[Manooti]

I was going to make a light table for weeding but then I found bulbs that were 365nm black light led. Figured why not.

Built it and the time doesn’t make sense.
Using chroma blue emulsion. Tried 160 mesh and nothing came out. All burned in. Timed at 6 minutes.

Downloaded anthems calculator and seemed a little better. I guessed I needed to lower my exposure time so I cut it in half.

305 mesh
27 seconds each section. The last section to get 27 seconds was almost there. Maybe 20 seconds?

It ain’t the prettiest spread lol. Should of taken my time coating it. Some of the emulsion blew out. Tried a garden hose to clear it and it wasn’t working so went to pressure washer and I got too close and too much time soaking? Idk

 

[NoXid]

How does it not make sense? Sounds like maybe you just need to run another test with smaller increments of time to get it dialed in.

The new UV LED commercial units tend to be pretty darn fast. Some DIY built ones on here got down below 10 seconds. My own DIY 1000w metal halide is 24 seconds with Saati PHU (a fast photo polymer).

 

[Manooti]

How does it not make sense? Sounds like maybe you just need to run another test with smaller increments of time to get it dialed in.

The new UV LED commercial units tend to be pretty darn fast. Some DIY built ones on here got down below 10 seconds. My own DIY 1000w metal halide is 24 seconds with Saati PHU (a fast photo polymer).

Wasn’t sure if a diy unit could be so quick.
What’s a good starting point?

 

[sben763]

Wasn’t sure if a diy unit could be so quick.
What’s a good starting point?

This all depends on emulsion, the LED light , wattage and spectrum and how that mathches up to your emulsion

My diy LED exposes 272 on up exposes 8 sec. 128-205 10 sec very thick stencils and 40 mesh 15 sec. I use Saati PHU and a 385-395nm. If I used a 365nm for PHU it was almost a min.

Just FYI if your bulb is a 365nm and wasn’t expensive it’s probably more in the 385 or higher range. There are many bulbs sold in the lower spectrum that are a rip off as unless you have a few thousand piece of test equipment you can’t prove what you actually received.

 

[Manooti]

Wasn’t sure if a diy unit could be so quick.
What’s a good starting point?

This all depends on emulsion, the LED light , wattage and spectrum and how that mathches up to your emulsion

My diy LED exposes 272 on up exposes 8 sec. 128-205 10 sec very thick stencils and 40 mesh 15 sec. I use Saati PHU and a 385-395nm. If I used a 365nm for PHU it was almost a min.

Just FYI if your bulb is a 365nm and wasn’t expensive it’s probably more in the 385 or higher range. There are many bulbs sold in the lower spectrum that are a rip off as unless you have a few thousand piece of test equipment you can’t prove what you actually received.

Oh I see. It was actually Walmart’s brand. Great value. 18 bucks a bulb and they screwed up and had them for 7 bucks a piece so I figured I’d try it and see.

Installed them in my light box that was for weeding to play with it. Have 4 of them in there.

Says do not look at the light as a caution on the box so that’s the only reason I tried it. Was thinking “unfiltered”

I’ll try maybe 10 second intervals on the calculator instead of 27 and see what happens

 

[Manooti]

been doing some tests and with 20 seconds it washes out good. spray gun on hose takes a little while but pressure washer gets it out fast. cant get the little fine details to break loose.

got some saati red because someone wanted waterbased. burned it at 30 seconds. took forever to wash out and screen is sticky. nothing fell apart after 150 prints tho. maybe i put it too thick. that stuff sucks, its literally bubble gum

just went over my pics and man.. that coat is embarrassing lol. im blaming dirt