What % does Isopropyl need to be...?

-Acid- · 05 January 2021, 18:54

I recently bought a Mediator for my A4000 and sometimes I was booting and it appears in the ESM and in WhichAmiga and could see cards and my Cybervision but now it won't appear at all. I'm also getting intermittent problems with it detecting my CF drives etc and I think it's probably all related (recapped in 2016-7).

But anyway I took it all out today and went to clean it, toothbrush and isopropyl in hand but then noticed on the bottle it's only 70%. Is this safe to use in the daughterboard connector slot (and general pcb cleaning) or do I need to get 99.9%?

pandy71 · 05 January 2021, 18:57

70% IPA is for medical use (disinfectant) - 99% IPA is solvent - higher water content raise concerns on drying.

DamienD · 05 January 2021, 19:33

How is this thread Amiga scene??? i.e: "Comment and discuss about the latest news, rumours..."

...mind you, it seems to be a recent trend, but unfortunately the GMods are not moving into the correct place.

Jesus guys, EAB is not that hard to navigate.

This most definitely belongs under the section support.Hardware.

It's not rocket science

Daedalus · 05 January 2021, 20:14

For cleaning PCBs, you should be using 99.9%. It probably won't cause any harm, but 70% contains 30% water which could be left behind under chips as the alcohol evaporates so you would want to leave the board for a lot longer to ensure all the water has dried up. 99.9% IPA will dry much quicker, will be better for removing flux and other residues, and won't leave water behind.

nogginthenog · 05 January 2021, 20:24

99.9% was expensive during the start of the pandemic but it seems to be more normal now. I bought 1L for £7 just the other day.

-Acid- · 05 January 2021, 21:45

I ordered some 99.9%... guess it'll have to wait some more days

grelbfarlk · 05 January 2021, 22:19

70% is fine, but even with 90+% I still use compressed air to blast the alcohol and anything else from under chips and keep rinsing until there is no more visible residue.

Jope · 06 January 2021, 08:38

You must also understand what you are cleaning when you consider what kind of IPA solution you are using.

If your dirt dissolves in alcohol, go for a stronger IPA concentration. If you have water soluble dirt, then IPA alone will not dissolve it, you should add up to 50% distilled water.

And as everyone already said, if there is water involved, you need to fully dry your circuit board before powering it up.

05 January 2021, 18:54	#1
-Acid- Registered User Join Date: Oct 2012 Location: South Shields Posts: 812	What % does Isopropyl need to be...? I recently bought a Mediator for my A4000 and sometimes I was booting and it appears in the ESM and in WhichAmiga and could see cards and my Cybervision but now it won't appear at all. I'm also getting intermittent problems with it detecting my CF drives etc and I think it's probably all related (recapped in 2016-7). But anyway I took it all out today and went to clean it, toothbrush and isopropyl in hand but then noticed on the bottle it's only 70%. Is this safe to use in the daughterboard connector slot (and general pcb cleaning) or do I need to get 99.9%?

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05 January 2021, 18:57	#2
pandy71 Registered User Join Date: Jun 2010 Location: PL? Posts: 2,745	70% IPA is for medical use (disinfectant) - 99% IPA is solvent - higher water content raise concerns on drying.

05 January 2021, 19:33	#3
DamienD Banned Join Date: Aug 2005 Location: London / Sydney Age: 47 Posts: 20,420	How is this thread Amiga scene??? i.e: "Comment and discuss about the latest news, rumours..." ...mind you, it seems to be a recent trend, but unfortunately the GMods are not moving into the correct place. Jesus guys, EAB is not that hard to navigate. This most definitely belongs under the section support.Hardware. It's not rocket science

05 January 2021, 20:14	#4
Daedalus Registered User Join Date: Jun 2009 Location: Dublin, then Glasgow Posts: 6,334	For cleaning PCBs, you should be using 99.9%. It probably won't cause any harm, but 70% contains 30% water which could be left behind under chips as the alcohol evaporates so you would want to leave the board for a lot longer to ensure all the water has dried up. 99.9% IPA will dry much quicker, will be better for removing flux and other residues, and won't leave water behind.

05 January 2021, 20:24	#5
nogginthenog Amigan Join Date: Feb 2012 Location: London Posts: 1,309	99.9% was expensive during the start of the pandemic but it seems to be more normal now. I bought 1L for £7 just the other day.

05 January 2021, 21:45	#6
-Acid- Registered User Join Date: Oct 2012 Location: South Shields Posts: 812	I ordered some 99.9%... guess it'll have to wait some more days

05 January 2021, 22:19	#7
grelbfarlk Registered User Join Date: Dec 2015 Location: USA Posts: 2,902	70% is fine, but even with 90+% I still use compressed air to blast the alcohol and anything else from under chips and keep rinsing until there is no more visible residue.

06 January 2021, 08:38	#8
Jope - Join Date: Jul 2003 Location: Helsinki / Finland Age: 43 Posts: 9,861	You must also understand what you are cleaning when you consider what kind of IPA solution you are using. If your dirt dissolves in alcohol, go for a stronger IPA concentration. If you have water soluble dirt, then IPA alone will not dissolve it, you should add up to 50% distilled water. And as everyone already said, if there is water involved, you need to fully dry your circuit board before powering it up.

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