# Home Made Exposure unit



## Kysmiley1 (Jul 14, 2007)

I am looking for some detailed schematics of home made exposure units. Right now the way i do it is kind of ackward. I would like to build one that you can place the screen in close it and set a timer. 
Pat


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## Fluid (Jun 20, 2005)

search the forums for exposure units and exposing. many threads have discussed this and some I believe have posted pics.


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## Paul204 (Apr 21, 2007)

I burn with a home built exposure unit and get good results. My advice to you is to stay away from a timer, though.

It's more advantageous for you to build one that is has a single point light source to burn your images so you get less undercutting of your positive. You can get 1000w metal halide ballasts and bulbs at any hydroponic shop in town.

So long as you don't use a reflector (these normally come with the ballast and bulb) and you buy the right kind of bulb, you will get good results. I looked at the product information on Phillips' metal halide bulbs, and a 7000 degree kelvin bulb is one that outputs the most UV-A light.

Building a vacuum sealing top is not too difficult. Buy a sheet of neoprene (from eBay or from a screen printing shop) and glue it to a frame the same size as your glass. Hinge that frame to the unit, put some weatherstripping on the bottom of it to ensure an airtight seal.

Then, you can just drill a hole in the frame, stick some garden hose into it and attach the other end of the hose to a shop-vac with a universal tool adapter. When you turn on the shop-vac, the screen should be brought into intimate contact with the glass.

The only problem with this set-up is that hydroponic metal halide ballasts are not designed to be turned on and off very often and they take time to warm up. You have to put in a shutter under your glass that you can pull out. You would let the bulb warm up, put the screen and image on the glass, turn on the vacuum, pull out the shutter, and after the time required, push the shudder back in.

This is why I recommend staying away from a timer that would shut the ballast off between every burn, it's not good for the bulb. You kinda have to plan it so that you burn a bunch of screens at once.

I use this set up and can burn great 55lpi halftones in a 196 mesh screen.


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## Kysmiley1 (Jul 14, 2007)

Ok, that helps but i'm not sure where to place the lights, and also is the neoprene glued under the glass. How is the glass held into place. Just a few questions for now
Pat


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## tpitman (Jul 30, 2007)

Instead of neoprene, you can also use pond liner from Home Depot. It's cheap, tougher than neoprene, and convenient. You've gotta build in slightly more slack than with neoprene because it doesn't stretch as much, but it'll pull your screen and film down tight to that glass. I bought some, then ended up using neoprene. When the neoprene got too many holes in it, I figured, what the hell, I've got the pond liner, I'll try it. It's all I'm ever gonna use.


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## Rmatheson (Jul 12, 2006)

Heres a few pictures of my home made Exposure Unit ? Just e-mail me for ? I can burn a screen in 2 min with this. works very well [email protected]

Image 1: http://www.cliparttrading.com/exposure_unit/1
Image 2: http://www.cliparttrading.com/exposure_unit/2
Image 3: http://www.cliparttrading.com/exposure_unit/3


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## rrc62 (Jun 2, 2007)

Rmatheson said:


> Heres a few pictures of my home made Exposure Unit ? Just e-mail me for ? I can burn a screen in 2 min with this. works very well [email protected]
> 
> Image 1: http://www.cliparttrading.com/exposure_unit/1
> Image 2: http://www.cliparttrading.com/exposure_unit/2
> Image 3: http://www.cliparttrading.com/exposure_unit/3


Is this metal halide or halogen?


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## Rmatheson (Jul 12, 2006)

500 watt halogen shop light i had.


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## rrc62 (Jun 2, 2007)

Rmatheson said:


> 500 watt halogen shop light i had.


 What are you using for emulsion? 2 minutes is impressive for a 500W halogen. I'll probably build a 1000W halogen this week. My black light florescent is just not making it.


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## Rmatheson (Jul 12, 2006)

I use s.e.x. emulsion for Performance screen supply 1 year shelf life.
I coat only one side of my screens.

