[rescue7394]

Ok before you throw mud at me I made a rookie mistake. I bought my first desktop uv exposure unit off e-bay and it appeared to be a good deal. Long story short the unit I got wasn't the one pictured (Yes i'm filing a claim). So far I have gotten no where so i'm looking for some help to try and salvage the unit.

It's a unit marked ASC365 with a 24" x 36" glass top - but it only has six bulbs, and two of them don't work. I had a friend look at it and after swapping some bulbs out they all work - but they aren't the correct bulbs. So my problem is will six lamps be enough for a good exposure? I did a little bit of research and it looks like I can get some 24" unfiltered blacklight T12 bulbs off the web. Is that enough UV light output to burn good halftones on 20 x 24 - 230 mesh using dual cure?

Anyone have any suggestions on any other 24" T-12 bulbs that may work better?

Appreciate your help in advance.

 

[acmebandsupply]

Exposure is completely unique to everyone?s own setup. Consider it trial and error until you come up with a combination that works. Someone here could list step by step how they come to a properly exposed screen, but it?s pretty worthless unless they?re using 100% of what you are, and the weather that person is experiencing is also the same. It doesn?t matter what exposure unit you bought, itl probably work. But you need to start testing. My guess would be on attempt 3-5 you?ll have something that comes out completely accurate. Get an exposure calculator to at least get you going in the right direction. And even that needs to be retested as seasons change, bulbs weaken, emulsion weakens it gets older, if you change coating procedures (1:1, 1:2, 2:2), how dark your films are... different exposure times for each different mesh and mesh colors..

 

[NoXid]

My first unit had only 4 of those tubes; it worked okay, but was no speed demon. Yes, you want the unfiltered ones. A lot of people have a setup equivalent to this. Can you see the edge of the glass? If it looks green, it is probably not low-iron glass. Replacing it with low-iron glass, or one of the even purer glasses (different brands have different names for it) would speed things up a bit more. Obviously it should have come with low-iron (or better) glass. But it also should have come with the correct tubes, so ...

Dual cure has Diazo, right? Diazo in general is slower than most Poly type emulsions, but I'm not sure how the dual cure compares. I now use Saati PHU, which is much faster than the Diazo I first used.

See the link in my sig for tips on getting your exposure time right. There is no need to guess, as you can get it dialed in with one or two test exposures and avoid a lot of frustration.

The other thing that will save some grief is not to go too thick on the emulsion coat. Thick coats tend not to dry right, and thus don't expose right. Also the greater the odds that a thick coat will leave the back side slimy and uncured when you wash it out.

 

[Danmark]

IF you can use a pure photopolymer emulsion it would expose much quicker. Dual cure are primarily for higher mesh counts and/or solvent based inks as the pure photopolymer are not solvent resistant to the same degree. As long as you are using the screens for plastisol or UV inks it will be better to use the photopolymer emulsions.

 

[djque]

I had this unit from asc365. And i will never ever ever buy nothing from this place again. First off they wanted me to pay cash and not on my card. I said no. So then they wanted $75 cash and the rest on the card.i told them no. So I buy the unit on my card and get it home and couldn't get no exposure times. Couldn't read the bulbs cuz they all were in Chinese. Called them to get times which they don't even know but in there shop it's perfect exposed screens on a bs press. So after a week trying I have up called to return it and got the run around for days. It was getting close to the return day so I just drove down there. They didn't want to refund my money and keep giving excuses. They had another customer there buying the same unit as I was returning so they was trying to keep us apart. I started going off on them cuz the owner got rude with me. I had copied the receipt like I always do all my receipts. So after going off on him and telling the person don't buy this piece of **** they refund all my money but $75 of it. Saying it's installation fee. They wouldn't give me the receipt back. They said take it up with my cc company no problem and I did. They fought it saying its was a installation charge and it was on the receipt. I tell my bank no it was all in the box and I had to put it together. So they sent the bank the receipt with my signature and on it it had $75 installation fee written on it. The bank emailed it to me and I laugh and said they wrote that on there after I returned it and left. I email them the copy of the receipt when I got the unit and it wasn't on there. They closed the case and refunded my $75 back. If you paid thru your back try and get the refund thru them. They might be trying to do you the same.