Fracking cheap white toobs
 

Unnngghghghhhhrrr . . . .

Many years ago, I bought from a now-defunct supplier a bunch of BT-50 equivalent toobs. I used them for my ongoing clone and DOM-plan projects.

I recently started work on two "kits" I bundled nearly ten years back, a Black Knight and a Commuter.

I was reminded again that not all tubes are alike. Both the Midget and Farside I built with the tubes suffered crack-ups which were far more damaging because the tubes are the cheap white ones. Today while slotting the tubes for the Black Knight I nearly crushed the **** things.

If you look on the inside of the tube, you can see that the brown "core" layer isn't continuous. There's an inner spiral gap. The light outer wrap is visible through it.

Ungh. I'm seriously considering scrapping the body tubes for the Black Knight and Commuter before I actually glue anything to them.

Hold them up to a light and you can see right through the spirals. That didn't happen with the good old brown kraft paper, yet some vendors say there's no difference other than color. :confused:

Our vendors are probably just parroting what Euclid or whoever is their supplier says. I never heard whether the white ones were cheaper than the brown ones. Some builders prefer the white ones because they are easier to cover with paint or they look better flying without a paint job or they are easier to color with markers for competition use.

I do not have data to back it up, but the brown tubes seem stronger to me. Especially the smaller and thinner two ply ones. And I do not think it is a racial bias...

If somebody is still looking for an R & D project for NARAM, there is still time to test the strength of white versus brown tubing. While not as earth shattering as government research into the subject of "tube alloys," the result of such a study will be very useful to prove or dispel this belief.


Bill

I am a tube buyer not a parrot. :D

The whitewall tubes are around 10% more money and that is just bleached kraft. They are incrementally weaker, but you can't tell in practice. If you want paper and also strength you want USR style SBS tubes which shocked Drake in the crush tests.

http://v-serv.com/usr/som.htm



The Euclid tubes are by far the best kraft tubes on Earth. The main reason is they are optimized for the task. Narrow slitting, thin virgin kraft layers, and higher than usual quality glassine to improve stiffness and finishing.

Ball Paper used to make the Estes motor cases which were also un"paralleled" quality.

Be picky about tubes. I am. I threw away 8 pallets of tubes once. I did the right thing.

Jerry

In recent efforts to get work out pricing for my upcoming line of rockets, I contacted three local area tubing manufacturers (one of which was Euclid Tubes, who are not in Euclid it turns out but actually a bit south of there and thus would add expense in shipping as opposed to the two companies within a ten minute drive, but I digress). In asking for quotes, I stated I wasn't aware of any standards of quality (ASME rating or equivalent) and asked if they could educate me. The silence was deafening.

From Ace Paper Tubing

"Hi, Bernard.
I want to personally thank you for inquiring about our tubes.
Rocket tubing requires a special spiral wound tube.
Unfortunately we can’t supply you with rocket tubing.
Thanks again for you interest in Ace Paper Tube.
Dave, "

upon pressing for more information I was handed off to a VP and after some correspondence ended with this...

"Hello again Bernard.
Unfortunately, I don’t have much information for you. As we do not manufacture glassine tubing I can’t compare it with the tubes we currently make. Also, after reading some of the forum you sent me it would appear most of the tubes were convolute (parallel wound) paper tubes not spiral wound. Euclid Paper Tubes was mentioned in that forum and they are still in business. You can find them on the web at:

There is a standard for measuring “ring crush” and “end to end” crush for spiral wound paper cores but those are much larger (3” and up) and much heavier (.125” to .500” thickness). I would not have a way to test the crush of a small diameter and small thickness tube.
Good luck in your search.
Norm Hensley Jr
Ace Paper Tube"

While I appreciate his candor, it says much that he was willing to send a potential customer to a competitor in this economic climate.

End result so far is that as far as I can find there is no standard for paper/ glassine tubing in the sizes model rocketeers use. :confused:

I may in the near future contact Norm again (his company is just down the street) and see if I can garner some information about the two tests he did mention for the larger tubes. What we can do with the information after that point is up in the air, maybe approach NAR?

It might be a good project for NAR to develop a crush standard of their own. It shouldn't be hard to set up a soda can crusher with a scale of some sort and smash some tubes.
_____________________

I respectfully disagree on this part. Estes has recently shipped several kits with the classic brown tubes. As examples, I'm looking at the BT-55 in the Photon Disruptor and the BT-60 in the Big Bertha. The seams are much tighter, tight enough that I can't easily measure a gap. The tubes also feel more substantial. The white tubes have measurable gaps at the seams and are extremely weak at those seams compared to the brown kraft tubes, allowing them to kink easily at the seams. I'm sure they will fare better on the crush test where the force is exacted perfectly along the axis, but seldom do I have a rocket land perfectly vertical.

As far as I know, BMS and SEMROC white tubes are both from Euclid, as are the brown tubes that are in Estes kits, therefore there shouldn't be any noticeable difference in construction or strength. However, I do see/feel a considerable difference in the finished product. Part of that is the wider seams, which may have to do with tolerances, but the brown tubes also seem thicker and harder, almost like they have an extra layer. Maybe the bleaching process results in a slightly thinner paper stock.

Of course you also have to deal with the secondary issue of safety.

While the tubes have to be airworthy, at the same time they have to crumble upon impact to protect those nasty rocket eating trees. So tubes can't be excessively sturdy.

There was recently a disruption in tube making guys at Euclid and for a time the tubes were crap. I would say that tubes MADE after April of this year, the over one year of disruption, has settled. I have been holding off on tube orders after the first bad report I heard.

Making tubes is a real art. And hectic!

Jerry

People were whining AFTER I posted a testing link.

I'm not whining. I'm just posting my direct observations.