Stupidly simple solution to the form wash evaporation woes

I actually like this idea. You could filter each time you refill.

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@bolsoncerrado I noticed a loss of about a liter per month which is by no means a big deal but since I only fill/drain once or twice a week it is just easier take a few minutes to drain it and to lose next to nothing. When I first started doing this I had exactly one tank’s worth in the carboy and could monitor how much I was losing. Even after about ten washes over a month I didn’t need to add a drop! Before I started doing it I was losing about a liter a month!

@Walter_Gillespie That’s not sexy enough for me :slight_smile:

Now if I could just figure out how to make it quieter than 1 million mating mosquitoes…

Ugh. While this is a nice hack, I can not believe this is the solution.

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Does good ole fashion plastic wrap help?

@shawny2005 yeah it’s a small inconvenience but this issue is nowhere near as bad as the noise. The whole office gets blasted with a high pitch ringing that’s incredibly annoying. You don’t want to be in the same room as this thing.

@momentif I’m sure it would but that seems wasteful and looks much worse than using the tank in my opinion

Stick a filter on the pump intake to catch the solid bits and now you’ve got an IPA cleaner! Paint strainer on the end of the line might also work.

I empathize with you. I wrapped my Form Wash in a clear plastic bag and twist the end closed when it’s not in use.

It may not be scientific, but I know it has some effect - the label on the front of my unit used to be held on with scotch tape, but when the bag was closed for several weeks the IPA vapors actually ate away at the tacky adhesive in the tape and it peeled off.

Starting today I think I’ll try just putting saran wrap over the bucket opening:


You can take the tank easily. without the pump even.


1L / week seems like an awful lot. I’m only losing a few mL per week, and only smell IPA when the lid is open.

@Rodrigue I’m well aware! As I said in the post I leave it in place, pump it out, then I pop the tank out of the wash and pour the remaining into my carboy

@Amanda1 as I mentioned in the edit that may be an exaggeration (probably more like 1L/month) but it was still enough to warrant constant topping off. My wash is about two feet from my nose when I’m at my desk so it became quite a nuisance.

Over a few weeks of no printing. I lose about 2" from the mid line of the recommended height. Thinking about printing a cap on my FDM printer and on the inside having some sort of seal. Removing the IPA isn’t a bad move but I’m lazy lol. I need it to be ready to rock even if I only print once a week.

For the people with high evaporation rates is it like 95F in the room you have this in? I don’t understand how there could be this amount of loss just due to evap. I’m 5 months in with our Form Wash and i add a liter once a month and attributed most of this loss to what comes out on the prints and evaps off them. We are averaging about 3 prints a week, was one or two a day for the first month. If you are losing a liter per month i think there is something else wrong here. Is the trap door that closes when the rack is full up closing?

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My place in the summer is at 82 on the regular I’m in Chicago

I lost about 1.5cm of IPA in two weeks.

Definitely won’t work for me without a gasket…

This works for me - simple and cheap solution

Fails after around 6 months but they are real cheap to replace - elasticated so it forms atight fit around the Form Wash


hahah bro fist :fist_right::fist_left::muscle::muscle::muscle::grin:

Your solution to the isopropyl alcohol evaporation problem is a good one. Thanks for sharing with us. I thought I would present my solution here in your thread.

I decided to look for a container that the tank would fit into. This army ammunition can from ebay is doing the trick for me.

I had to replace the seal with a new piece of 1/4" rubber so it could hold back the 0.7 psi of vapor pressure.

The ammo can lid is 15" by 12". That vapor pressure would result in a force on the lid of 126 lb. It really adds up for a container this large.



Isnt’ the evaporation happening anyway, just contained?

It happens until an equilibrium is reached between evaporation and condensation. That’s the concept of vapor pressure. If the Form Wash is contained, then there will be much less evaporation, as the vapor can’t escape and an equilibrium is reached quickly. On the other hand, with an uncontained, unsealed Form Wash, the vapor can escape and there will never be such an equilibrium, the IPA will just continue evaporating until it is gone.

Do you end up with a film of condensation coating the outside of your Form Wash?

Nice case BTW; guess the ammo box is also handy if your Wash spontaneously explodes.

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Only the tank from the Form Wash is in the ammo can. I have not noticed any condensation on it yet. If there is some after a longer period of time I will report back.

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