Do not use IPA to clean the FEP. Why not?  

Estimable Member

The handbook is very insisting on not to using IPA to clean the FEP film, but nowhere an explanation why not.

IPA is used to clean everything else for resin and is very effective at doing that. The recommend use of warm water and disc-wash soap is a little messy.

As I understand it, FEP is chemical resistant like PTFE (Teflon) and should not be damaged by alcohol (IPA).

Other SLA printer manufacturers suggest using IPA/Alcohol for cleaning their FEP films.

Is the SL1 FEP film special in any way or is there another good reason for avoiding IPA when cleaning the FEP film?

Take a look at my MK2S/MK2.5/MK3/S printer parts on Thingiverse ;)...
Posted : 09/09/2019 12:37 am
Active Member

Can’t say for certain, but it may have to do with contaminating the resin. Too much IPA and it simply won’t work anymore. 

Posted : 09/09/2019 1:35 am
Eminent Member

I bought an dry PTFE spray and sprayed the FEP, and with paper towel cleaned it, I haven't had a failed bed adhesion since that.

Posted : 09/09/2019 9:55 am
Estimable Member

I did some search on FEP and found, that it is used in the mold and chemical industry as a coating as it is very slippery (like Teflon), is chemical resistant and should not react to IPA.

Tried wiping the SL1 tank FEP film with paper soaked in IPA followed by wiping in dry clean paper. Result was a cleaner and more transparent film with no side efftects as far as I could see.

If the problem is contaminating the resin, make sure the tank is dry before filling it again with resin.

Anyone else have any experience using IPA to clean the FEP film?

Take a look at my MK2S/MK2.5/MK3/S printer parts on Thingiverse ;)...
Posted : 11/09/2019 1:09 pm
Veteran Member Moderator

I still use IPA to clean the FEP (did try dish soap and water, didn't get great results!), my SL1 printer is a beta test printer and is still using the original FEP...

far be it for me to recommend ignoring the Prusa recommendation...

I am simply a rebel... for example I wash both my PEI stickered Build plate and my Powder coated mk3 build plate with hot water and dish soap...

and I use glue stick for sticking paper together, 

worst of all, I used Hairspray to keep my hair tidy in the wind, yesterday!

but I do use talcum powder on the mk3 build plate, to prevent my TPU sticking too well.


I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 11/09/2019 5:28 pm
Eminent Member

I use IPA on the FEP on the SL1 & other Chinese printers, can't say I have seen any adverse effects, windex has also worked very well for me, perhaps even better than IPA.


once clean I give it a spray with rain x, not saying I recommend this, I don't have long term usage data yet.

Posted : 11/09/2019 5:41 pm

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