23 replies to this topic

[BrightStar]

I was pleased to find some Polycell LAP cold water starch paste in Focus DIY a few weeks ago and tested it making a small shell.

You do need to mix it at least 30 mins before use, but it works much better than instant pastes I've tried and dries rock hard. With smaller shells or with thicker paper, it still helps to add a small portion of white glue (PVA) for extra adhesion, but this is my best paste so far.

Edited by BrightStar, 06 November 2007 - 09:05 PM.

[GZ22]

14 years ago I saw this post on rec.pyrotechnics, and I followed the second paragraph - I filled a 10 litre bucket with the stuff, and left it in an old fish tank in the sun for a week until it had mould on the top (perhaps too long!) - the stench was absolutely revolting! But after decanting it was fine, didn't smell too bad and the glue was indeed very very strong, and allowed for a very small amount of slip too - perfect! It also kept for an age without deteriorating.
----------------------------------------------------------------------------------------------
A good, homemade glue that will make strong casings is made by adding 4 1/2
cups of flour to 3 cups of boiling water and then adding 1/8 ounce of alum
(aluminum potassium sulfate). Stir this combination until it is consistent in
blend. When it's cooled, it's ready to use. The flour is the actual glue. The
alum helps fireproof the mess and helps act as a preservative. This is
important, as wet flour will eventually spoil, and so this mess has to be
used up fairly quickly. Don't count on saving it for more than a couple of
days.

But if spoilage is a real problem, can we let the flour spoil BEFORE we make
the glue? This is not as silly a question as it sounds. By doing this, we
make a slop that can be kept a month or so, if it's also kept in a reasonably
cool, dark place. Just don't make it on a full stomach.

Pour anywhere from a few cups to a few bucketfulls of flour into a container
large enough to cover it with a good layer of water but still be only a third
full. How much water you use doesn't matter too much right now, as most of it
will be poured out later. Just make sure that you're making a batter, instead
of a dough. Stir it up good, but don't worry too much about little lumps.
That will be corrected later.

Now for the revolting part. Let the stuff sit for 2-3 days in a warm (90
degrees F) place and check it after then. If it hasn't begun fermenting by
then, drop in a few pinches of instant yeast. When the fermentation is finished
and there are no more bubbles forming, the flour will have settled as a gooey
layer at the bottom of a pool of revolting brownish liquid. Get rid of the
brown slop and note how much batter is resting in the bottom of the container.
Boil enough water so as to have a volume that's twice the size of the batter,
and pour it in slowly, stirring the flour briskly. It'll start out being easy
to stir, but will get thick in a hurry. If you're only making a few cups at a
time, it won't be heavy enough to hold still while you're trying to stir it, so
you might want to have the container clamped down solid.

If you did it all right, you should have a batch of clear, smooth paste that's
plenty sticky and fine for sticking your casings together. Since it's already a
spoiled batch of flour, it can't go bad a second time and needs no
preservatives.
----------------------------------------------------------------------------------------------

I rolled a good, strong set of tubes using this paste and kraft paper sacks. Total cost= a bag of flour!

Edited by GZ22, 06 November 2007 - 08:26 PM.

[icarus]

i agree lining paper makes weak cases if you cover your former ie dowel with a single layer of plastic brown parcel tape and slop paste onto former as you roll case you can twist the former and really tighten the case windings -the tape makes it slippery enough to get the wet tube off the former afterwards i use wallpaper paste for cheap cases but sodium silicate sometimes called water glass is a superb paste that sets hard and makes fire resistant cases i always slip a weak elastic band round each case before i take it off so it cant unwind then the wet cases go straight into the oven at about 130 c . (Wind cases whilst you are watching tv )then the same dowel without a layer of tape is a good rammer

[BrightStar]

I filled a 10 litre bucket with the stuff, and left it in an old fish tank in the sun for a week until it had mould on the top (perhaps too long!) - the stench was absolutely revolting!

Fascinating - I read something similar in Weingart, but yuk... I once had an expensive tub of PVA go green with mould... no idea how.

The LAP starch paste has preservatives and fungicides already in it, doesn't need preparation much ahead of time and can be stored dry. That's why I was so pleased to find it...

Whether it could prevent a big Maltese shell from being nibbled by karlfoxman's hungry mice is another matter...

Edited by BrightStar, 07 November 2007 - 10:49 AM.

[GZ22]

One thing I have found with wallpaper pastes is that once mixed, they settle out and become thinner and thinner after a few days, but as long as you only mix enough quantity for the job at hand, you won't suffer that problem.

[seymour]

I once had an expensive tub of PVA go green with mould... no idea how.

It amazes me what mould will grow in. I decided once to kill off the mould in about 200ml of old wheat paste with a gram or so of Copper oxychloride. NO EFFECT!! I added a few more grams and waited a few days. The mould kept on growing! I added a few grams of Boric acid, and it kept growing. I added some Copper sulphate, still no effect. I added a tablespoon of NaOH. Still, the mould kept growing. I have up after that and disposed of the toxic, but alive slurry.

[KarlosH]

Hallo. What is better? Wheat starch or wheat flour, for pasting?

[Yugen-biki]

Hello guys.
You have covered the subject but I would like to tell you how I make my glue.
I have tested different kinds of starch (wheat, potato...) but they are pretty much the same.

I stirr some cold water and flour togteher untill homogenous.
Then I heat it on the stove stirring untill desired consitence (I go for slime).
Finished!

OK heres is the trick to get you paper products hard and brittle:

Use a lot of glue and let it soak into the paper for a few minutes.
Then be sure to press hard when making tubes or pasting shells. Any trapped air will ruin the adhesiveness!
Let it dry for a few days at least depending on paper thickness.

OK! Thats it!

[MDH]

I am merely mixing a slight bit of water with elmer's wood glue and typical wheat flour, then dipping kraft paper in it. So far this has proved to work well.