I checked the shed again. It’s got a good skylight so it’s above 20C in there now. Tonight I would expect it to drop below 15C.
There has been little change to the second vitrine test (the deliberately poorly mixed one) after around 70 hours but the third vitrine test appears to be making good progress after 40 hours. Both are about 2cm in depth in separate ice cube trays.
We also have a toolshed under the stairs with access only from outside (probably originally designed as a coal bunker in 1960, this was then a coal mining area) and it may be consistently warmer there because it’s part of the brick-built edifice. I’ll try some curing tests there.
I’ve never poured resin before, just watched lots of videos about it (and that was for entertainment/relaxation only.) Does the climate make a difference in the ratios you need to mix? Would more or less of the hardening agent make a difference to curing time?
The ratios are fixed. It’s a chemical reaction so adding too little hardener or mixing poorly will leave you with parts that will never set. I think that’s what’s happening to the second test. On the other hand, adding a bit too much hardener will have little effect. The surplus will evaporate.
Most people strive to get the correct proportions if only because the kit they bought came with carefully measured amounts. It’s not that difficult.
UV? Yes, but I’m more interested in getting a very simple process perfected. If up here in northeastern England I can reliably cure resin with minimum quality control and simple equipment, it’s worth more to me than rapid turnaround. It’s not as if I couldn’t use a non-vitrine mignon while I wait for the resin to cure. If I get this process working then I’ll just stockpile vitrines to make future projects less dependent on curing time.
I’ve avoided repetitious posting of photographs because my equipment and skills aren’t sufficient to show what I can see with my eyes. The camera can’t see the state of the surface well enough to serve as illustration.
Just chipping in. Im enjoying following your process.
I’ve been slowly building up stock to do some positive photo etching of some old pcbs from the 70‘s and 80‘s (big “e” stock of old everyday electronics mags) and I’ll be using UV to expose the boards.
Im planning to make some very old EHX fx and the filter setup from the wasp. (Nothing like it).
Keep going and don’t let me put you off.
This is the final outcome of the second test, after around 80 hours. Excuse the Blair Witch-style photography, I just did this handheld and I was paying most of my attention to not getting resin where it shouldn’t go.
As the saying popularized by MythBuster Adam Savage goes, failure is always an option. We learn from our mistakes.
Edit: listening to the first part of that, I can clearly hear Angel the Pionus parrot shouting, and the two budgies (Stan and Ollie, my wife calls them) warbling to one another. I was in the kitchen and they were next door in the living room.
Me! I asked!
Bloody hell that was like watching a nature program as the tray gave birth to the wet bonny offspring.
You’ll get the method right and the mix and before too long this will be old hat to you.
Thank you for sharing!
I’m thinking with a coil or other inductors and bubbles (yes I know) you might manage a high frequency oscillation.
Before my venture into docuhorror with that Blair Witch-style video of test 2, I also took the trouble to capture photographs of tests 2 and 3 in the shed.
Test 3 is progressing reasonably well but an attempt to remove it from the tray convinced me that it still needs time. It’s had something more than 60 hours of curing, nearly all in the shed. It has now developed a crinkly surface, which may possibly be due to uneven temperature. This surface wouldn’t affect the usefulness of a vitrine made in this way, and unevenness on the surface can be sanded off once the resin has fully cured.
I didn’t embed anything in test 3. It’s purely resin. It’s in the bottom left cup of its ice cube tray. I’m particularly pleased at the translucence of test 3. I wasn’t sure this resin would give me that property at 20mm depth.
The mixed material ice cube trays I use as moulds work well so far. The upper part, in white, is hard plastic (polypropylene or something similar). The cups, in green, are made of a soft silicone-like substance and can easily be pushed hard from beneath to expel the contents. I still have a few silicone cube moulds but for batch production I would definitely go with these trays. They provide just enough space to encapsulate simple point to point soldered circuits.
Another idea that just occurred to me is that I could use several pours. I know my original 6mm vitrine in test 1 cured hard in 24 hours, and I see no reason not to do that as a first stage. The next day I can add another layer until I have a satisfactory depth of coverage.
This may have interesting effects on the appearance of the vitrine. I’m eager to find out whether such effects are good, bad, or something in between.
Meanwhile I want to try soldering those SMD transistors I ordered by accident. The trigger input circuit for Bela Salt uses four resistors and a transistor, and uses power from the +12V rail. I could squeeze one, possibly two, trigger inputs into a vitrine. Once I’ve tested that with real signals and a real Bela in chapeau form, I’ll be ready to perform a full test. But that may take up to a week to prepare given my novice soldering skills.
Before then I’ll have days of curing time so this evening I’ll probably start a layered vitrine.
If you’re going for layers then you could add a tint of colour each layer or fill at an angle.
I was also thinking you could save on resin and time if you add spacers (any object, magnet,stone,plastic. Etc) as part of the design.
Mignon arc en ciel?
Got to stop this @Bitnik. It just looks like im flirting in French!
One more idea…for now.
Add a pinch of glow in the dark powder or paint to each layer.
Write on each layer with a UV pen and add a low lumen UV led for a 3D message or pattern.
Enjoy!
Yesterday I disposed of test 2 after carefully photographing the results, and transferred test 3 to the disused coal bunker under our stairs, which we use as a toolshed.
About an hour ago, after roughly 90 hours of curing, I brought it indoors and made this video. The temperature inside the shed, incidentally, was 18C.
I remembered to use a phone tripod this time, and protective gloves. I think I probably got the phone tripod in a pound shop a few years ago. Highly recommended for casual YouTube work.
My mouth is healing and you may hear that in my voice. The loud fan noise is unavoidable. I share this space with Neve and it’s our bedroom, so all the fumes are sucked unceremoniously out of the open window.
Having an oozy mignon is progress.
I think you’re right about more mixing.
Off to the pound shop for a posh coffee stirrer!
Don’t worry about bubbles when mixing, they’ll hopefully rise out before it sets.
I hope at this scale the small bubbles of the type I got in vitrine test 1 won’t affect performance. I don’t plan to take them into account in my process unless it becomes necessary to do so.
I then poured the mixture back into the graduated column. A small amount was lost, as it’s rather viscous and my patience isn’t infinite. As I hadn’t spared the horses in stirring, there were many small bubbles.
I then filled ice cube tray cups successively up to the top of the green section. I got three full cups worth and a fourth filled about two-thirds of the way.
I measured the temperatures of the liquids here at around 30C, except the last cup which was closer to 25C. The ambient temperature was around 20C. At this stage most of the bubbles had disappeared without any effort from me.
Finally I cleaned up and stored the ice cube tray in the disused coal bunker. I estimate the temperature there is still around 18C.
I came to write this all up at 1900 BST, so we’re off on our potting adventure again.
