How to make coagulant.
Coagulant is a very important step in making your balloons.
I have found that there appears to be many secrets in coagulant formulations. Some are alcohol based and some are water based. I work with a water based version. The concept is the same only the drying times vary. The alcohol or water evaporate leaving a film on the former.
If you haven't read about latex now is the time.
Here is the basic latex coagulant process.
The primary ingredient of the coagulant is Calcium NItrate, CaNO3. Every thing else is to help in making a good balloon.
The idea is to get a very uniform coating onto the balloon former or mold. Smooth uniform coating = uniform balloon thickness.
We don't want the balloon to stick to the former either so we add a de-tack agent. Insoluble CaCO3 calcium carbonate works well for this purpose and is easy to find. The finer the powder the better! I have also heard that talc works for this purpose but I have no experience with it in coagulant.
The soluble CaNO3 calcium nitrate, usually comes from a fertilizer grade 15.5-0-0-19. There are other purified mixes out there but this is not needed. When we make the coagulant we will "clean" any dirt and debris.
The balloon former is dipped into the coagulant mix and allowed to dry. So we need to get the former to dry in a way that is uniform.
To help with that only one more thing is needed, and that is a wetting agent, or surfactant. Water has a surface tension and it wants to bead up. This is not good for making an even film. We need to get rid of this tendency. We do that by adding a non-ionic surfactant, or soap. Non-Ionic means it will not dissociate and react with the Ca+ and -NO3 ions.
Here is my method to make a 30% nitrate coagulant with de-tack.
You need to have 2 containers that will hold 5 gallons of liquid. I use plastic pails. I don't remember how many finished gallons this makes, but I think it is close to 5 gallons. I have only worked with simple water based coagulants, but alcohol and maybe even acetones may be used.
Chemicals:
Calcium nitrate fertilizer. It should be 15.5-0-0-19 or Ca(NO3)2-4H2O. You can find this on the internet, at a local garden store, and occasionally on e-bay. I checked today and E-Bay had a 35 lbs bag for about $37 delivered.
Triton-X100 concentrated surfactant. Try this link.. 100ml = 3.38 ounces. I am sure that there are other non-ionic surfactants that might work. This is what I have used with success.
Calcium Carbonate (CaCO3). This is limestone powder. You want this in a fine grind. Again E-Bay has many sources. This is the de-tack agent. I have also heard that talc powder can be substituted. I have not tried talc in my coagulant.
First add 3 gallons of water followed with 16 lbs of the fertilizer, stirring and dissolving as you go. If the fertilizer is not real clean don't worry. You might get some scum on the surface or rocks in the bottom. Let this settle out. Pour this thru cheese cloth layers into the second container to filter out any of the solids that didn't dissolve. Discard the debris from this container and clean. Agitate the 2'nd container to make it foam (stir air into the solution). We need to get rid of any surface scum that has developed. I manually skim off as much as I can. I use a thin pvc hose to siphon the clean fluid from the bottom of this second container back into the first conainer. The last little bit I throw out. The surface should be free of floaters. I shouldn't have to tell you this but I will. Do Not Use Your Mouth to Start a Siphon!
Now add 3 fluid ounces of the Triton X100 to this and stir in. This is the Base formula coagulant without a de-tack agent. If you are going to try double dips, you may want to keep some of this solution without de-tack and some with.
Now just add the insoluble Calcium Carbonate de-tack agent. 2.5 lbs for the entire batch. The Calcium Carbonate does not dissolve. This is why you have to stir the coagulant tank before dipping. It will settle to the bottom.
Well that's what I have done for my coagulant.
All of the formula details are here - 30% solution Spread Sheet - or 20% solution.