Application Note 14 - Educational Computing
- What is Stabilant 22?
- Stabilant 22 is an initially non-conductive block polymer which when used in a thin film
between metal contacts becomes conductive under the effect of an electrical field. This occurs
at an electric field gradient such that the material will remain non-conductive between adjacent
contacts in a multiple pin environment. In addition, Stabilant 22 exhibits surfactant action,
as well as lubrication ability providing a single component resident solution to virtually all
When applied to electromechanical contacts, Stabilant 22 can provide the connection reliability of a soldered joint without bonding the contact surfaces.
- Where can Stabilant 22 be used?
- Stabilant 22 can be used in all types of connectors, at frequencies from to DC to several gigahertz, on fader's or potentiometer's, or in non-inductive (non-arcing) power-interrupt switches. The number of uses are almost limitless.
- What is the effect of Stabilant 22 in computers used in education?
- The effect of Stabilant 22 in Computers, is to increase long-term reliability and reduce repair costs. This is done by reducing the
number of times the system "locks up" or crashes due to contact malfunction. This is the single greatest cause of computer malfunctions.
Often, the use of Stabilant 22 even eliminates non-software crashes completely.
There are a very large number of contacts in each computer. Some are used in switches, such as the keyboard's key switches themselves. Others are used in the socketed integrated circuits, and in the card-edge connectors used on plug-in boards. Yet others are used to connect the computer to its mouse and keyboard. Still others are used on peripheral equipment such as printers, scanners, etc. Often it takes just a single failure of one of these contacts to cause a computer to crash.
In educational applications, it's no secret that the computers receive very hard usage, usage that sometimes slips over into near-abusive levels. Quite often, a computer will be down because of an intermittent problem caused by a connector, a problem that may not reoccur on demand when the technician is attempting to service the unit. No one should be surprised at the fact that these problems are often almost impossible to locate even though it may be hard for the teaching personnel to understand why it is so difficult for the technicians to solve this type of problem on a permanent basis.
Let's review the conditions within a contact that cause this type of problem. If we were to examine the connecting surfaces of a contact under a microscope, we would find that the metal, which looks quite smooth to the naked eye, seems as rough as a mountain range. The actual contact is made by a number of points scattered over the total area of the contact. In between these points is open space. We grant you that the volume is small, but it does provide a path for the entry of airborne contaminants such as oils, waxes, chemicals, and even cigarette smoke and tars. While many contacts are gold plated to prevent corrosion, this does not prevent the entry of airborne contaminants. The situation is even worse for many contacts (such as some cheaper RS-232c printer connectors) that do not use gold plating.
Depending upon the type of connector, contaminant entry may cause several possible effects:
- The contaminant may swell, forcing the contact points apart,
- The contaminant may cause corrosion of the contacts. This can cause some very strange effects as many metal oxides and sulfides exhibit semi-conductive effects that may result in turning the contact into a rectifier. While this might not bother the signal by itself, it would make the contact very susceptible to any RF signal that might be picked up. Thus, a radio signal could cause a signal artifact within the computer that could cause it to crash, or could result in corruption of stored data
- The contaminant may cause corrosion of the contacts. This can cause some very strange effects as many metal oxides and sulfides exhibit semi-conductive effects that may result in turning the contact into a rectifier. While this might not bother the signal by itself, it would make the contact very susceptible to any RF signal that might be picked up. Thus, a radio signal could cause a signal artifact within the computer that could cause it to crash, or could result in corruption of stored data.
Sometimes the apparent solution seems as simple as unplugging and replugging the connector, although this may prove to offer only a temporary relief. In the case of RF susceptibility, the problem may only exist when the computer is in a specific physical location. Where FM or TV broadcast signals are the source of interference, moving the computer or its cables even a few feet may make the problem go away. To complicate matters, some broadcasting stations change their antenna-radiation patterns at different times of the day, which may alter the RF fields near the computer. Thus a computer that might fail in the classroom, might function perfectly in the test facility. But the potential for failure is still there.
There are other environmental hazards as well. No one would expect soft drinks or coffee to find their way into keyboard contacts, yet it does happen.
Contacts (and by inference, electromechanical switches) are generally the least reliable part of any system. As the number of contacts increases, and as the power level of the signals handled by these contacts decreases, the potential for system malfunction increases very rapidly. The shift to ICs requiring very low operating currents has cut the power requirements of microcomputers tremendously, but it has also made them much more susceptible to both RF interference (sometimes called Electronic Smog), and even the slightest amount of contaminant penetration.
