Rolling Tubes

[btdk34]

I've recently purchased a roll of 60# virgin kraft paper from Berlau Paper House (link) and have been attempting to roll tubes from it without much success. I'm trying to roll 3/8" ID, 9/16" OD tubes and am using aluminum stock to roll it. The glue I use is a mixture of 2 parts Elmer's Wood Glue and 1 part water. I know that I am supposed to roll in the direction perpendicular to the grain of the paper (when you wet the paper, roll in the direction of the curl), and this has helped a bit. But the problem I continually run into is my tube "bunches up", meaning the paper does not remain flat when I roll it. Any well-known methods/tips and tricks I should try?

 

I've been reading through the threads about tube rolling on APC and one method that looks interesting is the "calendar" method. USAPyro wrote a small write-up on this a while ago (link), but didn't use any glue. Anyone know a good method for making tubes with staggered sheets of kraft? I feel that this would give a very strong tube (I think I read somewhere that NEPT tubes are rolled this way?).

 

Any help is greatly appreciated!

Edited July 25, 2012 by btdk34

[dagabu]

A couple things I found in "rolling my own" was to keep the tubes shorter rather then longer. If your cut tubes will be 3" long, only roll enough for two tubes, say 7" of paper. Dont soak the paper with glue. Some glue the paper and them let it dry... that works fine but I don't like to wait that long. I use undiluted glue and a 2" wide China brush (chip brush) that has the nap cut back to 3/4" long.

 

Pre-roll the paper around the rod so it just overlaps, dip your brush and draw it away from you, do so quickly and then roll up the tube drawing the paper towards you. Don't let the glue saturate the paper and let it wrinkle. If the paper goes awry, let it, do better on the next one, don't correct it and don't unroll it. Once rolled, use a rolling board (plywood or other solid sheet of wood) wider then the tube and about 18x24" long, place that on top of the rolled tube on the rod and while pressing down with some force but not a lot, roll the tube up in the direction you hand rolled it by moving the board away from you.

 

Do this a few times and then PUSH the tube off the rod, don't pull it. If done correctly, you can dry the tubes on end or on their side, they will be plenty strong by this time.

 

I feel that 60 pound paper is way to light for tubes, I like 90 pound paper or even chipboard for small tubes.

 

-dag

[SunDevil]

I've recently purchased a roll of 60# virgin kraft paper from Berlau Paper House (link) and have been attempting to roll tubes from it without much success. I'm trying to roll 3/8" ID, 9/16" OD tubes and am using aluminum stock to roll it. The glue I use is a mixture of 2 parts Elmer's Wood Glue and 1 part water. I know that I am supposed to roll in the direction perpendicular to the grain of the paper (when you wet the paper, roll in the direction of the curl), and this has helped a bit. But the problem I continually run into is my tube "bunches up", meaning the paper does not remain flat when I roll it. Any well-known methods/tips and tricks I should try?

 

I've been reading through the threads about tube rolling on APC and one method that looks interesting is the "calendar" method. USAPyro wrote a small write-up on this a while ago (link), but didn't use any glue. Anyone know a good method for making tubes with staggered sheets of kraft? I feel that this would give a very strong tube (I think I read somewhere that NEPT tubes are rolled this way?).

 

Any help is greatly appreciated!

 

I have had success in the past by rolling my tubes on a smooth wood dowel, lightly coated with parafin wax. I have also tried using metal rods but I have found that smooth wood (maple) works best for me. Another tip, which has been already mentioned, is to start the tube as evenly as possible in the beginning, dry rolling a few turns and then glue the remaining paper. The tubes made in this manner will easily slip off the former.

 

If you continue to have trouble with the paper bunching up as you roll it, I would recommend going to a heavier weight paper. I know from past experience that this will help.

[Col]

I second dag`s suggestion of using a rolling board. I fixed a 2x2 to the top end of mine to create a shallow upward slope, the sloped board reduces the risk of you pushing the mandrel while rolling the tube which could be whats causing the bunching up.

I use the double glue method when i need super strong tubes but single gluing is good enough for most purposes.

The latest batch of 3/4" id x 3/16" wall tubes took almost 12ft of 70gsm virgin kraft and 47 turns

[dagabu]

Nice looking tubes there Col.

 

-dag

[Col]

Cheers Dag, believe me i would buy NEPT tubes if i could

I`ll do a destructive test on a 2" section tomorrow using Ned`s method to see what pressure it can take (unsupported)

[dagabu]

Cheers Dag, believe me i would buy NEPT tubes if i could

I`ll do a destructive test on a 2" section tomorrow using Ned`s method to see what pressure it can take (unsupported)

 

I am always on the fence with tubes, I am picking up 9 bundles of NEPT tubes at PGI since there is free shipping but I still hand roll about 1/4 of my tubes especially for smaller rockets.

 

I would like to see what you get in your test, I bet it is pretty darn good!

