24 replies to this topic

[Mixer]

By The Mixer.

 

This is a well tried and tested technique I developed for myself over a period of a few years of tube rolling. The main intention being ease of adhesive workability, low cost, with the  minimum of equipment needed.

 

I have tried different methods using Dextrin/Elmers/Wheat paste/Silicate/Casein etc but for various reasons I`ve settled for this method/adhesive as it fulfils all requirements.

 

Hopefully some of this info may be of some use for newcomers to tube rolling.

 

PREPARING THE LENGTHS.

 

I use good quality 35# strong, ribbed, virgin Kraft. The tensile strength measured with a pull scale in both parallel and perpendicular directions to the grain per 1 cm width is approximately 14 lbs for each (provided everything is done correctly this governs the final strength of the tubes). The roll is 24" wide so it takes several strips to roll a tube. The glue is neat, undiluted, READY MIXED WALLPAPER PASTE.

 

Cut the required lengths and coat them all both sides with a thin coat of paste and set them aside for a few minutes to dry and expand close to their limit, then re-coat one side of a length and line up another length over that (inset a 1/4") and then working from the centre outwards press them firmly together using a spatula or flexible metal dough scraper expelling any surplus paste and ensuring there are no air bubbles left trapped. So now all my lengths are two  layers thick. They are then put aside to thoroughly dry.

 

ROLLING THE TUBES.

 

 

The tube former is my first rammer with one layer of Kraft wrapped around and glued down to itself at one edge (making a slip on tube) this also gives a slightly larger diameter to allow for any tube shrinkage on drying. Before rolling I rub oil or wax over the slip on tube so that the finished tube comes off easier, sometimes it pulls off with the finished tube so I poke a stiff wire down between it and the inside of the tube to remove it then I feed it back on the rammer ready for rolling the next tube. 

 

 

A perfectly flat 15 - 25 degree inclined rolling board is very useful here rather than the flat work surface, but not essential.

 

Before gluing the first strip I dry roll it once around the rammer and mark it with a pencil, then I fold that part back underneath at the pencil line so that when the strip is laid down for pasting this portion is underneath and does not get pasted.

 

Thinly paste one of the strips, fold both ends over into the centre and flatten to prevent the paste from drying out too quickly, then turn the previously folded and marked end over and paste a 1/4" or so across that end - this ensures you have paste to paste at the start of rolling - without this the first end could later `pick up` in the tube when charging.

 

Carefully line up and roll the strip keeping tension on the paper by gripping the folded over far end with one hand while rolling with the other, re-positioning. and folding down the far end to re-grip as you go. Lightly roll the tube after each length with a flat implement then repeat the process for the other lengths.

 

To ensure more rapid drying I now half roll each tube, remove and let dry before applying the final layers.

 

If you do all of this correctly you should end up with very strong tubes.

 

For drying, the tubes are best stood upright on screen mesh or similar for good air circulation - or they can be threaded through with string and hung up to dry.

 

Testing tube strengths.

 

The 3/4" x 1/8" wall tubes all failed at 7,487psi.

 3/4" x 3/16" wall tubes all failed at  8,755psi.

3/4" ID x 1/4" wall tubes all failed at 9800 psi.

A single 1/2" ID x 1/8" wall tube failed at 8,423psi. 

 

Some mistakes to avoid.

 

Thinning the paste with water.

 

Rolling the whole tube in one go could result in a spongy tube.

 

Using too thick a paste can also result in a spongy tube.

 

Paste too thin may cause dry patches which can weaken the tube and can even cause`blowpast` in use.

 

Rolling over the finished tube too hard with a flat implement can alter the case thickness in places.

 

If your tubes are wrinkled or deformed in any way you have done something wrong

 

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Overall I think for home rolling the Ready Mixed adhesive is by far the best, it`s very workable, bonds extremely well and it`s pleasant to use.

 

Incidentally it`s also an excellent binder for glitters!

 

Click on first pic then hover mouse top right of pic box - click on next (it`s quicker)....

 

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If you have any questions just holler!

Edited by Mixer, 24 May 2016 - 07:08 AM.

[a_bab]

Thank you for the tutorial.

 

What would you think about rolling with thicker kraft? (70# or even thicker?)  Would it be more physically demanding?

The commercial tubes are all made with very thick kraft, the length of the unrolled paper would usually be under 1 meter.

[Mixer]

No more demanding - in effect I am rolling with 70# Kraft simply by laminating 2 layers together (and drying) before I start.

 

The main reason for this is because I couldn`t get 70# to start with. 

 

Done properly more laminations = stronger tubes.