14pg15


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## AustinJeff (May 12, 2007)

Here's a good video:

Youtube Exposure Unit

He discusses the type of light source needed, the importance of using single-point source, and the proper distance of the screen from the light.

He gives an email address at the end where you can send for plans. 

I built one of these, and it was very easy to build, inexpensive, and works fine (though I haven't tried it for anything particularly demanding.) My only complaint is that the halogen light is really freakin' hot.


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## moolashirt (May 23, 2007)

Rmatheson said:


> Heres a few pictures of my home made Exposure Unit ? Just e-mail me for ? I can burn a screen in 2 min with this. works very well [email protected]
> 
> Image 1: http://www.cliparttrading.com/exposure_unit/1
> Image 2: http://www.cliparttrading.com/exposure_unit/2
> Image 3: http://www.cliparttrading.com/exposure_unit/3


Hi Bro...
I also used the same specs for my exposure unit. (Halogen 500W)
Coz i'm still new in this t-shirt printing, my exposure time is 5 minute...
So for 2 minutes exposure time from your quote, it is a really-2X  good info there....
Hahaha...


Thanks mate!


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## shift_lock (Oct 21, 2007)

Rmatheson said:


> I use s.e.x. emulsion for Performance screen supply 1 year shelf life.
> I coat only one side of my screens.


How does only coating one side of your screens work out for you and what is the reason for only coating one side?


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## Rmatheson (Jul 12, 2006)

I only coat one side so i can get the finer Detail and half tones with my _home made Exposure Unit. in two mins ive been using it for about a year now and seems to work just like the good ones._


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## rrc62 (Jun 2, 2007)

I've been researching metal halide. It's really not that expensive. A bulb, ballast and reflector is around $200 from the hydroponic store, give or take a few dollars. Add another $100 in materials for a metal cabinet with vacuum hold down frame and I should have a 1000W MH unit with vacuum for between $300 and $400.


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## shift_lock (Oct 21, 2007)

Rmatheson said:


> I only coat one side so i can get the finer Detail and half tones with my _home made Exposure Unit. in two mins ive been using it for about a year now and seems to work just like the good ones._


Which side do you coat and how many shirts can be inked before it wears out?


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## Rmatheson (Jul 12, 2006)

Coat bottom side not ink side and it never wears out, Ive done about 500 and it was looking good could of done a lot more.


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## Rmatheson (Jul 12, 2006)

Rmatheson said:


> Heres a few pictures of my home made Exposure Unit ? Just e-mail me for ? I can burn a screen in 2 min with this. works very well [email protected]
> 
> Image 1: http://www.cliparttrading.com/exposure_unit/1
> Image 2: http://www.cliparttrading.com/exposure_unit/2
> Image 3: http://www.cliparttrading.com/exposure_unit/3


 


Update 
http://www.cliparttrading.com/exposure_unit/exposure.jpg


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## Kysmiley1 (Jul 14, 2007)

I have my main box made, but now I need to make the top. I am not sure how to go about making it so when I close it it does not close too tight that it breaks the glass, yet it needs to be tight enough to hold the screenj firmly against the glass. Some suggest using pool liner inside the top with a shop vac to ensure a proper seal. Does anyone have pictures of their top and how the vacum unit is placed.
Pat


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## madaradio (Nov 12, 2007)

Here's my homemade unit. Got the plans from Roger Jennins. I use a 500w halogen light and I made a stand out of some abs pipe. 25-30 minute exposer time. I may try the shiny metal on the inside for a quicker time.


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## Rmatheson (Jul 12, 2006)

Thanks for the picture cool way of do it with pipe.

Any way if you take the glass off of the 500 watt light you will get faster exposure time that glass holds back the uv rays. I think i read that some were.


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## SOBER (Aug 6, 2007)

wow!! so what distance is the light from the glass? and how good are the halftones comin out?


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## madaradio (Nov 12, 2007)

Rmatheson said:


> if you take the glass off of the 500 watt light you will get faster exposure time that glass holds back the uv rays. I think i read that some were.



Hummm... That's an interesting idea. I may try that. I think I'll also try the sheet metal on the side to reflect the light. That was a good idea.

