ColdHeat
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ColdHeat is an American company founded to develop and market products using the proprietary graphite-like compound it has named Athalite. The composite material is claimed by the manufacturer to have the unusual ability to conduct large amounts of heat and return to room temperature in a short amount of time.
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[edit] Soldering iron
The first two products are soldering irons. The manufacturer claims this soldering iron is unique in that its "Athalite" tip undergoes a temperature change from ambient temperature to approximately 800°F and back to ambient within three seconds when the tip is removed from the work.
The tip of this apparatus is split into two sections that completes an electrical circuit when something of low resistance is placed across the tip; e.g. solder. With a current flowing, the resistance of both the solder and the tip produces heat and causes the solder to heat up and flow. For light duty work it was designed for, the "Athalite" tip barely warms at all and can thus cool very rapidly; however if the user attempts to solder things beyond the ability of the iron, this absorbed heat can make the tip very hot and it can take over a minute to cool in some cases.
The original iron is powered by 4 ordinary AA (LR6) alkaline batteries for portability and is capable of melting solder up to 18–20 gauge. The second iron is powered by 5 AA alkaline batteries, to give it more wattage.
The soldering iron has a built-in light. The direct marketing campaigns are geared toward occasional users who may lack soldering experience and to whom safety is important.
The device works by running a high current (by electronic standards) through the tip. Running a high electric current through sensitive parts inadvertently may not be a good idea in certain instances. It is a great tool for hobbyists and people repairing metallic items, but if it is to be used on electronics, one should be well aware of how the device works and the sensitivity of components being soldered. When not in contact with a joint the split tip has 6 volts (7.5 volts for the second iron) across it, easily enough to destroy semiconductor p-n junctions on contact if the iron accidentally touches multiple closely spaced pads . This has nothing to do with static-electricity damage; a forward-biased p-n junction may be destroyed by less than 1V applied across it unless the current is limited to only a few tens of milliamperes, which ColdHeat does not do and could not operate if it did.
Some people debate whether the heat actually comes from the resistance of the tip or from the resistance in the solder. As one ColdHeat engineer said,
It’s a common misunderstanding that high current in the joint causes the heat. The heat is generated by resistance within the tip. Heat is then conducted to the joint just as in traditional solder tools. Also, current in the joint is limited to the small region between the two tip halves and doesn’t pass through the part being soldered. There is a tiny transient voltage when the tool is applied or removed, but it is orders of magnitude below the levels that cause static-electricity damage.[citation needed]
[edit] Criticism
Common criticisms include that the tip is very fragile and therefore easily damaged (and almost as expensive as the entire unit), that the unit doesn't have enough power for effective desoldering of many board-mounted and chassis-mounted components, and that the design of the tip is incompatible with some soldering techniques such as continuous flow soldering (a popular technique for hand-soldering high-pin-count SMT packages, based on the principles of wave soldering).
One thorough review [2] of the ColdHeat soldering iron has noted:
- "For the electronics hobbyist, one particularly disconcerting side-effect of the Coldheat way of doing things is that localised arcing and sparking may be produced sporadically when the heating circuit opens or closes. ... sparks anywhere near a semiconductor are an anathema to the electronics enthusiast. High reverse voltages can be produced in inductive circuits as well. ..."
- "The overall results of the soldering exercise were very disappointing. ... the test results on the p.c.b. were of extremely mixed quality. ... The quality of the soldered joints was extremely inconsistent, due to the lack of temperature control and other variables that affect the finished joint. ... perhaps 20% of the finished joints being of a reasonably good standard... It was difficult to feed solder onto the joint at a consistent rate because the heating effect was variable. ...The dull crystalline appearance of many joints points to inadequate heating, caused by the heat not sinking throughout the joint sufficiently to melt the solder thoroughly, before the iron was removed. Although a grey crystalline joint will often form a sufficiently working joint for non-critical applications, the circuit might have an intermittent fault because of this. ..."
- "There is ... no escaping the most fundamental principle of soldering: in order to make a good quality solder joint, all parts should be heated to the melting point of the solder so that it can flow properly. In the case of "cold-soldering" a p.c.b. (such as our Velleman kit), then only one half of the joint can effectively be heated by the iron, e.g. a cropped resistor lead that you use to short out the electrodes to generate heat. Solder can then melt onto the hot leadout but it is then forced to flow onto the other component (the p.c.b. copper pad) which is completely cold. Inadequate through-heating of components is the main cause of dry (gray) solder joints. What little heat there is, sinks away through the workpiece and the solder never flows properly. A crystalline, dull and brittle joint is formed. ...with our test circuit board... three p.c.b. copper pads were damaged by excess heat, causing the copper track to lift away from the laminate altogether. ... Unfortunately we failed to finish and test our sample board successfully, due to the damage caused to three copper pads."
- "... With just a little practice with an ordinary electric iron ...it is perfectly possible for any novice or hobbyist to produce good quality consistent results ...that are superior – and faster – than the Coldheat principle. ..."
- "Unfortunately, I can’t recommend the Coldheat Soldering Iron to the average electronics constructor unless they are extremely accident-prone, lacking confidence or have a real need to go cordless: they should save money and buy an ordinary electric iron instead. ...Users stand a much better chance of producing a higher quality and more consistent solder joint with an ordinary iron using accepted techniques... ."
Another issue is that the ColdHeat device causes damage to electronic components due to the high current that flows through the tip as mentioned earlier.
The device also does not work with rechargeable AA batteries. When directly shorted, as they are in this iron, such rechargeable batteries may explode, causing injury to the user.[citation needed]
Alkaline batteries are specified for use, but in rare instances, these too have been known to explode.[citation needed]
I bought one of the Coldheat 4 battery irons and I have not been able to make even one quality solder joint. I have over 30 years of soldering experience with many different soldering tools. This is without question the most useless soldering tool that I have seen. Other people agree, it gets a 1.5 out of 5 in the reviews at EHAM.COM http://www.eham.net/reviews/detail/4623
The five battery irons were sold under the Weller brand name, but they have been discontinued.
The Coldheat iron is patented, but a patent does not guarantee that the device works!
If you need a portable soldering iron, there are several good battery powered irons that use a conventional heating element. There are also, irons with catalytic heaters powered by propane. The propane models work very well if you need lots of heat.
[edit] Other Products
Currently ColdHeat features products other than the soldering tool that use the same technology, including a cordless hot-melt glue gun called Freestyle. It heats up much more quickly than others (but not instantly like the solder tool.) It comes with a built-in stand, a pack of mini glue sticks, rechargeable battery, AC adapter, and an instructional manual and a book with different project ideas.
ColdHeat has recently released a cordless heated seat, as well as a selection of heated pet beds.
[edit] References
- ^ NewTech Inc. - ColdHeat - Worst Soldering Iron Ever!
- ^ XYZ Computing - Home - Reviews - Misc. - ColdHeat Soldering Iron
- ^ The Moditory - ColdHeat Pro Soldering Tool:
- ^ Review: ColdHeat Soldering Iron | Applefritter
- ^ ColdHeat soldering iron - user experience | Applefritter
- ^ ColdHeat Soldering Pens. Do they work?
- ^ ColdHeat Signs Agreement with Soldering Tool Giant Weller
- ^ Glue Gun Article by The Craftster
- ^ Glue gun 'first look', Rainy Day Magazine
- ^ Cold Heat Soldering Gun Review
- ^ 1.5 out of 5 in the reviews at EHAM.COM
- ^ Patent Application No. 20050247692
- ^ Patent Application No. 20040149713
- ^ Patent Application No. 20020047001
