The Best and Cheapest way to clean Rosin Flux for your Board.

[wade7575]

I started using liquid rosin flux by Aim and MG Chemical's a few years ago and I tried using alcohol like everyone was telling me to use when I read about what to use as a cleaner but I never found it did anything at all so I decided to look at places like Accessotronik but the prices they charge for a proper board cleaner is outrageous so I decided to give up on that approach.

I thought about the problem for a good while trying to think of stuff I could use and it came to me try and find a bug and tar remover and something designed to remove tree sap from car's,so I headed off to Canadian Tire and got looking around and find something in the automotive section I forget what it was called and I found this stuff called Krud Kutter in the section where the paint was and read that back label and I seen that it said it removes tree sap so I thought I would grab a bottle of it as well.

I found the Krud Kutter worked best and I'm still using it,I find the Krud Kutter is amazing stuff and is a great house hold cleaner and everything I have tried it on that it claims it works on it seems to always work every time.

I mix the Krudd Kutter at 30 to 40% with water and most times I use it around 30 to 35% with water and you just it at room temperature and after I'm done doing a project I just dump it in my mixture and let it sit for an hour while I watch some boob tube and when I pick the board the board up out of the mixture most times it's broken the flux down so well that you can not see the flux at all on the board,I do not get up at all to swish the board I just set in the mixture and for get about it.

This is a transistor tester that I got from banggood a while ago and decided to build the other night,I just use a Q-tip to apply the flux and this board had a thick layer of flux on it in a few spot's.I put this board in the mixture before taking pictures but is was only in the mixture for about 2 or 3 minutes and I took it out to take the picture.

I sometimes let the board site for longer then an hour depending if the flux is not all dissolved,you can use the mixture many times.You can get Krud Kutter at Walmart Home Depot and most other big name stores.

At 13.97 a gallon if you ask me that's pretty good deal.

https://www.homedepot.com/p/Krud-Kutter-32-oz-Original-Concentrate-Cleaner-Degreaser-KK326/203396788

https://www.homedepot.com/p/Krud-Ku...oncentrated-Cleaner-Degreaser-KK012/202525368

 

[(*steve*)]

The obvious question is whether this stuff can damage LEDs, or other sensitive components. If it evaporates, what does it leave behind? Is it either conductive, or will it leave an insulating film (neither is great).

If it is at all corrosive (and anything water-based can easily become corrosive) then you can get into trouble quickly, especially if anything has this plating.

I used a specialist solvent designed to be used in an ultrasonic cleaner, however I typically don't pull out the ultrasonic cleaner.

 

[wade7575]

I have been using this Krud Kutter for cleaning flux off of boards for years and I have not had any problems with it at all.

I have project's that I made at least 4 years ago and still work I have soaked many boards with LED's diodes capacitors of all sorts,the only thing I leave off are rotary switch's and LCD screens.

I checked with Rustoleum who bought out Krud Kutter and talked with someone in their lab and they said that the only thing it will attack is polystyrene.

 

[(*steve*)]

Good to know.

I'm already concerned about things like those surface mount LEDs with the soft lenses.

Funny you mention polystyrene... Polystyrene caps are affected by alcohol and heat. Obviously not something you surface mount, but occasionally used where you need to clean the flux to eliminate conduction paths.

 

[dave9]

It is late so I may have misunderstood your post. If so, I apologize.

Alcohol does fine cleaning rosin core flux for me. Is this a board you soldered yourself and are sure it is rosin core flux, or is this a board that someone else produced and it's a water soluble flux and you need mild detergent water more than anything else?

However I should add, that I don't just dump alcohol or water-detergent solution on a board. I pour a little on, wait a dozen seconds or so, and use a toothbrush with more alcohol or detergent solution.

 

[(*steve*)]

If I remember I'll look up what is in the stuff I use. It works really well (far better than isopropyl alcohol in my experience). I really only have it because it was available really cheap when I first got it -- although I'm sold on it now.

What is it? It's the blue stuff in the plastic bottle with the red lid! (I'll post that too)

 

[wade7575]

That is a board I did myself and I do all of my own soldering for everything,it's MG Chemical's Rosin RA flux and also have Aim's RMA flux as well.

I just never found the flux to come very easy when I use the liquid stuff,now the if you just the flux that's in the solder and only that I don't know how easily it comes off because I like to use a bit of liquid flux as I have had boards in the past not that the solder did not want to stick to very well and my dwell time was longer without flux so I like to use a good liquid flux.

It is late so I may have misunderstood your post. If so, I apologize.

Alcohol does fine cleaning rosin core flux for me. Is this a board you soldered yourself and are sure it is rosin core flux, or is this a board that someone else produced and it's a water soluble flux and you need mild detergent water more than anything else?

However I should add, that I don't just dump alcohol or water-detergent solution on a board. I pour a little on, wait a dozen seconds or so, and use a toothbrush with more alcohol or detergent solution.

 

[kellys_eye]

I've never had any issue with using IPA - it's cheap, easy to obtain and does the job.

 

[(*steve*)]

This is what I have:



It's essentially ethanol, detergent, and water.

Apparently it's not toxic, but I've not tried it in a cocktail.

I find it cleans a lot better than isopropyl alcohol. Also it was a lot cheaper than IPA when I got it. I think I got mine when they did some sort of rebranding, selling off the old stock for a song.

 

[WHONOES]

I have used IPA to clean boards foe the last 40 years or so. I use a cut down 1/2" paint brush to scrub the board.
Then clean off with cotton based material, an old tea towel is perfect. Never had any problems.