What is the best glue for cardboard/paper tubes rolling

[Col]

I think it`ll be closer to 30% than 40%

[dagabu]

That's sounds like a sound plan on the face of it but considering the very strict rules in establishing an analog used as a benchmark, you will have to do multiple tests due to end grain differences.

Here is a frightening window into my thought process. Think of a bodybuilder type guy that tears phone books in half.

Wow! He is strong! Um, not necessarily. I have seen it done by normal sized guys too, showing the technique and the relatively small tear resistance that paper has.

If the bottom of the tube is square, good bonding of all fiber and a smooth surface are provided, you may get a 'burst' pressure.

If any tearing takes place (tearing takes a fraction of the energy to part than tensile strength shows) then it becomes useless as a analog.

I`ll have to test one both ways to see if theres a difference between tear strength and burst strength

Edited December 17, 2018 by dagabu

[Mixer]

I think it`ll be closer to 30% than 40%

I agree - retrying it now

[Col]

I think phone books are consigned to history, not that i could tear one in half. I dont expect a massive difference in the burst readings but the testing will be interesting either way. The wickes paste sample is down to 4.1g and still moist so its not there yet..

[Mixer]

Oddly enough they both seem to have the same solids 40% and yet one flows and the other doesn`t it`s sort of thixotropic

 

Viscosity is deceiving

 

The Polycell does seem to be stronger though.

Edited December 17, 2018 by Mixer

[dagabu]

Does it really loosen up when agitated or is it just a slight change in viscosity?

[Col]

temperature will usually have an impact on the viscosity, easiest way to check is to warm some of the glue up using a water bath.

 

I added a viscosity comparison vid to the post which you may have missed

https://www.amateurpyro.com/forums/topic/7820-what-is-the-best-glue-for-cardboardpaper-tubes-rolling/page-4?do=findComment&comment=181088

Edited December 17, 2018 by Col

[Mixer]

Here`s a level teaspoon of the two (same temp)

The Polycell gives the impression that it`s thixotropic but it isn`t.

Both 40% solids.

I think there may be more PVA in the Polycell.

 

https://photos.google.com/search/_tra_/photo/AF1QipMtkLhPMiQUZhVfVKncS4xJYIho0ePoUifhnAAR

 

https://photos.google.com/photo/AF1QipPQOJN6r5YuNOKFmx09JRDE_TlsMNjyG4aQCI9c

Edited December 18, 2018 by Mixer

[Col]

I`ve revised my 30% estimate for the wickes ready mix down to 20%. Its currently at 23%

Edited December 18, 2018 by Col

[Mixer]

We seem to be way apart Col. What are you using to measure yours on? I definitely make mine 39-40%

 

Update 34.81%

Edited December 18, 2018 by Mixer

[Col]

If you take a known weight of glue and evaporate all the solvent you`ll be left with the solids. Milk bottle screw caps are good for 10g samples, jott the dry weight of the cap on the bottom with a marker pen (typically around 1.35g) so you dont forget how much it weighs. Add 10g of glue to the cap and allow all the solvent to evaporate which can take a few days. The final dry weight will consist of the solids and the screw cap.

[Mixer]

Deleted.

Edited December 18, 2018 by Mixer

[Col]

A 10% wheatstarch paste contains 90% water and doesnt flow like water. If you increase it to 30% it becomes a solid block but it still contains 70% water I`m not sure why you used a 1.126g sample weight, 10g is a nice round number but apart from that, a bigger sample will provide a more accurate result. I`m not seeing the same result as you so something is amiss. Current weight of the sample is 3.5g and the dry cap weighs exactly 1.4g. The glue in the cap weighs 2.1g so the 10g sample is 7.9g lighter than it started out

 

Edited December 18, 2018 by Col

[Mixer]

I used 1.126g because I didn`t want to wait forever for the result.

 

Trials are made on a Sartorius industrial laboratory gram scale for complete accuracy.

[Col]

lol, i weighed the sample on a 20g x 0.001g scale, the 600g x 0.1g scale was close to hand. Either way its not going to be that far out, especially with the larger 10g sample size. If it was 38% the cap/glue should weigh in at around 5.2g, not 3.5g

Chucked a calibration weight on the scale, all good so its not the scale.

Edited December 18, 2018 by Col

[Mixer]

Col, have you spotted your mistake yet

 

Just kidding!

Edited December 18, 2018 by Mixer

[Col]

nope

[Mixer]

I think I would be a little pissed if I paid £8.79 for 4 Kilo`s of water

Edited December 18, 2018 by Mixer

[Col]

The water in a bottle of pva is more expensive, £3.50 for 500ml. Wickes sample is now 3.4g incl cap, 2g excl cap.

Start weight was 10g glue +1.4g cap (11.4g )

Edited December 18, 2018 by Col

[Mixer]

Yup, bulk buying pays.

[Mixer]

Col, calculating from your last post I estimate your solids (+ lingering water) at 30.7%

 

Maybe the quality of Wickes paste has gone down! Or possibly more stirring needed.

 

​My trial paste came from the bottom of the tub as most had been used.

 

I think it was your mention of 20% that threw me

Edited December 18, 2018 by Mixer

[Col]

If the glue started at 10g and its now 2g (8g of water evaporated) i dont see 30.7%.

 

 

 

There are three accepted methods used to dry down an adhesive sample to check the solids content.
One is to use a laboratory oven set at 105C. A liquid sample of approximately 5 grams is weighed and placed in the
oven for 3 hours and then reweighed. The dry weight is divided by the original wet weight of the sample
and multiplied by 100 to give the percent solids. Remember to subtract the weight of the weigh dish before and after the
sample is dried.

 

By that score, 2g /10g *100 is 20%.

If your sample started at 1.126g and weighed 0.734g after drying, you`d have 0.734 / 1.126 *100 which is 65% solids

Edited December 18, 2018 by Col

[Mixer]

Oh ok I mistakenly included your cap weight. I`m so used to my way - I just put any amount of the paste on a slide, and weigh the whole thing then re-weigh after the evaporation.

 

-20% seems poor

[dagabu]

I paid $22 US for 2 gallons of PVA and for the 2 gallons of Roman 880. Not cheap but per tube, the cost is acceptable.

 

NEPT tubes run $1 US each 7.5" unit making it $100 for 100pcs (of course).

 

My paper cost me less than $120 US delivered, I got 5000 sheets or 10 reams. Each sheet is cut into three 8" wide strips, it takes three strips to make a tube so 5000 tubes for $120 US.

 

= $0.024 US per tube for paper.

 

$11 US per gallon of adhesive, about 150 tubes per gallon un-diluted and 300 50:50 mix.

 

= $0.036 US per tube for the glue.

 

Total: $0.06 US per complete tube, ready to load. 16 tubes for the price of one isn't bad at all.

[Col]

Its supposedly the same paste in the same tub so i doubt they would have doubled the amount of water in it, its not what you could call a thin paste

Dag`s Roman 880 estimated 32% solids, might be worth a test to see how close it is. Cant find any spec for the wickes so there`s nothing to go on.

http://romandecoratingproducts.com/files/6515/1620/1781/PRO-880_TDS_011618.pdf

.

Edited December 18, 2018 by Col