# Exposure unit - build it or buy it?



## airraidapparel (Jul 6, 2007)

Hey guys, 

I want to upgrade to a better exposure unit (flood light isn't cutting it anymore). I was researching and I can get a decent sized UV exposure unit for around $450 + ship. I also came across plans to build what looks like the exact same thing for around $100 in cost of materials (+ time). In your guys' opinions, is it worth it to try to build one that may or may not work out for $100? Or would it be better to invest in an already built unit for over 4x the amount.


----------



## Six (Oct 10, 2007)

from experience, the cheap way usualyl ends up the most expensive. go with quality first it will save you $ in the long run... but i digress,

i use 2 blacklights under a piece of glass for my exposures...so far so good. cost me $100 AU


----------



## airraidapparel (Jul 6, 2007)

Six said:


> from experience, the cheap way usualyl ends up the most expensive. go with quality first it will save you $ in the long run... but i digress,
> 
> i use 2 blacklights under a piece of glass for my exposures...so far so good. cost me $100 AU


Well, I guess that sort of contradicts itself. I do agree about the cheap way being the more expensive way in the long run for most things, but in theory this is just a box with lights in it. Do you use the kind of black lights that you buy in party stores? or the kind from hardware stores?


----------



## Six (Oct 10, 2007)

party stores, ie the ones that make glow in the dark stickers go nuts !!

i guess with this i cheaped out and it works so far,

but in hindsight the reason it's cost me so much more this way is,

purchasing of materials, doing entire screens myself, exposing, buying new printer testing, re testing, changing idea, testing again. by the time and $ i have spent so far it would have worked out better for me to have had the screen print place burn my image into a screen.

eh win some you loose some.


----------



## jlcanterbury (Jul 26, 2007)

if you have any experience on electrical wiring, then building an exposure unit can be very cost effective and will produce the same results as many commercial units. However if you end up buying all the materials, and then fail to produce a working unit then you have just wasted a lot of money.

Make sure you buy fluorescent blacklight bulbs... you can find them at topbulb.com (link below, but beware my order from them took one month because the bulbs were backordered and then they forgot to ship, if you can find similar bulbs elsewhere use that option)

TopBulb.com - Product List


----------



## brent (Nov 3, 2006)

Topbulb did a similar thing to me. I needed 4 white blacklight bulbs and order 5, so I'd have an extra. They shipped 3 and put the other 2 on backorder for weeks.

Building a good unit yourself can provide an exposure unit that will suit you fine until you need to do more detail. Vacuum lid works way better than a compression lid, like my unit had. I recently got a HIX tt-180 table top unit and haven't had any screens not come out extremely well. With my homemade unit, perhaps a 4th of my screens didn't come out right, wasting my time and emulsion.


----------



## airraidapparel (Jul 6, 2007)

Six said:


> party stores, ie the ones that make glow in the dark stickers go nuts !!
> 
> i guess with this i cheaped out and it works so far,
> 
> ...


Six-

What was your exposure time with 2 black lights?


----------



## Six (Oct 10, 2007)

exposure time for me is 7 minutes


----------



## scottlanes (Sep 23, 2007)

i'm getting set up to burn my first screens and was going to build my won exposure unit. I was planning on using a 500w home depot-type flood light but the black light idea also seems interesting. how does black light compare to flood lights? also, does anyone have a link to plans for a blacklight unit?

thanks!


----------



## TeddyRocky (Mar 23, 2007)

Is time precious to you? If your time is worth money, I would buy a pro. unit and save yourself trouble. Also think about if you wanted to sell your equipment later on, at least you will get some money back. Not many people are interested in buying home built equipment.


----------



## DesignsToSigns (Aug 4, 2007)

I built mine for probably 100 dollars if not cheaper, Lost a lot of time getting it to expose properly, but if you are slow and handy I would do it, I think I am exposing for 3 minutes now... not to bad for home made without a vaccum


----------



## scottlanes (Sep 23, 2007)

TeddyRocky said:


> Is time precious to you? If your time is worth money


it is, its just that there arent enough people paying for my time yet to allow me to afford a commercial unit  I agree with you in principle tho


----------



## scottlanes (Sep 23, 2007)

astours said:


> I built mine for probably 100 dollars if not cheaper


is it a quartz/halogen type thing or is it blacklight?


