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I've tinkered with my paste recipe and have found a combination I like, but after about 60-90 minutes the mixture turns into glubber and I'm hoping someone can help me figure out what's happening.
My current favorite glue recipe is 6 parts CMC (Elmer's Art Paste), 1 part Elmers Glue All, 1 part laundry starch. When I first mix this, the glue and starch combine to make long stringy strands (it's a polymer, there are science explanations on the web about this) ... but if I let it sit for 3 minutes or so, the mixture settles down and is about the consistency of egg whites -- which is what I'm going for. I like this combo because it's stronger/stiffer than my previous experiments with CMC alone, or the 75% CMC / 25% White Glue that I had been using.
I should explain that when I mache, I laminate layers of paper with my paste mixture rather than dipping strips in the glue, or using my hands to spread glue on the paper.
(I use an old serving tray, squirt out a ribbon of paste, use a rubber brayer to spread it around, lay on a sheet of paper, squirt out another ribbon of paste, spread it with the brayer, etc. Then when I'm ready to use it, I squeegie/smooth the extra paste out of the sheets, and then tear strips as needed. )
I reuse the paste that has been squeezed out for the next sheets, adding new paste as well as needed.
This works fine until about 60-90 minutes in when I realize I can't spread the paste with the brayer anymore ... it's pretty much a glubber puddle.
If I put this back into my bucket of paste the paste will recondition the glubber, and I can continue using it.
I'm wondering what's happening, tho.
Is the CMC drying out? Is it absorbing into the paper faster than the starch/glue? So while it started as a 6:1:1 mixture it ends up with proportionally more of the glue/starch combo?
Or is this a result of my 'working' the glue? (Pressing it into paper and squeezing it out.)
I'll continue experimenting, but wanted to see if anyone else had suggestions or light to shed on the issue. Have any of you had experience with this kind of thing?
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I can think of two possibilities... Does guessing count?
One of the ingredients is setting up/hardening faster than the other ingredients.
Or there might be a chemical conflict between two of the ingredients, and I'm suspecting the white glue, which is a chemical plastic, and the other two are organic. Of course, it could be the CMC and the starch fighting, too. How's that for a definite maybe?
Perhaps you could do some experimenting by using your PM method with various combinations of two of each of your ingredients and see if you get the same results.
For instance, try CMC+white glue, and CMC+starch, and white glue+ starch. Use your brayer and the whole bit, including a similar time.
Personally, I'm of the opinion that the fewer ingredients the better, but others feel differently. Anything that causes me grief tends to be dropped by the wayside. My supply of patience tends to be rather limited... um.... EXTREMELY limited... 8-)
Sue
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I recently made home made "Silly Putty" for my grandkids using the following recipe:
Mix 2 tablespoons of Elmer’s Glue All ( PVA)
with 1 tablespoon of Liquid Starch.
It calls for food color but I used small amounts of Acrylic Paint instead that worked well.
When mixed add more starch if sticky.
It worked well and when stored in an air tight baggy in the fridge it lasts a very long time.
Then I had the following experience as I prepared my flour based PM paste.
My "standard" flour paste recipe is six parts flour + one part liquid starch + one part white glue. Mixed together with warm tap water to get a consistency of a very thin pancake batter.
This time I mixed the glue and liquid starch first then added the flour and got a doughy "silly putty" mess that acted more like "Silly Putty" then PM paste . Now I mix the flour and liquid starch together first then add the white glue and then the water to get the consistency wanted.
I suspect you mixed the CMC , Elmer's Glue All and laundry starch in just the right combination to get a variation of "Silly Putty"
Just my thoughts.
Bob C.
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Hmm... thanks. I actually mix the CMC and the Elmers first and then add the starch, but I'll the variation of mixing the CMC and starch first and then adding the Elmers.
And as Sue suggested I will continue experimenting.
I've already tried the CMC+starch variation, and it didn't flow nicely enough for me so I stopped that experiment pretty soon in. But now that I think about it, it did dry pretty quickly, so maybe I'll need to look at it again.
And I know the CMC+Glue works for more than an hour, because that's what I had been using prior to this. But I think I should do some more testing and see.
I've also saved the glubber from yesterday in a separate batch and will do a quick 3-part experiment. I'll split it into 3 smaller batches and add water to one, cmc to another and water+cmc to the 3rd.
My reasoning is that if what's happening is that it's drying out, then water might be the best addition to recondition it.
If the CMC is getting absorbed into the paper faster, then CMC might be the best.
