Actually, sanding veneer is not necessary, because all of Oakwood's veneer sheets are sold pre-sanded. Some people have reasons for sanding anyway, and necessary information is located below.
To get the best out of staining your veneer, be sure to sand it carefully and thoroughly. Sanding not only affects the staining process but also the appearance. Handling of the material and storage for long periods of time can result in a loss of finish .You can either use an electronic finishing sander or hand sand with sandpaper to get the job done.
Veneer is becoming thinner and thinner making the whole process more of a challenge. One sand through can become very costly in time and budget. Be sure to consider the following:
Sand your parts evenly:
If your parts are not sanded enough, your stain will result in a darker, blotchy appearance. If you do wind up with blotchy places when you stain, just give it another light sanding and then restrain.
Preliminary Sanding:
220 grit sandpaper should be good enough to deliver a well sanded surface to work with.
Never Sand Across Grain:
Be sure to sand with the grain to get a smooth finish. Staining an improperly sanded piece will only ruin your veneer visually and physically.
Stay away from belt sanders:
Remember that the veneer is thin, so don't over sand it or you will end up going right through it.
**Be Mindful of Species/Wood Hardness
It is easier to sand through softwoods, like pine and fir, than through hardwoods. Some woods that are technically hardwoods, like birch veneer, are still fairly soft. It is easier to sand through a birch veneer panel than through oak, beech, maple, or mahogany - so familiarize yourself with the species and proceed with caution.
Raise the Grain
Some species, like walnut, can be tricky to finish. If finishing walnut veneer, raise the grain before finishing. This involves wiping a damp rag over the surface of the veneer after sanding with a fine grit, which will cause the grain to swell slightly. Allow it to swell for 15 to 20 minutes, then re-sand it once more with a very fine grit. This will leave a very smooth, glossy surface that will respond nicely to a wide variety of finishes.
Start seeing yellow:
While you are sanding veneer, stop if you start seeing yellow. This means you are sanding right through the veneer.