What Kind of Alcohol?

Can I use other kinds of alcohol other than 99% IPA?  For example, can I used denatured alcohol?

We have not tested this, and ethanol (especially denatured with methanol), would likely absorb more into the resin than isopropyl alcohol, causing swelling and warping. Feel free to give it a try and let us know how it goes though!

I’m using a 70% Isopropyl alcohol I found over at a CVS. It seems to be working fine, but should I look for a more pure substance?

Looks the other 30% is mostly water anyway

90% or more is best. I can usually find 90% or 91% at CVS or Walgreens.

You can also get 99% IPA by the liter from Amazon ( http://www.amazon.com/dp/B005DNQX3C/).  Particularly great if you already have Amazon Prime and don’t want to head to CVS.

This one is a little bit cheaper – and if you get 3+ bottles you get free shipping (http://www.amazon.com/For-Pro-99%-Isopropyl-Alcohol/dp/B0006Q006M/ref=sr_1_1?ie=UTF8&qid=1367594161&sr=8-1&keywords=for+pro+isopropyl)

So how much will you order? It costs much less per unit volume the larger the container you purchase however Formlabs support site does not indicate the minimum volume required to half fill the rinse tank and the spray bottle therefore if you purchase less than what is the most economical volume to do so straight off it’s going to cost you more than it should later.

Come on Formlabs tell us what’s the minimum volume needed?

Hey Marc,

I measured it out. The rinse container holds approximately 2800ml and the squirt bottle holds 300ml. Obviously you want to use as little isopropyl as possible to conserve your refill abilities!

In terms of the minimum volume needed, we usually operate with a rinse tub around 1/3 full but you would want more alcohol for larger parts. I would order at least 1L to get started, probably 2L.

I just filled my rinse tub for the first time last night. It took a little over 1L to fill it half way and a little over 1.5L to fill both the tub half way + the rinse bottle. I’m planning on using the remainder of the second liter bottle to fill the rinse bottle when it’s low. I’m about to order some 99% IPA from Amazon and will probably order 4 bottles so I have an extra set once the tub is used up.

91% at the CVS I picked mine up at was $3.59/quart, so if there’s little to no advantage to 99%, I think I’ll stick with that…

hi there

for those in the UK, here are three sources of IPA that I’ve used if it helps any one.






Price dropped by a couple bucks on this one from Amazon:  http://www.amazon.com/For-Pro-99-Isopropyl-Alcohol/dp/B0006Q006M

Free shipping option for *four* bottles now, but it’s only $2.99 shipping for three…

Just to add to this thread, I also ordered some 99% from amazon for 12 dollars then I found the 91% at our grocery store for 3.50.  I bought 4 bottles of the 91% so I didnt have to wait on Amazon and it works great.  So save your money and get the much cheaper 91% over the 99%.  I probably wouldn’t go down to 70% though.

From my personal experience I found that IPA didn’t work that well for my prints. While it was ok to soak the large parts for 10 mins I’ve found that my smaller parts have started peeling off and still there’s some slimy residue on the surface that leaves the parts tacky. Plus IPA is extremely expensive here in my part of the world as they are only sold in small bottles in pharmacies. I spent over $20 to fill up a third of my tank and its saturated with resin in no time.Only yesterday did I saw that the other thread showed a neat trick to recycle the IPA but I’ve found something that works better for me.

After trying a coupe of different solvents that I can get my hands on I’ve come to conclude that Acetone (nail polish remover) works best for my prints. It’s still expensive as hell (like IPA they only come in small bottles) but it really dissolves uncured resin in a jiffy without damaging the parts. My process includes removing the parts from the supports (most of the residue resin gets stuck on the supports) and then use paper towels to get rid of as much resin as possible on the surface, then just move the part one by one in the acetone for about 10-20s, dry it with a large piece of cloth and repeat another time. That removes most of the slimy feel that I still get if IPA is used. For a thorough clean I use a toothbrush to scrub the parts but this process allows too much acetone to escape causing fumes and wastage so I skipped it and just leave the parts in the sun to postcure them. That should remove any minor bit of resin left on the surface.

Just to sidetrack a little, for me its best to use a small hammer on the hand scraper provided to chisel at one corner of base of the supports using the edge of the scraper. The scraper doesn’t really damage the aluminium if its angles almost horizontal to the surface. This is really handy and removes parts in seconds.

In the US I saw a gallon of 99% in a local hardware store for I think $26.  It was an ACE affiliated store, so some may have luck with that.

Still almost twice as expensive as 91%, but quite a bit cheaper than Amazon at the moment.

Can you reuse the alcohol for multiple parts or do you have to dump it after rinsing the parts made after one printing?  If it can be reused how many times before dumping it?  Maybe this is already answered?

Thanks Allan : Both Ethanol and IPA are relatively expensive in the UK and both come with very strict transportation regulations and therefore, high carriage costs :((

We buy ours through Grainger. It is 99% and goes for $40 US per gallon, however it is only sold in quantities of 4.

Our Purchasing Dept. supposedly gets a discount compared to the the prices listed on the Internet but I don’t know what that percentage is and who might be eligible for it.

I save our used IPA by pouring it in the empty IPA bottles. Once they have sat awhile the solids settle to the bottom and I pour off the “good stuff” to reuse. I only reuse that in my first bath.

Acetone, be careful with that stuff, much higher health risks if my memory serves me well, if it doesn’t, it’s the acetone that’s to blame. :wink: