Paper Tube

[jaysgoh]

I am thinking should i order the mortar paper tube ( 7.6cm x 80cm * 3mm thick) from China , its cheap i think around USD1 for each . But the shipping cause its big , its took alot of space and i have to pay the extra space fees .. so i wanna ask for opinions

 

Just now i build 2 tubes which is 52cm tall and ID : 7.6cm ; 7.8cm . Thickness are 2-3mm

I'm curious mine are a little bit soft . It doesn't like commercial paper tube hard and quality . I use two high strength cardboard poster and roll it with my bottle (Diameter 7.6cm ) i roll each tube two times so that i can get thick , strong . i found that its hard to cut with saw , razor blade . i guess it should be okay if flower pot ( i guess )

So do you think i should purchase the paper tube or try it first ? If i wanna order it may take 4-7 weeks to reach my door step . So should I ?

 

How does flower pot happend ? i afraid my shells is tight fit in the tube . i still got 4 months time to make everything.

Please dont try to scold me , i rather ask before i do . if not regret is too late .

Thanks Guys

Edited September 24, 2013 by gohjiejing

[leedrill]

no offence but this post really makes me question yours and others safety. If you are building mortar tubes im assuming you have shells to shoot and you should know the reasons that can cause a flower pot. Id suggest shooting some dummy shells that weigh more than the shells you will be shooting if you can repeatedly shoot something that weighs twice the amount of your shells the tubes will be fine but your picture tells us nothing about the strength the size sounds fine to me maybe someone else might disagree but im sure if your pasting method is sound it will be fine but 2 to 3mm think sounds way too thin id want 1cm or more for a paper tube

[jaysgoh]

thanks for your reply .

can i shoot using a tennis ball ? i make hemis from tennis ball .

[leedrill]

yeah you could as i said a good test is if it is heavier so maybe fill it with water or something

[nater]

Flower pots are caused by a weak shell. The shell casing fails during the lift causing it to ignite prematurely. A flowerpot may or may not result in a mortar failure as well. If the mortar is strong enough to contain the burst charge, the result is more like a mine. If the mortar fails, it can be quite dangerous for the crew shooting.

 

You can also have a situation where the mortar is too weak to contain the pressure of the lifting shell. This can be dangerous too as you would have a live shell with a burning time fuse someplace other than in the air.

[jaysgoh]

I guess I try to use this tube first. I will hold the order of the paper tube. Hopefully this homemade tube will works. Thanks guys

[dan999ification]

The advice is wasted.

A sub standard 3 inch tube is dangerous, supporting it will do nothing if the tube is weak.

Have you ever seen a ball shell lifted with an ounce of bp or a 400g mine with 50g lift or a canister shell weighing the same, dug your mortar from the mud due to recoil? This is normal use apart from the digging if you had i doubt you would consider using these.

my 1 inch walled 6 inch plugged tubes can take it but I would not use a weaker tube for my "normal use"

 

As said launch a dummy first with more than 10% lift and double the weight of your shells, you may get away with light use ( 100g streamer shell 10g lift) but even then re-using could be a problem if they get damaged.

 

I can roll good tubes but a 3" mortar needs to be strong enough to hold the plug and to not de-laminate from over pressuring it.

 

Where are you? You must be able to buy an actual mortar or some hdpe pipe, failing that I'm sure you can find 1" walled ones locally for nothing ( like me )

 

Dan.

 

Edited September 25, 2013 by dan999ification