THIS PAGE IS FOR USEFUL INFORMATION THAT I
HAVE FOUND WHILE SURFING OTHER FIREWORK SITES.
COPYRIGHT ACKNOWLEDGED TO THERE RESPECTIVE OWNERS.
TREATING CARDBOARD MORTARS.
One of the problems faced by
Pyrotechnicians is getting reasonable life span out of their cardboard mortars. Myke
Stanbridge documented this treatment which he claims will make cardboard tubes last 25
years or more. I'll report back in 2022 on whether it worked that well for me!
Perhaps the cheapest, easiest and most
effective treatment for paper mortar tubes is the following:
Clean out any debris, cobwebs, etc. Use
PVA adhesive to stick down any flapping edges.
Rinse each tube internally with a strong
solution of Calcium Chloride in water. Allow your tubes to stand until they are just damp.
Calcium Chloride is rather hydroscopic and will not dry past remaining damp.
Using a 25% W/W solution of Sodium
Silicate in water rinse each tube internally. Pour out the excess into your bucket and let
the tubes dry open end up. There is a chemical reaction that produces tough insoluble
Calcium Silicate in the structure of the paper. This hardens and binds the surface making
it resistant to damage by abrasion and alkaline residues. When dried give the tube a fresh
water rinse to remove residual Sodium Chloride produced in the reaction and let dry open
end up in a warm location.
Coat your tubes externally with a mixture
of Spirits of Turpentine 1 part ( pine spirit NOT mineral turps ) and boiled linseed oil 3
parts. Add 15 % lampblack if you want black tubes. Leave the tubes to dry for about two
weeks, open end up .......Omit this step if the tubes are for immediate use or will for
elements of a boxed mortar block....
still using tubes prepared like this 25 years ago, and they still function perfectly! The
method of treatment is very quick and cheap once you've got set up .... You can treat 1
hundred tubes in an hour or so for around 10 cents per tube. Painting costs around a
Dollar a tube and is not as effective.....Regards, Myke.