is one of the better choices for projects like trivets that will be subjected to high heat. I’ve taken pans straight out of the oven at 400F (204.4 celsius) and placed them on the trivet without experiencing any problems like wood discoloration, etc.
Polycrylic provides a clear tough finish that is water resistant, so can be used for coasters.
When to use: This can be used for all indoor applications, and is a great choice for coasters. I wouldn’t recommend it for items that come in contact with food; especially cutting board.
To Apply: Brush on a thin layer and let dry a minimum of 2 hours. Sand lightly and then brush on another coat. Continue this process until you reach the number of desired coats.
- Tough finish.
- Comes in a variety of finishes from matte to glossy.
- Cleans up with water
- Doesn’t have a strong odor (Brenda here – it reminds me of Elmers white glue)
- It is water resistant. (Brenda here – I did a test by placing a wet glass on it for several hours. Then I removed the glass and let the water ring dry on its own. After it was dry I couldn’t tell where the glass has been. Also I put a coffee cup filled with boiling water and let that sit for several hours. Again, it did nothing to the finish).
- We couldn’t tell the difference between wood treated with this and lacquer by just looking at it. If you touch it they have a texture difference as the polycrylic has a slight plastic feel.
- Need to lightly sand between coats.
- Unsure about how well the finish will age. We have a test piece sitting in a window to age in the sun, so will follow up later on how polycrylic ages.
- Makes the wood feel like it is coated with plastic and Brenda doesn’t care for that.
This is a plastic in the form of a liquid that goes on either brushed or sprayed and then dries to a solid firm coat. There are basically two forms – water based and oil based. Oil based is slightly tougher than the water based. I don’t worry a lot about toughness in a finish on artwork, usually, as I find it mostly stays indoors and on a well, but if the piece is going to get handled, then polyurethane good option if you don’t mind that it adds a yellow hue to the wood.
When to use: This finished will handle tough treatment and resist moisture better than lacquer, so it is good for furniture. Note that it adds a yellow hue to the wood that in some applications this is desirable. If the yellow hue is undesired, then use Polycrylic instead.
To Apply: in a WELL ventilated area, brush on a thin coat, and let dry 3-4 hours. Lightly sand (220 grit), apply a second coat, and let dry 3-4 hours. repeat. I typically apply 3 coats to a project.
- Tough finish
- long lasting,
- Easy to apply, but needs sanding between each coat.
- Comes in several varieties: matte, semi-gloss, gloss, and high gloss.
- Can be sprayed on or brushed on, whichever you prefer.
- Oil based handles heat better than water based.
- Water based finish has significantly less odor when applying.
- Water based doesn’t handle high heat well, so don’t use it for the finish on your coasters, trivets, or anything that receives what’s coming out of a hot oven or stove top as it will discolor.
- You have to sand between each coat; not much but it must be scuffed or the next coat will not bond properly.
- Oil based will add a bit of a yellow hue to the piece you are applying it to. Water will too, but not as much.
- Also oil based has quite a strong smell and you must have a large enough room with good ventilation to be working with this. (Brenda here – this stuff STINKS…a lot)
- Has a very noticeable yellow hue to it.
When to use: I have used this for woodworking (jewelry boxes), but I no longer use it. Also, it can be used on items for food, but make sure it is completely cured before using the items. I would not recommend it on cutting boards.
To Apply: In a well ventilated area apply a thin layer and let dry a minimum of 45 minutes. Then brush on another coat. Do not pour on additional layers and brush out as any pooled shellac. Otherwise it will dissolve/soften previous coats resulting in a pitted uneven finish.
- Easy to apply
- Food safe once fully cured
- Will discolor under heat and it imparts a tan or yellow hue to the wood.
- Not nearly as “aromatic” as polyurethane or spar urethane. (Brenda here – can’t comment on the stench factor as I’m not sure. Todd offered to let me sniff, but I declined)
This is a tougher form of Polyurethane with more solids in it and is consequently more durable. It is used primarily for outdoor wood or wood that will be left around the water. Same rules apply for putting it on as the polyurethane; sanding required between coats. Can be brushed or sprayed on as preferred.
When to use: If you want something for outdoor use (signs, tables, etc.,) then this is your product. Make sure to purchase the type for outdoor use (the picture shows the can show for indoor use).