----------



## sg613 (Jul 19, 2007)

Does anyone know where to get these BL Fluorescent bulbs in Canada. I looked at Home depot and all they had were the Hippie style purple ones. They did have some that were for growing plants and aquariums. I almost bought them thinking that they emit the proper amount of UV but just wanted to check to see if anyone knew if these were the right ones. Any ideas?


----------



## DesignsToSigns (Aug 4, 2007)

Black light and I purchased them online from Topbulb.com


----------



## fooledbyfresner (Feb 24, 2008)

I've been screen printing for about 15 years. I've had my own shop and worked for others and about 2 years ago reopened my shop. I've built a few different types of exposure boxes trying to save money. I've used floresent, black light, haligon, and sodium halide street lamp mounted in a box. The UV box was way too costly for what it was. The lamps burn out quickly, and my burn out I don't mean completly burn out- they just start getting less powerful and your times start going up and you waste alot of exposures. That can really leave you in a lurch when a job is pending. Aside from the fact that flouresant and black light are multiple direction lights and effect your image- they are not realy good for anything other than burning spot colors with easy registration. The haligon was by far my best and most consistant method. Only use one so that your light source is directional and does not shrink your image. When the black light box left me in a lurch I dug up the work lights from my old unit and simply taped the image to the screen, clamped a peice of glass on and leaned it toward the light sitting on the floor until I could figure out what to do next. I've been getting progressivly busier and busier and more people want half tone jobs for which you need a good strong single point light source and a good vacume balnket. I bought the Work hoarse Photosharp unit and eliminated a whole point of stress in my daily life. I never have to burn a screen twice and the contact is perfect. I'm doing alot of process printing with tiny halftone dots and this is the only way. There are so many other things to worry about in printing, this should not be a factor to deal with.


----------



## Gator9470 (Aug 7, 2008)

Hey, I'm new to screen printing too. I just built an exposure box using 2 24" shop lights with 4 fluorscent black lights. NOT the kind you had as a kid that were purple in color. The ones you need are black lights but they glow a bluish white and they dont filter the UV. I havent had time to get my exposure times down yet. I bought the lights online, got all 4 lamps for $28 with free shipping from a place in California. The sight is called Sandy the Lighting Girl...lol. Sandy if a trip to talk too but she is cheap and ships fast. Just make sure she knows you want the UNFILTERED black lights, F20T 12BL.


----------



## night rider (Jun 19, 2009)

after some trial and error and continuing trial n error, we have a working exposure unit. 

we have a 400w UV light that cost us just over 100 inc shipping built a lil box for it and the glass for up top. 

we did a screen in 10 mins without the box. havent done it with a fresh screen with the box yet hopefully cuts it down a lot and the bulb - uv doesnt fade to quickly and hence increase times. we are clothing company so not as often prinitng as screen printing but will b doin lots of desings n trial n error.


----------



## macumazahn (Jan 11, 2007)

I built a single point metal halide exposure system. The short answer is that is was way cheaper than a commercial system but it is not without its problems. First was the glass which was surprisingly difficult to source due to the need for it not to have a uv resistant coating, and the thickness and size. Then came finding the electrical set up which I got off of ebay, and the bulbs can be expensive as well. All and all it was a lot harder than I expected to get something that worked but it still costs a lot less than the alternative. Its really a trade off, you are trading your time in searching for components, building, troubleshooting and testing, and a myriad of other variables for cost savings. The only question is whether you are willing to make that trade.


----------



## Florafreak (Sep 22, 2010)

I recently built my own, and it will end up costing about 500$ though far worth it I think. 

I also tracked the build progress in its entirety, Exposure unit build | Facebook

hope it helps.


----------



## tpitman (Jul 30, 2007)

A commercially-made metal halide unit is usually the last piece of the puzzle that printers put in place when building their shop, but I've never met one that didn't say the difference between it and the ones they built over the years were like night and day, regardless of how nice the homemade ones were. I've built 3 and my storebought exceeds expectations.


----------



## ShirlandDesign (Nov 29, 2009)

I have worked in 5 different screen print shops over the last 15 or so years 4 of them with point light sources and I have to say the 1 home made unit had them all beat. Quicker and spot on exposures, cheaper and less expensive to maintain. Coudray said point light is the best and he certainly would be the one to know, but that hasn't been my experience.


