LYF

on designs: black is for copper, white prints transparent so that will just be the pcb after etching. seems like areas with alternating tones need bigger gaps or they expose thru and dont print well. i think thickness is the dependent factor here, but i need to test this more. if no air bubbles, solid copper is much easier to acomplish than solid pcb, esp if the pcb section is thin. print on transparent paper, do two layers and line up for better coverage.

on prepping the boards: DARKROOM FROM HERE UNTIL MASKING IS DONE (red light ok, minimize light souces)! don't cut film until the boards are prepped! minimize exposure and laminate asap. sand the copper w fine grit sandpaper and make sure to get rid of ALL the dust (use ipa and wipe twice!). duct tape to get rid of protective layer on one side, film on copper and smooth from one side like it's vinyl (AIR BUBBLES ARE EVIL EVIL EVIL !!), fold excess over the back so the film is taut across the front, don't tape it down. easiest to do long sides first so you can cut the short sides to remove the other side of the protection after masking. laminate 5x (make sure the machine is up to temp and wait for boards to cool down between passes).

on masking tape down the mask over the board so it's super flat and tight and the toner is touching the copper; flash cure 10 seconds in Lamp Holder V1, you can go a little longer if there's a lot of white space between elements, like 12-15 sec? the lamp is really strong so it's really easy to overexpose and mask more than desired. after the cure, REMOVE THE PROTECTION and submerge in 4% washing soda / warm water solution to remove the uncured film (makes u itchy if it gets on not palm skin btw :/), agitate solution and brush off the uncured mask. it'll come off pretty quick if it's not overexposed. make new solution if it gets too cloudy or cold. dump rinsing water tray as it turns blue. this part is easy and satisfying if the mask cured well :D. rinse after.

on etching lwk my pres did all of this. you can leave the darkroom now! all i know is that its FeCl3(?) and you can reuse it like 3x before you have to dispose of it (neutralization soup!). boards go in and you wait and wait and wait and wait and eventually the copper comes off the unmasked parts. sometimes there's sludge and you have to scrape it off. rinse the boards after. to get rid of the mask, dissolve a few scoops of lye (like fight club!?) in hot water (the vapor is not toxic according to pres) and submerge the boards. the mask shrivels and peels off in a very burn victim kind of way. yum! rinse again and you have an etched board !!

on cleanup we did a lot of potion brewing. this part takes the longest. oh my days. so many pH strips died for this. neutralizing FeCl3 was like 6 scoops of washing powder for a third of the neutralization soup canteen. lye solution okay to dump straight, washing powder solution too (the sewer system is the strongest soilder ever). wipe down everything with ipa to get rid of stains and residual chemicals. you did it!

the shack, 17 mar 2026  ·  #learning