Junk_Enginerd
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Is it reasonable to modify/crack paraffin candle wax to achieve different viscosity?
I dabble in model making and metal casting, and paraffin wax is a convenient material, except I would prefer it to have a broader melting point range
so that it gradually gets softer as it gets warmer, rather than suddenly melting at a precise temperature. More like ice cream, less like ice.
As far as I understand it, ice cream and glass alike achieve this by having components with a range of melting temperatures, which sort of "spreads
out" the melting point.
Now, I know there are waxes with the desirable properties that are hardly expensive and I could just buy them, so it's mostly a hypothetical
question... It would be an interesting project to attempt modifying it though.
Is it something that an amateur like me could pull off? The catalytic cracking process comes to mind, but I don't have any exotic catalysts for such a
thing. Plenty of high temperature stuff and distillation equipment though, so maybe that could do it?
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unionised
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Have you tried adding petroleum jelly?
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Junk_Enginerd
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Yes, I've tried mixing it with a few different things. Liquid paraffin oil, vaseline, some random leather grease I had. It doesn't quite have the
intended effect, and instead just gets gooey with two distinct melting points instead, one where e.g. the vaseline melts and another abrupt shift once
the paraffin melts. I guess maybe I need a wider range of chain lengths? As opposed to a mix of a bunch of similarly short ones and similarly long
ones... But I absolutely don't know what I'm doing or saying, which is what I hope to learn lol.
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j_sum1
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I have cracked parafin wax before using chips of crockery as a catalyst. The target was ethene however. And there was quite a bit of soot left behind.
My two cents.
If your goal is metal casting, just buy what you need.
If your goal is a fully otc project then have at it. But I eould not abandon the mixture route too quickly.
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metalresearcher
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Quote: Originally posted by j_sum1  | I have cracked parafin wax before using chips of crockery as a catalyst. The target was ethene however. And there was quite a bit of soot left behind.
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You mean: shattering old cups and plates and mixing it with old candles and heat the stuff in a retort and get some C2H4 (+ soot) in the receiver ?
How much temperature did you make ?
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Lionel Spanner
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Candle wax is already well refined, as it has a crystalline structure and a well-defined melting point - there's not much you can do with it
chemically.
What you need is a wax with a wider range of chain lengths, e.g. microcrystalline wax, and there are multiple grades of that available.
Also, when you mixed your wax with other materials, did you melt all the parts, mix them till uniform and allow the wax to re-set? That would work a
lot better than mixing them cold.
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Junk_Enginerd
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rquote=674018&tid=158637&author=j_sum1]I have cracked parafin wax before using chips of crockery as a catalyst. The target was ethene however.
And there was quite a bit of soot left behind.
My two cents.
If your goal is metal casting, just buy what you need.
If your goal is a fully otc project then have at it. But I eould not abandon the mixture route too quickly.[/rquote]
Yeah it seems "hard cracking" for lack of a better term, all the way to the shortest molecules, isn't too complex other than the pretty extreme
temperature... But there must be a way to "abort" the cracking before it reaches that point... Maybe? Or maybe that requires precise regulation of
conditions...
Well, yeah, of course. I already mentioned I could just buy it instead. This is purely about learning and maybe producing something useful as a bonus.
| Quote: Originally posted by Lionel Spanner | Candle wax is already well refined, as it has a crystalline structure and a well-defined melting point - there's not much you can do with it
chemically.
What you need is a wax with a wider range of chain lengths, e.g. microcrystalline wax, and there are multiple grades of that available.
Also, when you mixed your wax with other materials, did you melt all the parts, mix them till uniform and allow the wax to re-set? That would work a
lot better than mixing them cold. |
Am I wrong in the understanding that pretty much any alkane can be cracked into anyone of the shorter ones?
Microcrystalline wax... Thanks, that provides some much needed googling keywords.
Yeah, all melted. It's a bit difficult to mix candle wax with anything otherwise, heh. My best guess is that I just don't have anything that's close
enough in melting point. The paraffin oil has a melting point of like 5°C, so that's probably too extreme. Vaseline just makes it slimey instead of
malleable. I can't really think of anything between the oil and candle wax that's compatible...
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violet sin
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Bees wax works sometimes for softening other waxes and such. It's fairly easy to find around here physically at ACE hardware in pucks. Glycerin in
small amounts also.
