Photo resist paint for enclosure etching

[PMowdes]

Hi All

I came across this method of masking

https://dl.dropboxusercontent.com/u/8772719/LilEffectsPSPInstructions.pdf

Has anyone used this type of paint for transferring a design onto an enclosure for etching?

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20161208121107&SearchText=Photoresist+paint

[rocket88]

hey man. i've been looking at doing this for awhile, but didn't want to deal with the UV light. did some searching and found this instructable that uses that paint. i've also been concerned with the paint holding well onto the aluminum enclosure and standing up to the ferric chloride. but i can see i have nothing to worry about.

i've been looking at making my etch masks by screenprinting, in fact i've got a little kit, but this stuff is dirt cheap and i think i'm going to take the plunge and try it. since i sell i think this will make it cheaper to do, Press n' Peel paper is fucking expensive and i've had too many issues with large enclosures. in fact i have a monster build ready to be put in a 1790n, but haven't finished the enclosure cause the mask keeps getting fucked up and when i go to fix it i'm not happy with it. the only thing is this will definitely take more time to do. looks like 2 1/2 hrs for photoresist vs about 30min for Press n' Peel. but if the results are better and more reliable this is definitely the way to go.

i found the same stuff on ebay with just the paint or a kit, which tbh i trust much more then aliexpress. hear of too many issues with aliexpress from people.

[PMowdes]

I had a chat with the guy on FB, looks like he is in the US which is a win for you guys on the other side of the pond.

Here's his website https://lileffects.wordpress.com/

He's gonna get back to me about shipping, i'll let you know when he does.  I think he may be more reliable than the Chinese stuff, if a bit more expensive.

[PMowdes]

Here's an interesting instructable including a really cheap UV light source

http://www.instructables.com/id/Printed-Circuit-Board-Production-using-UV-Nail-Cur/

[Hozy31]

I use that UV nail varnish dryer for my PCBs, cost me just over £10 from ebay. I found it was quite strong so removed two of the bulbs (now have spares). Might give this idea a go. At the moment i paint my enclosures and add some decals and then gloss but in the winter months thats not possible as its too cold for the paint to spray properly. I have wanted to try etching enclosures for a while. Did try once with toner transfer and salt water but the toner transfer just wouldn't stick very well.

[PMowdes]

I'm going to try to see if the UV cure mask that is used for screen printing works.  just depends if it is resistant to Sodium hydroxide or acid.

[rocket88]

I don't see the paint on his site. May have to send him a message.

[PMowdes]

Looks like it's up for sale now.

http://lileffects.bigcartel.com/product/photo-sensitive-paint-psp

[rocket88]

Spoke to art over at Lil Effects and I've got some coming and should have it when I get home after finals, wish me luck on that front, and I'm going to give it a try. I also ordered from another source some special transparency paper that should make things even easier. The only thing I've got to figure out is the UV box. I'm not spending a bunch of cash on a UV exposure box, it's stupid expensive. I should hopefully be able to let you guys know how it all works out and my feelings on it compared to using Press n' Peel. I'm hoping they if it does what I expect that the time lost to having to bake the paint 2x, and develop it will be regained by only having to make the mask 1x and not have to spend the time touching up or redoing a mask with Press n' Peel when it doesn't come out as you want.

[PMowdes]

UV light box for nailpolish curing.  Got to be worth a go for that sort of dollar



I think the only issue I'd have was the curing.  There's no way I'd put it in my kitchen oven.

[rocket88]

looked at those, and a lot of people have used them, but not sure a larger 1790 will fit. i'll do some more investigating friday after my anatomy final. for curing it just use a cheap toaster oven. i use one already for baking the paint on my enclosures, and there's no reason it won't work for this too.

[PMowdes]

Good idea using a toaster oven.

I wonder if you could mount the UV thing to the top of a larger aluminium foil lined box, or just strip out the bulbs and ballast and re-purpose it into a bigger container.

