41 replies to this topic

[alany]

I am suprised no one has mentioned rolling boards in this thread, or did I just miss it?

Especially when I hear about wrinkled tubes and the general idea that rolling tubes is 'hard'.

Rolling tubes is a bit time consuming, but with a rolling board you get wonderful tight tubes with no wrinkles at all. All you need is a piece of smooth surfaced timber, say MDF (a laminex coated surface would be a plus for cleaning) with a door/cupboard handle or two attached to allow you to hold and use it more easily. It should be wider than the core or the longest tube you wish to roll with it.

The idea is to roll your tube around the rod in the usual manner, with the paper pinned and under tension to avoid bubbles and wrinkles. Then roll the paper flat and tight on the rod between the board and the desk top. It works wonders and has been the staple way of hand-making pyro tubes for at least 200 years.

The rod should be as highly polished as possible, timber covered in plastic tape works well too if metal isnot available, as lord_dranack already said. Adding a little paste to the rod first helps removal, which sounds counter-intutive, but gve it a try, it works as a lubricant.

It is easiest to cut the tube with square ends while still on the core and wet, just roll against a knife blade. This tends to score up your rolling rod though, so I avoid it and either roll the tubes with pre-sized paper or cut them once dry with a mitre box and fine toothed tenon saw.

This process works well for wet-rolled rocket and candle tubes, anything that needs to be strong. Dry-rolled tubes like crackers don't need it and can be just hand tightened before the last turn is pasted down.

[pyrotechnist]

its paper shells I want to bye I do not want to try plastic shells yet will sone thou they cost $0.70 for the full shell a 3" shell star shell seem dear that or can bye paper shell cheaper.

Edited by pyrotechnist, 11 January 2004 - 03:21 AM.

[alany]

I don't think I completely comprehended that post pyrotechnist?

But it really comes down to how much your time is worth. That 70c worth of polymer shell casing could save you an hour or two of pasting in and general stuffing around with paper shells. Plus hours vrs days of drying time.

It isn't such a big deal if you have all your mates over and can get a production line going I guess. Don't get me wrong I prefer to shoot paper. but plastic shells are *much* easier and quicker to knock out. Rolling the stars already takes too damn long.

[Steve]

I love roling boards, they really do make such a difference. I shelled out a bit for tubes and bough a teflon rod to roll round for about ?7. But it really makes Sliding the tubes off a pice of piss.

Steve

[dfk]

Bear thanks for the info
what is starpol? I think I have only seen it I a few comps
also is SGRS something that you can make? I like the, dries quicker idea.

[alany]

Starpol is yet another starch product, hydroxypropylated IIRC.

[BigG]

I've been rolling for 12 years and I don't use rolling boards. Come to think about it, I don't know many who do. I know it was used extensively before rolling machinery come into play, but I just have two left hands, and every time I roll with a board, it goes all wrong.

I find rolling on a flat board with my hand much easier, and I got to a level where I get very clean and strong tubes. As for sticking, well, I just don't put glue on the first few inches (depend on the size of my tube), so the first round of paper around the former is dry. This way it slides easily off everything – wood too.

Edited by BigG, 12 January 2004 - 09:23 AM.

[lord_dranack]

Is soluble glutaous rice starch (excuse spelling) avalible in the UK at all?

[BigG]

Is soluble glutaous rice starch (excuse spelling) avalible in the UK at all?

Non-glutinous rice starch is available as a binder from some art suppliers. Unfortunately, it is inferior and leaves cavities in stars. Glutinous type is not widely available outside the far-east, although I’m sure someone has a supplier for it.

[HJS]

About rocket tubes. I have had great success using VP-pipe. They are made for protection off electric cabels in houses. For 0,5 to 1 euro per meter, depending on size, the price is worth not having sour hand after days of rolling tubes . You might think the plasic may melt, but it doesn?t. One other thing: paper tubes may crack when ramming or pressing, but the plastic tubes are elastic. No more rockets thrown away because off the paper ruptureing!
I have some great pics of my rockets. Is it possible to post them here?

You can use http://www.imageshack.us/ for hosting/posting your pics. I'd be interested to see what everyone else is making too

HJS.

[sasman]

Non-glutinous rice starch is available as a binder from some art suppliers. Unfortunately, it is inferior and leaves cavities in stars.  Glutinous type is not widely available outside the far-east, although I?m sure someone has a supplier for it.

Bugger!! i have just orderd 2 kg of Rice Starch from an art supplier because it was under the Glue/Binders section i was sure it would be SGRS So BiG Have i just wasted my Money?

[pritch]

According to one guy on rec.pyrotechnics 70 gsm is too thin for use on cases.
I posted asking about my 70 gsm craft paper and he responded. Would you disagree with this mat considering you say you use 60 gsm craft paper?

To convert grammes per square metre to weight in pounds per ream we multiply the
gsm weight by the number of square metres per ream and divide the result by
453.6, the number of grammes per pound.

The basis size of kraft paper is 24x36 inches - thus there are 864 square
inches, or 0.5574 square metres per sheet. Kraft is a "coarse" paper, hence
there are 20 quires of 24 sheets = 480 sheets in a ream, and accordingly 267.55
square metres per ream (please note that this figure will be different when
discussing fine papers, which come 500 sheets to the ream).

Thus (70 gsm X 267.55)/453.6 = 41.2886 lb. per ream, approximately equal to
American 40-lb. If you have a micrometer, you will find your paper is about
..004" thick, which is much too thin for wet-rolled cases. About the only sort of
cases for which it might be useful would be those of lances, port-fires, or
small torches.

American kraft papers come in weights 30-, 40-, 50-, 60-, and 70-lb. By some
coincidence, these caliper respectively .003", .04", .005", .006", and .007".
This correlation between weight and caliper does NOT exist for other types of
paper, because paper density and the basis size (i.e., the dimensions of the
ream that weighs the designated number of pounds) differ for each size.

Incidentally, if you want to reverse the calculation and, let us say, determine
the number of grammes per square metre of a 70-lb. kraft, simply multiply by the
reciprocal of the above. Thus:

(70-lb. X 453.6)/267.55 = 118.6796 grammes per square metre

You will likely need something like a .018" thick chipboard to make suitable
cases for rockets, gerbes, or roman candles. It is better to regard the weight
figures, whether gsm or pounds per ream, as arbitrary numbers and buy your paper
based on its caliper (thickness) and how that suits it for the particular job it
is to do. Papers of .003" or .004" are useful for finish wrapping and for
pasting-in small shells and shell inserts. Papers of .007" are customarily used
for the inner cases of cylinder shells and for pasting larger shells. Chipboard
of .018" is useful for cylinder shell liners and for most wet-rolling of rocket,
wheel driver, gerbe, or roman candle cases. Chipboard of up to .030" may be used
for wet-rolling bigger sizes of cases.




In article <i0ced.2588$i02.858@fe1.news.blueyonder.co.uk>, Dave says...
>
>Hello I was lead to beleive that 70 gsm brown craft paper was a strong
>paper. So today I attempted to make a 2 foot long case using diluted pva
>glue and I realized that it was not building up much thickness. The
>paper is very thin. Also when I had glued it and was rolling it kinda
>felt damp on the other side.
>
>Is this normal when you're using craft paper? Is it thinner? I'm hoping
>that it will be thinner and stronger.