canister shell casings

[MadMat]

when making the casing for a canister shell, should the paper be completely pasted before rolling, or just glued at the seams (first edge and outside edge)? I have heard both ways; have tried simply gluing the seams and have gotten O.K. results.

[OldMarine]

Are you talking about the casing or the paste wraps? The inner casing only needs to be pasted on the longitudinal portion not pleated and then only on the end of the wrap. The individual layers don't require pasting.

I'm home sick so I'm actually reading Fulcanelli right now!

Edited June 2, 2016 by OldMarine

[schroedinger]

That depends on your style of building, either you paste the whole sheet (maltese style) or no paste af all. All you need is a strip of tape at the end (or glue the end).

[MadMat]

Well with the few cases I have made so far, I glued the seam at the first turn and then the seam on the outside of the case (I am doing three turns of 70 Lb kraft paper). My shells worked O.K., but after hearing that the paper should be maltese style pasted, I started to wonder if I was doing something wrong and just got lucky with the shells I've made so far. Thanks for the info.

 

I double checked the thickness of the paper and compared it to my chart. 70 Lb. paper is supposed to be .007" thick and 60 Lb. is supposed to be .006" thick. Hmm what happens when the paper consistently mic.s up at .0065" thick??

Edited June 3, 2016 by MadMat

[schroedinger]

I don't know where you read "should be pasted maltese style", because there is no should be. They are completly different methods.

[MadMat]

I just meant that I was "told" that the paper for my cases should be completely pasted before rolling, as I would my rocket tubes. I formed my cases by simply gluing the seams (I.D. and O.D.).

[Wiley]

You don't need any sort of adhesive or tape to make the casing hold its shape. Pleating the paper over a disk is sufficient to hold it in place. I've done it, and it works, but that's not what I'd normally do. I typically roll up my casing, then use a good quality glue stick or Elmer's glue to keep the strip from unravelling. That lets me use both hands to manipulate disks and pleats and such.

 

The integrity of a cylinder shell is derived from the rigidity of its contents, not the casing, as it is with ball shells. A filled cylinder shell should already feel quite firm, and when spiked, should be rock hard. The paste wrap further increases the shell's strength a bit, but it's primary purpose is to keep lift fire out of the shell.

Edited June 5, 2016 by Wiley

[Bangkokpyro]

Well with the few cases I have made so far, I glued the seam at the first turn and then the seam on the outside of the case (I am doing three turns of 70 Lb kraft paper). My shells worked O.K., but after hearing that the paper should be maltese style pasted, I started to wonder if I was doing something wrong and just got lucky with the shells I've made so far. Thanks for the info.

 

I double checked the thickness of the paper and compared it to my chart. 70 Lb. paper is supposed to be .007" thick and 60 Lb. is supposed to be .006" thick. Hmm what happens when the paper consistently mic.s up at .0065" thick??

 

Maltese shells irrespective of their size are all made from 2 turns of chipboard and 2 turns of 60 to 70 lb kraft paper. One side of the chipboard and one side of the kraft is pasted lightly. Maltese shells are never made from kraft paper alone.

[Mumbles]

It may not be entirely traditional, but I've been told by practitioners of the maltese/old italian styles that when you get to larger shells, in the realm of 10"+, that 3 turns of each is more advantageous. Your advice holds true for a vast majority of shells though.