Sciencemadness Discussion Board

melting point apparatus - ebay

Fery - 21-1-2023 at 10:05

I've bought cheap melting point apparatus from ebay, made in India.
https://www.ebay.com/itm/394205757794
The heating block is from aluminium and for 5 mm thermometer, so I had to make it wider by bore drilling to 6 mm as we such wide thermometers in my country. The electricity in India has the same voltage 220 V as we have here. I replaced India electrical plug which differs from the type used in my country. The wires are colored similarly (red = L, black = N, yellow/green = ground), but I verified that with ohmmeter to be sure. For the first time it slightly fumed from the heating element so it is good idea to place it outside for the first run. The quality is adequate to its low price, visible after opening it, but everything holds together and the functionality is OK.
I just added the item into watch list to buy it later and in 1 your an email arrived with a 5% discount. While ordering it also 21 % VAT was added so I hadn't to pay anything extra in my country (no customs fees for goods below 150 EUR, also no postal office fees in my country as postal office hadn't any extra work with declaration of customs fees either paying VAT as the VAT was already paid to ebay which sends VAT into my country).

Sulaiman - 21-1-2023 at 20:21

I think that your first usage should be to verify the equipment versus melting point standards
eg https://www.sigmaaldrich.com/MY/en/search/melting-point-stan...

Fery - 21-1-2023 at 23:04

There is a hole to insert own thermometer, there is no digital thermoprobe with display. You can adjust the heating power, thus the speed of T increasing and also max. T to be reached by trying various settings.
I have various organic compounds with melting points from below 40 C to above 300 C, I can compare with glass Thiele melting point tube filled with glycerin heated over gas burner which I used before buying this electrical device. Like azoxybenzene, 2-nitrophenol, 2,4-dinitrotoluene, naphthalene, vanillin, benzoic acid, anthracene, anthraquinone, carbazole etc. Glycerin bath is limited practically to 250 C although its b.p. is 290 C (air oxidation, hygroscopic thus some water always present), it always bubbles already before reaching 250 C.

Schleimsäure - 31-1-2023 at 13:10

Just bought a Stuart SMP-3, used. For 320 EUR as "price offer" accepted. Original asking price was 499 EUR.

Will make a test on a given substance when arrived. First will test some anyltical grade organic I have.

Schleimsäure - 2-2-2023 at 10:04

Quote: Originally posted by Schleimsäure  
Just bought a Stuart SMP-3, used. For 320 EUR as "price offer" accepted. Original asking price was 499 EUR.

Will make a test on a given substance when arrived. First will test some anyltical grade organic I have.


So did a test on Merck phenylacetic acid. Works like a charme. When first melting was visible in the chamber I pressed store button at 76,5 degrees.

Can recommend the Stuart SMP3, if someone stumbles upon one at good price.

Mateo_swe - 4-2-2023 at 15:28

Looks like a nice unit but the Stuart SMP-3´s i find on auction sites are at 1200 to 1800Euros used, 2100Euros new.
A little bit too expensive for an hobby experimenter, maybe a good deal can come if one have some patience.
A thiele tube works for now, maybe one can DIY something that works.

Fery - 4-2-2023 at 21:26

Mateo_swe - exactly. I used Thiele tube with glycerin for years and it was very precise. I wanted to try also something else in my life. This toy from India works well. It is not automatic - for the speed and max T you have to play with switch and wheel. It also misses digital part, so old good thermometer must be inserted. This 75 US$ toy is available for everyone doing nonprofit chemistry. There are also more rich members of the forum who buy something better.

Schleimsäure - 5-2-2023 at 09:35

Quote: Originally posted by Mateo_swe  
Looks like a nice unit but the Stuart SMP-3´s i find on auction sites are at 1200 to 1800Euros used, 2100Euros new.
A little bit too expensive for an hobby experimenter, maybe a good deal can come if one have some patience.
A thiele tube works for now, maybe one can DIY something that works.


Sure, those prices are way too high, I would not spend that much on it.
Just got lucky from a private guy, who sold lots of stuff from a lab or pharmacy dissolution, I guess.

More "manual" MP apperatus will do the job as well, guess.

dome13 - 13-2-2023 at 13:17

Fery, I just bought the same melting point apparatus after seeing your not so bad opinion about it. Today i received it and immediately tried how is it working. Well, the first time when I placed under voltage, flashed a bit, but the light bulbe was still ok, and a small amount of smoke. I turned off and on again. This time the light went off with some noise. I unscrewed the bottom and 2-3 wires was gone. I mean, two of it were a thin wire literally with plastic pearls (like a bracelet). It really has a purpose? I replaced the wires and tried to solder them together. I don't exactly know how it should be connected, but i saw the startes of wires and I tried figure it out. I replaced the light source with a small led and give it a shot. I turned on maxumim heating. At around 180°C it started slowing down, and at about 160°C continuously produced some light smoke, but enough to not see the capillary tubes. I regret buying this one and I try to get my money back. I think I stay with the glycerine.

Fery - 13-2-2023 at 20:36

Hi dome13, you should return the device and get your money back. I also unscrewed the box to see inside, e.g. whether the light bulb could be replaced. Before buying I asked the guy for voltage and he replied 220 V which is the same as in my country. In case the device voltage 110 V I wouldn't buy it. I observed the smoking at the beginning too, already at 40 C. I didn't hear any noise. My wires are in place.
Lucky Schleimsäure, he got good quality device.