And if a little of both is happening, then the combo should yield the better results.
I suppose if there's some greater chemical combo thing happening then none of my experiments will turn out. : )
It may seems silly to put this much effort in, and to be honest, the first time I used this combo, and it seized up after an hour, I threw it out as a lost cause. But the item I made was so much sturdier with the same amount of paper layers that I had to come back to the idea.
Thanks for your ideas. I'll post again when I get the results of my experimenting.
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I'm posting these results in case someone is interested at some point. I suspect this is way more detailed than most folk will care about ... but I have the info, so I might as well share it.
The original idea was to find out if there's something I can add to my paste in my tray when it becomes 'goo' while I'm working with it.
My hypothesis was that the CMC was absorbing into the paper quicker than than the other ingredients, so as I continued to use the paste there was a higher and higher ratio of PVA+Starch which results in 'goo'. If this is true, adding CMC to the mixture should recondition it.
My second hypothesis was that the paste was drying as I was using it, and if that's the case then adding water should recondition it.
I knew from experience the 'goo' could be reconditioned in original 6:1:1 but wasn't sure what proportions were required to make it work.
I ended up doing small quantity experiments over the weekend. I experimented with:
* 'goo' -- which is what I'm calling the seized/stringy CMC+PVA+Starch mixture
* straight CMC
* water
* 6:1:1 -- which is the original, unused CMC+PVA+Starch mixture -- called 6:1:1 because those are the mixing proportions.
First experiment: Goo + 6:1:1
First I mixed 1Tbsp goo + 1 Tbsp 6:1:1 and there wasn't much change. I added another 1Tbsp 6:1:1 and the mixture looked like it was starting to recondition but was still too stringy. When I added a third 1Tbsp 6:1:1 the mixture was reconditioned and was practically indistinguishable from the original 6:1:1. The result: goo reconditions in a 1 part goo to 3 parts 6:1:1.
Second experiment: Goo + CMC
First I mixed 1Tbsp goo + 1 Tbsp CMC and the mixture became a little more workable, but thick. I added another 1Tbsp CMC and the mixture was very workable, but still a little thick/goopy -- which was the texture of the CMC. Adding more CMC wouldn't help. The result: adding CMC seems part of the answer, but not the whole thing.
Third experiment: Goo + Water
First I mixed 1Tbsp goo + 1 Tbsp Water and the mixture broke. The stringy gooeyness was totally gone. Which isn't what I wanted. The result: adding water isn't the answer, or at least not the whole answer. Based on the results of the CMC experiment I wondered if adding water+CMC would smooth out the goopyness and prevent the strings from completely breaking.
Fourth Experiment: Goo + CMC + Water
First I mixed 1Tbsp goo + 2 Tbsp CMC (actually I used the cup from experiment #2). Then I added 1Tbsp of water. The result: goo reconditions (mostly, see below) in a 2:1 mixture of CMC + Water.
Based on results of experiment #4, I made up a separate mixture of watered down CMC (2 parts CMC + 1 part Water) and squirted some of this on my paper tray when my paste started to show signs of 'goo'. In practice it didn't recondition as nicely as in the experiment. Also, the reconditioned version is clearer ... implying to me that there's more of the PVA + Starch (which are the white/cloudy ingredients) absoribing than I'd originally thought.
I could probably learn more if did further experiments to refine the results. But I have the answers I was looking for, ie, there's no quick, easy mixture that I can add in the tray to recondition the paste, but I can recondition it in original 6:1:1. So now I use my paste until it's too gooey, and then I scoop it up and put it aside. Then, when I make a new batch of 6:1:1 paste, I add the goo back in as well.
I will also use goo+paste as a pulp clay base when I need a new batch of that, but I haven't been doing things that I needed pulp clay for, so that hasn't been an issue.
I know it seems like this is perhaps more trouble than it's worth, but I believe the strength of this paste is because of the strings that form (actually they're polymer chains) from the combination of PVA + Starch, and that's what I'm looking for. I just want it to be workable for as long as I can get it that way.
I may see about tweaking the recipe with more CMC (maybe 7:1:1 or 8:1:1?) ... but for now I'm happy.
If you've read this far ... thanks! : ) Hope the information helps. : )
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Part of the creative process and fun in PM is custom making our own recipes.
Sharing that process with the rest of the community provides more information to and expands the general knowledge base. It may also be just the spark someone needs to try a variation of their own to get what is needed for some nagging and unsolved issue.
Thanks for sharing these test with us as you said you would.
Bob C.
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