[Sensei Tim]

the UV light source just needs to be in close proximity in order to cross-link the polymers.  the further away it is from the paint, the longer it will take to cross-link. too far and there won't be enough energy to cross-link.

Those black lights that he used are "safe" to use without UV goggles, so i'm not sure you'd need to worry about exposure.

the most important thing here is that you have to ensure that your photomask is in intimate contact to the paint otherwise you'll get shadowing effects where the UV light will bleed under the edge of the toner and expose paint that shouldn't be.

can't wait to see your results.  I've had great luck with PnP for PCBs, but very lackluster results on enclosures. even if the up-front cost is a bit higher and processing time is a bit longer, not having to re-do the transfers 2, 3, or more times makes up for this (and NO FRICKIN PINHOLES) ;)

[Sensei Tim]

https://www.amazon.ca/Vishine%C2%AE-Professional-Phototherapy-Fingernail-Manicure/dp/B01MPZG3VN/ref=pd_sbs_194_1?_encoding=UTF8&psc=1&refRID=RA1YCWJ95YVGHX44R48J

something like this might work  if you place it on top of your enclosure.

Remember, you probably don't have to hit the entire artwork at once. you can probably expose 1/2 of it in one shot and the other 1/2 in a second pass.

[rocket88]

my thoughts exactly about the Press n' Peel. all of my enclosures have been etched using them, and really it hasn't been a big issue for the smaller boxes, plus i figured something out awhile ago to make it more reliable for large areas that are black, but still the bigger jobs it just doesn't cut it for me. it's actually why i haven't finished 4 builds that are sitting waiting to be wired up and boxed.

my only concern with doing different sides at a time is that you might not get all of it, and some may be over exposed. the bulbs he used are for bugzappers, so i've been on the hunt for a multi bulb fixture for them, which isn't going so well, due to them being 18" bulbs. what i've found are under cabinet lights, which would mean i'ld have to full disassemble and put together in a box instead of being able to mount 1 or 2 fixtures straight to a box. i do want to use these bulbs if i can since we know they work, the distance, and exposure time. just means the experimental phase would be a lot less intensive.

i think i'm going to see what i can find at a art supply or screen printing supply place for cheap. at this point if it's like $100 no biggy, but some of these uints are $500 and up.

[Travis]

The difference between the cheap exposure units and more expensive but ones is usually the vacuum. For exposing screens, the vacuum holds the transparency up to the screen/emulsion for the sharpest image. Without a vacuum, you'll need to figure out another method of holding the screen and image pressed together, like putting a book on the back side of the screen or something.

The vacuum units are definitely the way to go, but you should be able to find a work around for the cheaper units.

Obviously you don't need a large exposure unit for stompbox work

[rocket88]

True. From what I've read for doing pcbs using a piece of regular glass is the way to go without using a vacccum. The other thing to keep in mind is that I want the light coming from above not below, as most screen print exposure boxes are, so if I get one I'll have it upside down and on little legs. I think I've got it figured out how to make it, just have to figure out the fixture for the bulbs.

[PMowdes]

In case the paint doesn't work there's a possibility you could iron on some UV sensitive dry film

https://www.youtube.com/watch?v=cRCFGZxmob0

[rocket88]

True. I ended up ordering the same bulb model, but 24" length and some fixtures on Amazon. They're supposed to be delivered today so when I get home tomorrow I can put together the box then. I figure that I'll do it so I can put it upside down on little "legs" that will be at the right distance. I'm pretty excited actually for this to work. To hold the mask down, I just need a piece of glass that's not coated. Seriously the time it can save, even though it's technically longer, will be tremendous if it's more reliable the Press n' Peel. Not to mention cheaper.

[rocket88]

Just finished the box and going to test the paint tomorrow. I'm actually getting a 3rd fixture just to be safe, and so I can use it for doing some silk screen projects. I tested it up as soon as it was wired up and it all works perfectly. So fingers crossed all will go according to plan.