stiffening random cardboard tube.

[OzHybrid]

I've been using an ABS/ acetone slush to stiffen cardboard tube. Really thin, 3 coats (ish) Works really well. Adds about 1% weight. As I print my nosecones, the rest is easy.
Cardboard still gives the best bang for convenience and strength to weight. I'll ad a picture shortly.
Norm

 

[OzHybrid]

83mm thin wall post pack tube. 3 coats inside and out of slush.

 

[afadeev]

I've been using an ABS/ acetone slush to stiffen cardboard tube. Really thin, 3 coats (ish) Works really well. Adds about 1% weight. As I print my nosecones, the rest is easy.

Not sure how much strength you are looking to gain, but soaking cardboard tubes in thin CA goes a long way to stiffen the tubes (and balsa fins, if desired).
Little goes a long way, and you can remove access CA by wiping it off with a paper towel.

Cardboard still gives the best bang for convenience and strength to weight.

True.
Cardboard tubes are also easy to glue with basic and non-toxic wood glues. Easy to work with, simple, light.
Yet strong enough.

 

[OzHybrid]

Not sure how much strength you are looking to gain, but soaking cardboard tubes in thin CA goes a long way to stiffen the tubes (and balsa fins, if desired).
Little goes a long way, and you can remove access CA by wiping it off with a paper towel.



True.
Cardboard tubes are also easy to glue with basic and non-toxic wood glues. Easy to work with, simple, light.
Yet strong enough.

CA gives off cyanide fumes. The objective was to make a whole, normally soft tube, stiff enough to be usable. Water based glues make the cardboard soft while they go off and may warp the tube.

This works. Just presenting it as an option. Produces a phenolic like tube. Not as hard.

 

[rharshberger]

https://info.aronalpha.net/blog/com...dhesives-and-what-you-may-not-know-about-them

 

[OzHybrid]

https://info.aronalpha.net/blog/com...dhesives-and-what-you-may-not-know-about-them

I stand corrected. However having been in the presence of a 4oz bottle going off they are certainly irritating as described in the MSDS and Wikepedia which I've just read.......

Please let me know how you go with testing the stiffening method I've presented.

 

[rharshberger]

I stand corrected. However having been in the presence of a 4oz bottle going off they are certainly irritating as described in the MSDS and Wikepedia which I've just read.......

Please let me know how you go with testing the stiffening method I've presented.

Oh yes the fumes are nasty, not deadly but definitely not pleasant to nose or eyes.

 

[waltr]

I've been using an ABS/ acetone slush to stiffen cardboard tube. Really thin, 3 coats (ish) Works really well. Adds about 1% weight. As I print my nosecones, the rest is easy.
Cardboard still gives the best bang for convenience and strength to weight. I'll ad a picture shortly.
Norm
The objective was to make a whole, normally soft tube, stiff enough to be usable. Water based glues make the cardboard soft while they go off and may warp the tube.

This works. Just presenting it as an option. Produces a phenolic like tube. Not as hard.

Nice idea.
Question: What glues do you then use on the ABS impregnated tube?
I'm guessing wood glue does not work so Epoxy?

 

[afadeev]

Oh yes the fumes are nasty, not deadly but definitely not pleasant to nose or eyes.

That's why I've switched to Super-Gold CA. It's more expensive, but fume-less. Well worth it for me:
https://www.erockets.biz/search.php?search_query=super-gold&section=product

I've been using an ABS/ acetone slush to stiffen cardboard tube.

Norm, where do you source said "slush"?

 

[neil_w]

Cardboard tubes are also easy to glue with basic and non-toxic wood glues.

Not after soaking in CA...

Oh, and I'll put in another plug for foam-safe CA (e.g. Bob Smith SuperGold), which is essentially odorless. Marvelous stuff. It will not be cheap to impregnate large tubes with it, though.

 

[OzHybrid]

That's why I've switched to Super-Gold CA. It's more expensive, but fume-less. Well worth it for me:
https://www.erockets.biz/search.php?search_query=super-gold&section=product


Norm, where do you source said "slush"?

