I am currently attempting dyeing some of our Nylon 12 printed parts. I am trying to get a colour as close to true black as possible and am wondering if anyone has had any success with this and the methods they used.
I am currently using TCN Ultra Black 9093 GTC dye in a ratio of 9:1 (9 parts water, 1 part dye) in an ultrasonic heated bath. The dye mixture is heated to 80 degrees centigrade and I have left parts in for different lengths of time from 5 minutes all the way up to 35 minutes. The parts are then rinsed in clean water and left to dry before running them through the fuse blast. I am still getting parts that are closer to grey than black. Anyone have any luck getting a deep true black to their parts?
I use Rit ProLine black dye and get great results. The biggest issue I’ve run into is media breakdown in the Blast. If you’re using glass media and haven’t changed it over in a while, glass particles could be getting embedded into your part and you’ll never be able to dye it with a deep black. If you suspect this could be your issue, I’d try manually removing powder from a part and dying it.
Another issue I run into with dying is the dye bath longevity. Less than a week after mixing, my dye bath is no good and will only produce blue-tinted parts. It seems like blue dyes are the least prone to oxidation, and no matter how much extra dye is added, I can’t get back to a balanced dye bath. Because of this I refresh my dye bath every Monday. The Rit ProLine is fairly cheap so it’s only ~$5 worth of dye to mix up a new bath. I also add about 1/2T of dye every time I have to replace evaporated/removed water from the bath.
This is very similar to my process, only I can not get the Proline SKU so I use the the RIT DYEMORE graphite. 1x 307ml Bottle per 4Litres of Distilled water plus 1x pump of Dish Soap.
Shaken vigorously. Top up as the volume depletes. replace the whole vat every 21 days or every 7 days if using tap water. I find that if you let the dye solution boil to often it will no longer provided a rich black, closer to a “deep purple-ish” colour.
I’ve never considered using distilled water. If that really extends the dye longevity to 21 days, it definitely sounds worth it. I use a circulating pump to keep the dye bath mixed but I think that also causes the bath to oxidize faster. Not to mention my dye tank is not well sealed. I’ve got a few questions:
Do you use any form of agitation in your dye tank?
I was using an Ultra-Sonic machine for a bit before it sprung a leak.
Currently (and originally) I use a standard ceramic hot plate, So no agitation anymore. I have a timer to remind me to prod the parts periodically.
No seal save for the the tub lid
Rit says the soap “promotes level dyeing”, I would agree as I never get a “splotchy” result anymore.
One thing to note: If the parts are exposed to air before a thorough rinsing, AND if the dye is old or over heated, you will likely find a "“deep purple-ish” residue on the part which can be wiped off with some time, (Best to avoid this outcome however as it takes time to wipe the part clean)
I have not noticed a degradation in how the dye takes to parts even after weeks of sitting. I do refrigerate my dye tank between runs maybe this helps preserve the dye?
That’s interesting. I’m far from a chemist, so the “unbalanced oxidation” is just a theory based on my bit of research and experience. Is your dye tank well sealed and what kind of dye are you using?
I’m using RitDye, the same version @leadnav uses (carbon black or something like that). Im not very high tech with my dye operation, just using a large stainless pot with the straining insert to hold the parts. I put the lid on it and put it in the refrigerator after a cool down.
You can see my thread on this and what i use. Yes i use Graphite color Rit Dye because in my testing black just looks “fake and dye’d”… graphite complements the natural color better in my opinion.
I used to let dye sit in the tank for weeks but not anymore. I build up enough parts. Drain the tank and re fill it with water, two bottles of graphite rit dye, 1 cup of clear vinegar and a splash of dish soap.
I run 3-4 chambers of parts in this and the fry basket i made (in other thread).
If i leave the dye tank sit for a week or so… it was too inconsistent and you’d get green or bluer hues in the parts.
So now i will refill the entire tank and mixture whenever I’m about to run bulk parts.
If I’m running consistently for a week or two…i will run a few chambers for a few days and drain the tank halfway, re top off with water and add one bottle of rit dye etc…
I will let the dye sit in the tank for weeks though if I’m not running parts and wont drain till I’m about to use it again…essentually im never letting my tank sit empty.
The need for dish soap is only useful if you don´t have circulation in the dye tank. We used dish soap once and saw absolutely no difference as its primary purpose is to break the surface tension of the bath according to the tech we spoke with at TCN.
