Violin Forum/Message Board

[Barry Dudley]

Do you use a "Black light" drying cabinet? If so do you get good results?

[jethro]

I built one about 18x20x32 inches out of 3/8 ply and then lined it
with aluminum foil. Put in two single bulb flouresent lights (24 inch).
I really can't tell if it helping or not. I think I could have used 4 bulbs instead of 2. Just from observing- I can't tell if the warmth or the UV
part is helping. One good thing though-- It certainly is a good place
to put the instrument untill the varnish dries enough that dust from the
air won't stick in it. After a brush coat of oil varnish I can just touch
the surface after 24 hours but I can still feel a sticky, rubbery consistancy.
So far it is about 4 or 5 days till I can see it "shrinking" down.
I wonder if a dust free cabinet with infra red bulbs wouldn't work just as
well (????????????)

Tim

[JWH]

I get excellent results with my UV box having six 24" Sylvania BLB's. The box is foiled, there are two bulbs on the back wall, two on the front, which is the inside of the door, and one each on the sides. They are set about 4" from the instrument. I have a speed controlled fan for circulation which I don't use. I have one 60 Watt incandescent for added heat which I don't need as well. The BLB's provide just enough heat themselves and with limited passive air flow from the bottom intake of the fan and out a 3" hole in the top, works great.

My coats are thin with some dryer and are dry to touch in 5 or 6 hours. If left in a 70 degree room with little reflected window light, it takes about 30 hours.

[Andres Sender]

Jethro--your drying box uses regular fluorescents?

[jethro]

No Andres it has two 24 inch UV flourescent bulbs. Two single bulb
fixtures. I am pretty sure I need more bulbs though! I'd say 4 bulbs
minimum. Now it gives me for oil vernish- 24 hours slightly sticky but
dust won't stick - another 24 and it is not sticky and can be handled
but the varnish hasn't "shrunk" yet . It takes about 4 or 5 days for it to
shrink down. I will add more bulbs I think. I may add 2 more twin lamp
fixtures to gibe me 6 total. Now with only 2 bulbs it runs about 85 degrees F in the box. I think I could go up to about 110 F I would think..
Tim

[mapleleaf_gal]

[jethro]

Maple-leaf :
NO .... I don't think I meam full spectrum ..... I think those are the ones
for growing plants and for reversing cabin fever- they are a white light
output. The ones I mean are the ones that put out very little white light.
They appear purple when operating. They are the bulbs used to energise
glow in the dark painted displays and to show the flourescence of rocks in
museum cases. They are about 12$ for 1 2 ft bulb. I don't think the
ones you are refering to will have enough UV to have a great effect.
You can get UV flood type incandescent bulbs but they generate a LLOOTTT of heat !!!!!!!

Do you know the bulbs I am describing ?
( or was the "full spectrum " part a little joke to tweak the tree huggers ?

Tim B. (tree sawer - )

[jethro]

Maple-leaf-
Wow I really enjoyed your pictures ! Your work is so gloriously neat!
I work "in the dark" metaphoricly... you appear to do it literaly !
You look like you never make mistakes (on the wood ..) like I do -like sanding through the varnish removing a dirt chunk........
I did cut my nail a while back using a little circular saw blade in the dremel
( OW-that hurt !)

Good pictures !

TB

[mapleleaf_gal]

[mapleleaf_gal]

[Michael Darnton]

Tanning bulbs aren't "full spectrum", which are bulbs like Verilux makes: completely accurate to sunlight in all respects, not overdosing on the UV end of things. You can read verilux' take on this on their webpage: http://www.verilux.com/ Verilux fluorescent bulbs are really great shop lights--you won't even know they're on--the color is identical to what comes in the window, and they're not dangerous, like tanning bulbs are, since they're not disproportionately loaded with UV. The first place I became aware of them was for industrial photography, where they would be substituted for all of the fluorescents on office and factory sets so that color filming could be done. There is also research showing that school kids do better in rooms lit with them. I haven't checked, but I bet that lizard bulbs are either genuine full spectrum, or maybe just a bit more UVed up, but not anywhere near tanning bulbs. You can also buy full spectrum lightbulbs, which I doubt are as accurate as Verilux bulbs, but are great as for simulating daylight as one of the several different sources you should use to check your retouching.

Tanning bulbs are quite high in UVB, I think, and are essentially the same bulbs I bought as plain UV bulbs 25 years ago, before the tanning craze turned them into "tanning" bulbs. UVB is what's responsible for skin cancer, and vitamin D. The black bulbs are blacklights, which are also UV, but without much visible light, mostly UVA, which is relatively safe, and why they were all over the place in the 60s without anyone going blind. All of the various types put out different amounts of different wavelengths, but it seems that the various UV types do work for varnish. I haven't tried Verilux in my light box, but I doubt they would do much, since they're not particularly overloaded with UV as the other types are. I've got four two-footer tanners in my lightbox, and varnish dries variously from one to two days. Generally,varnish that has aged dries much quicker--my varnish, fresh, can take three days, but a year or two later dries in less than a day.

You can sunburn your eyes by looking too long in a box with tanning lights. I've done it, and it's not nice. So be careful. There's another degree of UV germicidal bulb that's used in sterilizing. They look a lot like tanning bulbs, but are even stronger, in the UVC frequency. They're a whole bigger level of bad mojo than even UVB, and you shouldn't mess with them.

If you want to geek out on this topic, Wikipedia's write-up is pretty good: http://en.wikipedia.org/wiki/Ultraviolet#Sun_Tanning

There's always a lot of confusion about UV when the topic comes up among violin makers, and I inevitably have to go re-research every time. Part of the problem is that I don't think the drying process is too well understood, given that a lot of different things are happening, involving various degrees of evaporation, polymerization, and oxidation, thanks to different components of light, heat, and air circulation/humidity.

Another topic where science gets sacrificed on the altar of violin making is the subject of wood tanning, relative to UV, "ozone" (which I believe actually has no effect in tanning, contrary to violin making lore), nitrogen dioxide (and the resulting nitric acid--the real culprit in the "ozone" story), and water (without which nitrogen dioxide won't turn into nitric acid).

[Barry Dudley]

Michael I didn't read where you gave an opinion about "black lights" What is your opinion?

[Michael Darnton]

I haven't used them, so I don't know where they fit. Some people do use them for varnish, and they are easier to get, but I think that UVB are better, and I have heard that UVC are better still, but I don't have personal experience to validate any of that.

[mapleleaf_gal]

i've got (3x) 4' bulbs like this in my box:

http://www.topbulb.com/find/Product_Description.asp_Q_intProductID_E_44298

they work very well.
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[Michael Darnton]

Yes, that's basically what I use, also.