Mixing and coloring resins....

Metal, Wood, ... the heavy stuff can be found here
Post Reply
Posts: 363
Joined: Sun Aug 16, 2020 5:32 am
Location: Australia

Mixing and coloring resins....

Post by Downunder35m »

If we check what is available for our printers we get a growing selection including ceramic and metal particles to create stronger or heat resistant models.
But sometimes we prefer the basic approach to keep costs low and to not have a grwoing collection of resin bottles around.

UV curable resins are used for cast models but the normal resins have very similar properties - except for the way they cure.
Means what works for normal resins will in most cases work the exact same way for our printing resins.
You could just have one clear and one white resin as your base materials while dyes, pigments and fillers in tiny quantities make your resin used to print things.
Leftovers can still be collected and combined for quick test prints, prototypes and such.

What should you never do or try here?
Using dyes for water based resins on those requiring alcohol to wash them - obvious really....
Not so obvious is the use of dyes.
Some can be used for both types of resins but you should always try a tiny sample you cure with your lights to see the results and possible bad effects.
In terms of pigments and fillers like the all time favourite, glitter....
Printing resin is usually required to flow properly and have a certain viscosity.
Pigments anf fillers NEED to match these properties!!
Never use particles that might sink down and accumualte during the print time - so test tube samples to check how long it takes for seperation effects to show!!!!
Some pigments are abrasive in nature and won't really dissolve.
Being very small in size does not prevent the long term effects on your film when those particles are squeezed out.
Keep that in mind and if doubt replace the film as soon as it start to show signs of wear.

What can you do then after this long list of bummers?
If you already found a great clear resin or a colored one that is available as clear then you can basically create every color you like.
A color shifting or intensifying tall build ?
No problem, just add the resin in small increment with variations of the dye amounts...
Need something to match a color as good as possible but can't find a suitable resin anywhere?
Make you own....
A flat or shine white resin as the base and you add the dyes to turn it into what you need.
Just try tiny samples and cure them or if you somehow happen to have the required reference charts use them to calculate the required amounts.
Might not end up with a perfect match but you might be surprised what you can do with some dye and pigment....
If in doubt only use dyes you tested in small samples and with your curing lights and pigments you can confirm to be not of the abrasive kind.

Special case: Fillers....
We know from those ceramic resins that that they require a lot of attention to print parameters and often a printer capable of handling those rather thick resins.
Not every hooby level printer will be able to ...
And as with all things added to somethin without dissolving we have to consider the affects.
You light can only penetrate so much of "debris" to cure the layer thickness required and for those special resin the time to cure a layer is often significantly longer than for standard resins.
Makes sense if you consider that the filler material means there less stability and bond until the model is fully cured.
Ideally the filler material would be fully transparent to UV light, have a rough but non abrasive surface and be small enough to be invisible to the naked eye....
A UV absorbing filler material would mean we create a lot of tiny pockets of uncured resins - the shadows of this these particles.
For obvious reasons they should be avoided or used in the lowest amounts possible.
For those not so familiar with the obvious:
Absorbing the UV light means the particles heat up, in return our model and resin heat up.
If the critical temperature is reached the print will be ruined.
Some potential filler materials are reflective to UV, similar to those UV active pigments and dyes.
This mean curing time could potentially lowered but also that scatter light can create a build up of grwoing "ghost particles" - floaters of partially cures resin growing over time when too close to more scattered UV light.
Experimenting with your own filler materials like glow in the dark pigments means you first really need to know the resin you are using for your experiments.
Going from known and established settings to trying to find new settings one by one to get the same or better results.
Some slicers can print several models at once with different print settings for each model - a great way to reduce the testing time ;)
Installing a good quality and high res cam with lights not creating too many reflections on the resin certainly helps to monitor those test prints.
Even if tests with curing lights seem to come out fine - a suspended model on a build platform is a different beast to handle...
You might be tempted to try tings like wood or even carbon fiber material but be warned about the aggesive natures of these particles and how badly they heat up with UV light!
If you are unsure what qualifies as a potential filler check what is available for normal resins that use an activotor or 2k system.
Espcially for those casting resins you can find a nice inspiration.

What to do if things go terribly wrong and you realised too lated you model got stuck or you printed a huge blob on your expensive film that won't come off?
Trust me: Things will go wrong at some stage if you experiment with resins....
For things stuck on a solid metal build plate we can use heat to soften the plastic enough to get it off, then solvents to clean it properly.
Not so much for our FET film and those more expensive types...
Getting the resin out and cleaning what is stuck in the tray is one thing - not wrecking the film a whole different story...
Designed to not stick and to not bond with the resins we use a severe blob is bad with normal resin - a testing filler might turn the blob into something rather hard and solid.
Some peole upload videos showing how they tap a stuck blob off - I don't like them....
Although durable those film can get damaged from stretching - the won't always shrink back fully.
With a stuck model this creates stretchlines - a possible weak point later on when you print a bigger model.
I prefer what already worked well in the early days of 3D printing - my freezer.
The film and the plastic stuck on it will shrink differently with the changing temperatures.
Often less than three cycles of freezing and thawing make a blob pop off - without stretching the film ;)
If you play with electronics a lot you might have freezing spray to test them - might work quicker than a freezer but requires a good control to not cool down the film too much so it won't turn brittle from the cold.
Although not the most efficient use of your screen and light using rather small test models that have no overlaps can mean you only have individual blobs instead of one huge blob filling it all...
Exploring the works of the old inventors, mixng them up with a modern touch.
To tinker and create means to be alive.
Bringing the long lost back means history comes alive again.
Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest