How to prepare a flour glue

This week we had a cookery course during our mosaic practice. No, we didn’t prepare stone soup. But we have learned how to make a temporary adhesive for rovescio su carta, the indirect mosaic technique with which we started here at school. Although the adhesive holds the tiles firmly to the paper, the glue can be easily solved by wetting the paper back once the mosaic is glued to its permanent base.

Of course you could buy a similar compound in a store. But that would be more expensive and not half as much fun. So here’s the recipe for the sticky mass that looks a bit like peanut butter.

 

Recipe Colla di farina (flour glue)

Ingredients

Flour, water, liquid glycerol, formalin (can be replaced by cider vinegar)

Kitchen appliances

Saucepan, wooden spoon

Preparation

According to my teacher this recipe works by eye. For the ratio of flour:water I would say it is about 1:2, though. So if you use two cups of flour, then this is filled up with about 4 cups of water.

Preparation: Stir the flour with a little water in the pot to a creamy mass. There may not remain any lumps, but the flour should be completely dissolved in water. Now bit by bit add the rest of water according while stirring.

On the stove: Once a homogeneous liquid is formed, slowly heat the flour -water mixture on the stove at medium heat, stirring constantly. Once the mass has become something solid (about 1-2 minutes) and forms lumps, remove the pot from the stove. Continue stirring so that the clots dissolve. Add 2 teaspoons of formalin (or cider vinegar) and 2 teaspoons of liquid glycerin while stirring. Store the prepared glue in a Tupperware bowl.

Tips

The whole process must be very fast, because if the glue cooks for too long it won’t be sticky enough and the mosaic over time could come loose from the paper. So don’t leave the pot on the stove for too long and under no circumstances use a gas stove. It would heat the mass too fast. A moisty flour glue is better than a dry one because by time it will loose some moisture. Formalin or cider vinegar ensure that the glue does not get moldy. The glycerin makes the glue soft.

All information given without liability.

If you try the recipe at home tell me how it worked.

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15 Comments

  • The diverse ways in which humans use flour is fascinating. I have always been fascinated by its use as a glue and your blog encourages me to have a go as I would like to stop using PVA glue. How long would the glue last for and do you need to refrigerate it? Thanks..

  • Dear Luis, yes these inventions of mankind are great, aren’t they? Concerning the durability of the glue: we are consuming a portion of glue in a month I guess. But I would say it also stays fresh longer. You don’t need to refrigerate it, but it is important to close the bowl when you don’t use it. We prepare a bigger portion we keep in the tupperware bowl and put smaller portions on the lid of a small plastic box (of spreadable cheese or anything similar). Enjoy!

  • Dear Miriam,

    I tried this recipe using flour, water, and vinegar and it worked great for a few days. After that it lost its thickness became very watery. I’m going to give it another try with the glycerin and see how it works. I also wonder if I cooked it too long. Well, we’ll see. Thanks again, Justin

    • Dear Justin, great that you tried it out. Please tell me if using glycerin works better for you. In fact, it is what we use in school and therefor should work well.
      Best wishes, Miriam

  • Hi Miriam.
    I hope all is well with you.
    A quick note to let you know I have cooked some flour glue which I will try later on today.
    Do you have any experience of using to stick the tesserae on plastic that covers the paper with the design?
    Looking at the image, I guess my glue is slightly runnier than the one on the blog post. I do hope it works. Thanks.
    Kind regards.
    Luis

    • Dear Luis, nice to hear that you are trying out the recipe!
      I guess the tesserae won’t stick to plastic with this kind of glue. We use the flour glue only on paper which is produced especially for this purpose and has a rough surface. So maybe try to find a paper to which they stick and print out only the outlines of your mosaic on this paper. You can compare colors etc. with the design you keep near to your mosaic.
      If the glue is to runny just let it get more solid leaving the container open for a day or longer.
      Hope this helps, if you have any more questions let me know!
      Cheers, Miriam

  • I love your blog… I have been using for a long time the “flour glue” but as I had problem with the paper : the surface was not flat because the paper was crumpled… And you could see the marks on the mosaik. How do you do to have a perfect plat paper on the back….

  • Inthe list of ingredients you give
    Flour, water, liquid glycerol, formalin or cider vinegar

    And then during the recipe
    Add 2 teaspoons of formalin and 2 teaspoons of liquid glycerin or cider vinegar.

    So is it liquid glyceryn or cider vinegar
    Or
    Formalin or cider vinegar ?

    Thank you, as usual, I really enjoy your posts.

    • Dear Frederic,
      thank you for your feedback on the recipe! In fact there was a mistake in the text: I meant 2 spoons of formalin OR cider vinegar. I corrected that. And also the ingredients section might have been misleading. So I put cider vinegar in parenthesis.
      Thank you for following this blog and making it even more useful with your comments!
      Best wishes
      Miriam

  • Dear Miriam
    Just for you andcyour reader to know… I triedcthe recipe on part of my last mosaic. It works beautifully. However, something very unexpected happened. On the morning after I completed the mosaic -reverse method – I found the mosaic vandalized. Most of the tesserae glued wit hte cola di farina were shattered around on the table. But none of the tesserae glued with my usual commercial glue.
    I found the vandal, or one of them later in the chicken pen, dead. A rat.
    My workshop is in the back of my garden, with my chickens living behind it, and a corn field behind. There are some rats around… they smelled the flour and decided to have a feast and lick the tesserae. As I used small pieces of glass in this piece, there were little shards embedded in the glue and the little bastard probably died of internal bleeding…
    I have almost finished the repairs, 6 hours of work, now I cover the mosaic eve4y time I go out of the shop, and I have bought rat poison.

    • Dear Frederic,

      I am really sorry to hear that these little vandal ruined your work! And I am very sorry for the rat, too!
      It is good to know that the flour glue attracts animals. In case I work outside I will remember this story. Thank you very much for letting me and the readers of this blog know about that.
      I hope you continued your work without any further interrupting.

      Best wishes
      Miriam

      • OH, I got plenty of other problems on this particular piece, that’s how you learn.

        Among other things, I did not refrigerate the glue (as you recommend it) and it fermented, loosing lots of ots sticking pwer, which I realized too late… Here in Alabama, the temperatyurs get high in the afternoon !

        I really made all possible mistakes on this piece, after 8 or 9 years of work, you would think I ‘d know better !

        I will blog about all these mistakes, can be interesting for other fellow mosaists !

        • Hey Frederic,

          sorry I went through the comments now and found to not have answered you in June. Have you had any other experiences you would like to share?

          Cheers
          Miriam

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