Stabilant 22, and the isopropyl alcohol diluted version designated Stabilant 22A offer the only active means of ensuring contact reliability. Unlike cleaners, the material is applied and left in place! It this is what is technically termed an active-resident treatment. Use it once throughout a computer and the probability of crashed due to contact problems are virtually eliminated. This translates into very large savings in maintenance not to mention an improvement in the availability of computer resources to the instructional program itself!
- Why should we use Stabilant over less expensive alternatives?
- Granted that the material itself is expensive, however it is unique in having a very long useful life once in place. Unlike other so-called
contact treatments, Stabilant 22 will not cross-link (becoming varnish-like) under the action of sulfur based curing agents in
elastomers, cutting oil residues, or the sulfur-bearing free-machining metal alloys used in some contacts. In most types of service work,
the cost of the down-time involved in removing and replacing a board will be much greater than the cost of the Stabilant used to treat the
board. Here what is important is that not only will the proper board treatment cure existing contact problems, it will prevent others from
occurring, thus eliminating the necessity of repeating the treatment at a later date!
In other words, why do a job more than once?
- What are the effects of Stabilants when used in computer peripherals?
- It is just the same as when used in computers. Printers usually work without trouble for the first few months. But there comes a time when
it seems as if they are possessed. This is especially true of units which are operated from the parallel interface (the so-called Centronics
standard) as this type is much more susceptible to connector malfunction. Treatment with Stabilant 22 can prevent these problems.
Stabilant can bring reliability to LANs as well. Whether the LAN uses unshielded wire and telephone type connectors, or co-axial cable and BNC connectors, Stabilant 22 applied to the connectors and to the card-edge connector used on the LAN boards can ensure years of trouble-free operation.
When used on socketed IC's, photo-couplers/isolators, rotary, push button, or slid switches, the net effect is usually to make the operation of the equipment less erratic, and in the case of IEEE 488 buss-controlled equipment, to cut down on the potential for system lock-ups.
- Can the Stabilants be used on Audio-Visual equipment?
- Most A/V installations do not have nearly so many contacts as computer systems an therefore the effects of using Stabilants are not quite
so dramatic. Nevertheless, there are many places where the Stabilants can stop annoying malfunctions, in crease reliability, cut down
on signal distortion, improve signal-to-noise ratios, an save maintenance costs in these installations. We have been told of several
cases of language labs that were almost unusable because of age-related problems! There was excessive noise and distortion in the
audio channels, switching was not reliable, and even the headphone connectors were intermittent. The cost of equipment replacement
was well beyond the school's budget and maintenance costs were increasing rapidly. After all the connections were treated with the
Stabilants (man connections could be treated with the dilute form - Stabilant 22A - without disconnection of the wiring) the labs
functioned smoothly and reliably once again!
Maintenance costs also dropped to a much more manageable level.
- What packaging is available?
- Many manufacturers make large volume purchases, diluting the material for specific applicators used on their production
lines. We can supply the concentrate (Stabilant 22), in 0.5 mL, 15 ml, 5O mL, lOO mL,
25O mL, 5OO mL and 1 litre bottles. The dilute (Stabilant 22A or Stabilant 22E, the
latter which is available in a limited number of bottle sizes except on special order), are available in 5O mL,
lOO mL, 25O mL and 5OO mL containers. We do not have a 1 litre container of the dilute as 500 mL is
the largest size bottle that can be shipped by air (in single or multiple packages) without additional restrictions. We
maintain our stock in depth and ship most orders the next day that they are received. ( On large quantities , more time
may be required) For companies which want to use the material as a stock store item, we can produce custom labels with
your part or stock number. The 15 mL sizes are in dropper bottles, and these are available on request for the
50 mL sizes as well.
Custom labelling has been provided for many manufacturers who wish to assign their own stock control number, or to distributors who wish to market the product under their own logo. Obviously this requires purchase in of the product in suitable quantities.
- What is the difference in use of these materials?
- Stabilant 22 is most useful where the connections are out in the open - such as card-edge connectors or where the lubricating properties of the material are useful -such as an aid to installing microprocessor IC's or on switches. Where the connections are not too easy to get at or where the user wishes to apply the material to something such as a socketed IC (without removing the IC from its socket), it is easier to use the alcohol diluted form (Stabilant 22A or Stabilant 22E). The alcohol diluent serves ONLY to carry the concentrate into the connector.
- Is it available in a spray can?
- No. Why waste the material? We would like to think we are environmentally responsible and safety conscious. This ruled out
the use of either a chlorofluorocarbon or highly inflammable mixture of butane and propane as a propellant.
