Strange cleaning issue--sidewalk chalk residue

[rpe290]

So I had my glass carboys sitting in the garage with oxy clean soaking to clean up, and along comes my 18 month old who thinks its fun to put sidewalk chalk in things!

I find it say a month later, no big deal you think, that will come right out, wrong--some kind of residue I cannot get out of there from the chalk, one thick line of it near the bottom and a little film everywhere else. Not PBW, not some other dish soak cleaner--any chemical experts know what might get this stuff out? I am thinking only a stronger acid and that may not be worth it IMO.

From what I can gather, the sidewalk chalk is calcium sulfate (gypsum)-- however, I don't know how it reacts with the percarbonate oxyclean over time to precipitate out like that and stick to the walls. Would wipe off if you could get in there but obviously not.

Anyone know for sure?

 

[sniktaw]

I'd try vinegar or star san. Both are food safe and likely to do the trick. I would not cap it and would do it in an easily cleaned area in case it reacts a little strongly. Might take a couple of rounds.

 

[Mismost]

I assume, it has to be on the outside. So, really it ain't hurting' nothin' but your feelings!

A little perspective may be in order here. My 18 month old is now 28 years old. One of my prized possessions is a magic marker drawing on the inside of my shop door "gifted" to me by my daughter! I could have painted over it many times, but I know I never will. I smile every time I see that stick figure piece of artwork, it's proof I raised a joy filled little girl. Some things are worth keeping!

Or try the vinegar, it's really good stuff...it eats calcium deposits off our water fixtures...it oughta eat sidewalk chalk.

 

[rpe290]

I assume, it has to be on the outside. So, really it ain't hurting' nothin' but your feelings!

A little perspective may be in order here. My 18 month old is now 28 years old. One of my prized possessions is a magic marker drawing on the inside of my shop door "gifted" to me by my daughter! I could have painted over it many times, but I know I never will. I smile every time I see that stick figure piece of artwork, it's proof I raised a joy filled little girl. Some things are worth keeping!

Or try the vinegar, it's really good stuff...it eats calcium deposits off our water fixtures...it oughta eat sidewalk chalk.

Nope, dropped into the inside, hence the issue.

 

[Rhumbline]

It's on the inside, right.

Can you wrap a rag around the end of a stick or such to put a little elbow grease on it?

 

[theseeker4]

So I had my glass carboys sitting in the garage with oxy clean soaking to clean up, and along comes my 18 month old who thinks its fun to put sidewalk chalk in things!

I find it say a month later, no big deal you think, that will come right out, wrong--some kind of residue I cannot get out of there from the chalk, one thick line of it near the bottom and a little film everywhere else. Not PBW, not some other dish soak cleaner--any chemical experts know what might get this stuff out? I am thinking only a stronger acid and that may not be worth it IMO.

From what I can gather, the sidewalk chalk is calcium sulfate (gypsum)-- however, I don't know how it reacts with the percarbonate oxyclean over time to precipitate out like that and stick to the walls. Would wipe off if you could get in there but obviously not.

Anyone know for sure?

Pouring a bunch of concentrated star San in there would likely be a bit expensive. Get some muriatic acid and try that if vinegar doesn't work. Just clean well afterward before you brew in that carboy again.

ETA, definitely use it outside, the fumes are bad...

 

[augiedoggy]

This is an issue with aquariums too especially on the top were the water disolving leaves a ring.... There are solutions that work to clean the glass... Of course I cant remember what they are off the top of my head... maybe google it in reference to aquarium uses and see what comes up?

 

[Redlantern]

Chalk has a lot of calcium in it (Calcium Carbonate)

Is also acidic

Wonder if drain cleaner (a base) would do the trick? (Lye)

Love that stuff. People get nervous about it, but it is a lot more common than you might realize

Here is a twist for all those folks that are twitchy about lye - it is used in the food industry to get the nice brown color on pretzels and listed on the ingredients as "soda" when used

 

[brewcat]

carboy brush?

 

[soccerdad]

Whatever else comes of it, I would keep the kid ! At least until it happens a second time.

 

[sniktaw]

Just wondering if anything has helped so far, curious to see how it turns out?Also, if I'm not mistaken, chalk is alkaline not acidic and may need an acid to disolve it. Not saying the lye wouldn't work, just that an acid might work better.

 

[Redlantern]

Just wondering if anything has helped so far, curious to see how it turns out?Also, if I'm not mistaken, chalk is alkaline not acidic and may need an acid to disolve it. Not saying the lye wouldn't work, just that an acid might work better.

Yup. You are right - it is alkaline

 

[Twinky]

You could try a mouse with a tiny scrub brush. That's what the original owner of my carboy did.

 

[sleepspeaking]

I've got really hard water, and if I leave any glass in an oxyclean bath for more than a few hours the come out coated in a layer of gunk. This stuff is stubborn and looks like chalk residue. But vinegar cuts right through it. A little white vinegar sloshed around and left to sit for 5-10min light scrub, and its crystal clear.

Hope your's cleans up as easy. Let us know what worked for you.

 

[rpe290]

I have both lye and vinegar, will try vinegar soon...

 

[rpe290]

Used lemishine (acid) then vinegar, dissolved all of it, thanks all!