----------



## varsityink (Jul 29, 2009)

My box holds 2 screens, and is homemade, works just as good, and we do ALOT of halftones. Perfect ones. I don't know how much it cost to build, but it was cheaper, just doesn't have a vacuum. We have heavy square pieces covered in a nylon fabric that we set inside of the screen to get a nice flat screen on the glass surface, and 5 minutes later, my 2 screens are ready. Works like a charm, never had to replace the uv bulbs (I think mine are the unfiltered blacklight ones as well-blue light), but a timer on it and set it, and it when it shuts off I wash them out no problem. My washout booth is way better than anything you can buy and it is homemade too. Holds 4 screens, is deep, and has a misting system you can turn on to wash out burned screens while you are doing something else.


----------



## SoloStampede (Aug 4, 2007)

I built a 24x22" exposure unit out of book shelves and 8 under cabinet lights. I replaced the cabinet lightbulbs with UV bulbs from topbulb. And then I bought a thick piece of 24x24 acrylic from dickblick.com. You don't need to know any wiring crap. the under cabinet lights have cords.


----------



## ELLECTRICFEEL (Dec 11, 2010)

what is the difference between using metal halide bulbs and unfiltered blacklight tubes? I want to do be able to print both half tones and solid colors but more so the half tones.


----------



## SoloStampede (Aug 4, 2007)

ELLECTRICFEEL said:


> what is the difference between using metal halide bulbs and unfiltered blacklight tubes? I want to do be able to print both half tones and solid colors but more so the half tones.



both will work, but all I can think of is maybe uv bulbs are cheaper...


----------



## varsityink (Jul 29, 2009)

exposure time is the main difference. I expose my screens with unfiltered blacklights in five minutes, while metal halide can be done under a minute, usually about 30 seconds.


----------



## jiarby (Feb 8, 2007)

This thread made me think of the balance of life...

Everything seems to boil down to this:

"Do it myself or pay someone else to do it..."

The correct answer depends more on YOU than on what other people have been able to do. 

Obviously, with the right mix of talent and skill, intelligence and determination, capabilities and resources you can do just about anything yourself. 

That is where the hitch comes in... 

Often someone asking this question has neither the resources nor the capability to do it themselves or they would have already bought what they need or already be in the garage making it. 

You want to be in the shirt business....

If you have enough resources you would just buy your shirts already made by someone else. Then you can keep doing whatever it is that makes you money. If you can earn $75/hour then do not do any work you can pay someone $15/hr to do for you. That is the idea. You do not do dishes, housework, landscaping, printing, design, etc... You pay people to do that while you manage your business. You job out manufacturing and focus on distribution and sales because that is where you make your money. 

Can't afford that? OK... then set up yor own shop. Buy tools needed to manufacture them yourself. 12 station automatic press, Exposure, Dryer, Flash, Washout, etc... Lease a MFG building and hire a crew to do the work. You focus on distribution and sales because that is where you make your money. 

Can't afford that? Ok... Buy your own equipment and lease an industrial warehouse space... but do all the work yourself. Get a manual press, 6-8 color. In addition to your manufacturing and design responsibilities, you are also responsible for distribution and sales because that is where you make your money. 

Can't afford that? OK... start with a manual table top, 4-color, 1 station (like a Ryonet Silver). A small flourescent exposure, an itty bitty conveyor dryer, a washout booth, pressure washer. Set up shop in your garage or mother's basement. You focus on distribution and sales because that is where you make your money. 

Can't afford that? OK... build all your own equipment. You are pretty handy and have lots of mechanical skills and tools to build stuff. Maybe you are just a cheapskate and hate paying $2000 for something that you can build for $250 in parts. So, build your stuff, set it up in your garage, design and manufacture your shirts and then focus on distribution and sales because that is where you make your money. 

No tools/skills/experience? That's OK...Ask for advice somewhere in a forum on the internet. There are 1000's of people online that have done exactly what you are thinking of doing. Do the internet-vulcan-mind-meld and get the knowledge you need. Then borrow tools from your brother/neighbor/dad/father-in-law and start building something. That is how you get the experience. 

You do not want to mess with that? Setup an account with an online fulfillment company like Cafe Press or Zazzle... upload your designs and sit back and wait for the money to come rolling in. 

