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HotPot -Must-Knows&TIPS&TRICKS


HotPot -Must-Knows&TIPS&TRICKS

Latest updates on 19-02-2017
Because most of the questions and comments show, that many customers who want to try a HotPot have followed little or no training and have as little understanding of glasfusing, the key issues for use of the HotPot will be put on the site.

More info will follow, incl. tips and tricks.
Kind regards, Philip / www.glashobby-4all.nl 

Needless to say, we are Official HotPot dealer and sell only Hotpots of the official German manufacturer. So no import or counterfeit versions are sold.

Looking and cooling:
Note: To see how the work is progressing the lid is usually lifted. However lift only one side of the lid. NEVER take the entire lid off. Also when letting it cool down NEVER remove the cover completely.
By removing the cover completely from the bottom while it's still hot, cooling is accelerated too much.  Because the sheath isolates stronger, it cools more slowly than the coating layer. 
The coating layer will then shrink faster than the outer sheath. 
The result of this is that after a few times of use the coating layer is literally shrinking of the sheath and thus releases, at the Giant Hotpot (170 mm) even lowering  from upper side.  The HotPot will thereby be irreparably damaged.
Moreover, risks to the glass workpiece is also: when solidificating, a thermal (shrink-) shock occurs.. When this occurs when rapid cooling is too intense, the chances are that the workpiece cracks.
Recommended is: let the workpiece cool in peace. This usually takes about 75 minutes and is easy to control: the top and side of the HotPot lid will than feel lukewarm with touched with bare hands.

How quick:
There is considerable difference between the standard HotPot (80 mm), the Maxi HotPot (110 mm) and the Super HotPot (Giant, 170 mm). The Maxi for exemple is about three times larger and 2.5 times heavier than the standard. The Giant is even larger and heavier. Because the mass to be heated is much greater in a maxi or giant it also takes longer to arrive at a full-fuse stage.
Moreover, it is completely manual manufactured. This allows differences to occur in the density of the sheath (and therefore in insulation). The better the insulation is, the less heat is lost during operation and thus the faster it will warm up.
The coating layer is handiwork too; The composition may thus vary somewhat.
Rule: the bigger the HotPot, the longer it takes, and ... not every HotPot works like his twin brother. So you have to get to know every HotPot by testing, and - especially the first few times - continue to observe how its progressing. Making notes of the results with certain wattages and times helps getting acquainted.

Which microwave:
For a standard HotPot a microwave with an output of 600 watts usually proves enough. Please note that this is applied power (output), not consumption; because consumption is always higher!
For a bigger HotPot 600 watts is  too little. It would take too long. Preferred is, therefore, to purchase a microwave with output of at least 800 watts.
Many people choose to buy a 2nd hand one on the Internet. It is good to realize that older microwave ovens almost always have power loss. In other words. When new it had an output of 800 watts, but extended use may have reduced that to 600 watts or even less.
Always a microwave with a functioning  turntable. It is said that you can place the HotPot just without the turntable on cubes on the bottom in the microwave, but this almost always leads to uneven heating. The result may be that one side of the workpiece already melts, while the other part has yet to begin. Thus the glass might flow towards the side which melts first. And it remains a daunting task to find the correct position where even heating occurs.
The purchase of a combi-microwave is no problem. The hot air and grill functions however must never be used. The microwave therefore must be able to operate in microwave mode only. Some modern microwave ovens have metal detection security and switch off at detection. This presents a problem if you start working with metals or metal oxides. E.g. embedding metal or di-chroics.

Insulation Blocks:
The supplied isolation pads are required to place the HotPot on. Place them evenly divided under the bottom of the HotPot so stands stable. The blocks are handicrafts too and sometimes don't have quite the same size. Tip: turn the pieces until they all have the same height. Then place a dot on the upper surface with a permanent marker. Then you don't have to check anymore whether the proper side is up
The function of the blocks is simple: keeping  the HotPot isolated from the glass turntable. If the HotPot would be placed directly on the glass disk, there would occur too much loss of heat and the heating process would take much longer. At the same time the dis would be heated up too much and the temperature in the microwave oven would be much higher. Some microwaves would then switch off as thermal protection.

