good flux remover

[mazurov]

What were the design considerations that made IPA the best solution?

It depends, again, on what is considered "best". IPA is cheap, easily obtainable and relatively safe on plastics and on the operator (I saw people cleaning freshly built clean rooms with IPA and not wearing respirators). It can be recycled, too.

Are a fume hood and fire suppression needed?

It depends on your facility. If you're aiming to be ISO-certified then I'm not the right source of advice. I run small scale operation and it seems safe enough for my needs.

[UPI]

What were the design considerations that made IPA the best solution?

It depends, again, on what is considered "best". IPA is cheap, easily obtainable and relatively safe on plastics and on the operator (I saw people cleaning freshly built clean rooms with IPA and not wearing respirators). It can be recycled, too.

Are a fume hood and fire suppression needed?

It depends on your facility. If you're aiming to be ISO-certified then I'm not the right source of advice. I run small scale operation and it seems safe enough for my needs.

We let the boards drip relatively dry over the ultrasonic and then rinse with DI. The DI goes down the drain. The flux-off is changed out quarterly and is disposed of according to local, state and federal guidelines.

I am always open to better/safer/cleaner ways of doing it. 

[cwalex]

he didn't say what the additive was just that it isn't methanol like I thought it might be. He wouldn't say what it was

I can't use such chemicals. I need to know what's in it or at least an exact list of "anything".

Yeah, the only thing he would say is that the additive is in such a small quantity that I can just use it as though it isn't there. Having said that I'm going ot order some ISO and maybe some xylene from a chemical supply company when I get back to work tomorrow.

[mazurov]

I don't drain anything. IPA is extracted from the dirty wash, salted out to 99%, distilled and recycled. Solids are stored on site in old milk jugs, typical accumulation is one gallon per 10 years. Final dealing with solids will be left to my estate :-).

[mazurov]

Yeah, the only thing he would say is that the additive is in such a small quantity that I can just use it as though it isn't there.

This is nonsense. Can you, for example, drink it pretending it's not there? Or drinking is not  considered "use"?

[cwalex]

Yeah, the only thing he would say is that the additive is in such a small quantity that I can just use it as though it isn't there.

This is nonsense. Can you, for example, drink it pretending it's not there? Or drinking is not  considered "use"?

yeah I don't exactly trust the advice I was given by the rep but to be fair, you can have poisonous substances that poisonous at minute quantities so he may be telling the truth.

I have been using it so far with decent results but like I said before I will be ordering some IPA or maybe large qty of some solvent blends that are designed for the purpose.

I'll be watching this thread in case someone chimes in with a better idea

[SeanB]

Normally the additive is a bad tasting flavouring like Vilex or Bitrex. Others use methanol or propanol as additives to make it unpalatable. Others add esters to give it a odd taste or ketones to make you violently ill. Really depends on the supplier, and often varies from batch to batch. Generally there is a light analine dye added as well to colour it. If you are worried pass through an activated charcol filter and a lot of the additive will be held back. you can recycle through the charcoal filter as well to remove a lot of dissolved solids, though you will need a prefilter of around 0.3 microns to remove a lot of the solids.

[cwalex]

Normally the additive is a bad tasting flavouring like Vilex or Bitrex. Others use methanol or propanol as additives to make it unpalatable. Others add esters to give it a odd taste or ketones to make you violently ill. Really depends on the supplier, and often varies from batch to batch. Generally there is a light analine dye added as well to colour it. If you are worried pass through an activated charcol filter and a lot of the additive will be held back. you can recycle through the charcoal filter as well to remove a lot of dissolved solids, though you will need a prefilter of around 0.3 microns to remove a lot of the solids.

Thanks for the info. The product I have is called methylated spirits and the brand is called diggers. It's a brand name sold by a company here called bunnings. I kind of assumed by the name it was methanol that is the additive but the rep I spoke to wouldn't confirm or deny it. Iso is really expensive from normal places but I think I can get it for a decent price if I look hard enough. Suppliers in east of australia have some decent prices but I'm in the west so shipping adds a lot to the price. I haven't looked around locally yet though.

[robrenz]

Look at your auto parts store for gas line antifreeze that is 99% isopropyl. In the US I buy it for $1.39 for 10oz. bottle (case price) which works out to $17.79 per gallon.  This is the cheapest 99% I have found in the US.

Do you even need gas line antifreeze in Australia?

[notsob]

Please clarify 'gas' line, in australia gas actually means gas only, it does not refer to a liquid.


Oh and Santa didn't bring me your workshop.   (putting it on next years list)

[robrenz]

Gasoline or Petrol (Liquid) the stuff you put in your car

Sorry to hear about Santa dropping the ball.

[SeanB]

Just note if the additive is methanol you cannot filter it out, or distill it out either, as the boiling point ranges for methanol and ethanol overlap quite broadly. Normally the bitter and odour is added as a tracer, the methanol being the adulterant to make it lethal to drink ( though the gents of the road here can drink it neat........... must have livers you can use as shoe soles) in any amount.

[mariush]

I've bought 99.6% ipa at a small local electronics store for about 2$ for 0.5 liters. It's really not that expensive.