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cessnapilot
08-06-2010, 11:08 AM
After finishing my first SS16 I had read to clean off the excess flux with rubbing alcohol. I used 99% and dipped a toothbrush into the alcohol and scrubbed the bottom of the board.

As it was drying it was sticky and now has dried with a white film. It seams I can rub off the film with my finger.

Is there a better way to clean the flux off after soldering? Is the sticky reside and white film flux or did the alcohol take off some of the protective coating on the board. I think it looked better before I cleaned it:neutral:

cessnapilot
08-06-2010, 12:22 PM
Here is a picture of it.

LabRat
08-06-2010, 12:25 PM
I was reading a website about this. That's flux residue build-up.

A couple of points.
Rubbing Alcohol = 30% water... not recommended for this purpose
The website recommended using flux remover and holding the board veritcal, allowing the excess to "drip off". (seems a bit odd)

Alternatively - using denatured alcohol, with a follow-up of distilled water.

I don't have practical experience... just what I googled last night.

IdunBenhad
08-06-2010, 12:34 PM
Hi:
My wife, who is (was) an expert solderer/pc board repairer, etc. (she was the other half of the family support) says she used toluene, and/or acetone to clean circuit boards. She worked at this stuff for over 30 years.

Turns out the Super Tech Brake Parts Cleaner from Walmart has: Methanol, toluene and acetone. And, it is low cost. About $2.50 a can.

She says they did not use alcohol because of what you found: sticky, white residue.

I would use it sparingly and don't get it on any of the plastic parts on the board, but it should work very well.

By the way, there was another post a few days ago that mentioned using brake parts cleaner to clean his boards.

Good Luck.

ben&bobbi
08-06-2010, 01:50 PM
i cleaned ours with rubbing alcohol, pretty much have to keep it wet, almost flowing, scrub with a tooth brush and blowoff quick with an air hose. I started on one end and kept it tilted down, so the flux ran to one end of the controller.

ErnieHorning
08-06-2010, 02:17 PM
At work we use flux cleaner, scrubbing it lightly with an acid brush. Then one more dripping wet with the flux cleaner and then blast it off with an air hose. We hold it over a large lined garbage can.

Watch it when hitting it with the air, the stuff in the garbage can is nasty.:shock:

ukewarrior
08-06-2010, 02:29 PM
This is how all my boards turn out too.
I'm perfectly fine with it.
I don't think that residue hurts anything.
I have zero problems with my boards.
The other option is to use some very caustic chemicals.
Rubbing alcohol is safe for direct skin contact.
None of the other options can say that.


After finishing my first SS16 I had read to clean off the excess flux with rubbing alcohol. I used 99% and dipped a toothbrush into the alcohol and scrubbed the bottom of the board.

As it was drying it was sticky and now has dried with a white film. It seams I can rub off the film with my finger.

Is there a better way to clean the flux off after soldering? Is the sticky reside and white film flux or did the alcohol take off some of the protective coating on the board. I think it looked better before I cleaned it:neutral:

Wayne J
08-06-2010, 02:34 PM
I get my flux remover from McMaster-Carr (http://www.mcmaster.com/#7655a14/=8aebqg). This is the BEST flux remover (part# 7655A14) I have ever used.
I spray a bit on, loosen it up with a toothbrush, then hold verticle and spray it clean, working top to bottom. Removes all the flux with no residue.

cessnapilot
08-06-2010, 02:58 PM
Thanks for all the suggestions.
Just to clarify I had used 99% isopropyl alcohol not Rubbing alcohol.

I tried some finger nail polish remover (that's what I had around the house) and seemed to work great. I'll have to stop by the store and get some pure acetone (without the additives in nail polish remover) and finish cleaning it.

And I'll have to try the flux removers for my next project. Don't want to have to wait for shipping.

Wayne J
08-06-2010, 03:37 PM
Thanks for all the suggestions.
Just to clarify I had used 99% isopropyl alcohol not Rubbing alcohol.

I tried some finger nail polish remover (that's what I had around the house) and seemed to work great. I'll have to stop by the store and get some pure acetone (without the additives in nail polish remover) and finish cleaning it.

And I'll have to try the flux removers for my next project. Don't want to have to wait for shipping.

Haste makes waste. ;)
If you do get the product I mentioned, you will be very satisfied. Even if it will be used on your next project. ;)

oldcqr
08-06-2010, 04:08 PM
Thanks for all the suggestions.
Just to clarify I had used 99% isopropyl alcohol not Rubbing alcohol.

I tried some finger nail polish remover (that's what I had around the house) and seemed to work great. I'll have to stop by the store and get some pure acetone (without the additives in nail polish remover) and finish cleaning it.

