Category Archives: All things UV

T12 lamp ends for our ultraviolet (UV) lamps

Had a lamp that got smacked into a post here, broke, so I thought I would take advantage of the misfortune by showing you the parts we use. This belongs to a Flower Power FR40T12 but it is the same lamp end we use on all T12 lamps. Extremely beefy parts that allow us to take a lamp designed for 40 watts, and push it all the way to 100 watts if you want. The part itself is actually a stolen design from my days in the tanning industry: essentially the same part we used on high end 120 watt tanning lamps. It is obviously a bit more expensive than using generic F40 ends, but it means the lamp won’t die prematurely and can operate on a wider range of wattages: Use them as you like, they can take it.

Here you can see the beefy posts and the heavy heat shield. This protects the glass, makes them less likely to get black ends (killing phosphor) and extends the life, particularly if you overdrive them.

Another angle shows the coil. We actually use a preheat coil for compatibility. This means it will work with any ballast: old choke or magnetic ballasts, or new program start, instant start or high frequency electronics.

The short of it is that we use the beefiest, sturdiest parts that money can buy when building our lamps. They won’t die early or fade out when you need them most.

Dennis Brown

Lamp life for cannabis UVB lamps

Been a while since I’ve written, but I get a lot of questions about lamp life as it applies to lamps for cannabis, and felt an article might clear up a few misconceptions. It is different than how you figure lamp life for other UV uses, like curing violins or aging materials.

First of all, if you are a serious cannabis grower with at least 8 hoods, you need to invest in a UVB meter. Solarmeter makes a great one for around $250, you can find it on Amazon. You can’t really compare one lamp to a different model lamp (trust me, it has to do with spectral weighting, but they don’t compare cleanly). You can measure your new lights, then measure once a month so you know when you should change bulbs. I recommend changing once the UVB reaching 70% or of the original output.

To get a first reading, you should age the lamp for at least 10 hours by simply running it. then hold the meter to the lamp, at the glass, in the middle, and the highest possible reading you can. Do this for each of your lamps, and average your results. This is your reference reading. Once the lamps are down to 70% of this reading, when measured the same way, then it is time to swap lamps. If you are using pulse lamps (like the Flower Power) you can cheat a little and squeeze some extra life by simply increasing the time exposure per day, to maybe buy you another month or so. But this method will prevent you from buying new lamps too early, or too late, and it pays for itself in a year.

Now to the main topic, which is lamp life. Lamp life is determined solely by the UVB output of the lamp, it isn’t about about the lamp burning out. A typical UVB lamp will give 1000 hours of usable life, yet continue to burn for up to 3000 hours. It simply gets weaker and weaker until it is useless as a UV lamp once you get past 1000 hours. But lamps do not die an “even” death. As they age and get to their expected life, the spectrum of the lamp changes dramatically.

In order to produce UVA and UVB, you have to make a glass tube with at least two different phosphors in it. One for the UVA, one for the UVB. Our lamps typically use several phosphors, including some for buffering, to prolong the life. Each phosphor is a chemical that will produce a particular set of frequencies (the primary frequency and often, harmonics of that frequency). The glass tube is actually clear, the white stuff you see is the phosphors. So the difference in your average office light and a UVB light is mainly decided by the different chemicals we put in the tube. One phosphor might make the color “red” at 633nm, another phosphor might make the color “ultraviolet” at 365nm. All Solacure lamps (curing and horticulture) are 100% UV phosphor. We don’t use any visible spectrum phosphors. The visible light you see is a combination of harmonics and the fact that you are running plasma inside a tube, which always makes visible light. This is why they look dimmer than a regular light as well. All the real energy is in the UV band, where you can’t see it.

The problem with UV phosphors is they break down. Well, really, all phosphors can break down, but it takes a lot more energy to make a photon of UV light, which puts a strain on the phosphors. So UVB phosphors break down quickest, then UVA phosphors break down moderately fast, and visible spectrum phosphors break down slowly because they are lower energy.

When we rate the life of a lamp, we are really only rating the life of the UVB, because we know the UVA will still be fine. An an imaginary example, lets say you start with a 10% UVB / 90% UVA lamp. By the time you to 70% of the original power, it is likely a 7% UVB and 93% UVA lamp. We have shifted the spectrum towards UVA simply because the UVB is wearing out. if you keep going for 2000 hours, eventually you get a lamp that has 1% UVB, 99% UVA *but* the overall UV output is less than half.

These percentages do NOT tell you total power, they just tell you ratios. Just like how you can take two glass that are half filled, but if one is a 4 oz. glass and the other is a 8 oz. glass, they aren’t equal. They are both 50% full, but the total mass isn’t the same: One glass has 2 oz. of milk, the other has 4 oz. of milk. I say this because it is easy to get tripped up on percentage ratings of lamps. You can take two 20% UVB lamps, and find that one is actually twice as strong. Just like the glasses above, the ratio can be misleading. Ratios are handy for measuring the difference between otherwise identical lamps, like two lamps from the same manufacturer, but it isn’t for comparing two different brands of lamps.