To Apply: this works just like the polyurethane. In a very well ventilated area apply a light coat and let dry 3-4 hours. Lightly sand (220 grit), apply another coat, and let dry 3-4 hours. Repeat. Outdoor items need a minimum of 3 coats. Let sit for a minimum of 24 hours after last coat before placing outdoors.
- About as tough a coat as you can get although poured epoxy might be tougher.
- It is the only type finish/sealant recommended for outdoor use.
- Will really yellow up your wood, however, if that’s an effect you want, based on your subject matter, composition, or preference, it can be an advantage.
- Has quite a strong smell and you must have a large enough room with good ventilation to be working with this product. (Brenda here – this means that this stuff is really, really stinky)
TRU-OIL (birchwood casey)
Tru-oil is designed to provide a protective finish to gunstocks. There is also a version for guitars. Easy to apply, but extremely stinky in my opinion (brenda here). The oil is a “blend of linseed and natural oils.” Can be buffed to achieve a luster finished.
When to use: I don’t use this product and have no experience with it. It is a favorite for those who refinish gun stocks, but note that it imparts a yellow hue to the wood.
To Apply: Pour oil directly from bottle onto properly prepared wood surface in a well ventilated area. Spread evenly with the grain and allow to thoroughly dry. Buff lightly with 00 steel wool between coats. Repeat until desired finish is achieved.
- Very easy to apply
- Need to lightly sand/buff between coats.
- Adds a tan/yellow color to the wood
- Is a touch smelly. (Brenda here – this was the nastiest smelling stuff! It smelled worse to me than any of the other finishes and I can’t even put into words what the foul smell reminded me of).
Sealing Wood with Color Pencil Work
October 2017 –
We’ve learned the hard way that color pencil will smear when lacquer is brushed on. To prevent this from happening use a spray on finish. Apply 3 layers of spray on and then you can switch back to brush on (if you so desired).
Make sure to use the same type of finish for both spraying and brushing on.
THE TIME TEST
The below latest edition to the test panel was added on March 28th, 2019
March 2019 – All of the finishes have been on the board for over a year now, except the TruOil (applied July 2018 instead of Feb).
Lacquer and Polycrylic are remaining the best for staying clear. The Mod Podge had been the clearest of the sealants, but it has now yellowed to the point where I think it’s darker than the Lacquer or the Polycrylic.
The test colors along the left of each panel have remained vibrant and don’t show signs of fading. Most of the panels have one or two colors that bled a little during the initial application of sealant, but remember that all of the sealants were brushed on. Spraying on the finish avoids this problem.
In this photo I’m holding the board to angle it towards the sun in an effort to show the sheen of the different finishes. (this photo does not have the TruOil on it)
Our Preference for Fine art is Lacquer
Lacquer is our sealant of choice as it doesn’t discolor the wood as much as the other sealants, it has a short cure time, it has a matte or satin finish, and it doesn’t have a plastic feel to it like the Polycrylic does.
Todd uses a 2” wide brush to apply. The first coat is a 50/50 mixture of thinner and lacquer. Subsequent coats are full strength lacquer. Most of my pyrography art is sealed with 5 coats, but some items that get more handling (like flutes) receive more coats.
As mentioned before, lacquer is rather smelly so use in a well ventilated area.
Todd has found that it’s easiest to keep three mason jars filled with different solutions of Lacquer or thinner on hand. The glass jars don’t rust out, the wide mouths easily fit the brushes, and he can write the mixture on the top. Another advantage is if a jar gets contaminated, only a little amount of the product is lost.
In the photo you can see the 3 jars; The first one is full strength lacquer, the middle is half strength lacquer (50/50 mixture of lacquer and lacquer thinner), and the last one is filled with all lacquer thinner. The white stuff at the bottom of the lacquer thinner jar is lacquer that has settled to the bottom after I clean the brush. Eventually the thinner jar will get enough lacquer residue in it, that it gets poured into the 50/50 mix jar and I start over with fresh lacquer thinner.
Lacquer = Fine art & musical instruments
Mineral Oil = Cutting boards & trivets
Polycrylic = Coasters. Can use it for fine art, but it does have a plastic feel which Brenda doesn’t like.
Spar Urethane = Outdoor applications (signs, furniture)
Modge Podge, Polyurethane, Shellac, & Tru Oil = We don’t use. Not to say they are bad products, but we prefer to use one of the above finishes instead.
That’s it for this blog. Hope it answered some questions and helps you with your projects.
Todd & Brenda
January 2016 (original posting)
Last updated July 2019