I was making chasing pitch for copper work at home. Actual pine pitch, canning wax, candle wax, glycerin and bees wax with tissue paper kneaded in
seemed to do ok.
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Lionel Spanner
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| Quote: Originally posted by Junk_Enginerd |
Am I wrong in the understanding that pretty much any alkane can be cracked into anyone of the shorter ones?
Microcrystalline wax... Thanks, that provides some much needed googling keywords.
Yeah, all melted. It's a bit difficult to mix candle wax with anything otherwise, heh. My best guess is that I just don't have anything that's close
enough in melting point. The paraffin oil has a melting point of like 5°C, so that's probably too extreme. Vaseline just makes it slimey instead of
malleable. I can't really think of anything between the oil and candle wax that's compatible... |
The nature of the wax is determined by the nature of its constituent alkanes, and in the case of candle paraffin wax, these are mostly linear, making
it highly crystalline and brittle. Cracking them would result in a similarly brittle wax but with a lower melting point.
More malleable waxes, e.g. microcrystalline, contain a substantial proportion of branched and cyclic alkanes, which are simply not present in the
paraffin wax.
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Twospoons
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You could also try dissolving polyethylene in your paraffin wax. Resulting product becomes more pliable when cold, compared to pure wax. I've used
this mixture as an encapsulant for high voltage components.
Helicopter: "helico" -> spiral, "pter" -> with wings
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Junk_Enginerd
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| Quote: Originally posted by violet sin | Bees wax works sometimes for softening other waxes and such. It's fairly easy to find around here physically at ACE hardware in pucks. Glycerin in
small amounts also.
I was making chasing pitch for copper work at home. Actual pine pitch, canning wax, candle wax, glycerin and bees wax with tissue paper kneaded in
seemed to do ok. |
I have considered bees wax, so that's encouraging. I'll see what sort of store might have it... What's the intended use of it? Might help with finding
a store. Don't think I've ever seen it in a hardware store. Glycerin? Interesting. I wouldn't have expected glycerin to have a place in waxes and
oils... I'll do some experimentation with that too.
| Quote: Originally posted by Twospoons | You could also try
dissolving polyethylene in your paraffin wax. Resulting product becomes more pliable when cold, compared to pure wax. I've used this mixture as an
encapsulant for high voltage components. |
Dissolve polyethylene!? I thought that was basically PTFE as far as inertness goes, but yeah, now that I think of it it's kind of a very hard
polymerized paraffin in itself I guess? That's super interesting. Definitely trying that out.
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Twospoons
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Perhaps 'alloy' would be a better word than 'dissolve'. Note that some hot-glue sticks (the white ones) are primarily polyethylene or a similar
polyolefin) , albeit with a few extra things to modify the melt/stick properties.
Helicopter: "helico" -> spiral, "pter" -> with wings
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violet sin
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https://www.acehardware.com/departments/automotive-rv-and-ma...
It's basically to lube nails and other fasteners entering wood. Kinda like the "green sinkers" vinyl coated framing nails.
It really helped with the chasing pitch, cost and availability wise as well as performance.
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Lionel Spanner
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| Quote: Originally posted by Twospoons | | Perhaps 'alloy' would be a better word than 'dissolve'. Note that some hot-glue sticks (the white ones) are primarily polyethylene or a similar
polyolefin) , albeit with a few extra things to modify the melt/stick properties. |
Or "oleate".
There are a number of polymeric materials such as PE that modify key physical properties of oils and waxes; polymers incorporated into a water-based
system for similar purpose are described as "hydrated", so the equivalent in an oil-based system would be "oleated".
[Edited on 7-6-2022 by Lionel Spanner]
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Fantasma4500
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im almost certain i managed this using just .. sunflower oil a while back?
rapeseed oil i once heated with hotglue sticks in varying proportions until i got a gel i found desirable as fuel/plasticizer
i dont see why this wouldnt work out with oil
maybe you would wanna aim for a mixture of saturated fat vs unsaturated fat, and then mix that up with paraffin wax? honestly i think you might just
wanna add in a bit of the parrafin wax to the oil rather than the other way around
saturated fat is easiest to get in blocks of coconut oil, pigfat, where more typical liquid at room temperature plant oils will be largely unsaturated
fat. depending on the usage regular solvents might also do something, gasoline, gasoline fractions.
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