Make it. Acetone and few metres of filament or scrap from previous prints. I only print ABS normally. After applying allow full day for all acetone to evaporate.
Norm

 

[OzHybrid]

Nice idea.
Question: What glues do you then use on the ABS impregnated tube?
I'm guessing wood glue does not work so Epoxy?

Epoxy and key the tube with coarse sandpaper. Same as you'd do for plastic tube. I suppose you could use a very thick slush of ABS if you were gluing to something porous like a centring ring. But with epoxy you know the cure time.
Norm

 

[jqavins]

Make it. Acetone and few metres of filament or scrap from previous prints.

A few meters of filament to how much acetone? Can you give a ratio? Using mass of filament, preferably, since filament diameter is not a constant (as I understand it).

I suppose you could use a very thick slush of ABS if you were gluing to something porous like a centring ring.

That's essentially Testers. There's is a different solvent, but the same idea.

 

[dhbarr]

I'd imagine this falls somewhere between a rubberized CA and wood hardener in terms of thickness. Makes sense!

 

[OzHybrid]

Just made up some by eye...... 4g of fillament in 60g of acetone. (you could add more) Like water. That did a tube inside and out 400mmX83OD 3 coats using a 1"paintbrush.
Roughly...... You want it thin to get fullest penetration. You'll get that on the 1st coat, so I do that one generously. Do this on a low humidity day. Acetone will cause the surface to get cold as it evaporates and you can get sort of condensation....
YMMV
Norm

 

[OzHybrid]

A few meters of filament to how much acetone? Can you give a ratio? Using mass of filament, preferably, since filament diameter is not a constant (as I understand it).
That's essentially Testers. There's is a different solvent, but the same idea.

The testors solvent takes longer to evaporate. This allows it to melt the mating parts better. I believe its one of the chloroform family......

 

[jqavins]

OK, now I just have to Google it.

<tap tap tappity tap>

According to the SDS I got from Tertors, item 3501X (red tube, plastic models) consists of toluene, 50 to 75%; and polystyrene, 25 to 50%.

Item 3505X (green tube, balsa models) is Isopropyl Acetate, 10-25% ; Toluene, 10-25% ; Acetone, 10-25% ; Nitrocellulose, 10-25% ; n-Butyl Acetate, 10-25% ; 2-Propano, 2.5-10% ; Ethanol, 1.0-2.5% ; 2,2,4-Trimethyl-1,3-Pentanediol Diisobutyrate, 1.0-2.5% ; Naphtha, Petroleum, Hydrotreated Light, 1.0-2.5% ; and Allyl Isothiocyanate, 0.1-1.0%. That makes it a distant cousin of good old NC lacquer.

 

[rharshberger]

Nevermind....

 

[OzHybrid]

OK, now I just have to Google it.

<tap tap tappity tap>

According to the SDS I got from Tertors, item 3501X (red tube, plastic models) consists of toluene, 50 to 75%; and polystyrene, 25 to 50%.

Item 3505X (green tube, balsa models) is Isopropyl Acetate, 10-25% ; Toluene, 10-25% ; Acetone, 10-25% ; Nitrocellulose, 10-25% ; n-Butyl Acetate, 10-25% ; 2-Propano, 2.5-10% ; Ethanol, 1.0-2.5% ; 2,2,4-Trimethyl-1,3-Pentanediol Diisobutyrate, 1.0-2.5% ; Naphtha, Petroleum, Hydrotreated Light, 1.0-2.5% ; and Allyl Isothiocyanate, 0.1-1.0%. That makes it a distant cousin of good old NC lacquer.

Pretty sure mine had the dichloromethane in the 60's...... Seems there's a range depending on your brand and timeline. Tippy Tappy......

 

[rharshberger]

Pretty sure mine had the dichloromethane in the 60's...... Seems there's a range depending on your brand and timeline. Tippy Tappy......

DCM is nasty stuff, but it works amazing, especially stripping paint to bad its hard to come these days.

 

[OzHybrid]

DCM is nasty stuff, but it works amazing, especially stripping paint to bad its hard to come these days.

