exposure problems am i doing it right?

[workshoprat92]

Ok I purchased the speedball products from the local art store. I also checked michals and hobby lobby and they both sell speedball products. I cant say I am impressed with speedball. Their directions are abysmal. I guess the directions are good for them as you will never figure it out and end up buying more product if you dont burn out and burn off of the project first. Thank god for youtube to pick up some of the finer points and missing information.

Ok so i have tried to make three screens so far. the third one being the best except the emulsion has just about completly washed out of the ink side of the screen. The first two I figured out that i was using way to much emulsion and it was making it way to thick and darn near impossible to wash out. also the third one i used some foam on the back that was covered with a black fabric to back it up. my negative is a piece of glass with my pattern cut out in sign vynly. It is a really good sign vynl that is very very opaque. The first two i didnt use the foam and fabrick and i think the light getting through the emulsion and would expose the backside of my pattern from underneath making it very hard to wash out. I would have to wash it out so hard it would peel off parts i didnt want peeled off. The third screen washed out very easy. Again maybee to easy on the ink side as it seems all the emulsion washed off this side. Is this normal? Is this screen usable as its the best looking one so far? What am I doing wrong and why isnt the backside of the screen curing when i expose it.

Also my exposing light i am sure is not the best. Speedball has the instructions for a 150 watt buld and the pie tin reflector method. I have two lights on my desk and one has a 75 watt bulb and the other has a 95 watt bulb. I figure between the two its over 150 watts combined. I used the speedball time of 1.5 hrs with this wattage and distance from screen figure.

Is my light not strong enough wattage wise to cure the back side of the screen properly?
thanks
Jeremy

[workshoprat92]

After watching some more youtube vids it looks like most people only coat one side with emulsion. why does the spedball book say to coat both sides? so do i coat just one side or both sides? there seems to be some difference in opinions on this . I guess I wont worry about the emulsion washing off the ink side. I guess after what i have seen it makes sense to only coat one side as the back side of the light will not cure and just wash off anyhow.

[tompaine]

It's quite common to coat both sides of the screen, print side/squeegee side/screen side as a 2/1 etc. You need to encapsulate the mesh.
Try this http://www.positivityltd.co.uk/Tutorial ... ation.html to get the exposure right.
Your wattage is the power consumtion of the lamps, it doesn't measure the uv output of the bulbs, so it doesn't actually tell you anything.

[workshoprat92]

Thanks for the link. What are your thoughts on the squeegee side not curing out and washing out?

My thought on my lamp was if i had two it would be cumulative. as in 95 watt + 75 watt = 170 watts. I may be way off and need to just go get a 150 watt bulb like is recomended by speedball.

I just want to add I am a total hobbiest and not doing this for a business. I just want to print my own signs for my own purposes. maybee some ts also if i get it down lol.

[d fleming]

I'd use sunshine before a normal light bulb. Speedball is junk. You may want to build yourself an inexpensive light box using proper bulbs and get some decent emulsion. A few cheap screens(wood frame) from melray or some other supplier couldn't hurt either. Run some searches on this site, you'll get some great info.

[workshoprat92]

Screens are so easy to make. I made several wood frames already.

I think your right on the speedball products. It is junk and their instructions are also junk. Its to bad its the only thing sold locally.

What is a good emulsion to use and where would you get it? I already have 28 bucks tied up in the speedball junk and am kind of mad its all just gona get waisted. The thing that really makes me mad about speedball is that they only sell the 26.6 oz bottle. There is no way im gona use that much. I need a supplier that will sell a way smaller quantity. like i say im just a hobbiest and there is no possible way i can use a 26 oz bottle before it goes bad.

[d fleming]

28 bucks is too much and 26 oz is too much. Stick to speedball. Screen printing is not a cheap hobby.

You can buy a kilo of emulsion (rlx, it is fairly forgiving to room light) from nazdar. Screens (properly stretched with quality fabric) from Melray. Inks fro Nazdar as well as chemicals for ink use and reclamation. Good luck.

[workshoprat92]

I made a run of 80 coroplast signs. they are not pro quality by any strech of the imagination but they are just fine for my purposes. the idea anyhow is quantity rather than quality. they really do look great from a distance and are tons better and way esier than the stencil and spray can method. I made 80 signs in less than an hour. my wife was placing them to dry as fast as i could make them. I used the bullseye paint sold at the art store and the screen was made from hancock fabrick polyester. way cheaper then the 28 bucks a yard screen material. Dont bother trying to wash the screen out with mineral spirits as it would be way to costly. just trash the screen and make a new one for each run. its easy enough and cheap enough to do so.

All in all I got what i want. Signs that are easy to read can be made fast and cheap to make. despite the flaws I am very happy with my outcome.

[tompaine]

There is a market niche for everyting