Also, I'm thinking about making a vacuum sealed top. We'll see though... I want to keep this homemade project as low costs as possible, just for fun. At present, its cost me around $30 to make.


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## Rmatheson (Jul 12, 2006)

madaradio said:


> Hummm... That's an interesting idea. I may try that. I think I'll also try the sheet metal on the side to reflect the light. That was a good idea.
> 
> Also, I'm thinking about making a vacuum sealed top. We'll see though... I want to keep this homemade project as low costs as possible, just for fun. At present, its cost me around $30 to make.


 
Let me know how you are going to do the vacum top. I was thinking about it and have a few ideas.


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## kel don (Nov 10, 2007)

*Rmatheson i just received some S.E.X. *_ emulsion to try... have you ever coated both sides? if so....using your home built unit how long was the exposure time? i am not worried about fine detail or half tones. also, with a 500 watt halagen bulb and a funnel shaped unit under the glass, how do you controll the heat build up? do you find that it is not a problem do to short exposure times? i am new at this and am trying to get my mind around all the info being found here. thanx don _


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## smitee (Dec 18, 2007)

Hi. I’m want to start screen printing and have been looking into making one of these, so thought I’d get in on this thread.



madaradio said:


> Here's my homemade unit. Got the plans from Roger Jennins.


Have you still got those plans? I emailed Roger a few days ago but haven’t heard back.


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## funkymunky (Dec 8, 2007)

Hi guys,
It appears that here in the U.K we expose on a budget in a different way

The main differance is that we expose from above rather than below. I have just purchased my exposure unit from Ebay here in the U.K and was looking for one currently listed so I could post a picture easily, but guess what ? None currently listed.

Basically it is constructed from a purpose built aluminium frame on top of which are two external 500W halogen light units which shine down upon your coated screen. There is a switch fixed to the frame also to opperate the lights. Included with the light unit is a 'slab' of charcoal coloured foam which fits inside a 20 x 24 frame. Apparently all I have to supply now is a sheet of glass to place over my artwork to produce a vacuum.

I will post pics when I get the unit out of the box and assemble it but this will not be until we move premesis in the New Year !

Phil


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## Rmatheson (Jul 12, 2006)

Cool i cant wait to see what it looks like.


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## Black MacGuyver (Jan 30, 2010)

I have built one myself, tested it and it burns perfectly. See my pics at www.blackmacguyver.webs.com good luck. give comments and thoughts. Thanks


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## Black MacGuyver (Jan 30, 2010)

Check out my exposure unit and homemade 4 screen press. The exposure unit was pretty simple from materials used from unused things around my shop. http://www.blackmacguyver.webs.com


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## the_um (Sep 25, 2009)

AustinJeff said:


> Youtube Exposure Unit












This is how I image what he is trying to say. Should I put a dark cloth over the whole thing so light doesn't go through. Is this image I drew completely wrong?


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## werdizthaword (May 13, 2008)

i use a homemade with a 500 and burn in 2.5 mins.....and also only coat 1 side....the emulsion i use is the ulano qtx....or which ever the purple one is.....i used to use the pink but way to expensive....looking to upgrade my exsisting one with the black lights and possibly vacuum...esp since i left plenty of room for mods...it is a 4ft x 6ft box with 3 500s halogens and 1/4 inch plate glass....


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## edward1210 (Nov 7, 2009)

rrc62 said:


> I've been researching metal halide. It's really not that expensive. A bulb, ballast and reflector is around $200 from the hydroponic store, give or take a few dollars. Add another $100 in materials for a metal cabinet with vacuum hold down frame and I should have a 1000W MH unit with vacuum for between $300 and $400.


 Here is my exposure unit, 2 500 watt halogen lights.
3Mins and 25 seconds.
screen came out perfect.


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## selanac (Jan 8, 2007)

Nice job. $20 for the shop lights?


