glue for hand rolled tubes

[OldMarine]

I know this probably off topic, but has anyone tried the poly coated kraft/baking method of tube rolling? I've seen it mentioned but never any reports of success or failure.

I've so far only used water/pva in my rolling attempts and I'm sure there's something better.

[Col]

The glue formulation sets the solids percentage, viscosity, initial tack and open time. Just because a glue is thick doesnt mean it has high solids, the maximum you can go with wheat starch is about 30% solids, above that you`ll have a useless jellified block In comparison, with dextrin you may manage 60% solids, it will have a massive amount of initial tack but the open time will be very short. A mixture of wheat starch and dextrin can be used to provide an intermediate solids glue with good tack and a useful amount of open time.

Pva can be mixed with wheat starch paste to lower the viscosity so its easier to apply, it will also extend the open time. Diluting pva with plain water to lower the viscosity reduces the solids content. The wheat starch (paste) contributes some solids to the mix where plain water doesnt contribute any.

Edited March 27, 2016 by Col

[Sparx88]

The 1# tube was done with a thicker ratio to water with titebond. 80% glue. Need to work a little quicker but still had a few minutes before it would seize up. The 4 oz tube with the same kraft paper and glue but was too thin of a ratio of 50/50. You can see all the wrinkles and warping that happens on the 4 oz when your glue is too thin>>>> I won't use them for rocket motors but they found use as inserts :)

Edited March 27, 2016 by Sparx88

[lloyd]

You can be certain that companies like NEPT (and all others) do NOT let their tubes dry "on the mandrel". As soon as they're wrapped, they're stripped, and often fed into cutting equipment even before drying completely.

 

It's a non-problem, complicated by techniques not well-optimized by most amateurs. Some folks, like Carl Kern, can roll tubes in a blink of an eye that challenge the quality of the very best machine-made commercial tubes.

 

Lloyd

[Fulmen]

you need to work on your glue application method

Or I can just stick with my current method that works fine for me

 

I know it's a bit unconventional, but the results are good and fast enough for my needs.

[lloyd]

Well, I (honestly) wish you luck with that. You probably won't see a need to change the method until you really start to 'push the envelope' concerning core sizes and compositions.

 

Lloyd

[Fulmen]

That might be, but so far they've behaved quite reliable and since I make all the tools myself I don't really need to push the envelope. You could try it once, it's a fairly simple method once you find the balance between wetting and glue consistency. You don't have to work fast, and you can even unroll the tube if it starts out wrong. The only downside is that it can be hard to get the end to stick, but that is solved with a dab of undiluted glue.

[lloyd]

Oh, I've done it many times, and don't like the long drying times, the "tying up" of my mandrels, and the distortions that result ultimately in a weaker tube.

 

I like a BARELY damp-glued, virgin kraft, convolute-wound tube that is dry enough upon 'slicking' the last wrap to take off the mandrel and set aside immediately, with sure knowledge that it will not warp or change dimensions upon drying.

 

But again, that's not to say yours don't work fine for what you do with them. Those are my preferences.

 

In general, I like to use commercial tubes... but even then, they need to be inspected for the sorts of defects we've been discussing. I've seen the 'best' NEPT tubes with separated turns or oval shapes.

 

Lloyd

[Col]

If you can unroll the tube you dont have enough tack, thats why the end flap wont stay stuck

Looking back at my notes, neat Evostik "Resin W" waterproof PVA wood glue (blue bottle) has a solids content of 52.5%. If your pva is a similar quality, you`ll reduce that by 30-50% with dilution. Its the reason you dont have enough tack

Drying a tube on the mandrel takes a lot longer cos the moisture can only escape from the outside surface of the tube,

Edited March 27, 2016 by Col

[Fulmen]

I know the lack of tack is due to the dilution, it takes a few minutes before the paper absorbs the extra water. But it's not a big deal really, I just use a dab of straight glue for that. And these don't have to stay on the mandrel until dry, after 8-12 hours they are dry enough to dry off the mandrel without warping. I get that it's not as fast as other methods, but I don't use dozens of tubes per day. The point is that it is simple after you work out the kinks and produces surprisingly good tubes. It might not be to everyone liking, but for those that struggle with other methods it can be worth a shot.

[Col]

.If you`re happy with the method and the tube quality is consistant, thats what counts. My tubes come off the mandrel as soon as they`re rolled, having to wait 8-12 hours for the mandrel would really slow things down.

 

[mikeee]

.If you`re happy with the method and the tube quality is consistant, thats what counts. My tubes come off the mandrel as soon as they`re rolled, having to wait 8-12 hours for the mandrel would really slow things down.

 

tubes.JPG

Those are nice looking tubes!

[lloyd]

Yeah, they are!

[rsambo]

Unless I've missed it I've not seen Col divulge his actual formula ;-), I have been watching like a hawk in vain hoping to craftily benefit from all his hard work. Just maybe, just maybe if I massage his ego enough he might just post the mix, just maybe... Until then I'll have to keep going with my sub-standard inferior glue mix.... sigh.

[Col]

The paper quality and rolling method is just as important as the glue. It would have saved me a lot of trial and error if NEPT had posted their glue recipe, paper supplier and rolling methods If i was in the states i would have just bought NEPT`s.

[schroedinger]

Col why not buy eger then?

[Col]

They`re alright for the money but not exactly close to NEPT quality. The blue 1lb`ers i tested werent made from quality virgin kraft. They managed 5100-5600psi unsupported, not great but no worse than other tubes i`ve tested in the 50p price bracket.

[rsambo]

dammit didn't brown-nose enough, still don't have the glue formula.

 

[stix]

dammit didn't brown-nose enough, still don't have the glue formula.

 

 

ooooohhh... yuk!!!... Although I do remember a disturbing incident... slipping over on some inappropriately placed failed glue experiment - flat on my face in amongst its foul stench. Yuk!!!....

 

The next morning when I woke up and looked in the mirror, there was indeed a distinct brown streak across my nose. It was probably the slightly burnt dextrin mixed with casein. Well, at least that's my blurred recollection anyway - I'll never remember the formula. I prefer not to talk about it.

 

[EDIT] Let's hope that Col is kind enough to give the formula up, because I certainly wouldn't want to go through that episode again .

 

rsambo, that's the way you do it.

Edited March 31, 2016 by stix

[rsambo]

Stix, now i think I just wet myself laughing.

 

toilet humour, gotta lov it. Awesome.

[Mixer]

I submitted an extensive article over on fireworking.com which covers pretty much everything.

[Mumbles]

I submitted an extensive article over on fireworking.com which covers pretty much everything.

 

 

Did you happen to crack the secret on Col's caesin glue? He's very tight lipped about it.

[Mixer]

Once you find an adhesive that can hold the maximum break strength of the Kraft there really is no need to look any further.

 

I think I must have tried (over a 2 year period) virtually every adhesive on the market before settling on this one.

 

The tubes properly rolled will out-perform NEPT tubes.

 

Burst strengths etc are all explained in the article.

[OldMarine]

Mixer, great article. I'm going to try your method for my spollette tubes.

[Maserface]

Mixer, would you be willing to post your work here? I think it would be very well received amongst many of us.