 

-dag

[bob]

Dont soak the paper with glue. Some glue the paper and them let it dry... that works fine but I don't like to wait that long. I use undiluted glue

 

Don't let the glue saturate the paper and let it wrinkle. If the paper goes awry, let it, do better on the next one, don't correct it and don't unroll it. Once rolled,

Do this a few times and then PUSH the tube off the rod, don't pull it. If done correctly, you can dry the tubes on end or on their side, they will be plenty strong by this time.

-dag

 

this is funny cause I use a mix of 9 parts wood glue and 1 part water and I don't worry about them getting to saturated

I always correct them when the go crooked

I let them dry on the tube I find that when I let them dry of the tube they shrink a little and then my rammer does not go in very well

 

please don't take this as I think your wrong dag

I'm just saying that what I have had good resolts with and what you have had good resolts with is completly diffrent and I wonder why this is

dag has WAY more experience then me

bob

Edited July 25, 2012 by bob

[btdk34]

Wow, lots of information! Just the way I like it.

 

Dag/Col, never even though of "after-rolling" with a flat board! I'll definitely have to give that a try. Both dag and SunDevil mentioned going to a higher weight paper... I'll definitely consider that. Are there any other suppliers of 90# virgin kraft paper besides Berlau Paper House?

 

Also, could someone explain the "double-gluing" method? I am intrigued by the sound of that!

[dagabu]

Wow, lots of information! Just the way I like it.

 

Dag/Col, never even though of "after-rolling" with a flat board! I'll definitely have to give that a try. Both dag and SunDevil mentioned going to a higher weight paper... I'll definitely consider that. Are there any other suppliers of 90# virgin kraft paper besides Berlau Paper House?

 

Also, could someone explain the "double-gluing" method? I am intrigued by the sound of that!

 

At :21 seconds into this video, you will see the dry rolling of tubes and the rolling board they use.

 

http://www.youtube.com/watch?v=VB-1txW0HMw&feature=related

 

 

Double gluing is achieved by first pasting the paper as you would normally do and then let it dry, glue it again and roll the tube.

 

-dag

[dagabu]

please don't take this as I think your wrong dag

I'm just saying that what I have had good resolts with and what you have had good resolts with is completly diffrent and I wonder why this is dag has WAY more experience then me

bob

 

Many ways to skin a cat Bob, if your way works, don't change a thing. My reply was really based on making the chore as easy as possible and introducing as few pit-falls as necessary.

 

-dag

[Col]

Double gluing just involves brushing glue on and letting it dry.. The 1st coat causes the kraft paper to "give" at right angles to the grain. The 2nd coat reactivates the 1st coat but not wet so it retains its strength. If you hit it with a single thick coat it would be wet and soggy and wouldnt have time to "give". The more "give" you have the tighter the tube will be when its dry.

By my reckoning, you`ll need a 594mm strip of 60# kraft to make your tubes, dont put glue on the first 30mm as that bit wraps around the former. The tube should need about 15.87 turns.

[nater]

I am always on the fence with tubes, I am picking up 9 bundles of NEPT tubes at PGI since there is free shipping but I still hand roll about 1/4 of my tubes especially for smaller rockets.

 

I would like to see what you get in your test, I bet it is pretty darn good!

 

-dag

 

 

I just bought and cut up a few bundles of tubes from Jim B, and will be picking up more from someone else at PGI. I have had okay luck making tubes wet rolled from manilla folders and 50/50 wood glue and water. Considering the price of tubes larger than 1" ID, I should keep practicing and roll my own high quality tubes. BangkokPyro's large gerbs inspire me to play around with them, but commercial tubes that big make it expensive to experiment with.

[btdk34]

Col, thanks for the explanation of how and why. I will give that a try and see what effect it has once I can roll single-glued tubes! I'm planning on making a few tonight, keeping your guys' tips in mind. I'll see how close your 594mm strip gets me to 9/16" OD.

 

Another quick question. When you roll the board over the finished tube and apply pressure, does this make the roll become tighter? I often struggle with getting the paper tube ID to match the outer diameter of the roller I am using...

Edited July 26, 2012 by btdk34

[Col]

You might find the double gluing makes it easier as the paper will be less likely to stretch as your rolling it. Small diameter tubes are more fiddly to roll than larger ones.

I dont use a board, i burnish the tube with a 3/4" aluminium rod after each strip. Btw, what are the tubes going to be used for?

With practice you can get fairly consistant outside diameters, its better to be slightly under than over as you can make up the difference with a few turns of kraft.

Edited July 26, 2012 by Col

[btdk34]

Col,

 

I tried double gluing tonight with little success (see attached picture). For some reason, my paper always gets super bubbly. I tried once using plain Elmer's Glue-All, and once with my mixture of 2 parts Elmer's Wood Glue, 1 part water. Both gave the same results.