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## edward1210 (Nov 7, 2009)

how many inch below the glass?
Thank you


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## edward1210 (Nov 7, 2009)

how far do you have your 3 light from the glass, i'm having the so hard time now, I used to have two light, and used another emulsion sati, but i change to hifi, the center of the image burn ok, but the size or edges not washing out.
Thank you for your help


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## patlew (Jul 10, 2012)

I made this one about a month ago and it has been working great. 2 min burns and vacuum top is very helpful. PM me and I'll give you the info if you are interested.

Best of Luck!


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## InkedApparel (Mar 18, 2009)

patlew said:


> I made this one about a month ago and it has been working great. 2 min burns and vacuum top is very helpful. PM me and I'll give you the info if you are interested.
> 
> Best of Luck!


very nice , thats how a home built exposure unit is done!

Inked


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## selanac (Jan 8, 2007)

Patlew, how long does it take to burn/expose


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## InkedApparel (Mar 18, 2009)

> 2 min burns and vacuum top is very helpful


looks like 2 minute burn time...if you read the post!

Inked


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## sweetts (Apr 4, 2010)

What emulsion are you using


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## patlew (Jul 10, 2012)

I use Ulano QTX pre-mixed emulsion. Burns in 2 mins. I use to use a 500w halogen work light 20" under the glass but it was taking 12 mins to burn a screen and glass was getting too hot. Had to put a fan on the glass while burning. Black lights are much better and faster. There is much talk about under cutting of the image/screen but I haven't noticed it. Just make sure the image/screen is tight.

Best of Luck!


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## patlew (Jul 10, 2012)

InkedApparel said:


> very nice , thats how a home built exposure unit is done!
> 
> Inked



Thanks InkedApparel!


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## miktoxic (Feb 21, 2008)

i wanted to ask if it's possible to convert this light box i have for tracing purposes to a lightbox for exposing screens.

here's what the unit looks like:



















i bought this of ebay for the purpose that i mentioned but was hoping i could just switch out the bulbs and use it to expose screens. i'd have to replace the white mylar that inserted to trace an image by hand with glass, but after seeing how this guy made this unit.......

it's essentially 5 small untis that are usually used for under the counter kitchen lights that each have their own on/off switches (obviously all turned to 'on' since the is a switch on the outside of the unit that turns the unit on altogether.

the units themselves are 120 volt 60hz 8 watts but then it says 120v 70 watts max on the other side. the bulbs themselves look very small and are 12" long.

any electrical genius out there that could tell me if i could just replace with black lights and have it work or should i start planning on making a unit from scratch.


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## Ujudgnme2 (Mar 28, 2006)

I am considering a unit using sheet metal instead of wood or a metal box to start with but I cant find the correct metal box.


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## tpitman (Jul 30, 2007)

miktoxic said:


> i wanted to ask if it's possible to convert this light box i have for tracing purposes to a lightbox for exposing screens.
> 
> here's what the unit looks like:
> 
> ...


The problem you'll have is finding unfiltered blacklights that size. I don't know if they make them. Shortest unfiltered blacklights I've seen are 24" long. Can't use the purple party bulbs. You could reuse the box and glass if you can fit fixtures in it that will hold the correct bulbs.


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## Ujudgnme2 (Mar 28, 2006)

patlew said:


> I made this one about a month ago and it has been working great. 2 min burns and vacuum top is very helpful. PM me and I'll give you the info if you are interested.
> 
> Best of Luck!


 
I sent you a bunch of questions -- you might want to post the answers here.


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## Ujudgnme2 (Mar 28, 2006)

can I make an exposure unit from a 2 drawer lateral filing cabinet? I really want a metal cabinet for my unit ...thought about framing it with wood and adding metal for the sides.


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## selanac (Jan 8, 2007)

Do you really need it or did you just want to make something?


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## throde (Feb 19, 2013)

Where can you get the black light setup. Not the box jut the light fixture


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## selanac (Jan 8, 2007)

You can visit your local Lighting store and have them order an Unfiltered Black Light. 

Once I ordered online, and the company took like a month, and still never found the light. They said it was on back order because they moved. The company was 1000 lights. 

I believe they just take orders and then wait until they find a broker sellings lights. 

We changed to using a Halogen Shop light and it works really well.


