Unquestionably, wood aging is more art than science and there are no hard numbers you can give someone on how to do it properly. Every piece of wood is different, so you may have to age two similar boards for different periods of time to get the same result. There are no exact tables of time vs. shade, it just doesn't work that way. That said, it is often one of the most rewarding jobs in woodworking, being able to match up old and new wood in a measured and consistent way.
Of course, everyone wants to age wood in a day, and often that is enough but other times it may takes days or even weeks. What is needed is adequate UVB, but it is the UVA that does most of the heavy lifting. UVA also penetrates more deeply, giving the wood a natural aged effect. Is it as good as natural aging over time? No, but it is the next best thing and takes much less time.
Our lamp of choice for aging is the Solacure SG1
. Unquestionably, it will deliver more power in the right frequencies than any other lamp by any other maker. While we call it our "first generation" lamp, it is actually built upon years of testing, and is so unique that is operates under patent. It is a bigger lamp, 6 foot long, and best powered by the SunHorse
ballast (120v or 230v, both are equal in output), which can power 4 of the lamps. We do have other lamps available, but nothing beats the performance of a 4, 8 or 16 lamp rig with the SG1.
Our Universal UV
is another fine choice, with more UVB than the SG-1 but lower overall output due to being smaller lamps. They are an FR32 (4 foot, 1/2" diameter) and can be used in any standard 32 watt light fixture, such as a shop light or similar, which can be found on the cheap at Lowes or Home Depot. You can also power them with the Workhorse 8 or Workhorse 7 ballast for faster action.
This is an example board, just 1x3 furring pine, exposed with 6 of our first prototype FR32/40W UVA only aging lamps. The right side was exposed about a day, the left side for two days, the center was masked the whole time. As a point of references, our Universal UV lamp would be slightly slower to age, but deliver about 4 times more UVB during the process, which would give a harder surface age. If the item is already finished and you want the finish to look worn, this would do it but at the price of darkening the underlying wood a bit less. Whether this is right for you or not, that is up to you. Using the SG1 lamps should be at least twice as fast, if not more.
The finish on this board is a single rough (but thin) coat of UV curing resin from Solarez®