[Col]

If you stack 2 identical sheets of dry paper and roll them on a former, you`ll find they dont finish at the same point. The top sheet has to travel further than the bottom sheet and its cumulative with each turn

If you glue the 2 sheets together and allow them to dry, the two sheets cant move in relation to each other. The top sheet will have to stretch to make up the shortfall. The resulting tension will either cause the glue line or the paper to fail

If you plan to laminate 2 or more sheets, you have to do it while they are wet and you have to keep the sheets seperated until they meet the mandrel.  Another benefit of this approach is the sheets will be completely interleaved so there are no weak points. With series wound sheets you have what is effectively a set of tubes glued together by one turn. If the glue joints fail you`ll be able to push the individual tubes out like a telescope    

Edited by Col, 05 June 2016 - 05:03 PM.

[OldMarine]

I've been playing with tube rolling and have found that your adhesive needs to be slick rather than tacky to allow those sheets slide on each other or all the problems you just mentioned happen.

[Col]

Keeping the ultra tacky, non-slick, non-soggy sheets seperated until they reach the mandrel will give you a much better tube. You want the glue film thickness to be minimal and as uniform as possible. The more glue you slap on the paper, the higher the risk of tube deformation and voids appearing between the turns as it dries. Ideally, you want the tube to be almost dry as it comes off the mandrel

[OldMarine]

I've been rolling mine with the sheets staggered only by  1 tube circumference difference 

in spacing with a mixture of Elmer's and water that gives me good adhesion yet allows for the sheets to slide upon each other. So far so good!

[DavidF]

I've never rolled a good tube in my life. But I have taken a few apart. NEPT tubes (the old ones at least) have layers glued together before rolling. It seemed to me that the adhesive used to glue the layers together was different than the stuff used to roll up the tube. The layers did not soak apart in water. The long strip of layered papers that the tube was rolled from easily unwound itself when soaked in water.

[OldMarine]

I've got end pieces of thick wall NEPT tubes lying about outside where I'd cut them earlier and after a rain they de-laminated and just like you described, they seemed to be held together by two different adhesives.

[Mixer]

If you stack 2 identical sheets of dry paper and roll them on a former, you`ll find they dont finish at the same point. The top sheet has to travel further than the bottom sheet and its cumulative with each turn

If you glue the 2 sheets together and allow them to dry, the two sheets cant move in relation to each other. The top sheet will have to stretch to make up the shortfall. The resulting tension will either cause the glue line or the paper to fail

 

This will only happen if you use inferior adhesive. Provided the two sheets are firmly bonded and previously dried they will become and behave as one single layer. This is no different than rolling with a single layer of thicker paper, here the outer fibres will be under a little more tension than the inner fibres, but its of no real consequence.

 

 

If you plan to laminate 2 or more sheets, you have to do it while they are wet and you have to keep the sheets seperated until they meet the mandrel.  Another benefit of this approach is the sheets will be completely interleaved so there are no weak points. With series wound sheets you have what is effectively a set of tubes glued together by one turn. If the glue joints fail you`ll be able to push the individual tubes out like a telescope  

 

 A moot point here as the whole purpose of the exercise is to not let the glue joints fail, simply by using the correct adhesive - this will obviate all of the above theory.

There are various ways of rolling tubes, this is my way, and I think it works very well as the burst strengths suggest.   

[Mixer]

I've never rolled a good tube in my life. But I have taken a few apart. NEPT tubes (the old ones at least) have layers glued together before rolling. It seemed to me that the adhesive used to glue the layers together was different than the stuff used to roll up the tube. The layers did not soak apart in water. The long strip of layered papers that the tube was rolled from easily unwound itself when soaked in water.

Yes, if I remember correctly approximately one third of the tube was scrub tapered thicker laminated layers, with as you say a continuous thinner outer winding. I found the inner layers did de-laminate after a prolonged soaking.

Edited by Mixer, 06 June 2016 - 04:47 AM.

[Col]

I`d like to see your method of laminating 2 big sheets of paper so they look and behave like a single thicker sheet

Applying a perfectly even film of glue to the whole sheet in a few seconds is tricky. Without a calender roll to apply heat and pressure to consolidate and dry the layers you`ll end up with sheet that isnt flat with air bubbles and wrinkles

Try soaking an nept in a alkaline solution, it`ll come apart pretty quick.

[Mixer]

You are correct, it would be virtually impossible BUT mention was never made on `laminating 2 big sheets of paper `

 

My method is clearly explained in detail in the Tutorial.

