Regrettably, there is a lot of bad information about all sorts of things on the Internet, in magazines, and on TV. Whether it be related to health, finances, or even woodworking, myths are everywhere and they grow like wild-fire. Let's take some time to set things straight about the most common veneering myths.
Myth 1: Veneered projects look cheap and fake.
I've heard this from a lot of woodworkers. None of them have seen a properly constructed veneer panel. Instead they are thinking of particle board covered with melamine or some other thin plastic that looks like wood. Take a look at the projects on this page and tell me they look cheap or fake!
Myth 2: Ripples in a finished veneer panel are caused by water-based glues.
Not true at all. Ripples are only caused by the use of too much glue or not using enough pressure on the panel while the glue cures. This is discussed in detail on this page.
Myth 3: Yellow glue is fine for veneering.
Despite the dozens of comments I have received about this over the years, I can honestly say that yellow glue is far from ideal for veneering. This is largely because it does not dry hard. Instead, it stays rubbery and semi-flexible. Have you scraped a glue drop off your shop floor after it has hardened? Did you notice it was still bendable? Glue-line flexibility is not good for a veneered panel. "Cold creep" is a phenomenon in which the veneer expands and contracts from seasonal humidity changes on the substrate material often causing delamination problems. A yellow glue can allow the veneer to move around or creep on the substrate and will eventually lead to delamination. And since yellow glue dries with a soft glue line, it is also very difficult to sand the edges of the panel.
Myth 4: Contact cement is fine for use with raw wood veneers.
This myth has been around for a couple of decades. Simply put, contact cement doesn't dry hard. It stays more flexible than yellow glue so it will clearly create problems with cold creep and delamination. Contact cement is only suitable for backed veneers.
Learn more here.
Myth 5: Shop-sawn veneers (thick veneers) can be applied with any veneer glue.
Not true. There are a lot of woodworkers out there who are painfully aware of this. A thick veneer has a greater tendency to expand and contract with seasonal moisture changes. Because of this, it requires a much stronger adhesive. In this case, I highly recommend a pre-catalyzed powder resin (PPR) glue.
Myth 6: A thicker veneer is easier to work with than a thinner veneer.
While a thicker veneer may seem easier or less risky to sand smooth, the truth is that thicker veneers are very hard to keep flat in the shop environment. A thick veneer is also highly prone to "cold creep". If you must use a thick veneer, you need an adhesive that is stronger than an ordinary veneer glue. A pre-catalyzed powder resin (PPR) glue is ideal because it is strong enough to overcome seasonal veneer movement.
Myth 7: If a veneer is not perfectly flat, it must be softened and flattened before being pressed to a panel.
Slight waviness in a raw wood veneer is very common. Veneers that have some curl or warping do not necessarily require flattening before use. The vacuum press will have enough force to set the veneer flat against the substrate. However, exceptionally brittle veneers should be flattened before use to prevent cracking that can occur when the wavy areas are pressed down.
Myth 8: You don't have to veneer the back side of a panel if you use plywood for a substrate.
This is partially correct. Yes... you don't have to. But you should. Why take a chance on ruining a nice piece of veneer and wasting all that time and money? Just get some backer veneer and do the right thing!
One of the most common problems is the tendency of the panel to warp after it is removed from the press. There are two easy ways to eliminate this. Be sure to veneer both sides of the panel. A backer or balance veneer should be used on the reverse side of the substrate. This will even out the stress placed on the substrate as the glue dries and the veneer settles onto its final position.
Myth 9: Oily veneers require special adhesives.
I don't give it much thought when it comes to oily woods. I just wipe down the glue-side of the veneer with naphtha and apply the glue as usual. I've veneered many panels with rosewood, teak, and bubinga and I have never had any troubles.
Myth 10: A vacuum press is a difficult project to build.
I've been known to lurk on many of the woodworking forums around the Internet and every once in while, I see a post from someone who says that a vacuum press is too complicated to build. What can I say? I estimate that as of January 2014, over 3,300 vacuum presses have been built using the instructions found on the JoeWoodworker website. I don't think many of these people found it terribly difficult to build their press. This page will show you some of the many fine examples of DIY vacuum presses that have been made over the last few years.
Myth 11: Sequentially cut veneers are identical from sheet to sheet.
Many websites make it seem that sequential veneers are identical. In other words, each veneer sheet from the log will look exactly the same. This is not true at all. Veneer that is kept in the sequence in which it was sliced will have slight variances from one sheet to the next. A log is not a single-patterned block of wood. It has various grain patterns throughout. If you were to cut a tree into 15 boards of wood, each would like slightly different than the next. Veneer is the same; though the variances can be much less obvious. In a lot of 20 veneer sheets from the same bundle, the top veneer may show a bark patch and the bottom veneer may be flawless or the grain may shift from one side of the veneer to the other.
Myth 12: It's OK to spray water on the veneer to prevent curling.
Veneer can have a tendency to curl up when it is placed on the wet glue layer on the substrate. It is not ok to spray the face side of the veneer with water to counteract the curling. The addition of water to the veneer causes excessive expansion of the wood cells which can cause the veneer to split later in the day as the moisture evaporates from the saturated wood cells.
Myth 13: A paper-backed veneer with a 10 mil backing is not suitable for use with contact cement.
This myth is floating around the internet on various woodworking pages and forums. It is perfectly acceptable to use a 10 mil backed veneer with contact cement. For the vast majority of projects, the only time to step up to a 20 mil backer is when the substrate surface is not perfectly smooth or when the veneer is made from a species with a fragile grain such as a burl.