# Exposing with flood lamp...



## OneOffCustoms (Nov 11, 2015)

Any advice on resorting to a flood lamp to expose ??? 600w


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## PositiveDave (Dec 1, 2008)

You can expose with anything that gives out uv, a 600W lamp doesn't give out much, try this http://www.t-shirtforums.com/t-shirt-articles/t106506.html


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## williekid (Apr 22, 2009)

There is success in exposing with a lamp. You need 1000 watt bulb, I believe I would 28-32 inches above screen and I exposed 13 minutes. All will vary depending what emulsion you are using.


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## outbreak (Jan 9, 2010)

I use two - 500 watt halogen lamps (protective glass removed) about 20" or so below the glass. I expose for 7 minutes with no problems.


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## VR46 (Feb 3, 2016)

I use a 400 Watt lamp, 14/15 Inches above the screen, with a piece of glass too.

Burn time works at 12 mins, but is hard to wash out, so I'm going to try 11mins next time.

I'm a newbie to all this though, so take my advice as you will.


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## Ripcord (Sep 2, 2006)

I tried a 500W halogen for 15 minutes and it washed right out. Don't know what I did wrong.


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## VR46 (Feb 3, 2016)

I had to make sure mine was directly above the screen image i was burning. Make sure it's close enough, 12-15" above it. I used the glass covering from a photo frame. 

Also, you have to take the glass out of the front of the halogen light as it's UV protected and you need the UV to burn the screen.


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## williekid (Apr 22, 2009)

Chances are 400 watts isn't enough, and you should also check the opacity of your film is able to block the light. If 500 watts at 15 mins washed out it is possible your screen is under exposed. Many factors have to be troubleshooted to know what the problem is. What emulsion are you using? Is your coated screen dried completely? Is your light source strong enough? Opacity of your film? Exposure time?


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## sben763 (May 17, 2009)

Wattage isn't the issue here. Distance and amount of usable UV is. A 500w photo bulb at 12"-16" can expose photopolymer in 4 min and dual cure in 7 min give or take. A standard halogen puts out much less usable UV. Glass used can change factors greatly. Standard glass from any home store or glass company contain large amount of iron and will greatly reduce the UV reaching emulsion. A piece of sapphire glass from PPG is about the lowest iron glass and is the clearest glass in the industry. 

Make sure the glass on the flood lamp is removed. Glass on those light are high iron and as have extra filters to reduce UV. Use a uncoated screen to obtain you distance. You just need to cover the area of you screen. The close you are the more UV that reaches the screen and further penetration of the stencil. A fan is recommended as heat can cure most dual cures even in positive area. Getting a 500w-1000w halogen photo bulb is best if your going to be using a flood light.


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## Ripcord (Sep 2, 2006)

williekid said:


> If 500 watts at 15 mins washed out it is possible your screen is under exposed.


Yes it was severely underexposed. Since I already had a working fluorescent light table I didn't pursue longer exposure times because it would take longer than what I'd been using for years. Here in the west we have a lot of sunny days so whenever I can I expose screens in the sun. It takes about one minute and you can't get a better single point light source. (And it gives me an excuse to get outside.)


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## Ripcord (Sep 2, 2006)

sben763 said:


> Getting a 500w-1000w halogen photo bulb is best if your going to be using a flood light.


So the 500W halogen work light that I tried isn't the same as a 500W halogen photo light? ('Cause there's no way that thing could expose a screen in 4 minutes or even five times that. And I did remove the UV filter.)


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## sben763 (May 17, 2009)

Ripcord said:


> So the 500W halogen work light that I tried isn't the same as a 500W halogen photo light? ('Cause there's no way that thing could expose a screen in 4 minutes or even five times that. And I did remove the UV filter.)


Nope. The make up of the filiment will dictate the spectrum and amount of usable UV. Photo bulbs are or were used in photo processing years back. With metals making up a filiment there are limitations and why metal halide bulbs are used. 

You time in the sun seems long. With photopolymer I'm at 10-15 sec and dual cure 30 sec. Although been years since I used dual cure. You are correct that the sun is a single point but many factor effect this. its a very large and the strongest single point available. Correct angle facing for the time of day, UV reflections, ones location someone in FL will expose faster the say someone in CO but only a few seconds difference.


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## Ripcord (Sep 2, 2006)

Is this what I'm looking for Sean? Seems like it could use a reflector behind it. Maybe I'll try one. This one is only ten bucks.


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## sben763 (May 17, 2009)

Ripcord said:


> Is this what I'm looking for Sean? Seems like it could use a reflector behind it. Maybe I'll try one. This one is only ten bucks.


I think you forgot link but probably not. the photo halogens seem to be getting harder to find. Impact FCM Lamp (1000W, 120V) FCM B&H Photo Video

I think this one works well. Ill have to find the info, brain has been on overload with all the testing, engineering I've been doing with my LED exposure unit. I think I still have a 1000w laying around with the numbers on it which is how I was ordering them years ago. I have most of the ones I had to members here so maybe one of them will read this and get the numbers off the bulb.

A good indication that its better then a standard halogen is that it say contains mercury. Standard halogen bulbs are a tungsten filament with iodine or bromine, photo bulbs have mercury gas added in addition or as a replacement to the iodine or bromine


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## williekid (Apr 22, 2009)

If you purchase a 1000 watt bulb it will solve your problems. You can find a pack of 2 bulbs for about 3 bucks. Also what emulsion are you using?


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## sben763 (May 17, 2009)

williekid said:


> If you purchase a 1000 watt bulb it will solve your problems. You can find a pack of 2 bulbs for about 3 bucks. Also what emulsion are you using?


Not all halogen bulbs are create equally. A standard tungsten/iodine halogen in a 1000w is not a fix all. It's best to order the correct bulb so that a strong UV in the correct range is used. I don't want to list the members I sent my old bulbs to but hopefully one will read this and post the huge diffrence. 1 or 2 of them had 1000w lamp from a box box store like Home Depot or Menards. The diffrence is night and day. You also get more full cross linking of the emulsion so finer details and halftones are retained. As I posted in the link above the photo bulbs are $3-$5 a peice. They last 400 hours and dince you expose in 50%-70% faster then a utility bulb last a long time.


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## Ripcord (Sep 2, 2006)

That looks like the one I already have. This is the one I found online


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## sben763 (May 17, 2009)

LOL Neil all the RX7 bulbs look the same. Its what gas inside that counts which is invisable. You can get a Iodine or Bromine bulb at any big box store. The photo bulbs add mercury gas which is what is in Fluorescent bulbs and why the all have the frosted UV filter. Mercury is also one of the components in a metal halide bulb. On a new metal halide bulb you can see some mercury rolling around but usally after the burn in period 1-2 hours its all gone

make sure it says for film, or photo processing some of the bulbs and specifically the ones shaped like you posted are photo enhancing bulbs, and although they are better then the standard bulbs you want the most UV available per watt you can for fastest exposure and best retainage of detail


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