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Arguments against 1(or 2)-ethoxy-propanol (aka SC01)?

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#76033

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 20 July, 2016

Hi, is there a reason why washing "no-clean" flux residue off of boards with 1(or 2)-ethoxy-propanol is not a widespread practice? This chemical is more commonly known as Henkel/Loctite/Multicore SC01.

I've long known, as I'm sure most people do, that if you try to wash no-clean flux residue off of boards with acetone it simply turns the clear residue into much uglier flaky crusty white residue. I recently discovered by accident that this crusty white residue is exceptionally soluble in SC01. So if you rinse the board with acetone, then rinse with SC01, you wind up with a perfectly clean residue-free board.

Surely I am not the first to figure this out. So why isn't the practice more widespread?

I'll admit that I've never tried water washable fluxes. I've heard they have disadvantages, like washing being required (not just optional) to prevent corrosion, short stencil life, humidity sensitivity, etc. Why don't people just use no-clean and wash it with acetone followed by SC01?

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#76039

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 21 July, 2016

Water washable no-clean flux works fine.

Acetone, eew!!!

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Tom

#76041

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 21 July, 2016

Acetone is flammable and hazardous to deal with. The fewer fire hazards and nasty fumes the better in my opinion. I would either go with a alcohol based no-clean for economical processesing and boards that can't be washed, or water washable if you can afford the equipment (spray fluxers, batch washers and filtration, etc.) I've also heard of simply dunking in barrels of DI and air drying. We currently do no-clean foam fluxing and works out well but water wash would be nice.

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#76042

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 21 July, 2016

> Water washable no-clean flux

Hrm, I have not heard of paste that is both of these things (water-wash and no-clean-safe) at the same time, at least not as a solder paste vehicle. Does Kester make one? Can you recommend a particular product (preferably PbSn 63/37)?

> Acetone, eew!!!

C'mon, it's on the FDA GRAS list. It's allowed to be present in your food in unlimited quantities!

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#76043

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 21 July, 2016

> flammable and hazardous to deal with

Just want to point out that this is redundant, the only hazard is flammability.

Acetone is about as non-toxic as it gets (as long is it isn't in your EYES) and probably *the* most safety-studied solvent in history. People often confuse it with IPA which has all sorts of neurological effects.

The fumes are strictly a nuisance matter, and if the building is ventilated decently they won't even be that.

> alcohol

IPA is infinitely more toxic than acetone. Maybe you like its odor better, but your neurons don't.

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#76045

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 22 July, 2016

Cleanable no-clean solder paste suppliers:

* Yes, Kester makes one, as do all major suppliers

* No recommendations ... Too many friends in the trade

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Tom

#76046

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 22 July, 2016

Acetone has hazards other than flammability and odor including potential effects on the nervous system, skin, kidneys, GI tract, as well as blood and bone marrow according to the CDC.

Perhaps you misunderstood what I was saying regarding alcohol; I was referring to the chemistry of foamable no-clean fluxes (for wave) I was not suggesting using IPA as a solvent.

We would prefer no flammable solvents because of the hazards which is why we currently do not clean our no-clean fluxes. The preferred solvent for cleaning is clearly water but by our understanding this requires some different process technology (spray fluxing) and possibly cleaning equipment- but like I said I've seen a water bucket and drying shelf do the same thing for cheap.

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Tom

#76047

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 22 July, 2016

I just wanted to point out that although acetone is GRAS the allowed quantity is certainly not unlimited. In specific categories it is allowed to be between 5-8mg/L.

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#76051

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 23 July, 2016

> No recommendations ... Too many friends in the trade

Fair enough.

Dave, I'd like to thank you for making your previous comment, which got me over my irrational fear of water-washable paste.

My first tube wasn't the "no-clean-washable" kind -- couldn't find any suppliers whose website would ship one automatically with just a credit card number, so I went with whatever I could get next-day. But it was still a rather dramatic experience. Seeing the boards foam up in the ultrasonic bath and the gooey crud just float away was so cool!

I just can't understand why this stuff (washable paste) isn't the standard.

There's a lot of fearmongering out there about washable paste, and I'm now kicking myself for listening to it the last two years or so. Should've switched a long long time ago, but it wasn't until recently that we had a mandatory requirement to remove the flux. Now that I see how easy it is, why not? No more cruddy probe tips.

Anyways, thanks again for the encouragement to try something new!

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#76052

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 23 July, 2016

> Acetone has hazards other than flammability and odor including potential effects on the nervous system, skin, kidneys, GI tract, as well as blood and bone marrow according to the CDC.

And that's why you simply forgot to include a link to the CDC website where this information is displayed?

Seriously this is just fearmongering. Or else you've somehow mixed up minor fume inhalation with ingestion of massive quantities. Or are using data from the flawed pre-1995 EPA study that was retracted.

In ordinary use IPA is toxic, acetone is not, and you're furthering peoples' confusions of these.

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Tom

#76053

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 23 July, 2016


Tom

#76054

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 23 July, 2016

I don't understand why you think I'm fear mongering simply because I'm pointing out that acetone has potential hazards vs. water. Sure it may be less hazardous than IPA but I never suggested using IPA for anything so I don't know why you are focusing an IPA vs acetone argument at me.

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#76068

Arguments against 1(or 2)-ethoxy-propanol (aka SC01)? | 27 July, 2016

Adam ... I like washable no-clean because it provides for process / customer flexibility.

YES!!! I hate ... fault => can't troubleshoot fault => oops, we skipped MDA maintenance => never mind

Glad that it worked for you.

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