And I'll have to try the flux removers for my next project. Don't want to have to wait for shipping.

I did a little searching a few days ago, and found someone (a pro) who suggested a mix of 91% isopropyl and Acetone (finger nail polish remover). In fact the one she had and used was scented and she said it didn't make a difference.

I was going to try this mix sometime this weekend.

james70818
08-06-2010, 04:41 PM
I have to agree with WayneJ here. He suggested it to us a few weeks back after he found it and it does work well.

James

Jrd
08-07-2010, 08:12 PM
Wayne does Mouser sell this product or just McMaster?

And is just spraying it on enough or do you have to scrub/wipe some? If so then what do you use? I would think the soldered connections would tear up paper towels, cotton balls, and cotton swabs.

budude
08-07-2010, 08:22 PM
I use the Flux Cleaner from MG Chemicals - not sure if Mouser has it but Frys has it usually...

Jrd
08-07-2010, 09:02 PM
Here is what Mouser carries in the way of Flux Remover from MG Chemicles, is it in this list? http://www.mouser.com/MG-Chemicals/Tools-Supplies/_/N-5gg1Z1z0zl4u?Keyword=flux+remover&Ns=Pricing|0&FS=True

budude
08-07-2010, 09:18 PM
Here is what Mouser carries in the way of Flux Remover from MG Chemicles, is it in this list? http://www.mouser.com/MG-Chemicals/Tools-Supplies/_/N-5gg1Z1z0zl4u?Keyword=flux+remover&Ns=Pricing|0&FS=True

I think it's this (http://www.mouser.com/ProductDetail/MG-Chemicals/4141-340G/?qs=sGAEpiMZZMtyU1cDF2RqUM5GB9DKDhl%2fq3RDvmFAUyM% 3d) one - don't have the can in front of me. I didn't pay that much at Frys - more like $12 or so as I recall. Who knows - might be the same thing as brake cleaner!

Wayne J
08-07-2010, 09:23 PM
Wayne does Mouser sell this product or just McMaster?

And is just spraying it on enough or do you have to scrub/wipe some? If so then what do you use? I would think the soldered connections would tear up paper towels, cotton balls, and cotton swabs.

McMaster is the only place I have found it (cheap). You can just spray it and it cleans well, but if you spray a small amount on the board (holding horizontal) and a quick scrub with a toothbrush, then a spray down while holding vertical, you use a lot less of the product.
If you cruise around on McMaster, they carry a ton of stuff we use (can use) here. You can very easily put together a large order for your hardware and display.
I actually bought all of the hardware for my MegaTree, all of the stand off materials for my enclosures, my solder, heat shrink gun. The list is long.

Jrd
08-07-2010, 11:07 PM
I think it's this (http://www.mouser.com/ProductDetail/MG-Chemicals/4141-340G/?qs=sGAEpiMZZMtyU1cDF2RqUM5GB9DKDhl%2fq3RDvmFAUyM% 3d) one - don't have the can in front of me. I didn't pay that much at Frys - more like $12 or so as I recall. Who knows - might be the same thing as brake cleaner!
I found the datasheet (http://www.mgchemicals.net/msds/english/4141-aerosol.pdf?PHPSESSID=cc32d6f5cff9075781363e66424c 0e83) on that can and it looks like it has some nasty chemicals in it, of course they probably all do. I am pretty sure I have a can of brake cleaner around here somewhere I will try to find it tomorrow and see whats in it.


McMaster is the only place I have found it (cheap). You can just spray it and it cleans well, but if you spray a small amount on the board (holding horizontal) and a quick scrub with a toothbrush, then a spray down while holding vertical, you use a lot less of the product.
If you cruise around on McMaster, they carry a ton of stuff we use (can use) here. You can very easily put together a large order for your hardware and display.
I actually bought all of the hardware for my MegaTree, all of the stand off materials for my enclosures, my solder, heat shrink gun. The list is long.

Ok, thanks for the tips, sounds like you had a big bill.

IdunBenhad
08-08-2010, 12:06 AM
Hi:
Jrd, I already told you what was in the brake parts cleaner. It was in an earlier post on this thread. At least, the brake parts cleaner I have.


Turns out the Super Tech Brake Parts Cleaner from Walmart has: Methanol, toluene and acetone. And, it is low cost. About $2.50 a can.

Ronp
08-08-2010, 06:18 PM
I wounder if starting fluid would work well methyl ether

bmcgeeny
08-08-2010, 07:35 PM
I wounder if starting fluid would work well methyl ether

Be great, until you passed out, the water heater came on and the house blew up.