 

I'm using these for little 3/8" rockets. That's part of the reason I want such a consistent ID, so that it will fit the tubing. I have had success tonight using dag's method of spreading plain Elmer's Glue on the paper, then instantly rolling it. What I did was only "paint" 3" sections at a time, then roll, then paint 3" more, etc.

 

 

That tube "compressor" is a really good idea! And that tube looks fantastic. How did you do it? Also, when I use 594mm (~23.5"), I get an OD of 0.600". Of course, it should be 0.5625", so perhaps I need to roll harder?

Edited July 26, 2012 by btdk34

[Col]

The tube will shrink back slightly when its fully dry, 0.9mm seems reasonable. I use a neat pva that has the consistancy of thin yoghurt, i guess about 1/3-1/2 the viscosity of a good quality white wood glue. I start at the bottom and finish at the top, working from the middle out to the sides diagonally which encourages the paper to stretch lengthwise as i go.

I have a long vertical and a shorter horizontal line marked on my rolling board so i can align the paper, i use the horizontal line which is a few inches wider than the strip to align the former. The first turn is the trickiest because you have to tuck in the paper so its tight around the former while your fingers are sticking to the glue which forms the glue to glue seal on the first turn. As you roll the tube you may find you generate some slack in front of the former, keep some weight on the former so it cant move or twist, grab the top of the strip and gently pull out the slack (using the vertical line to stay aligned). The top of the rolling board tends to get a little tacky after a while which helps hold the retensioned paper in position. Keep as much (controlled) weight on the tube as you can when your rolling, all your weight will be mostly on your fingertips so it should feel like you`ve had a workout.

The tube support is just a length of seamless chrome-moly tubing (28mm id x 2.5mm wall) split lengthwise, i have a smaller one for 1/2" tubes which is 17mm id x 2mm wall. The tubing came from a fold-up scooter like this one tubing donor, so you could say it was re-cycled

 

Pressure tested two 2" sections and they both failed at 5700psi, which is about 1100psi short of an NEPT tube.

Edited July 26, 2012 by Col

[dagabu]

Pressure tested two 2" sections and they both failed at 5700psi, which is about 1100psi short of an NEPT tube.

 

Damn good performance!

 

-dag

[dagabu]

Col,

 

I tried double gluing tonight with little success (see attached picture). For some reason, my paper always gets super bubbly. I tried once using plain Elmer's Glue-All, and once with my mixture of 2 parts Elmer's Wood Glue, 1 part water. Both gave the same results.

 

That's the extra water you are using causing the bubbling, don't add water or use a shorter section of paper or use thicker paper.

 

I'm using these for little 3/8" rockets. That's part of the reason I want such a consistent ID, so that it will fit the tubing. I have had success tonight using dag's method of spreading plain Elmer's Glue on the paper, then instantly rolling it. What I did was only "paint" 3" sections at a time, then roll, then paint 3" more, etc.

 

If it works, it works!

 

That tube "compressor" is a really good idea! And that tube looks fantastic. How did you do it? Also, when I use 594mm (~23.5"), I get an OD of 0.600". Of course, it should be 0.5625", so perhaps I need to roll harder?

 

 

 

[btdk34]

Col, what pound paper are you using? It must be pretty thick! Either that or you roll fast! The idea of marking the rolling board is a good one!

 

I tried the same method you mentioned with my paper (60#, 7" wide x 22" long strip), but it almost instantly bubbles, even with straight Elmer's glue. Like dag said, I'll probably stick to what works for me, but I would love to find ways to improve upon that method.

Edited July 26, 2012 by btdk34

[Col]

I used the spare piece of tube with the support tube, no visible damage with 9,500psi so that`ll do for me.

I`m using 70gsm virgin kraft (40lb) for no other reason than it was a 220m roll of bankrupt stock going cheap. I`m sure your tubes will hold up just fine so crack on and get some rockets made ..lighting visco is a lot more fun than rolling tubes

[btdk34]

Yeah, good point. I do have some decent tubes made, so now all I have to do is machine some rammers to go with my spindle!

[Col]

It only takes about 20 minutes to glue and roll a tube, you`ll get quicker with practice.

I decided to do a comparison test using the same length of kraft (11.87ft ) but with homemade wheat paste. I used the double glue method so it may take a few days to dry out. Judging by the grip it has on the T6 mandrel i might need the press to get it out

[btdk34]

Wow, that looks nice! Yeah I've heard about using wheat paste/dextrin... do you just mix with water and use it as glue?

[Col]

I used what was in the cupboard, the bag said "strong white flour" for breadmaking, (contains gluten), ingredients: wheat flour. It sounded like just the job and into the pan it went

I used 3x level 15ml scoops of flour and 250ml of reverse osmosis water in preference to the very hard tapwater. I mixed the flour with some of the water until it was a runny pancake batter consistancy and put the rest in a pan to get hot. Pour the flour mix into the pan and stir with a balloon whisk until it boils. When its thick enough, let it cool and you have a pan of sticky goop to roll tubes or paste shells with

Edited July 26, 2012 by Col