How to make slime activator with baking soda and water

Making AMAZING slime is all about having the right slime ingredients. The best ingredients include the right slime activator and the right glue. Here is my BEST slime activator list to get you started, and I will share some tips for making the easiest slime ever with these different slime activators. Discover how easy it is to make your own slime!

BEST SLIME ACTIVATORS FOR MAKING SLIME!

How to make slime activator with baking soda and water

WHAT IS SLIME ACTIVATOR?

A slime activator is one of the slime ingredients needed for the chemical reaction that takes place to form slime. The other important piece is PVA Glue.

Slime forms when the borate ions in the slime activator (sodium borate, borax powder, or boric acid) mix with the PVA (polyvinyl acetate) glue and forms this cool stretchy substance. This is called cross-linking!

The glue is a polymer and is made up of long, repeating, and identical strands or molecules. These molecules with flow past one another keeping the glue in a liquid state. Until…

You add the borate ions to the mixture, and it then starts to connect these long strands together. They begin to tangle and mix until the substance is less like the liquid you started with and thicker and rubbery like slime! Slime is a polymer.

Picture the difference between wet spaghetti and leftover spaghetti the next day. As the slime forms, the tangled molecule strands are much like the clump of spaghetti!

Is slime a liquid or solid?

We call it a non-Newtonian fluid because it’s a little bit of both!  Experiment with making the slime more or less viscous with varying amounts of foam beads. Can you change the density?

Did you know that slime also aligns with the Next Generation Science Standards (NGSS)? 

It does and you can use slime making to explore states of matter and its interactions. Find out more below…

  • NGSS Kindergarten
  • NGSS First Grade
  • NGSS Second Grade

No more having to print out a WHOLE blog post for just one recipe!

Get our basic slime recipes in an easy to print format so you can knock out the activities!

  CLICK HERE FOR YOUR FREE SLIME RECIPE CARDS!

How to make slime activator with baking soda and water

BEST SLIME ACTIVATORS

Please note the common ingredients in all of the slime activators below are derived from borates and are in the boron element family.

If you want to get really specific, that means you would not label any of these slime activators as borax free. Find out more about borax free slime.

Note: Recently we have used Elmer’s Magical Solution for making slime. While it does the job, it was not a favorite among my kid testers. We still prefer to use a good saline solution instead. You may need to add more of the solution than recommended.

1. BORAX POWDER 

Borax powder is the most widely known slime activator and contains borax or sodium tetraborate. It also has the most controversy surrounding it.

To make this slime activator, mix a small quantity of borax powder with warm water.  Use this solution to add to your slime recipe.

You can purchase borax powder online or in the laundry detergent aisle of your local grocery store.

Click here for borax slime recipe and VIDEO!

How to make slime activator with baking soda and water

2. SALINE SOLUTION 

This is our number one favorite slime activator because it makes the most awesome stretchy slime. It’s also more easily available for UK, Australian and Canadian residents.

NOTE: Your saline solution must contain sodium borate and boric acid (borates). 

This slime activator is also commonly used as a contact solution but I highly recommend picking up the lesser expensive saline solution instead.

We prefer Target brand Up and Up for Sensitive Eyes which you can also order online. You can find the saline solution online or in the eye care section of your grocery store or pharmacy.

This slime activator does not need to be made into a solution first but does require the addition of baking soda for thickening.

You CAN NOT make your own saline solution with salt and water. This will NOT work for slime!

Click here for saline solution slime recipe and VIDEO!

How to make slime activator with baking soda and water

Make shaving cream slime or fluffy slime using saline solution slime activator too!

Click here for saline solution fluffy slime recipe and video!

How to make slime activator with baking soda and water

3. LIQUID STARCH 

Liquid starch was one of the first slime activators that we ever tried! It also makes an awesome, quick 3 ingredient slime. There are less steps for this recipe making it ideal for younger kids as well!

This slime activator contains sodium borate common to laundry cleaning agents. You can also find liquid starch in the laundry aisle of the grocery store. Common brands are Sta-Flo and Lin-it brands.

Note: You may need to add more Sta-Flo brand starch to your slime than Lin-It brand. Our stores carry Lin-It brand so are recipes are based on that specific brand which may be stronger than the other brand.

You can not make your own homemade liquid starch or use spray starch. Cornstarch is not the same as liquid starch.

Some slime recipes use a laundry detergent like Tide. I tried this type of slime recipe and found it irritating to the skin, so we did not make any more.

Click here for liquid starch slime recipe and VIDEO!

How to make slime activator with baking soda and water

4. EYE DROPS OR EYE WASH

Last on our slime activator list is eye drops or eye wash. The main ingredient you will find in this slime activator is boric acid.

Boric acid is generally not found in a cleaning supply type of product as it is a preservative. It is specific to drops you put in your eyes as opposed to rinsing lenses.

Because eye drops do not contain sodium borate, you will need to at least double the amount you would use for our saline solution slime recipe. We made a DOLLAR STORE SLIME KIT with eye drops.

How to make slime activator with baking soda and water

HOW TO MAKE SLIME WITHOUT ACTIVATOR

Can you make slime without a slime activator and glue? You bet! Check out our easy borax free slime recipes below.  Though do remember a borax free slime will not have the same amount of stretch as slime made with activator and glue.

We have tons of ideas for edible or taste-safe slime including gummy bear slime and marshmallow slime! If you have kids who love to make slime, you should try making an edible slime at least once!

GUMMY BEAR SLIME

Melted gummy bears with a cornstarch mixture. Kids are sure to love this slime!

CHIA SEED SLIME

No slime activator or glue in this recipe. Instead use chia seeds to make your slime.

FIBER SLIME

Turn fiber powder into a homemade slime. You would have thought!

JELLO SLIME

Mix up Jello powder and cornstarch for an unique type of slime.

JIGGLY NO GLUE SLIME

This recipe uses guar gum instead of glue. It really does work!

How to make slime activator with baking soda and water

MARSHMALLOW SLIME

Slime with marshmallows instead of activator and glue. You might want to eat it!

PEEPS SLIME

Similar to our marshmallow slime above but this one uses peeps candy.

How to make slime activator with baking soda and water

There are tons of fun ways to dress up your homemade slime with color, glitter, and fun theme accessories. You can even make slime to give to friends, have slime parties, or put together a homemade slime kit for a great gift.

THE BEST SLIME ACTIVATORS TO GET YOU STARTED!

There are some many different types of slime. Try our best slime recipes right here.

How to make slime activator with baking soda and water

No more having to print out a WHOLE blog post for just one recipe!

Get our basic slime recipes in an easy to print format so you can knock out the activities!

  CLICK HERE FOR YOUR FREE SLIME RECIPE CARDS!

How to make slime activator with baking soda and water

How do you turn baking soda into slime activator?

How to Make a Slime Activator with Baking Soda. A simple and effective baking soda slime activator you can make is four pinches (about 1/2 tsp.) of pure baking soda and 3 tablespoons of multi-purpose contact lens solution. This amount is just right to mix with a 4-6-ounce bottle of glue.

How do you make slime activator?

Fill a bowl or measuring cup with 1 cup of warm water. Then add in 1 tsp of borax. Mix until all of the borax is dissolved. And that's it, it's ready to use.

Why is baking soda not activating my slime?

Either you have not kneaded your slime long enough, or you haven't added enough activator.