Don't forget the most important thing about your business...

Focus on distribution and sales because that is where you make your money. 

Without distribution and sales you do not need to bother manufacturing anything... later on someone will be buying your homemade gear on craigslist because your wife wants it out of the garage!


----------



## jayman2143 (Nov 22, 2008)

In my opinion, buy it. I built my first exposure unit and I was not getting consisten burns. It was so unreliable and it made me so frustrated.

I then bought a professional exposure unit and it solved all the problems that I had. It may cost money now but it will save you a lot of time and stress.


----------



## SoloStampede (Aug 4, 2007)

If you have basic carpenter skills, I would build it. All an exposure unit is is a series of light bulbs laid out in a column. Its really not difficult at all.


----------



## jiarby (Feb 8, 2007)

I am building one too! I am one of those cheap bastards that hates paying $2000 for something I can make for $200.

Go for it! It is pretty easy.


----------



## BroJames (Jul 8, 2008)

Why buy if you can build it at a fraction of the cost?

If you have a large business to run or don't have the time or the DIY skills for it, and have the funds, then buy it. I am sure that peace of mind comes along with it. It should in my mind. If you are printing small scale, just starting up, etc, build it. Money saved is money earned.

I started burning with a household fluorescent unit. Takes me 12-15 minutes to burn a screen. Then made my on 500w halogen unit. Burn time at 18-24 inches is 5-6 minutes. Tried a 1500w halogen unit but too hot for me so shifted back to the 500w halogen. Then I DIY a 250w mercury vapor lamp that burns in 1 minute to a minute and a half. Next is a 500w mercury that exposes in less than a minute. Now, I've switched to a 400w metal halide unit. Along the way, except for finding the correct exposure time especially with the mercury lamp, I have not experienced the problems as mentioned above. Granted I do not expose as many screens a full scale shop does, and I did not have the opportunity to compare it with a commercial unit, however, I did not shell out $3-4,000-plus another grand or two in shipping and custom duties. 

For people who have the funds and bought a commercial unit, I think that is a good business decision. For people on a smaller printing scale, especially with lesser funds and opted for a DIY, I also think they made a good business decision. In our country, except for the larger and newer print shops, I think almost an entire industry was founded on DIY multi-directional household fluorescent units, DIY presses, DIY flashcures, DIY ovens, etc. Except for the ill-managed shops, I don't think they are losing out to modern print shops in terms of quality. Many shops with automated and imported manual presses, imported and branded exposure units, etc, outsource their jobs to these DIY shops. They wouldn't do so if the quality is sub par.

I recently read an article, forgot where, that claims that a vacuum top is necessary. As I said, I have not used a commercial exposure unit. However, I have tried a DIY vacuum top. Granted that there are other variables to consider and the test is not exhaustive, aside from the extra time and noise from the vacuum suction, I don't seem to notice any difference. Well, except that my wallet is lighter but $20 for the DIY vacuum top.

I am sure that a vacuum top is helpful especially in reducing or controlling the variables that may affect exposure quality. It also ensures the best possible film contact. However, the article I read simply stated that placing weights on top of the frame for contact, let's say 40 lbs, is no match for the 2500lbs or so equivalent pressure that a vacuum top can apply to the transparency. Now, I am just thinking out loud, with the ink on the transparency in direct contact with the emulsion, what could a 2500lb equivalent pressure do that a 409lb weight could not do. Granted that there may be some fine differences down to the microscopic level, I don't think people walk around with microscopes. 

IMHO, unless some screen printing manufacturers develop and/or released an integrator for sun exposure units, I don't think they have the best interest of printers in mind. At most, we're only secondary to their pockets.

_Edit: I am not against commercial equipment. If I have the funds and not the time, and want peace of mind, I'd buy commercial equipment and tools.The halide bulb doped for to produce the best UV for exposure and the light integrator are 2 very compelling reasons for a commercial unit. But I think that in some instances, the advantages of commercial products are overhyped._


----------



## tpitman (Jul 30, 2007)

BroJames said:


> Why buy if you can build it at a fraction of the cost?
> 
> IMHO, unless some screen printing manufacturers develop and/or released an integrator for sun exposure units/I]


Oddly, I recently saw somewhere a thread that mentioned a device capable of indicating full exposure using sunlight. The downside of using the sun, obviously, is hauling the exposure setup in and out of the shop, depending upon how heavy it is, or night shots. Kind of hard to beat the sun for a source of UV, though.

