Wax W the hard one
Following up from the article “Which Wax?” here we focus on the hardest of the three which is Wax W.
Apiezon Wax W has found many uses over the years and has some unique properties that make it a very versatile product. In the first instance it can be used as a vacuum sealant, heated up to 130°C it becomes a liquid which can be poured into joints and upon cooling it hardens into a permanent or semi permanent vacuum seal. The very low vapour pressure of Wax W makes it suitable for use down to 10-9 Torr at 20°C.
Wax can also be applied for encapsulating electrical or electronic equipment. The unique benefit of Wax W is that unlike epoxy based potting compounds the component can be easily removed from the wax by reheating. Any residue can then be cleaned off with the use of hydrocarbon solvents, such as limonene. This is especially useful for short to medium term experiments where components need to be protected from moisture or harmful chemicals.
Two other common uses of Wax W are for mounting substrates and for etch resist. For mounting delicate components heat the wax up until it is sticky, apply the substrate and let it cool. Result – one mounted device! Want to get it back off? Simply warm the wax back up or dissolve it in a suitable solvent. No mess left at the end and no damage to the component during removal.
Wax W also makes an excellent etch resist, since it is impervious to a wide range of acid and alkali etchants. For application to a substrate the wax can either be melted, or dissolved in a solvent and spin coated on. This second method is the best to get a thin conformal coating of wax. When the etching job is done the wax can be removed completely with a solvent.
Using Wax W as a hard wax mounting substrate or as etch resist are just two uses, but there are no doubt many more and we would love to hear from you about your use of our wax…