How do I clean up Accu-Cast alginate?

Article courtesy of Smooth-On, Inc.

As you may know, alginate doesn't stick to non-porous surfaces like skin and table tops. It DOES, however, stick to your shirt or to the carpet.

We've all done it. Get a little enthusiastic in your mixing or application and alginate ends up somewhere it shouldn't and you've got an alginate mess. If you're in the middle of an important job, you don't want to take time to clean up just then- and by the time you get around to it, the alginate is completely set.

Don't panic, it can be removed pretty simply. It is much easier to get out in the first few minutes because as it dries it hardens.

  1. Scrape off whatever alginate you can by hand. A dull knife like a mayonnaise spreader can help here.
  2. Make a pretty strong solution of baking soda and water. Add 4 tablespoons of baking soda to 1 quart of warm water and stir until dissolved. Baking soda is non-toxic and won't make its own stinky mess so it's perfect.
  3.  Soak the affected area with the baking soda/water solution and leave for about 30 minutes.
  4. With a stiff brush, scrub the affected area. The alginate should come right off. Depending on the nature of the cloth/carpet, it might take more than one application.

This same solution is great for cleaning up your mixing tools. Soak your Jiffy Mixer, kitchen whisk or mixing bowl and you should be able to just rinse off the alginate residue.

This also works for plaster based gypsum cements like LiquiStone.


This FAQ article is offered as a guideline and offers possible solutions to problems encountered during mold making and casting. No warranty is implied and it is up to the end user to determine suitability for any specific application. Always refer to the provided Technical Bulletins (TB) & Safety Data Sheets (SDS) before using any material. A small scale test is suggested to determine suitability of any recommendation before trying on a larger scale for any application.