As for vacuum tops, their advantage is in their ability to apply EVEN pressure across the entire image, in addition to pulling the face of the film and the ink itself into virtually microscopic contact. It helps in getting better halftones and very thin lines, and to help negate the scattered light undercutting effect of multiple-bulb exposure units. It's a relatively cheap way of eliminating a variable in your exposure routine.


----------



## BroJames (Jul 8, 2008)

If you come across that sun exposure article again, maybe a new thread would be of interest. Who knows, in some not so distant sci-fi future, UV-sensitive optic cables, can actually deliver the UV-A we need indoors.

As to the vacuum top, there is no argument of its benefits for establishing a guaranteed full contact between transparency and emulsion. My comments above on commercial exposure units is based on the comparison between a 40lb weight and a vacuum that is said to exert the equivalent of about 2500weight and is a necessity. If one compares a vacuum top with an improperly "pressed" transparency then the differences would indeed be intolerable making a vacuum top a necessity. But for a 2500lb equivalent pressure to yield a noticeable superior contact results than a 40lb evenly applied pressure, applied to a dried and solid ink that is already in full contact with the dried and solid emulsion, is a little incomprehensible for me. *How much more contact can one really squeeze out of these dried and solid objects that a 40lb pressure can't?*

I am not saying that is not true, not trying to argue on the benefits of a vacuum top which I have already acknowledged, but just incomprehensible for me that a well pressed transparency should fare poorly and must be necessarily replaced by a vacuum top_(I've tried a DIY vacuum top but acknowledge the possibility that maybe my lower end printer and my not so perfect UV lamp may not be up to the task of creating a perfect emulsion negating the visible advantages of a vacuum pressed top over an evenly balanced weight pressed top)_.

Possible poor results may be from uneven pressure. Uneven foam pressure as some brands do soften up a bit much sooner. The hardness or softness of some of these foam may be grossly uneven in the first place. Warped boards beings used on top of the foam like this once almost perfectly level plyboard 
[media]http://i7.photobucket.com/albums/y295/BroJames/silkscreen/platenlevel.jpg[/media]Click on the picture. Look at the far end of the board. It has a notch and a metal support because you are seeing the underside of one of my modular platens. This platen was as level as a plyboard could be._

Note: Make sure that the board you use on top of the foam is perfectly level. Use a metal that you know is perfectly straight and lay the edges of that metal across the board to check if the board is level. A light source at the other end will help make you see the features of the board more easily. Wood does not always warp forming a valey and through. Sometimes you can see several small valleys and throughs and usually woods with these appears to be even to the naked eye._

People using weights to press the transparency against the board should use a foam or other soft material which can help disperse the weights, use a perfectly level board on top of the foam(You can also use a glass or ceramic tile) and regularly check if the board is still level, and placed weights evenly across the board. In this respect, an uneven board negates the purpose of an evenly distributed weights.

Again, buy a commercial unit if your business is big enough and/or if you can afford one. It makes no sense to disrupt your business with experiments or adjustments. However, don't be afraid to build your own unit. Just understand the variables involved and do your best to put them under control.


----------



## JayJaySerious (Sep 19, 2007)

I saw this article, but haven't tried it:

Just Seeds: Blog: SILKSCREEN POWER: How To Build a Portable Silkscreen Exposure Unit


----------



## poker (May 27, 2009)

I plan to build an exposure unit and use it for what it can do. But if for reason I'm faced with an order that requires a high end exposure unit then I'll just take my films and screens to a local pro shop to get them exposed. They said they would do it for $15. 

I think I'll have the best of both worlds this way.


----------



## BroJames (Jul 8, 2008)

JayJaySerious said:


> I saw this article, but haven't tried it:
> 
> Just Seeds: Blog: SILKSCREEN POWER: How To Build a Portable Silkscreen Exposure Unit


Now that's lightweight and mobile. I think they're the same as what we refer to T5 sized lamps. I do wonder how many minutes it takes to expose a regular emulsion.

One could also use regular 18-201 UV lamps with those plastic multi-purpose box to make exposure. Box would be larger though but nonetheless mobile enough. I've seen some large enough to accomodate these UV lamps.


----------

