UW Leak detection..

[off-track]

Ok, in keeping with my alias, I thought I'd toss this out to the DYI crowd..

I've been seeing several threads here lately about difficult to find leaks. I see you can get UV dyes for most any automotive fluid at most FLAPS (even in single/two dose) packs. When I looked at the loan-a-tool programs it appeared that they didn't have the UV light source to complete the diagnosis. Is that true or not? I didn't want to add the suggestion without trying it myself.

Anyhow, (I'm thinking of a low dollar addition to the tool kit) it got me to thinking about maybe changing out the LED's from the now common LED flashlights with UV LED's available at RS for ~$0.90 ea. I see that there are several UV lights you can buy on-line but what's the fun in that? Anyone gone down this road?

There was also this type of thing but it appears that the blue backscatter might be too much?
http://www.officedepot.com/a/product...ection-System/
Would a yellow filter help?

[ahimsa1]

Here is the ultraviolet light I use:

http://www.petsmart.com/product/inde...ductId=2751995

It's probably available at your local PetSmart.

Another possibility: they probably carry 110V plug-in versions wherever blacklight Jimi Hendrix posters are sold in your town.

[madpogue]

Off-Track, MadCat or Mounds will have one of ^^^^^ those, and the money stays local. I've seen some such products even bundled with yellow-filter goggles; you should wear 'em anyway, just to impress the neighbors with that CSI look.

(Your thread title made me think it was gonna be about some political intrigue at the University...)

[off-track]

Originally Posted by madpogue

(Your thread title made me think it was gonna be about some political intrigue at the University...)

Oh crap! Did it again! = me Darn bifocals and the low 'puter chair!

I can't really tell what that thing is like (size wise).. I was thinking more like a small penlight or the compact LED form factor for small/tight places..

[OldNuc]

For a bit under a $10.00 bill you can buy a LED UV flashlight that will do the job.
http://www.allelectronics.com/make-a...-12-LED/1.html

This link is a bit more expensive but several steps up on the tree also.
http://www.maxmax.com/

[off-track]

Originally Posted by OldNuc

For a bit under a $10.00 bill you can buy a LED UV flashlight that will do the job.
http://www.allelectronics.com/make-a...-12-LED/1.html

This link is a bit more expensive but several steps up on the tree also.
http://www.maxmax.com/

Yeah, I saw those too. I was trying to come up with a more universal solution. Aka, something that people could find/make locally for a few bucks without having to order a tool. In retrospect, for the $5-10 tags I found it's probably not worth it?

[fdryer]

The issue with uv lights are that the small portable single LED ones may not work at all in bright daylight unless you're serious about dye illumination. Ever see those ads for tents that cover the engine hood to black out the area for daylight dye illumination? This seems to be for the commercial a/c shops needing a portable dark area. Couple that with unfamiliarity with dye. Unless you've used one and only go by advertisements, there may be more to a simple inexpensive light for making dye glow. A good example is a recent Vue member complaining about an a/c leak.

The original thread was posted over a year ago and it was mentioned that a leak was the issue. Of course it was denied until the new season, this year, started and a/c was needed again. Well, extensive uv light searching by an a/c tech couldn't expose the leak. Even with the large uv light!? Guess who found the leak? The Vue owner with darkness on his side, suggestions, and a small uv light. A picture was posted. Serendipity. How can a trained a/c tech fail to find dye while an untrained Vue owner find it with a cheap LED light? This is just one extreme example of dye detection.

Fluorescent dye used for marking most likely won't be seen in the daytime to the unfamiliar attempting to find refrigerant leaks. Sunlight will drown any puny LED light unless shading is used as in the black tents sold for commercial purposes. Very small leaks would result in even smaller dye marking the spot. The cover of darkness is a better background for finding dye as the LED light isn't competing with sunlight to drown the eyes. Just like a dark room is a better contrast for uv illumination in large areas or lighting up one poster. A search for some threads will show dye almost glowing by itself in daylight but found easily because of its location - behind a bumper by the filter/drier on the driver's side of the condenser coil. Compressor leaks seem to show up well in pictures too, although it may be from the effects of electronic flash amplifying the fluorescent dye.

In the end, a small inexpensive uv light may not work if attempting to find leaks in the daytime outdoors. Better inside a closed garage with minimal indoor lighting to use as a low light background where the small LED uv light will have a better advantage.

[OldNuc]

Even with the large 120vAC UV inspection lamps used in industry you have to use a dark hood or turn off all the lights.

If a person decides to use the UV dye to find a leak you will be looking for the leak in the dead of night to find it. Your eyes have to become accustomed to the low levels of light emitted from the dye. Even after you have found a dye stain you will have a tough time seeing it in the daytime with a hood.

But, the dye does work and as long as you understand teh limitations it will identify very small leaks.