Posting some thoughts from others but feel free to contribute with ways of getting a m.p. tester.

"Swim recently read an thread discussing various ways to produce simple melting point tests.

The gist was to use a somewhat insulated cookie sheet (using wax paper as a kind of insulation) and several oven thermometers (to average readings for slightly better accuracy). The idea being you could place a small amount of powder on aluminum after bringing the oven up to your lower temperature (a temperature you hope the substance wont melt at) and then gradually bring the temperature up by a few degrees until you find the melting point.

I'm sure a lot of you chemists might be horrified by something this inaccurate but I'm wondering if some of you you might be willing/able to help develop (or at least validate) some kind of simple protocols people without training/access to proper lab equipment could use to begin collecting basic mp or even bp data on rc chemicals.

Also, any suggestion for similarly constrained solubility tests would be interesting. Some chemicals/solvents are more readily available to the home user, such as Propylene Glycol, Vegetable Glycerin, some kinds of acetone, various grades of ethanol (Everclear, vodka), distilled water and even various oils for lipid soluble substances. But again, without proper lab equipment, hotplates or stirrers I'd like to hear if any of you have suggestions on simple (but potentially useful) ways to collect this kind of data.

Naturally, the margin of error using such developed protocols would probably be higher, but at least we'd have rough data that could act as a point of reference should anyone with greater experience and access chose to perform proper analytic tests.

Melting point and solubility data in particular can be very useful and more often then not is simply missing or even guessed at."


Duo.


swim struggled for a very long time to build a simple device that would reveal this all important number...

a simple $14.00 supermarket digital cooking thermometer that can measure up to 200 deg C is used. A decent sized chunk of aluminum... a block about 6" long and 3" on the other two sides has a piece of thin glass stuck on it with heat sink compound. A hole the same diameter as the probe of the thermometer is drilled right next to the glass and the thermometer is inserted into this hole with heat sink compound. The thing is placed on the hotplate... or for even better readings, in a skillet of sand placed on the hotplate. The sample is placed on the glass and observed with a magnifying glass. The thermometer can be watched with the other eye.

To find the MP, simply turn on the hotplate and watch the sample. It could require a very, very long time to heat up, but this is good because these thermometers, while amazingly accurate for the price, don't respond as rapidly as more expensive units.

to make sure the readings are precise, one should calibrate the device...

At the low end with sodium acetate.

Sulfamic acid has a melting point of 200, 205, or 215 deg. C., depending on the source referenced for the value. This is good for high end.

Benzoic acid melts at 122 deg. C and is useful for mid range.

using these reagents, swim was able to establish that his device was dead on the money with no additional calibration required... lucky perhaps, but swim thinks this sort of device to be intrinsically quite accurate due to the physical properties of the materials involved (aluminum/glass/heat sink compound).

he has built a more accurate one but not finished assembling it... basically swim studied a commercial Meltemp device and replicated it... the one he has described already is the same design, but the newer one has a machined cavity with a glass lid to eliminate air currents and the probe is in direct contact with the glass. The entire thing is insulated with rockwool under heatproof aluminum tape and is powered by a thousand watt soldering iron whose tip is embedded in the aluminum block.

This is a picture of swim's earliest prototype of the device... it isn't the identical one he uses now, but same basic idea...



It will be noticed that the thermometer in the picture is stamped as having a max temp of 150 deg C... later modles of this device go up to 200 deg C. But swim has found that both models will read very far beyond what is stamped on the cases... it seems the limits are not true representations of the device's limits but rather have to do with the plastic housings being prone to melting at high temps... swim's later versions involved removing the plasic housings as they will melt and the electronics will overheat... simply removing the housing and relocating the electronics away from the heat source eliminates any such issues... these devices, while very cheap and quite ghetto in appearance seem very, very accurate.

The sample on the device is naturally occuring mescaline HCl extracted from a cactus. The published MP of this compound is 181 deg C. The sample in the picture melted abruptly and all at once at 180.7 deg... this is not a staged picture... swim had an associate standing by with the camera and he snapped the picture at the exact moment swim said, "now". But the device's temp rises slowly enough that the cheap thermometer can keep up (the reason for the very large block of aluminum)... The slightly depressed MP was to be expected... notice that the sample is not absolutely white?."

Also is Thiele tub or Kofler bench an option for DMT ?

And fuck this being another thread with no replies.

Nice!

Now we could maybe confirm MP en BP of DMT freebase? I would really like to know these figures.

In the past I thought of doing this with an infra red thermometer but I'm not sure how accurate that is.


Kind regards,

The Traveler

Great idea, Shaolin!



Recently I,ve been thinking a lot about such a device. But I was working on a somewhat different approach - using liquid heating medium (Thiele tube, etc.). I am ready to test a prototype but could not find a source of glass capillar tubes. Well, there is a supplier but they sell them by 16 kg boxes 400 USD each.

Your approach has certain advantages, esp. above 100 C but I see some potential problems. The piece of glass contacts room temp air and its temp will be lower than that of aluminum. Of course if the device is carefully calibrated with standard clean substances that would not matter, but I would think of adding a transparent heat-resistant enclosure, to minimize air circulation.

Indeed your accuracy is unusually high which may be explained by several systematic errors that compensate each other.

I would also think of adding a cheap web camera for recording the process in case there is no assistant.

A block of copper instead of aluminum?

swim thinks alluminium and copper would work both.. in swim opinion the best would be heat a cylinder with 1mm narrow hole to put a glass capillar with stuff into likes the labs devices.
anyway the method used by shaolin would be accurate enough swim thinks,he will be unaccurate by 1 grade maximum swim thinks, one grade more or less,who cares?

It might be a better idea to use a cube/rectangle of stainless steel with a hole drilled for the temp probe and a depression for the spice/material to sit in. I wonder how well the heat is transferred from the heat source to the aluminium block to the spice? The glass being the main problem here. Still, this is something that people have mulled over for a long time for congrats on taking the first steps.

It is not a big problem if you have a reference substance with mp close to that of DMT. Just note the difference between the thermometer reading and the reference substance actual mp.