UV Cabinet

[Ken_N]

Yeah, I know cabinets have been discussed before, but I want to make one now.  The wind blew my garden hook holding the violin over yesterday.  I came home from work last night at 11:30 and couldn't see it by the side of the garage!  I thought it would dry fast in the bright sun, it's been very gloomy, but not face down on the wet grass. My varnish dries in a couple hours max in full sun.  It doesn't dry at all without it. Hazy days don't do much either.

But looking around the internet I wonder, are the 20 watt black light bulbs going the way of the Dodo bird?  The last 40 watt bulbs I got for the basement were led's.  That's what they say they are, they look just like the fluorescents, but brighter.  They weren't like led strips.

I'll probably just use 4 cheap 2 foot fluorescents for now.  Maybe buy some replacement bulbs when I'm done. But in the future, are they going to be obsolete?  Would it be better to set it up with something else?  When we do end up changing over, what will we change to?  I saw Andrew Carruthers used led tape.  Weird.  I know nothing about led's.  Buying a familiar tube is easy.

[Thomas Coleman]

I use 8 18w 24" Philips Master Actinic bulbs.  I get them from lightbulbs dot com.  part number PL286716

Ive also bought PH286708 from topbulb dot com

I got the lead on these from the Oldwood 1700 website.  They work very well for curing varnish, only so so for UV tanning.

[Ken_N]

Reef tank bulbs?  How do they compare with the blacklights?  I know that they 'seem' brighter visually.

[Thomas Coleman]

I don't know about reef tank bulbs.  Maybe some people use them for that.  They are blacklights but not your traditional hippy flourescent poster blacklights.  They will easily dry any oil varnish that I've used.  I never have tried to apply more than one coat in a 24 hour period but I know that with some varnish that i've used it can be done

https://www.lightbulbs.com/product/philips-286716

https://en.wikipedia.org/wiki/Blacklight

[Thomas Coleman]

They still look much different than a regular florescent.  I guess the difference between them and the purple blacklight is the lack of a coating on the inside. 

[Urban Luthier]

i think this is the same product Thomas refres to above  

[Don Noon]

It looks to me like actinic or reef tank bulbs have the bulk of their energy in the 400- 450 nm range (violet and blue).  Almost nothing in UVA.  BL350 has output in the UVA range, around 350 nm.  The BLB versions with the dark filter just remove the visible stuff.

I don't know how well the longer wavelengths work for curing varnish; I just use the 350 nm versions.  I ordered a lifetime supply of them, and something went wrong with the order and I ended up with twice as many.  I'll have to look into reincarnation so I can use them... and all the spruce I have.

[Thomas Coleman]

This is the data for the bulbs I use. 

[Urban Luthier]

The chart Thomas posts above and the the data sheet I attached for the Philips actinic BL bulb looks like the peak is at ~375nm. Which is what Koen Padding suggested for drying varnish in his VSA article "use of ultraviolet light sources in Lutherie" 

This isnt my area and I'm also struggling with purchasing bulbs for a new cabinet. If i'm reading correctly, Thomas's suggestion of the Philips Master Actinic is spot on

[Jim Bress]

Here’s what I’m using for tanning and varnish drying. No complaints. 

[Michael_Molnar]

UV cabinets are not high tech rocket science. Use as many black lights you can afford to cut down the drying time.

Done.

[arglebargle]

41 minutes ago, Michael_Molnar said:

UV cabinets are not high tech rocket science. Use as many black lights you can afford to cut down the drying time.

Done.

Also, save time and effort by using a grow tent, like this. Worth every penny.

[Urban Luthier]

26 minutes ago, arglebargle said:

Also, save time and effort by using a grow tent, like this. Worth every penny.

These grow tents look promising but I cant see a way to attach the lights to the tent structure

[Nick Allen]

2 hours ago, Urban Luthier said:

These grow tents look promising but I cant see a way to attach the lights to the tent structure

Velcro? A zip tie? 

[arglebargle]

3 hours ago, Urban Luthier said:

These grow tents look promising but I cant see a way to attach the lights to the tent structure

It's not a problem. If you can make a violin that needs to be varnished, you got this.

[not telling]

From Koen Padding's article mentioned by Urban Luthier.  He recommended a specific bulb but it is no longer manufactured. Someone recommended lizard lamps to my husband, with a mix of UVA and UVB, in addition to the long low wattage bulbs. Works fine, but any of these setups work fine. Whichever bulbs you use, when you make your cabinet you may want to bear Padding's advice in mind as far as construction concerns. Hope this helps.

[David Burgess]

13 hours ago, Urban Luthier said:

These grow tents look promising but I cant see a way to attach the lights to the tent structure

Hang the fixtures by one end from the upper support rods with strong twine, coat hanger wire, or some such thing

[Don Noon]

I would probably make some wooden adapters that clamp to the steel tubes in the corners, and fasten the light fixtures to them.  If I didn't already have my lightbox, those grow tents look like the way I'd go.

[JacksonMaberry]

So Koen was not keen on tanning, it appears. 

[not telling]

Not too keen. I am sure everyone agrees that sunlight is the best way, but most probably do some tanning in the light box (especially this time of year). The Michetschläger book is pretty good to have, just to know his thoughts. At one time, nearly all professionals relied on his varnishes and accepted that his opinions regarding varnishes and such were all formed through research. But at the same time, I think most also relied on some mix of uva/uvb in the light box (he advised low watt UVA only) and most were doing some tanning, and continued to do so.

 

[uguntde]

I recently tried UVC 35W for tanning (2 90cm tubes) - works extremely well. Just need to switch it off before opening the box, as UVC damages about everything on the human body.

[Urban Luthier]

19 hours ago, arglebargle said:

Also, save time and effort by using a grow tent, like this. Worth every penny.

I think I will get one of these -- did you get the 60 in one? Large enough for a cello?

[Thomas Coleman]

3 hours ago, uguntde said:

I recently tried UVC 35W for tanning (2 90cm tubes) - works extremely well. Just need to switch it off before opening the box, as UVC damages about everything on the human body.

I mention this only in the spirit of safety, but DO NOT use UVC bulbs for tanning.  UVC is used for germicidal purposes.  

Edit:  I see now that I misunderstood!  Please, use the UVC for tanning your instrument! :-)

 

Edited October 17, 2018 by Thomas Coleman

[arglebargle]

39 minutes ago, Urban Luthier said:

I think I will get one of these -- did you get the 60 in one? Large enough for a cello?

Mine is 24"x24"x55". This is the one I bought. I could hang a cello and two violins in it with no problem. I picked this size because of space constraints, but it works fine.

[Ken_N]

We went to Home Depot today.  I bought a galvanized trash can.  Light.  Portable.  Not very stylish.

$26.50

The lights are 4 el cheapo black light fixtures from Walmart.  Lights of America.  Yeah I know they are cheap, but these don't seem too bad.  I've seen worse. 

$46.50

That's about the cost of four 20 watt Actinic bulbs.

A long dowel to hold the violin on was free.

Seventy three dollars total. 

If I had an outbuilding, or I really planned on staying in this house, I'd build a bigger one.  Real fixtures.  A door.  All professional looking.  But I don't.

The light doesn't give off much blue like Actinic bulbs do.  Hard to tell that they are even on.  But when the violin is in there: IT LOOKS HORRIBLE!  I mean, it is ghastly!  Has anyone noticed that before?