PCB etching - what lamp for safe light

[neil]

Hi folks,

I'm going to be etching some plates similar to PCB etching. I'll be using spray PRP emulsion to coat the plates prior to exposure. I have all the gear for exposing etc but I will need to use a non UV light/lamp when working with the pre-exposed plates. I've searched the web and most folk are recommending 'yellow bug lamps'. I believe they are used a lot in the USA but seemingly not available in the UK? Searching for alternatives has drawn a blank as I don't know how to refer to what I need. Can anybody advise me on what exactly I need and ideally where I can get them.

I should mention this isn't a commercial setup - it's one step up from a hobby so I'm not looking for expensive equipment, just the type of lamp I need.

Many thanks - Neil

[NT]

Can you not look at what the mfr of the emulsion advises? CFLs are available in various single colours. Red is of course the safest, as red light has the least actinic power.

NT

[SteveW]

I had no problem using a normal incandescent lamp years ago. You're looking at a fairly lengthy exposure, very close to the tubes of your light box to produce the image, so a short exposure, at a distance, to an incandescent light is going to have a negligible effect.

Just try it and see.

SteveW

[The Other Mike]

Can't you do it all in the dark?

If not total dark then maybe on a moonlit night in the arse end of nowhere?

[Dave Plowman (News)]

I've found a 5 minute exposure time is about right using my UV box. Normal handling while putting the board in place etc doesn't matter. Either in daylight or artificial light.

[Bill]

In message , "Dave Plowman (News)" writes

Seconded, I've etched numerous PCB and a minute or so of exposure under normal room lighting, incandescent and fluorescent has not been a problem. Compared with the UV light box it is a very small percentage of UV and has had no noticeable effect.

As you are applying your own emulsion you have the ability to experiment before the final exposure, so maybe try a few samples. You can always wash it off and try again under different room light if you think there has been a problem.

>

[Man at B&Q]

Why? Prepare the material immediately before putting it in the exposure unit and you wil not have any problems in normal subdues light.

BTDTGTTS

MBQ

[Graham.]

I think you are looking for a solution to a problem that dosn't exist. No safelight required, just don't prepare them in direct sunlight.

[John Williamson]

+1 If you're still feeling paranoid, just close the curtains and use a 40W bulb in a standard lamp. It'll be okay for a day or so after coating unless the sunlight or flourescent light gets near it.