Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: pomprocker on January 28, 2009, 11:57:00 PM

Title: alcohol
Post by: pomprocker on January 28, 2009, 11:57:00 PM
What is the best alcohol to use for cleaning the resin/flux off of a pcb after a soldering job?

Is the alcohol sold at drugstores the same as the alcohol sold at electronics shops?
Title: Re: alcohol ;)
Post by: paulstreats on January 29, 2009, 06:01:59 AM
Isopropyl alcohol is used for this (also known as rubbing alcohol in some places).

In the UK they used to sell it in hardwared stores and drugstores. Because of the crazy laws, they are not allowed to stock it anymore over here but they can order it in (you usually have to suffer an interrogation process at BOOTS chemist.... why do you want it? whats it for? etc...). In the UK you cant even get plain acetone anymore, cellulose is only sold in tiny 250ml bottles. Shops arent allowed to stock flammable products in any useful volume....
Title: Re: alcohol ;)
Post by: pomprocker on January 29, 2009, 11:24:13 AM
alright thanks, cause I saw isopropyl alcohol as well as ethyl alcohol at my local drugstore, both were called rubbing alcohol. I also saw isopropyl alcohol for sale at my local electronics shop, and I wanted to make sure the stuff they sell in both places was interchangeable.
Title: Re: alcohol ;)
Post by: HDL_CinC_Dragon on January 29, 2009, 03:13:34 PM
Isopropyl is the way to go for pretty much any cleaning needs :) I use it at work all day every day in fact for cleaning our devices that we manufacture :) I use it at home too for various things. I can say im glad I dont live in the UK if you cant even get a hold of some IPA(Isopropyl Alcohol) lol
Here we can get it in pretty big quantities pretty much anywhere lol. I actually have a 1quart bottle of it sitting right behind me :)
Title: Re: alcohol ;)
Post by: paulstreats on January 29, 2009, 04:01:50 PM
You can get it online from farnell/maplin but there are laws now preventing shops from keeping anything that is really flammable instore.(unless they can provide explosion proof storage ::)) . Its funny cause I can never ever remember hearing about a shop blowing up cause a can of ipa spontaneously combusted
Title: Re: alcohol ;)
Post by: frodo on January 31, 2009, 06:00:37 AM
You can get it online from farnell/maplin but there are laws now preventing shops from keeping anything that is really flammable instore.(unless they can provide explosion proof storage ::)) . Its funny cause I can never ever remember hearing about a shop blowing up cause a can of ipa spontaneously combusted
neither have i, come to think of it and i live in the UK aswell. i didn't know they had stopped stocking acetone and IPA. Darn. won't be able to make PCBs now as i'm only 12  >:(
Title: Re: alcohol ;)
Post by: HDL_CinC_Dragon on January 31, 2009, 01:09:23 PM
I want to get my hands on a big bottle of acetone so I can make my own plastic :D

I havnt looked into getting though so Im not sure where/if I can and how much of it... perhaps I can inquire where my work gets it :)
Title: Re: alcohol ;)
Post by: paulstreats on January 31, 2009, 01:43:16 PM
I use cellulose for the same thing. You can get this in small 250ml bottles. Its used for cleaning paint brushes and thinning paint down
Title: Re: alcohol
Post by: pomprocker on January 31, 2009, 09:46:37 PM
At my local drug store (CVS)...I saw Isopropyl Alcohol 91%, 70%, and 50% bottles  ???

Before I plunge a whole couple of bucks into a bottle, I wanna know which solution would be the best for removing resin/flux from pcbs!!

EDIT: I just found the spec sheet of the Isopropyl Alcohol Sold at my electronics shop and it says 99.9% pure alcohol
http://www.action-electronics.com/msds/GC10-1507%20IsoAlcohol%20SPEC%20SHEEET.pdf (http://www.action-electronics.com/msds/GC10-1507%20IsoAlcohol%20SPEC%20SHEEET.pdf)

That leads me to believe, the more alcohol the better

Title: Re: alcohol
Post by: Soeren on February 01, 2009, 12:17:07 AM
Hi,

Yes, you want to get it 99.9%, as anything lower will contain other stuff which will be either damaging for some of the things you're gonna use it for, eg. white spirit which will damage some plastics, or which contains lanolin or similar which will leave a thin greasy layer on everything it touches.
Title: Re: alcohol
Post by: pomprocker on February 01, 2009, 01:24:44 AM
Thanks! 99.9% Isopropyl Alcohol it is!
Title: Re: alcohol
Post by: pomprocker on February 05, 2009, 11:07:31 PM
ok i got the 99.9% alcohol.

is it normal for your boards and hands and sink to get all sticky after ??
Title: Re: alcohol
Post by: frodo on February 06, 2009, 02:19:20 AM
yes alcohol can be sticky
Title: Re: alcohol
Post by: pomprocker on February 06, 2009, 10:46:10 AM
I read somewhere that before it dries you're suppose to rinse it off with distilled water
Title: Re: alcohol
Post by: paulstreats on February 06, 2009, 01:49:43 PM
The idea is that the alcohol dissolves the dirt and grease and other stuff your cleaning off, so you can end up with a greasy / sticky solution on everything because its the dissolved dirt. Now if you leave it then the alcohol evaporates and the dirt dries back onto the surface. So it does make sense to rinse it off before the alcohol evaporates.

If you dont want to use water (because of obvious drying problems) then you need to make sure there is plenty of alcohol and use an air spray to blow it away. (just compressed air, you used to be able to get it in a spray can)
Title: Re: alcohol
Post by: pomprocker on February 06, 2009, 04:14:47 PM
The idea is that the alcohol dissolves the dirt and grease and other stuff your cleaning off, so you can end up with a greasy / sticky solution on everything because its the dissolved dirt. Now if you leave it then the alcohol evaporates and the dirt dries back onto the surface. So it does make sense to rinse it off before the alcohol evaporates.

If you dont want to use water (because of obvious drying problems) then you need to make sure there is plenty of alcohol and use an air spray to blow it away. (just compressed air, you used to be able to get it in a spray can)


you still can get it in a spray can!!

thanks for the heads up!
Title: Re: alcohol
Post by: HDL_CinC_Dragon on February 06, 2009, 10:21:32 PM
Just a little update: One of my local hardware stores has 5 gallon drums of Acetone sitting on their shelves lol. I got a 16oz container of it :P They also only had 16oz bottles of 70% IPA which was a little disappointing... oh well