91% Alcohol vs 99% Alcohol


It has been replaced as a cleaner long ago. I read about similar.


Just to add some value, it is recommended to keep IPA at least 30 cm from any electronics.



will this work? $2.50 per 32 fl oz.




Works for me…


Advised distance to avoid fumes from igniting.


started using my form wash with 99% and overtime I’ve slowly diluted it with 91%. Haven’t noticed a change

so might just go with lots of 91% bottles once the 99% quarts run out

I two bucket larger and parts before they go into the wash


And where is the source of ignition, the spark, going to come from?

I’ve had bottles of IPA sitting right up against my PC for the last couple of years, and never had any issues. And the large tubs are also nearby but their lids are closed.

IPA would need a flame or a spark to ignite, and I really can’t think on how a computer, or any modern electronic would provide that spark, unless it shorted out and started a fie of its own. If you’re worried about heat igniting it, the self ignition temperature for pure IPA is 400°C. I doubt any type of device, electronic or otherwise could produce that type of head and not self-destruct.

There is such a thing as common sense and precaution, but it doesn’t need to border on fear and paranoia.


I think you misunderstood my view on this as I am in agreement with you. I came across the information researching IPA. It was a lab handling and use article stating 30 cm from all electronics.

I believe this to be a precaution in the event of the device failing and emitting a tiny spark. Obviously this would be more risky with 99.9% vs. 71% IPA as well.

It would take some Final Destination event for it to ignite from a computer or something similar. I can see it now. Maybe my watercooling loop in my PC springs a leak, the non-conductive fluid meets dust on the motherboard and becomes conductive resulting in a short and spark. Then boom lol.


Maybe my watercooling loop in my PC springs a leak, the non-conductive fluid meets dust on the motherboard and becomes conductive resulting in a short and spark. Then boom lol.

So just use 99% IPA as your coolant, no conductivity = no shorts, duh



Actually, it’s been tried. The problem with IPA in a cooling system like for a PC, is that the pump and piping are usually made of some sort of acrylic plastic. Alcohol (IPA or other types) has an affinity for water and will dehydrate any type of plastics that contain water molecules. This is the reason why why it deteriorates our resin tanks.

So while it does sound like a good thing, especially since Alcohol doesn’t freeze or become viscous at low temperatures , it will eat through the plastic in pretty short order.


Lol it was a nice thought, but I’ve been at the watercooling for years and the only way for IPA to be a coolant would be copper piping. Not sure how corrosion would work though. Also, it does tend to present the same issue of ignition, but just brings the two closer together. I’ve never had any failures resulting in sparking in all my years with the exception of a bad gasket dumping my reservoir into my dusty PSU.


You want to see sparks from a modern piece of SLA equipment? Try plugging the power plug into a SparkMaker with the power on. Just sayin…


I was kinda wondering if it would be possible to recondition the IPA to some degree instead of disposing of it?

I recently acquired the Form Wash which takes up a lot of IPA so I was considering mixing both sides of my Cleaning Station into it but before doing that I calibrated the supplied Hydrometer with a fresh batch of my usual IPA and then tested it on the dirty side of my Cleaning Station reporting it as basically unusable which got me thinking into running it through a Coffee Filter.

10 Filters ( the resin is clogging it up really fast ) and two runs later I was standing in front of a much less opaque solution that was still as bad as it was before so I did a quick search and found that Active Charcoal is being used to clean Alcohol though it mentions being used for crystalline contaminants which I believe does not apply with resin?

Should I consider ordering a distillery kit on Amazon? xD


If something similar hasn’t also been posted here, this document might be of interest regarding exposure to IPA:


91% is optimal, really, 99% is a waste.

91% is azeotropic, meaning the percentage will remain the same no matter how much evaporates (because water and alcohol will evaporate at the same rate).

In other words, your 99% will become 91% anywas if you leave it open.


Filtering IPA won’t help very much. The resin is dissolved in the IPA so only distilling it will remove the resin.


If you’re from eastern Europe, then wouldn’t it be loza? If I’m spelling it correctly.

I use 99% and find it washes better and with a shorter soak duration. I use the same two bucket method mentioned above. For some parts, I’ll wash in the FormWash as a final process.

I have tried that Australian product, resinaway, but for me, it sucked. I see now Formlabs also recommends/supports the use of TPM but I am unable to find it and searching online only mentions it as an ingredient in cleaners.


Filtering would help with removing bits of resin that are inevitably left behind in the IPA before it reaches saturation.


We’re using TPM now for about half a year with the original Form Wash and it’s the best solution for us.

Yes - it’s more expensive
Yes - you need to wash the TPM away after washing your parts (we use hot water)


  • It smells so much “better” than IPA
  • higher boiling point (3times more -> 82°C IPA / 242°C TPM -> this is causing the “better” smell)
  • flashpoint 10x higher (12°C IPA / 127°C TPM)
  • higher resincapability (we can use TPM almost two times longer than IPA)

So for us as a company, the advantages are much higher than the price-disadvantage. We use “Dowanol TPM”, if you are interested in.

Alternate Wash Solution