So to recap, when we rate lamp lamp, we are rating how fast the UVB phosphors will break down. Using them past 70% of the original life can be done, but it is a problem because you have less output and a very different spectrum, so the results won’t be the same. This holds true for all UV lamps, regardless of brand.

Dennis Brown

Lamp life

I finally had to change out a set of lamps in my primary rig, which uses the 4 foot long, Solacure SG-1-40. Most of the time, I run it at 32 watts, but also run it at 60w at times, and I choke the air flow, so it is a bit rough on the lamps. I rate the SG-1-40 lamps at 1600 hours at 40-50w, but I managed to get 2200 hours out of them this time. Keep in mind, I don’t cycle the lamps on and off a lot, which is what kills lamp life. Instead they run for days or weeks at a time, which is what builds up a lot of heat.

Your mileage will vary of course, but this just further demonstrates that you should get a minimum of what rate the lamps at, and how cost effective they are.

Dennis Brown

Daphne Blue Cabronita

I had planned a beautiful spalted maple over cherry wood project, but there was an accident with the luthier, ruining the wood, so I had to go to Plan B. For this plan, I’m going kind of cheap, for a fun little project; a home made Cabronita Telecaster.

daph7I start with an XGP body from Guitar Fetish, which put me back about $85 cheap, shipping and all. It is a Telecaster style body, Daphne blue, dual humbucker. This is supposed to be one of their better bodies. Got it in, there are a couple of minor flaws, but all and all it is a pretty solid body with good cuts. The goal is to lightly sand it down and put a medium layer of nitrocellulose over the stock polyurethane finish. This is tricky, as some poly finishes will curl up and off

Next, I take a neck I bought some time back for almost $34, shipping and all, of eBay, from China. Actually, it isn’t a bad neck, although it doesn’t compare to a good US, Japanese or Mexican made neck. Here it is before we started, click for a better view:

I aged it down for around 3 days, and it looks a lot better, warmer, darker and more expensive. This was just using a low power rig, 6x 32w lamps, SG-1-40s with a lot of hours on them. Aging necks and the like is easy stuff. The thicker the finish, the slower it will age, and finishes that have the antique vintage tinting to them will likely take a very long time since the tinting obscures the UV. Personally, I hate fake tinting. It is just too easy to age it with real light.

daph5 daph6

Next, I decided to use some Gretsch pickups. Gretsch Blacktop FilterTron G5400, to be exact, the same used in the Tim Armstrong signature guitars. These are actually quite nice, and I found a great deal on them, $65 shipping and all, so I couldn’t argue. They give the guitar a twisted Cabronita sound and look. The rest of the hardware I will figure out later, I have plenty of parts in the spare parts bin for a bridge and the like.


Started putting the nitrocellulose over the urethane finish on the blue Telecaster, and there was NO curling up of the finish. That is a problem with some finishes, but I had it on good authority that I could maybe get away with it on urethane. This means that coating the necks shouldn’t be a problem either, as they always have a urethane finish. Once dried, I will try to finish check the nitro, to make it look like an old Daphne blue guitar, to age the top coat. I have to add the nitro to do this, urethane won’t age, it will just fade a bit.

Next, I will do the same with the neck, which had a light sealer or coat of urethane on it, but I want it aged before I put the nitrocellulose clear coat on. I’m thinking this will make a really interesting cheap guitar. Not sure if I will keep it or set it at cost of parts and finish materials when I’m done. I already have a couple of Cabronitas, but this has the promise of being something really unique, yet really inexpensive. Something that is worth more complete than the parts would have you believe.



A lot of people still pine for the days of nitrocellulose finishes on guitars, swearing they sound better and look better. In fact, nitrocellulose was only one kind of finish they used on 50s/60s Fenders, the other was acrylic lacquor, which is more colorfast. Some colors only came in acrylic (like Lake Placid Blue) while others only came in nitro (like Sonic Blue). They were using car paint on guitars, after all, so they ordered what was available because it was cheapest, and Leo was notoriously frugal. Acrylic is actually a better product as it resists fading, cracking and chipping, but that is exactly the opposite of what everyone wants, it seems.

Everyone wants a guitar that will soon like it is 40 years old, even dipping parts in acid to age them. Even our lamps are designed to speed up time. Just about any of our lamps will work to age a nitro finish, although the SG series are the fastest. We are going to be doing some detailed finish tests in the months to come, so stick around. We will always publish the details in the “how to” section of the main website as well, which is probably easier to search.

Those of you relic’ing guitars or just aging them down really do need to take a look. We’ve been testing and working with this for over a decade and have a pretty good idea of what can be done. See our Projects page for actual photos and examples. Wood doesn’t lie.

I’m going to test using some Deft nitrocellulose lacquer, and I’m going to take my personal 2005 US built Fender Precision Bass with factory nitro finish (Highway One model) and subject it to thousands of watt hours of ultraviolet to see if we can induce some aging, fading, cracking, or whatever else happens. I can’t think of a better way to show trust in my lamps than putting my main bass guitar through the gauntlet. It has a small ding or two plus some yellowing of the pickguard, but it has never been through what I have planned. Be sure to bookmark the Projects page (linked above) and check back.