91% Alcohol vs 99% Alcohol

General Discussion
41

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.

42

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

1 Like
43

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.

44

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

45

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)

BUT:

  • 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.

3 Likes
46

Please help - would using a 70% with 5%aqua and 25%Methyl salicylate stop my project from curing?

47

and 90% not a fire hazard?! gto

48

You’ve heard of static electricity??

49

Sure, and what exactly would create this static electricity in the computer which would ignite the bottled IPA sitting next to it?

50

Unless you live in the Amazon ,static electricity easily created just by dry conditions and movement. I recommended anti static mat

51

Have you ever actually tried to ignite IPA?

I just did, and while it’s easy enough with an open flame (a match), it’s nearly impossible with just a spark.

I have an old wand lighter (out of fuel), but the electric piezo/quartz igniter still works. I tried and tried, no luck. So unless you have such massive quantities of alcohol in a huge open vat, that is evaporating and permeating the room with volatile alcohol molecules, I don’t see how you could possibly ignite bottled alcohol, especially when it’s covered.

52

Actually flalabs seems cheaper than zoro
https://www.zoro.com/techspray-tech-spray-isopropyl-alcohol-1-gal-998-1610-g4/i/G3552884/

vs

https://flalab.com/product/isopropyl-alcohol-99-anhydrous/

$157 for zoro
$72 for flalabs