Hi

I have read that spraying anti corrosion spray on AC PCBs help them to stay longer and delay corrosion which is done due to sea, moisture/humidity and corrosion due to bad smells of drainage systems. I have a sharp Inverter AC and am using it for the last 3 years but recently I have heard that many PCB have blown as we have a big drainage near our house which when corrodes the copper, PCB blew away and after that its repair is very costly.

Corrosion is like an atom bomb for inverter ACs as nobody knows when it will explode and destroy the PCB of the AC. For protecting the PCBs and similar components, anti corrosion spray or Conformal Coating or Clear Lacquer is used. I want to know the following:

1. Which one of these or any other is better for protecting PCBs?

2. Are there any disadvantages of using these sprays?

3. How can we use these sprays on PCBs?

4. What type of cleaning of PCBs should be done beforehand of using these sprays?

5. Precautions needed?

Has anybody used any such sprays and if yes, how long it was effective?

Regards

 

Hello, welcome to the forums.

A conformal coat is either sprayed onto a PCB or the board s dipped to coat the entire assembly. Items that should not be coated (electrical connections, devices dissipating heat, etc) first need to be masked.

The board must start clean. Dedicated solvent cleaning machines re used in industry.

To home brew this you would need to disassemble your inverter, rinse in something like isopropyl alcohol, let dry, mask, spray coat, reassemble. There is much to go wrong here meaning you may destroy your inverter in the process.

Are you so sure your unit is uncoated?

 

Thanks for the inputs. I am currently using Sharp 18PET model inverter AC. Yes I am sure that it is uncoated.

Secondly, I had the leakage in my AC after the finishing of the 1st year itself due to corrosion and I have heard failures due to PCB in our area through the nearby mechanic. So in order to protect my AC I did spray the full AC with anti corrosion spray 2 months back after cleaning the whole AC leaving out the PCB. Accidentally just to check I also sprayed on the PCB but as it was very dusty, I just pushed the spray only once.

Later I read that PCB should be separated from the AC, cleaned and then Conformal Coating should be done in order to protect it fully. I can remove the PCB (I think) as I have many videos on youtube but needed support after that.

Here you have suggested to use isopropyl alcohol, let dry, mask, spray coat, reassemble. Please elaborate, where can i get isopropyl alcohol or is there any similar product which I can use and what is masking and what spray should be used. Can anti corrosion spray will do? Any video on this?

regards

 

Lastly I am also looking to buy another AC and am confused if I should buy another inverter AC or a non-inverter AC. If I can spray the PCB, I would be buying inverter AC else..../???

 

Will this spray work on PCB for its protection?

 

I have no idea how that product would work on a PCB. Techspray among others makes a product designed for this purpose, PN 2108-12S

Isopropyl alcohol can be found at any hardware store.