Leveling the microwave:
It is of great importance to level the magnetron (and the HotPot in the microwave oven). The turntable can produce some vibration and shocks when turning and when not leveling the upper layer glass will almost certainly slide lower down to the lower area. Also millefiori remain hardly in place if the microwave is not leveled. Besides that, it is advisable to use fusing glue (see below) to keep everything in place until the fuse is reached.

At what wattage should you fuse:
Glass is a poor conductor of heat. It therefore needs time to come up to temperature in all areas. Point B (see drawing) will become heated later than point A. It is therefore important to start gradually.
First start 5 minutes at +- 300 watts (phase 1).
Then continue for 5 minutes at + - 450 watts (phase 2). Keep watching the operation of the HotPot. jotpots are not all equal and standard HotPot works faster than a Maxi. A standard HotPot will often be ready with fusing at 450 watts and thus be finished phase 2. The maxi HotPot usually need a little longer.
Then start stage 3. The first time you start using the new HotPot you also start phase 3 at 450 watts and stay alert. Usually, the Maxi will fuse within 4 to 5 minutes in fase 3. If you don't have a full-fuse in phase 3 after 5 minutes, then turn up to +- 530 watts (or, if necessary, +- 600 watts). This way you learn at what wattage you have to fuse in phase 3. Typically, the orange glow appear within 10 to 15 minutes (all the stages added up and depending on how fast your HotPot is).
Full-fuse is indicated by a soft orange glow. If you continue to heat, a bright-orange or orange-yellow, yellow or even yellow-white glow will appear. Then you are heating much too long and the temperature gets way too high. Chances are that you irreparably damage the HotPot, parts will come off of the coating, the outer shell may even melt or your glass may even burn through the release agent and into the surface of the bottom. We will soon post pictures of such situations.
Please note that we test the Hotpots for their operation! If they do not fuse within the 15 minutes and wattge at up to (max.) 650 watts then we disapprove them and they not sold. Have you bought a HotPot at our store and it does not work within the time specified here, try another microwave! It is quite possible that your microwave does not supply the power that you have set (see above).

Fusing lijm:
Fusing lijm is geen echte lijm, maar we noemen het zo voor goed begrip. In echte lijm zitten bestanddelen voor duurzame hechting. Als dergelijke bestanddelen tijdens fusen zouden worden gebruikt, zouden ze door de hoge temperatuur verbranden en permanente asvlekken geven in je werkstuk.
Fusing lijm moet kunnen verdampen tijdens het fusen. 
Sommigen smeren het gehele oppervlak in. Dit heeft een aantal nadelen. Ten eerste moet de lijm kunnen drogen om de beoogde werking te hebben. Maar omdat glas geen damp door kan laten moet het uitwasemen via de zijkant. Het drogen zal dus aanzienlijk langer duren. Zou je gaan fusen terwijl de lijm nog niet droog is, dan kunnen door verdamping luchtbellen in het werkstuk ontstaan.
Tweede nadeel is, dat glas aan de buitenkant (punten A in tekening) altijd iets sneller aan het fusen is dan in het midden (punt B). Dat betekent, dat bij volledig insmeren en/of teveel lijm gebruiken de lijm op punt B nog niet helemaal weg is, terwijl op de punten A het glas al vast/dicht zit. De lijm kan dan niet meer weg en verbrandt alsnog, met als gevolg asvlekken!
Aanbevolen: doe wat lijm op een  schoteltje, leg het glas op elkaar en tip slechts op een paar punten met een penseel wat lijm op de naden. Dit is meer dan voldoende en voorkomtasvlekken. Tegelijk droogt de lijm sneller. Bovendien verbruik je veel minder en werkt dus goedkoper.
Dit geldt voor alle lijmen. Daardoor kun je prima werken met de door ons verkochte Blue Glue die ook een stuk goedkoper is en doordat deze ook wat stroperiger is dan de andere merken heb je ook nóg sneller resultaat.