wncranger Posted August 13, 2020 Posted August 13, 2020 Hello everyone! I hope all of you and your loved ones are hale and hearty. I have a problem which I desperately need help with. I've posted this question on fireworking.com also to expand input. I'm trying to hand roll convolute tubes from 4 1/2" by 10" sheets of virgin Kraft paper around a 3/8" aluminum mandrel. I've used Elmer's, wood glue and paste (all straight or with and without water to thin). I also utilize a rolling board, making sure to roll in one direction (that of the winding), to compress the layers. The problems I'm having are with internal voids and loose tubes on the mandrel that start out tight. The internal voids appear when compressing the layers with the rolling board. The sheets are rolled parallel to the grain. I've tried dry sheets, wet sheets, spreading thin layers using a card to remove excess adhesive, spreading thin layers and then drying before rolling, etc. Nothing is working. It's like the adhesive is binding rather than allowing the layers to slip. The tubes start out tight on the mandrel but wind up being loose. I've read every thread on tube rolling, watched every video on youtube and have read literature. There is something I must be missing. I need an adhesive that with allow the paper to slip when compressing rather than bind up and create internal wrinkles. Any and all help, comments and criticisms are welcome. Thank you!
Mumbles Posted August 13, 2020 Posted August 13, 2020 There is a member here, Col, who has put a lot of work into this. He'd be one of the first people I'd turn to in order to get some information on this. I included a couple of relevant threads below that might contain some helpful information. I'll try to gather some more information I have on this and get back to you. I don't have access to most of my files at this particular moment. https://www.amateurpyro.com/forums/topic/7820-what-is-the-best-glue-for-cardboardpaper-tubes-rolling/https://www.amateurpyro.com/forums/topic/12817-homemade-glue-roller/https://www.amateurpyro.com/forums/topic/12482-tube-rolling-help/
wncranger Posted August 13, 2020 Author Posted August 13, 2020 Thank you!!!!! I really want to master this art.
snapper Posted August 13, 2020 Posted August 13, 2020 the first wrap or two should not have glue on it, if still stuck roll against the wrap direction to create the slack needed
wncranger Posted August 13, 2020 Author Posted August 13, 2020 (edited) Thanks, snapper. I've tried it both ways from reading threads. Some recommend a wet mandrel, some recommend a dry. Some recommend wet with adhesive, some recommend without. Some recommend not pasting the first roll, some do. Some recommend pasting the back of the first roll (or at least, partially), some don't. I've literally tried all of these techniques. Edited August 13, 2020 by wncranger
wncranger Posted August 13, 2020 Author Posted August 13, 2020 I'm going to try white glue with hand pressure only and no rolling board to see where that gets me. Maybe, that's all this heavy stuff needs with the viscosity and tack of the glue.
BetICouldMake1 Posted August 14, 2020 Posted August 14, 2020 I've played around with this a bit. The one thing I can say regarding wet vs dry mandrel is that it's very adhesive dependant. Something like a dextrin based glue or wheat paste has far less initial tack and can be rolled fully wet as long as you're quick. PVA glues have a fairly high initial tack and will not slide off your mandrel. I personally believe that's why, apart from cost, that dextrin glues are so commonly used for tube rolling. They allow for a very high solids content while still allowing the paper to slip over itself and roll tightly while still being relatively easy to remove from the mandrel. Leaving a dry turn of paper is tricky. If your paste line is too far out you end up with a loose flap of paper in the tube, too far in and the adhesive squeezes out and gets on the mandrel anyway. Good luck with your experiments. Simple paper tubes are more complicated than they seem.
wncranger Posted August 14, 2020 Author Posted August 14, 2020 Thank you all for your suggestions. Eliminating the rolling board did the trick for these little tubes. I'm rolling thin wall tubes for skyrockets (3/8" ID, .470 walls) using hot BP to form a core burning grain and kitty litter/graphite nozzle. I'm not waxing the tubes, only moistening the BP and hand ramming with a 2oz mallet. My initial tests, ramming with no tube support, were successful. I haven't had any CATO's and boy do they take off and fly high. My goal was to remove as much dead weight as I could and commercial tubes were just too thick and heavy. When I get an arbor press, I plan on testing whistle fuel. I don't know if they can handle the pressure, but should as they are nozzless. We shall see, lol.
markx Posted August 17, 2020 Posted August 17, 2020 Two things that might help with the wrinkling problem: 1) Try thicker paper....cardboard type with at least 0,5mm thickness. I do not know if that is available in your neighbourhood, but here we have a product called "construction cardboard/paper". It is a thick cardboard type of paper that is sold in big rolls and is dirt cheap. I've had great success using it for tube rolling. It does not expand much in contact with white PVA type of glues and does very well without voids and wrinkles developing during rolling. 2) Try using a solvent based glue (like a contact glue type). Solvent based glues do not expand and soften the paper structure as much as water based glues. So it usually helps to avoid the defects that you talk about.
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