Wheat paste

in one of the threads some of you guys pointed out that wheat paste was the ultimate glue when it comes to shell-pasting.

as i've never seen anything called wheatpaste no matter what shop i was in, i wondered if thats just a mixture of wheatflour and water?

can i make wheat paste at home by simply stirring wheatflour and water together... maybe heating it? or is it a little more tahn that?

thanks for some infos on that...
Skipjack

Never done any pasting myself, but here's what I googled:

Wheat paste, etc

Seem to be a few interesting products:
Belgian rice starch (could this be anything like SGRS?)
Zen instant wheat paste.

Not really sure how useful this is

"Harvest" wallpaper paste seems to be the brand most US pyros use.

AFAIK it is made from modified wheat flour.

Cornstarch whisked in boiling water straight from the kettle works just fine for me when doing small jobs. A blender helps for larger batches, or a saucepan and an electric mixer. Only tried adding waterglass once, didn't seem to help much.

Commercial wheat past is sometimes hard to find, but homemade paste is easy to make. Bill Ofca provided a procedure in one of his "Technique of Fire" books, and I modified it to avoid lumps: Bring 9 cups of water to a rolling boil. In a blender, add three cups of cold water followed by 2 cups of all-purpose flour. Quickly put the cover on the blender and start the blender on a medium setting. After about 20-30 seconds, stop the blender. This will release a strange air bubble that seems to form in the flour mixture. Start the blender again, and then mix for another 30 seconds while using a spoon to carefully dislodge any wet flour clinging to the blender's container. Quickly add the flour mixture to the boiling water and immediately start to stir the hot mixture. An electic mixer works very well for this purpose. As the mixture comes to a boil, reduce the heat. Mix/stir for another minute, then turn off the heat and mix/stir for another minute. (This avoids having the bottom burn or cook much more than the rest.) Cover the pot and set it aside to cool for several hours. Paste prepared in this manner will spoil within a couple of days in warm weather, but its pot-life can be extended by adding a small amount of boric acid or salicylic acid.

Commercial wheat past is sometimes hard to find, but homemade paste is easy to make.  Bill Ofca provided a procedure in one of his "Technique of Fire" books, and I modified it to avoid lumps:  Bring 9 cups of water to a rolling boil.  In a blender, add three cups of cold water followed by 2 cups of all-purpose flour.  Quickly put the cover on the blender and start the blender on a medium setting.  After about 20-30 seconds, stop the blender.  This will release a strange air bubble that seems to form in the flour mixture.  Start the blender again, and then mix for another 30 seconds while using a spoon to carefully dislodge any wet flour clinging to the blender's container.  Quickly add the flour mixture to the boiling water and immediately start to stir the hot mixture.  An electic mixer works very well for this purpose.  As the mixture comes to a boil, reduce the heat.  Mix/stir for another minute, then turn off the heat and mix/stir for another minute.  (This avoids having the bottom burn or cook much more than the rest.)  Cover the pot and set it aside to cool for several hours.  Paste prepared in this manner will spoil within a couple of days in warm weather, but its pot-life can be extended by adding a small amount of boric acid or salicylic acid.

Hello to ALL,

just wanted to add, that wheat paste is EXTENSIVELY used in Malta, very practical to work with.

best regards

Stanley

Just spent a long time on ebay searching for anything pyro related, and came across this:
paste
looks ideal for pasting shells, anyone think it would be ok? They sell smaller tubs/bags of it too.

I made some paste for the first time this weekend and it was quite easy. The recipe I used called for 3 tablespoons of white flour mixed into an equal amount of cold water. (From cooking I believe this is done in order to get a smooth mix, vs dumping it into a larger quantity of water where lumps are likely to form. I use this technique when thickening stews.). Per the recipe, this mix is then added to a cup of very hot water. I found on the 1st attempt that this caused it to lump up badly when it hit the hot water, so on my 2nd try I just added the 3TBSP cold water/Four mix to 1 cup of cold water. Perhaps the water was too hot on the 1st attempt.

