One of the most frequently asked questions we receive deals with substrates. As craft and hobby vinyl enthusiasts discover the appeal of rustic substrates, we receive more questions about putting vinyl on wood blanks. Many people call asking why their vinyl won't stick to the wood and assume there's a defect with the vinyl. As the old Porgy and Bess song says, "It ain't necessarily so". When vinyl doesn't stick to wood, the problem is usually with the wood. But there are ways to make it work and things to avoid.
Wood is not the best choice for Vinyl
Actually unsealed wood, plywood and even painted plywood are not good substrates for vinyl. Vinyl is an adhesive backed film that is expected to last for years outdoors in all kinds of weather. To achieve that longevity, the adhesive must have a firm bond with the substrate. This requires the use of very smooth substrates like glass, corrugated plastic, foam core, and painted aluminum.
Rough surfaces like unfinished wood will not provide a sufficient bond with the adhesives used on vinyl films. The vinyl may stick initially, but sooner or later (probably sooner), it's going to come off.
For long term outdoor graphics, the smooth substrates mentioned above are the best choice. For larger graphics, heavier substrates are required. The most compatible options will be aluminum composite materials. These products are comprised of a sheet of aluminum laminated to a thick, flex resistant core made of a corrugated composite or plastic product. There are different trade names for these, but if you look for Alumacore, Alumalite, or DIBOND®, you’ll be able to find a reliable substrate for long term outdoor signage. MDO plywood composite is also a commonly used sign substrate. But If you choose MDO, please make sure it’s properly prepared and painted. If you absolutely must use unsealed wood for your vinyl graphics, keepsake, or bit of rustic restaurant decor, sand it first to get it as smooth as possible. Give the vinyl a fighting chance.
How to Make it Work Better
Another question we hear often is about what kind of painted substrates are suitable. There are two things to watch out for; porous paints that won't make a good seal with the adhesive, and uncured paint. The best paints to use are those developed for sign making, like 1 Shot brand. If you can't find One Shot, try an enamel paint. Make sure if you're putting vinyl on any painted surface that the paint is completely cured. Fresh paint emits VOCs (volatile organic compounds) that may react chemically with the vinyl's adhesive and degrade it. This can cause adhesive failure after application. Trapped VOCs can also cause bubbles to appear under the vinyl. This is often a precursor for eventual adhesive failure.
For more tips about suitable substrates, visit ORACAL.com and read the FAQ. There are differences in the performance of acrylic and solvent-based adhesives that can affect adhesion to non-standard substrates. You can read the full story in our Adhesives 101 article, but the short summary is this.
Solvent based adhesives are a little more effective on porous or less than ideal surfaces like wood and stainless steel. If you're having trouble, try a different kind of vinyl, or purchase one with a solvent-based adhesive to give yourself the best chance of success.
Even when you have everything right, sometimes the challenges of the porous substrate make it hard for the vinyl's adhesive to bond or 'wet out' quickly. Sometimes when you remove the transfer tape, the letter come up with it. This is not necessarily a sign of failure. Some adhesives take more time to bond. This is more common with acrylic adhesives. Use good firm squeegee pressure to press the film onto the wood and, if it's not sticking, give it up to 20 minutes to set before you try to remove the tape. If it' still not working, and if you're using paper transfer tape (not clear), you can moisten the back of the tape with application fluid to soften the tape's adhesive and weaken the bond between the tape and the vinyl. Spray it on, spread it around and give it five minutes to soak into the tape. Then give it one more try. If that doesn't work, you may be dealing with a substrate that's just not compatible with vinyl graphics.
Summary: Tips for Applying Vinyl on Wood.
So here are the bullet points for better adhesion of vinyl on wood.
- If the wood is rough or porous, sand it so that the surface feels smooth to the touch. Then make sure there's no sawdust or residue on the wood before applying the vinyl.
- If it's been painted or sealed, allow a few weeks for the paint or sealant to cure before applying vinyl.
- If you have a choice of paint, use 1shot or an enamel paint.
- Try a vinyl with a solvent adhesive.
- If the vinyl letters are coming up with the transfer tape, give it some time, and/or moisten the tape.
- If none of that works, try the stencil option and just paint the wood instead. It might be just as pretty.