In addition even Stabilant 22A for example, has only about 71200th the solvent impact as conventional contact cleaning solvents, over a three year time span. As Stabilant 22 contains no solvent it has absolutely minimal environmental impact and is, therefore, becoming the treatment of choice for many service organizations!
- Is Stabilant 22 just another contact cleaner?
- No, Stabilant 22 is a resident potentially electrically active material which through a synergistic combination of effects enhances conductivity within a contact without causing leakage between adjacent contacts. Thus large quantities of the material do not have to be "hosed" on, as is the case with cleaners.
- Just how much should be used?
- Normally, a final film thickness of from 0.5 to 2 mils of the concentrate is all that it necessary. In other
words, you want just enough to fill up the interstices between the contact's faces. When using Stabilant 22A,
or Stabilant 22E, use enough so that once the isopropyl alcohol (or ethyl alcohol), evaporates the desired
0.5 to 2 mil film of Stabilant 22 remains.
In applications to moving surfaces, such as in slip-rings or potentiometers, film thickness should be minimized to the point where "hydroplaning" won't occur.
- What is the 15 ml service kit?
- This was made up at the request of several manufacturers who wanted a standard kit that they could issue to their service personnel. It consists of a 15 ml dropper bottle of Stabilant 22A and some applicators, all in a small capped cardboard tube that can be tossed into a tool box without damage. As noted, we can provide these kits with special labels when large volume orders are involved.
- Why would anyone want to buy large quantities of the concentrate?
- Many manufacturers make large volume purchases, diluting the material for specific applicators used on their production lines.
Many end users have found that the material cuts their service costs so much that is more economical to purchase Stabilant 22 in the larger container sizes rather than run any risk of being without the material. The number of uses tends to increase users discover the large number of problems that can be solved by the material. One user routinely applies it to the flashlight switches and batteries it issues to its security guards and has reported that the number of requests for replacement units has dropped appreciably.
- How can I be sure that Stabilant works?
- The best way to find out just how well it works is to try it out; that's why we have samples available. Almost every service shop or manufacturer has equipment available where the switches or connectors have become erratic over the years. Use Stabilant 22/22A/22E on them and satisfy yourself. A word of caution. Don't try to evaluate Stabilant 22's performance on brand new connectors. Instead, use it on connectors that are corroded, or dirty or just plain unreliable. We are sure that any organization dealing with electronics will have at least one piece of unreliable equipment on which the Stabilants can be tested!
- Is Stabilant hazardous to use?
- Stabilants have very low oral toxicity. Under normal workplace conditions no skin sensitization effects have been noted. In the undiluted form, it is non-flammable although if heated above 200° Celsius the decomposition products would burn. And Stabilants are environmentally friendly materials.
- Will the Stabilants cause damage to the equipment?
- No. These materials have been extensively tested for compatibility with circuit-board materials, conformal coatings, as well as with the various plastics and elastomer encountered in electronics. That's not to say that there is no chance that somewhere, someone may be able to devise a cheap plastic material that might show susceptibility to degradation from the Stabliants, but because of all the solvent compatibility requirements that are in place in the industry, it is doubtful if this would ever be used in any commercial quality electronic equipment.
- Can Stabilant be used by untrained personnel?
- Thousands of applications of the consumer version of Stabilant 22 have been made over a period of several years now without any reported problems.
- What is the best way to apply Stabilant to a contact?
- The 15 ml (and the 50 ml) container have "controlled-dropper" type caps that allows Stabilant 22A to be applied directly to such components as socketed IC's, switches, connectors, etc. Some end users prefer to use industrial syrettes to apply the material. Camel's hair brushes can be used to brush it on card-edge connectors or they could be dipped into the dilute material. Most metering type liquid dispensing systems can be used as well.
- Does the action of Stabilant deteriorate with age?
- In some field trial applications lasting over fifteen years Stabilant 22 has shown no sign of reduced effectiveness. With a high molecular weight and a very low vapor pressure, little is lost by evaporation. Unlike some other contact protection oils, Stabilant 22 will not cross-link when exposed to free machining materials such as high sulfur brass, or when used on contacts where agents used to promote cross linking of thermosets or elastomers are present in the environment or in the actual connector components. Unlike non-saturated oils, Stabilant 22 does not "varnish".
Stabilants™ are a product of Dayton Wright research & development and are made in Canada
NATO Supply Code 38948
15 ml of S22A has NATO Part # 5999-21-900-6937