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## throde (Feb 19, 2013)

Ok thanks sounds like shop light it is


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## patlew (Jul 10, 2012)

Hi Guys,

Ok, so I have had many questions about the exposure unit I made so I'm gonna give you some details.

1) The lower box is 28"x30"x5.5" made from 2"x6" I had laying around with a 1/2" plywood bottom. 

2) The glass was one of the most expensive pieces of the build. It is 28"x30" @1/4" thick and make sure to tell them you DO NOT want it to block UV. Cost me about $70. Maybe your local glass shop will be cheaper.

3) There are 6- F20T12BL 24" fluorescent bulbs that I got from lampline lighting inc. online for $5.40 each. One of the bulbs was bad when I turned the box on and the folks there at lampline sent me a new one no charge. I thought the bulbs were pretty cheap but maybe you can find at a better deal. The bulb holders are T12 (12 ea.) from semperlite.com at $.62 P/N LH0652 and they are just screwed into the plywood. The 3 ballast are Advance HM-2SP20-TP each suppling power to 2 bulbs also screwed into the plywood. Got them off of ebay. Wiring is very basic and the diagram is on the ballast itself. The ballast were wired together and to a standard plug. A switch can be incorporated but I just plug it in and remove it when the time is up.

4) The top is made from 1.5" wood that was screwed together and reinforced with a angle brace in each corner. The vacuum material was had from a local recycle store. It is the same material used on an umbrella. Basically any material that you cannot blow thru will work ie plastic sheet, neoprene. On the top material I had to make it extra big because it doesn't stretch like neoprene. I made a small hole in it at the corner and reinforced it with screen tape top and bottom. The valve used was a tire valve stem from a car wheel that has a nut on the back side. Rubber stems won't work, has to be one for mag wheel but any wheel shop will probably have it. The vacuum top was just attached with spray glue and wrapped around the top frame. Make sure to leave excess material so it will form to the screen under vacuum. Where the top frame meets the glass I used 1.5" wide closed cell foam weather stripping on the perimeter which I got from my local hardware store. I used regular door hinges on the back side but any hinge will do. The top is latched down in the front by a couple of suit case latches from the hardware store. The vacuum top stem is attached to a rubber hose and then I have it tapped to the hose of a small shop vacuum cleaner. 

That's pretty much it. Nothing fancy but it does the job and for a fraction of what you will pay for store bought unit. The vacuum top makes a huge difference in keeping the film positive tight against the screen.

I hope this helps everyone. If you have questions or need detailed info, PM me and I'll get back to you.

Thanks for reading and Best of Luck to everyone!


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## Ujudgnme2 (Mar 28, 2006)

awesome -- thank you for being so detailed with the response and your time.


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## isded12floz (Mar 22, 2009)

Patlew has it all rght. My unit looks almost identical to the pics posted. Part numbers are even the same on the bulbs. I'm looking to add some vacuum action as well but lines have been tight so no worries.

The comments made about the bulbs and the glass should be taken truths. Got my "special" glass from a local glass shpp and it was about 70 dollars as well. Without the glass allowing the uvs to pass though you'll be there hours not minutes.


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## selanac (Jan 8, 2007)

As far as the Glass goes, I bartered for it. Gave someone free artwork and an Ad on a compaign I was doing. 6 Ads on a mug, they received one. 

I had done a 1/8" before, and ended up giving it to a friend of mine when I bartered for the 1/4".


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## selanac (Jan 8, 2007)

Patlew, what about exposure time? Have you used it yet to exposure your films?

Sorry, Just went to Page 3 and saw you mentioned 2 minute burns. Very nice.


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## 2020 PrintWorks (Apr 22, 2011)

I'm building mine now. Just using 4 bulbs for now. We'll see how that goes. I'll add more if I need to. The Vastex I used to use only had four black light bulbs and it burned screens in about 3.5 mins.


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## patlew (Jul 10, 2012)

Thanks guys and I give thanks to all those who have posted in the past. Without this forum I wouldn't been able to do half the things I'm doing now. 

Best of Luck!


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