Konform AR Acrylic Conformal Coating

Full cure is when it meets all the final specifications. There might be some out-gassing, but it will be as hard as it is going to be, and adhesion is as good as it gets.  Tack-free is as the name suggests, not sticky so you can move it along the assembly process.

Every organization using hazardous chemicals within their facility has the responsibility to equip their facility and personnel to maintain exposure levels below the TLV. Personal monitoring badges can be used to measure exposure of a specific material. Then, depending on the threshold limit and the application, exposure can be controlled with PPE like masks, face shields, respirators, and even coveralls. If they don’t reduce exposure below the recommended limit, you will need to consider a special ventilation hood or even containment booth. As you can see, as the exposure limit gets down to a certain level, the equipment required to safely use the solvent can get impractical. At that point, your best option is to consider a safer alternative.

The dielectric strength is material intrinsic property and withstand voltage is surface property which depend on thickness of the material. They can be slightly different for thicker materials, but for conformal coating, the two numbers should be very close or the same. That is because we test coating at 3-5 mils thickness, calculate, then report the value per mil.

Conformal coating with UV tracer can be inspected with any typical UV lamp which has wavelength of 320-380 nm.

Toluene can be used as a thinning agent. Make sure it is anhydrous, so contains as little moisture as possible.

Apply to clean, moisture-free surface.  Areas not requiring coating should be masked. Application: Coating may be applied by spraying, brushing, dipping or flow coating.  Allow coating to flow around components. Cure:  Room temperature cure: A 1.0 mil coating will be tack-free in 30 minutes.  Full cure requires 24 hours @ 77˚F (25˚C). Heat cure: 8 hours @ 170˚F (77˚C). An open vessel of water placed in the drying chamber will facilitate curing. UV detectable for QC inspection. Removal:  Coating may be removed by soaking in Electro-Wash® Two Step Cleaner Degreaser. Use CircuitWorks® Conformal Coating Remover Pen for spot removal. After the new component is installed, areas should be cleaned and recoated.

Shake well. SURFACE MUST BE CLEAN & MOISTURE FREE. Areas not requiring coating should be masked. Coating:  Spray top to bottom, allowing coating to flow around components. Rotate board 90˚ and repeat process 2 or more times.  If nozzle clogs, clean with solvent or use new nozzle. Cure:  A 1.0 mil coating will be tack-free in 30 minutes.  Full cure requires 24 hours @77˚F/25˚C. Heat Cure: 8 hours @170˚F/77˚C. An open vessel of water placed in the drying chamber will facilitate curing. UV detectable for QC inspection. Removal: Coating may be removed by soaking in Electro-Wash® Two Step. Use CircuitWorks® Conformal Coating Remover Pen for spot removal. After the new component is installed, areas should be cleaned and re-coated.

In almost all cases, the cloudy or milky cure comes from coating in higher humidity conditions. The white foam (from an aerosol) is caused the same way. We have the following suggestions:

1. If possible, allow the substrate and coating material to come to approximately the same temperature when applying.
2. Avoid applications in RH > 60%. High humidity ranges will discolor some coating resins and will start curing others. Besides the aesthetic value, it certainly may affect adhesion to the material.
3. Specifically on the silicone coating, if the resulting application is foamy, increase the focal point of the can, ie back off to about 10 -12” from the substrate & make 2 -3 light passes rather than one heavy pass to coat the board.

Wet film thickness = Sq. ft. per gal.

0.1 mil = 16,040

0.5 mil = 3,210

1 mil = 1,600

2 mil = 802

3 mil = 535

4 mil = 401

5 mil = 321

6 mil = 267

7 mil = 229

8 mil = 201

9 mil = 178

10 mil = 160

Metal 5-gallon containers come with a flexible pop-out spout for easy pouring. 55-gallon drums are compatible with standard 2" spouts.

It may be different state-by-state, so contact your state environmental agency for regional specific regulations. For a general guideline, here is the process according to EPA hazardous waste regulations 40CFR. The can has to be brought to or approach atmospheric pressure to render the can empty. Puncturing is not required, only that it “approach atmospheric pressure”, i.e. empty the can contents until it’s no longer pressurized. This insures that as much contents as is reasonably possible are out of the can. It is then considered “RCRA-empty”. At that point it can be handled as any other waste metal container, generally as scrap metal under the recycling rules. Note that the can is still considered a solid waste at this point (not necessarily hazardous waste).

The shelf life of a product can be found on either the technical data sheet (TDS), available on the product page, or by looking on the certificate on conformance (COC). The COC can be downloaded by going to https://www.chemtronics.com/coc. Once you have the shelf life, you will need to add it to the manufacture date for a use-by date. The manufacture date can be identified by the batch number. The batch code used on most of our products are manufacture dates in the Julian Date format. The format is YYDDD, where YY = year, DDD = day. For example, 19200 translates to the 200th day of 2019, or July 19, 2019. This webpage explains and provides charts to help interpret our batch numbers: https://www.chemtronics.com/batch-codes.

I suggest you get into the habit of clearing the valve after every use. You turn the can upside-down and spray until it only sprays propellant. If you don’t do that, you run the risk of dried coating building up in the valve or actuator button. If in the button, you can switch it for another one and it should work. If in the valve, there may not be much you can do to save the can.