 

"Cut the required lengths and coat them all both sides with a thin coat of paste and set them aside for a few minutes to dry and expand close to their limit, then re-coat one side of a length and line up another length over that (inset a 1/4") and then working from the centre outwards press them firmly together using a spatula or flexible metal dough scraper expelling any surplus paste and ensuring there are no air bubbles left trapped". 

[Col]

The issue with gluing and stacking the sheets prior to rolling is they cant move in relation to each other as you roll the tube

If you keep them seperated they will automatically correct for diametrical differences when they combine at the mandrel. 

For example, if you are rolling a 1lb x 3/16 wall tube using 7x 2ft long strips of 35lb kraft, the combined thickness of the stack will be over 0.5mm which doesnt sound that thick until you try to roll it around a 3/4" mandrel. On the first turn, the top strip will need to gain around 1/8" in length in comparison to the bottom strip because its effectively winding onto a mandrel thats about 1mm larger in diameter. If the glue in the stack holds, the extra length will have to come from stretching the paper and it has to be found within each turns length because every turn has to stretch   

The stretch will create excessive paper tension which builds a huge crushing force into the tube causing it to deform as it dries.

You can get an idea of the forces by wrapping turns of paper or masking tape around your finger under tension

Edited by Col, 06 June 2016 - 11:53 AM.

[Mixer]

The issue with gluing and stacking the sheets prior to rolling is they cant move in relation to each other as you roll the tube

If you keep them seperated they will automatically correct for diametrical differences when they combine at the mandrel. 

For example, if you are rolling a 1lb x 3/16 wall tube using 7x 2ft long strips of 35lb kraft, the combined thickness of the stack will be over 0.5mm which doesnt sound that thick until you try to roll it around a 3/4" mandrel. On the first turn, the top strip will need to gain around 1/8" in length in comparison to the bottom strip because its effectively winding onto a mandrel thats about 1mm larger in diameter. If the glue in the stack holds, the extra length will have to come from stretching the paper and it has to be found within each turns length because every turn has to stretch   

The stretch will create excessive paper tension which builds a huge crushing force into the tube causing it to deform as it dries.

You can get an idea of the forces by wrapping turns of paper or masking tape around your finger under tension

 

Col, again I agree with everything you are saying, BUT none of this applies as that is NOT what I am doing!  I am rolling with one laminated length at a time. Please read my Tutorial carefully ( including previous posts) and you should fully understand exactly the process I am using.

 

This process does not give me any problems at all, they roll nice and the tubes come off in perfect shape, they are extremely tough and as you can see from the pressure testing - way more than adequate.

 

Respectfully, if you had read the Tutorial carefully at the start we could have avoided all this typing

Edited by Mixer, 08 June 2016 - 12:00 PM.

[a_bab]

You can get an idea of the forces by wrapping turns of paper or masking tape around your finger under tension

Then you insert a pin in the finger tip ?

 

Can someone measure the calendered paper thickess NEPT uses? Or, cut a 10x10cm square and weight it?
I think it will be around 300 gsm (180 pound) ?

Some people are just good at paper rolling...

[lloyd]

NEPT doesn't use paper that heavy!  They laminate several layers of thinner paper into one piece of 'rolling stock'.

 

I've used hundreds of thousands of NEPT tubes, and probably unrolled two or three hundred over the last 15 years.  It's pretty apparent how they're made once one gets damp and starts unraveling on its own.

 

LLoyd

[a_bab]

Lloyd, NEPT supposedly gets that "rolling stock" from a paper supplier which in turn manufactures it by calendering the regular kraft if I'm not wrong.

 

Either way, if one can get hold of very heavy kraft he can roll good tubes without the regular issues such as paper being too damp, shrinkage etc.

 

In fact, some old tutorials I've seen recommended Manila paper which is really thick.

[Mixer]

Manilla paper isn`t as strong as virgin Kraft.

A tube rolled from thick Manilla wouldn`t be very strong (if that is the aim)

Generally, the thicker the paper the weaker the tube.

Edited by Mixer, 09 June 2016 - 10:24 AM.

[lloyd]

Lloyd, NEPT supposedly gets that "rolling stock" from a paper supplier which in turn manufactures it by calendering the regular kraft if I'm not wrong.

 

Either way, if one can get hold of very heavy kraft he can roll good tubes without the regular issues such as paper being too damp, shrinkage etc.

 

In fact, some old tutorials I've seen recommended Manila paper which is really thick.

---------------------

ALL finished papers are "calendered".  That has nothing to do with the discussion.  I have unrolled hundreds of NEPT tubes.  They're not made from "180lb" kraft!  Period.

 

LLoyd