I brought this mix to a boil in a small pan for a couple of minutes and it seemed to work very well. I used it to make some 1.75 inch round paper shells in a mold I made with plaster of paris and a shell half from a class C shell I disassembled.. They seemed to come out fairly well, though not as perfectly round at the seams as I would have liked. There were slight gaps when attempting to put the two halfs together. They came out very hard at least, once dried.

As an attempt to preserve the paste for later use, I reheated it and disolved in a teaspoon of salt. I have no idea if this will work but I made the assumption that that high amount of salt content would keep any bacteria from forming. This seems to work with beef jerky in terms of keeping it from spoiling.

If anyone has any ideas of how to make the shells come out more perfectly shaped at the seams, I'd love to hear about them. I'm also curious if anyone has had sucess using paper mache products for round shells.

-Strobe

I've just been pasting a 4" paper ball shell, using 70 gsm virgin Kraft strips (the Passfire 3-strip method). I used generic DIY store 'All purpose, extra strong wallpaper paste granules', mixed fairly thin.

It seemed to work, but allowed lots of slip while wet and didn't seem to fill gaps - it's just not very 'sticky'. This is a bit frustrating when trying to tuck in any pointed edges etc. It'll be a few days drying before I can judge the real results... The wallpaper paste was cheap, fungicidal and seems to work - is it weaker than proper pyro wheat paste though?

I tend to mix in some PVA to the same stuff for rolling tubes, but had avoided this for the shell, for fear of the first layers not drying. The PVA might make it more sticky, but would it also make for a stronger shell?

Edited by BrightStar, 28 April 2007 - 09:22 AM.

I just use kinder eggs, they work a treat and are edable. They kinda explode in a rounded rectangle shape though.

I just use kinder eggs, they work a treat and are edable.

LOL madtrick ... The wallpaper paste was just about OK. I got the 70 gsm kraft to conform reasonably well by pre-soaking it, but there are are still evident raised kinks along the edges of the 2cm * 10cm strips.

Out of interest, does anyone know where to source thin kraft paper in the UK? The standard US weights of 60lb and 30lb for shell pasting are roughly 100 gsm and 50 gsm, but I haven't found anything less than 70 gsm...

I've only made wheat paste once so far, but it seemed to work well for me when I rolled wet tubes with it and used it to make my own paper hemispheres. One thing I tried that worked out well was to add a teaspoon of salt to the mixture (about 1 cup total was made) when cooking it. I did that to help preserve it and it kept in the refridgerator for about a month and a half without any mold or problems. I figure if it works for beef jerky it should also work for wheat paste.It did end up spoiling after a few days when I forgot to put it back into the fridge after making some tubes one day.

It sounds like you can use Boric acid for the same purpose based on another earlier post.

When my dad was a kid, he lived in asia were they were they were kinda poor, so they made their own pastes like the method to make wheat paste only using SGRS instead of wheat flour. They also added a little vinegar to prevent rotting. Would either SGRS and vingar be a better alternative to use for wheat paste?

LOL madtrick ... The wallpaper paste was just about OK. I got the 70 gsm kraft to conform reasonably well by pre-soaking it, but there are are still evident raised kinks along the edges of the 2cm * 10cm strips.

Out of interest, does anyone know where to source thin kraft paper in the UK? The standard US weights of 60lb and 30lb for shell pasting are roughly 100 gsm and 50 gsm, but I haven't found anything less than 70 gsm...

Hi Brightstar,
i use wallpaper lineing paper to past my shells,it is avalable in a few different grades and its cheap,can be found at most diy stores etc.The only thing is the paper is white,which if you are a purist might be a prob,
regards,
Vince.

only problem is that lining paper is not grained and is therefore relatively weak even when thick or in multiple layers.

I always use wheat paste, for inner liners for my Maltese shells I use lining paper, then the rest of the wrap is potato sacks. Using this type of paper makes the casing almost no cost. The wheat paste also drys very hard and shrinks the paper quite abit so the contents of the shells are loaded when the case is damp. When dry it will hold everything even tighter. Will not use any other paste, also adding copper carbonate stops rodents eating your cases

Edited by karlfoxman, 03 May 2007 - 10:07 PM.