Jrd
08-08-2010, 11:50 PM
Hi:
Jrd, I already told you what was in the brake parts cleaner. It was in an earlier post on this thread. At least, the brake parts cleaner I have.


Turns out the Super Tech Brake Parts Cleaner from Walmart has: Methanol, toluene and acetone. And, it is low cost. About $2.50 a can.

Yes, I know :rolleyes: and I thank you. But I have brake cleaner from Advanced Auto Parts around here somewhere (couldn't find it today) and I want to see if it has the same ingredients.(Probably does but it may not) I found some Automotive Cleaner today but none of the ingredients looked familiar although I did not read it thoroughly.

cessnapilot
08-09-2010, 05:12 PM
Yes, I know :rolleyes: and I thank you. But I have brake cleaner from Advanced Auto Parts around here somewhere (couldn't find it today) and I want to see if it has the same ingredients.(Probably does but it may not) I found some Automotive Cleaner today but none of the ingredients looked familiar although I did not read it thoroughly.

Looks like it has Tetrachloroethylene in it.
http://www.aapmsds.com/msdsimages/radiator%20specialty/a5000.pdf

Acetone seemed to work well but I will have to order some of the Flux Cleaner and give that a try. How much is shipping at McMaster? Couldn't find anything on their site about costs.

David_AVD
08-09-2010, 05:20 PM
If you use a good quality "no clean" variety solder, you don't need to clean the board at all. Why waste time and money sniffing the flux remover when you don't have to?

jcizek
08-09-2010, 05:26 PM
I use straight "Toluol" (not toluene, toluene is essentially octane is gasoline) You can buy it at ACE hardware. It is much safer than nail polish remover (which is acetone) because the acetone will soften or melt plastic parts rapidly (like the plastic case on your transistor) if you get any on it. Toluol leaves NO residue, is very volatile so dries very quickly and won't melt the plastic parts on your circuit board, the plastic toothbrush you scrub with or the silkscreened mask on your circuit board! My $0.02... -James

Wayne J
08-09-2010, 06:42 PM
How much is shipping at McMaster? Couldn't find anything on their site about costs.

Shipping is very good. The last order I did was kinda heavy, it had turnbuckles, screws, nuts & bolts, the flux cleaner, and other odds and ends. $100 worth of stuff. The shipping was $6 :cool:

Jrd
08-10-2010, 08:15 PM
Can you see the flux residue? Does a board always need to be cleaned? Or does the solder not always splatter and the flux not always leave residue?

LabRat
08-11-2010, 08:51 AM
If you use a good quality "no clean" variety solder, you don't need to clean the board at all. Why waste time and money sniffing the flux remover when you don't have to?

See discussion on soldering the Ren48LSD. There are times that a "no clean" variety solder just won't cut it. (But I do agree with the sentiment that for the most of what we do, additional flux shouldn't be necessary)

David_AVD
08-11-2010, 05:36 PM
It's hard to follow that thread as it goes for so many pages. Are we talking about boards that are bare copper or are they tinned?

LabRat
08-11-2010, 09:17 PM
It's hard to follow that thread as it goes for so many pages. Are we talking about boards that are bare copper or are they tinned?

The first round of REN48LSDs weren't tinned, so a solder flux becomes almost essential. My normal solder (with flux in it) just wouldn't cut it. With the use of liquid flux, the soldering became a breeze. I've almost recovered enough that I can see well enough to try and build the second board. :mrgreen:

David_AVD
08-11-2010, 10:39 PM
Ugh! Bare copper boards are a complete pain.

The only way I've done those is to scrub the board perfectly clean and solder without delay. Keeping your oily mits off the bare copper is essential too.

For tinned boards, there's no reason for using extra flux. Also no reason to remove the slight residue that any decent solder would leave.

budude
08-11-2010, 10:58 PM
OK... just to clarify they weren't meant to be untinned - I failed to check the correct option when I sent the boards out to be made...

LabRat
08-12-2010, 12:22 AM
I hope it didn't come across as a complaint. I was just observing that there are times that the flux enabled solder just isn't good enough. That's all.

ErnieHorning
08-12-2010, 10:30 AM
II was just observing that there are times that the flux enabled solder just isn't good enough.Bare copper will oxidize just by heating it. Once it turns that darker color, it wonít take solder. At this point, even liquid flux wonít fix it. You need the flux covering the copper before you heat it. It wouldnít matter whether itís liquid or paste.

I mill most of my boards, so Iím always using bare copper.

BTW, I noticed that the liquid flux that I was using had an initial alcohol smell. So I tried using isopropyl alcohol and found that it worked about half as good. In a pinch, it would work too. Just watch out for the vapor when you hit it with the iron.:rolleyes: