28 replies to this topic

[FaithlessRock]

Hi all,

I have just got some cardboard mortar tubes rom Essex Tubes, and have never used card before. Does anyone have any ideas/thoughts/advice on how they can be better protected against the elements - ie whether it is a good idea to coat them in something to protect against the damp conditions/being splased, etc. and if so what products may be ideal? I'm keen on prolonging their life as much as poss. and don't look like they will hold up as well as GF tubes.

Many thanks,
Mark

[Arthur Brown]

Stand them in bin liner bags to help keep the moisture out. Big tubes staked individually can have a bag over the bottom and a bag over the top.

Tubes kept really dry will last well, But inspect them before use - just like any tube inc GRP or HDPE.

[FaithlessRock]

Stand them in bin liner bags to help keep the moisture out. Big tubes staked individually can have a bag over the bottom and a bag over the top.

Tubes kept really dry will last well, But inspect them before use - just like any tube inc GRP or HDPE.

Thanks Arthur, good advice.

Are there any products which you would advise to coat the tubes - particularly the top rim, as these are just exposed cardboard?

[Karl Mitchell-Shead]

Wax them

[FaithlessRock]

Wax them

Something like Mould Release Wax?

Apologies, waxing is something new to me, so I want to make sure I'm buying the right product!

[Night Owl]

plain old candle wax beads (Ebay) melt the wax and dip the tubes in it, even candles will do, Simple!

Edited by shell shooter man, 22 February 2010 - 04:49 PM.

[Karl Mitchell-Shead]

Yes thats right just dip them in molten wax, the card will absorb some as well as it be coated, this is how commercial card mortars are protected

Sorry was in a rush when i wrote just wax em!

[Vic]

Or you could try this method by Myke Stanbridge:

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 hygroscopic 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 to the mixture 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 form elements of a boxed mortar block...

Note: I'm still using tubes prepared like this around 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 a hundred tubes in an hour or so for around 10 cents per tube. Painting costs around a dollar per tube and is not as effective... Regards, Myke.

[crystal palace fireworks]

Faithlessrock,; I think this is a good opportunity to experiment, why not coat a couple mortars in polyurethane resin, acrlic resin or varnish and compare them to the wax coated mortars?

As arthur said,..you still need to keep them dry and out of the sunlights UV rays to reduce degridation.

[Karl Mitchell-Shead]

Soak them in rainex

[Arthur Brown]

In reality your tubes will spend 8000 hours a year in a store where dryness is essential, in the field a bag under and a bag over will continue to keep the tubes dry.

[Karl Mitchell-Shead]

Ive worked on some straight up shite jobs where our mortars are exposed to everything the weather can throw at em, remember one or two where rain was sufficiently heavy to fill a 6" mortar (luckily fibreglass) with a good inch of water in the time from the shell perforating the foil tape to kicking the racks over while we loaded for a hasty retreat!

Moisture in the air will take its toll as too will heavy dew, sometimes mortars are setup on some of the larger jobs ive done for 2 days! Thats dew in the evening, dew in the morning and dew again before firing! Bagging em seems to make it worse as dew likes to condensate on nice plasticy surfaces

Has anyone noticed the burnt BP residue seems to draw moisture like a chav to an adidas sale?

Mortars are full of that after firing.....

Buy fibreglass..... waterproof, hardy supposedly twice the reccomended firings and you can jetwash em clean

[Night Owl]

Oh yes plastic, very slippy when wet, my point about bin liners and cardboard tubes was dew and rain will find a way in and soak unprotected cardboard tubes, boy those plasticy tubes are slippy:)

[Twotails]

I used to coat the outside with a spray-on waterproof electrical tape(it was sprayable vinal) three coats sufficed, and i havent had trouble with the tubes, This way there protected from harsh northern winters. I did coat the insides with a wood hardener ,and allowed that to dry before spraying the tubes. They work grate, even if you leave them exposed to the elements(atleast for a while)

[CCH Concepts]

i have read a few articles about treating tubes and choose not to because some mentioned the hardening of the tube meant that if there was a cato some of the hardened paper could become shrapnel.

now i did have some ruined tubes due to getting wet if this isn’t correct then i wish i had treated them.