The Problem With Borax and Spray Bottles

I’ve been writing this blog for several years now and that means I’ve tried and shared lots of recipes over the course of that time too. Today I’m thinking more specifically about the homemade cleaners I’ve tried and and how some of those recipes have been real winners that I continue to use all the time (my furniture dusting spray), some I use more sporadically (toilet bowl cleaner), and some have been real duds (failed dishwasher soap hack).

So when someone emailed this week about one of the all purpose cleaner recipes I shared back in the early days of this blog, I realized it was a recipe that I really liked for a while, and then stopped using, and that maybe it was time for a quick update.

Homemade cleaners and Borax - does it clog spray bottles?
This was a homemade cleaner with borax in the mixture. Now I know borax is under some scrutiny lately on if it is a safe enough and “green” enough ingredient, but that’s not what caused me to fall out of love with this homemade cleaner.  Instead it was the clogged sprayers.  Yes, it seemed like whenever I put borax in a homemade cleaner in a spray bottle, sooner or later the bottle would just stop working and I’d be left scratching my head and wondering  . . . can borax clog a spray bottle?

When I looked back at the original post I wrote about this spray cleaner with borax I had already made mention of a clogged sprayer and that it was helpful to look for spray bottles with little filters on the spray tubes. But then I forgot my own advice, made the mixture in one of my favorite spray bottles and never thought about looking if it had a little filter or not, and it clogged up. And that was then end of my favorite spray bottle. And the end of making that cleaning recipe.

The problem with borax in your homemade cleaners and spray bottles

So why the clogs?

At first I thought maybe I just wasn’t getting my borax thoroughly dissolved when I made the mixture.  But I always used very hot water, and it always look dissolved when I stirred everything together.   AND, the clogging never happened right away.  It always happened several months after I had made the mixture and was still using it up.

What else could be going on?

Have you ever seen the homemade science experiment of making crystallized snowflakes? What are they doing? Well, they’re mixing borax in hot water, and then letting it cool. Pretty much the same thing we are doing when we make this homemade cleaner. Here’s a quote from the Steve Spangler Science borax snowflake recipe and why it works:

“When you mixed the borax and water, you created a suspension of borax. A suspension is a mixture that contains solid particles large enough to make the liquid appear cloudy or murky. By mixing the borax into hot water, instead of room temperature or cold water, the borax can stay suspended much longer. Very hot water can hold much more dissolved borax than cold water. Hot water molecules are moving very fast and are spread way out which makes space available for more borax to dissolve into it. As the mixture cools, the water molecules slow down and move closer together. That means there’s less room for the dissolved borax and it begins to fall out of the water.

As the borax settles out of the cooling suspension due to gravity, it bonds with other borax on nucleation sites (bumps, tiny cracks, impurities, etc. in the container) and begins to form seeds for further crystallization . . .”

Even though there’s more in our homemade cleaning mixture than just borax and water (also some vinegar and soap), I still suspect that this type of crystallization effect could be what’s causing the clogged sprayer problem.

My borax always looked dissolved when I made the mixture with hot water (appearing cloudy and murky as Steve Spangler says), but of course the mixture then cooled down.  And as the months went by as I used this cleaner, I really do think that this same effect was happening and that some of the borax was crystallizing.

The beginnings of little science snowflakes in my spray bottles 🙂

I guess I have no absolute proof of this, but it seems a very likely theory.

Homemade All Purpose Cleaner

Some other ideas:

I will note that I was always happy with how that mixture cleaned.  The original recipe is:

2 cups hot water
2 tablespoons borax
2 tablespoons vinegar
Squirt of dish soap

A few ideas to adapt that would be to:

. . . substitute washing soda for the borax

. . . or perhaps heat the mixture again from time to time

. . .  make a smaller version that will be used up faster before crystallization can begin

. . .  or just clean a lot and so this size batch gets used up faster {{ not my favorite option }}

I find myself just using some of my other recipes. I can always rely on my all purpose vinegar and water mix, and I always like to always keep a homemade soap cleaner in the house too.  Both of these mixtures are handy all purpose cleaners to have around.

So for now I’m leaving the borax out of any homemade cleaner in a spray bottle. It’s so frustrating to lose a favorite spray bottle and I could never find a way to fix or clear out the clogged ones.

Am I the only one?  I would love to hear if others have had this experience too.  You can leave me a comment below, or email me at themyozone [at] yahoo [dot] com

You might also like to read: What to do about clumpy borax and washing soda
(another common problem with borax!)

Homemade cleaners and Borax - does it clog spray bottles?



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  1. wow my friend! you have no idea how much better I feel knowing that I wasn’t the only person having a nervous breakdown over a spray bottle! shew…

  2. Well, the water evaporates in the spray head leaving it clogged with super fine crystals. I suggest we make it in a separate jar and just add to spray bottle when needed. Immediately pour back unused solution, fill the spray bottle with hot water and spray until solution is flushed out. Empty bottle, done : ) MY experience comes from dissolving menthol crystals in isopropyl alcohol.

  3. I discovered the problem and solution to the borax clogging up the spray bottles. As the other person eluded to, it’s supersaturation. Wikipedia lists the solubility of borax at 31.7 g/L. There’s also a chart and solubility curve for various temperatures. At room temperature (68f) the solubility is just over 4%. If you plan to use the mixture for cleaning at room temperature keep your mixtures to 4% and you’ll be fine.
    You’re welcome…..

  4. did you try using hot water to declog the bottle? how about other soluble solvents? “ Borax is poorly soluble in cold water, but it’s solubility increases with temperature. It is soluble in some organic solvents, like ethylene glycol, glycerol, while moderate soluble in diethylene glycol, methanol. Borax is only slightly soluble in more common solvents like acetone, ethanol, ethyl acetate”

  5. I’ve had the same issue with spray bottles clogging with either borax or baking soda. I’m going to adjust my recipes too to leave out any powdered ingredients.

  6. My suggestion would be to dissolve it at 55-60 degrees instead of 70-100.

    Then straining out the excess. Thus at Temps it will be used at it will never be super saturated, and thus never recrystalize.

    P.s. shaking when supersaturated may actually be facilitating the falling out of suspension and speed / causing the crystals to form.

    P.P.s. I was investigating using crystals of actual boric acid vs. Borax. The salt (was thinking of adding salt anyway) and o2 sound interesting (is that kinda like hydrogen peroxide. )

  7. Solubility of borax in water is 2.5% at 20°C i.e. 2.5g/100ml
    metric cup then at 250ml will accommodate 2.5X2.5=6.25 grams
    As room temperature may go below 20°C at times it would be best to go with a little less than 6 grams of borax to 250ml water.
    A LEVELED Tablespoon of borax is ~6g so to be on the safe side go with 2 3/4 teaspoons per 250ml.
    Now you can apply it to make your recipe clog free in your sprayer.
    Assuming a metric cup then I wouldn’t use more than 5 1/2 teaspoons and it should dissolve in warm water not hot. Then add the soap and vinegar.

    1. But what is it with the vinegar…
      And actually I was considering 80:20 alcohol:vinegar & saturated boric acid solution (boric acid crystals not powder vs borax).

      This post has me considering borax, and doing the dissolving at 60°f. And of course straining the crystals. To prevent micro crystals clogging. (Kinda hard to strain borax powder vs the large boric acid crystals)

      Previous recipe was leave crystals in the container, but was using eye dropper for ears vs sprayer for surfaces

  8. –4 tablespoons 20-mule borax
    –2 tablespoons boric Acid (amazon Florida Laboratory)
    –24 oz water (preferably distilled or RO) The less minerals in the water the better.
    — stir and heat in microwave

    Has stayed dissolved for 4 weeks… at some time in the future solution may recrystalize? Pour in back into glass jar and stir and heat. Put nozzle in warm water and use warm water in jar to clean nozzle by pumping…

    may not be waht you want for cleaning am making borax solution for making my wood-house-siding more fire resistant. It is also very useful for toenail fungus and seems to be generally good for skin…. don’t get it in eyes

  9. Did you ever find a method to unclog the sprayer? I think I have similar issue with my homemade weed killer mixture of vinegar, soap and salt. Pretty sure the salt is ultimately clogging things up rendering the sprayer useless. So far unable to fix it.

  10. What about a squirt bottle? Or a glass jar or bottle?

    May use slightly more product and effort, slightly.

    You can get the cloth you use wet with water so it doesn’t suck up too much cleaner. If using a super saturated solution (heating the solution of borax and water that allows more borax to be dissolved in the water) you will have a stronger solution that can afford to be diluted anyway.

    It’s ok to shuffle the focus on convenience to use, instead of packaging and application. 🙂

  11. I filter mine through a fine metal sieve, blinding will occur (filter clogs) so stir while it drains. then I run it through a fairly coerce coffee filter. Then mix with the together. I have not had a clog in about 2 months finger’s crossed

  12. Your science explanation is deeply flawed. A suspension means the solid is not dissolved, but rather floating about. Borax can be dissolved in water. The hotter the water, the more can be dissolved. Once the capacity for water at a given temperature to dissolve more is exceeded, the rest just lays on the bottom as a solid. Now lets say you just dissolved all of the borax your very hot water can hold, nothing more. As the water cools, it is possible for the excess borax to stay dissolved. When this occurs the solution is said to be super saturated. Super saturated solutions are unstable, the excess dissolved solid is always looking for a way out. When the temperature drops low enough, any solid, be it undissolved borax, dirt, a bug or even a sharp edge can trigger the excess solid to precipitate. The sharp edges of the suction tube or the filter screen at the bottom are perfect places to trigger this. This is why your bottle can sit for months, then bam, it precipitates and clogs up.

  13. using a twist tie, i tied a cotton pad from dollar tree to the bottom of the tube as a filter
    we will see how it goes

  14. Looks like that is has all of my spray bottles not working anymore and they all have that metal spring inside them. 🙂

  15. I’ll add my 2 cents to the mix. I’ve never made this solution, but I have used spray bottles for lots of things such as vinegar & water or bleach & water. I have found that one of the biggest problems with spray bottles is that the sprayer mechanism has a metal spring inside which becomes subject to corrosion depending on the liquid being sprayed. So if the liquid is acidic (vinegar) or has a lot of salt/sodium (bleach, baking soda, etc) it tends to quickly corrode the spring and the bottle will no longer spray. I found the ONLY bottle (so far) that doesn’t have a metal spring mechanism (so it will not corrode) at Walmart. It is their Mainstays brand.

    1. This is good info Irene – thanks for sharing! I will take a look at Walmart for that brand of spray bottle.

  16. hmm, a bit of logic here. Only dissolve in cold water, that borax shouldn’t drop out of solution as it’s not a saturated solution. You sort of answered your own question without realising it.

  17. I can’t say with any certainty if the borax is causing the problem or not – I’ve not used borax in my cleaning solutions. (It’s kind of pointless to use borax and vinegar in the same solution – one’s an acid, the other alkaline and they cancel each other out -think baking soda/vinegar- … better to use an acidic solution OR an alkaline one. I use vinegar as a base for mine, hence acidic.)

    That aside, I ALWAYS have problems with my cheap bottles working for a while, then eventually not working … but only when I put essential oils in the mix. Straight water, or straight vinegar (windows & mirrors) are fine in the bottles and work until the bottle usually falls and cracks. The minute I add essential oils, the bottle’s days are numbered! I’ve figured out that the cheap bottles (like I use and you have pictured) have plastic parts in the sprayer mechanism that are VERY sensitive to the oils. Unfortunately, essential oils DO eat some plastics over time, and eventually my bottle’s sprayers will fail to work.

    My solution to the problem: I only use the cheap bottles (as I said) for plain water and plain vinegar. For my cleaning solutions with essential oils, I recycle the bottles from the ONLY cleaning solution I buy in spray bottles: stain remover. These bottles are made with a more durable plastic to withstand the chemicals used in the product. They also withstand the ‘melting’ that essential oils tend to do. Once cleaned well, I’ve NEVER had one of these bottles fail. 🙂

    1. Thanks for sharing your experience on that Valora! When I decided that borax was clogging my spray bottles, I decided not to use it in any of my favorite bottles, because I did not want my favorites to stop working. But maybe that was the wrong approach! Maybe the more expensive bottles would not have had the problem in the first place. Something to think about I guess. I have never encountered a problem with oils in my spray bottles so that is an interesting observation too.

  18. I have never had trouble with borax clogging the sprayer, but in looking at the quantity in yours it may be you are using too much. I only use 1 teaspoon or a teaspoon and a half per 16 oz of water, rest of the ingredients are the same except sometimes I use more vinegar. I also sometimes add either a few drops of essential oil or use scented castile soap. This makes a good all purpose cleaner.

    1. Thanks for that advice Norma. I might have to try this again with a smaller amount of borax in the recipe.