Tippy Tappy etc etc.... Seems it's readily available here in OZ

 

[Ronz Rocketz]

Tippy Tappy etc etc.... Seems it's readily available here in OZView attachment 507523

That stuff is almost as bad as tributylburnyourlipsoff and methylethyldeath.

From the SDS:

Warning! Methylene chloride is metabolically converted to carbon monoxide after systemic absorption, which yields increased concentrations of carboxyhemoglobin in the blood. Harmful if swallowed. Causes eye, skin, and respiratory tract irritation. May be harmful if inhaled. Potential cancer hazard. This substance has caused adverse reproductive and fetal effects in animals. May cause central nervous system effects. May cause kidney damage.​

Target Organs: Blood, central nervous system.​

​

Potential Health Effects​

Eye: Contact with eyes may cause severe irritation, and possible eye burns.​

Skin: May be absorbed through the skin. Causes irritation with burning pain, itching, and redness. Prolonged exposure may result in skin burns.​

Ingestion: Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause kidney damage. May cause central nervous system depression, characterized by excitement, followed by headache, dizziness, drowsiness, and nausea. Advanced stages may cause collapse, unconsciousness, coma and possible death due to respiratory failure. May cause carboxyhemoglobinemia.​

Inhalation: Inhalation of high concentrations may cause central nervous system effects characterized by nausea, headache, dizziness, unconsciousness and coma. Causes respiratory tract irritation. May cause narcotic effects in high concentration. Vapors may cause dizziness or suffocation. May cause blood changes. Overexposure may cause an increase in carboxyhemoglobin levels in the blood. Can produce delayed pulmonary edema. Because of its high volatility, airborne concentrations of methylene chloride can accumulate in poorly ventilated areas. Odor is a poor indicator of possibly dangerous air concentrations of methylene chloride.​

Chronic: Possible cancer hazard based on tests with laboratory animals. Prolonged or repeated skin contact may cause dermatitis. May cause reproductive and fetal effects. Laboratory experiments have resulted in mutagenic effects. Chronic exposure may cause lung, liver, and pancreatic tumors. May cause conjunctivitis and/or corneal burns.​

Thin CA is considered an irritant except when it bonds your eyelids to your eyeballs.

INHALATION Irritating to respiratory system. May cause damage to mucous membranes in nose, throat, lungs and bronchial system.​

INGESTION May cause discomfort if swallowed. May cause stomach pain or vomiting.​

SKIN CONTACT Irritating to skin. Prolonged contact may cause redness, irritation and dry skin.​

EYE CONTACT May cause severe irritation to eyes. Irritation, burning, lachrymation, blurred vision after liquid splash.​

 

[rharshberger]

That stuff is almost as bad as tributylburnyourlipsoff and methylethyldeath.

From the SDS:

Warning! Methylene chloride is metabolically converted to carbon monoxide after systemic absorption, which yields increased concentrations of carboxyhemoglobin in the blood. Harmful if swallowed. Causes eye, skin, and respiratory tract irritation. May be harmful if inhaled. Potential cancer hazard. This substance has caused adverse reproductive and fetal effects in animals. May cause central nervous system effects. May cause kidney damage.​

Target Organs: Blood, central nervous system.​

​

Potential Health Effects​

Eye: Contact with eyes may cause severe irritation, and possible eye burns.​

Skin: May be absorbed through the skin. Causes irritation with burning pain, itching, and redness. Prolonged exposure may result in skin burns.​

Ingestion: Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause kidney damage. May cause central nervous system depression, characterized by excitement, followed by headache, dizziness, drowsiness, and nausea. Advanced stages may cause collapse, unconsciousness, coma and possible death due to respiratory failure. May cause carboxyhemoglobinemia.​

Inhalation: Inhalation of high concentrations may cause central nervous system effects characterized by nausea, headache, dizziness, unconsciousness and coma. Causes respiratory tract irritation. May cause narcotic effects in high concentration. Vapors may cause dizziness or suffocation. May cause blood changes. Overexposure may cause an increase in carboxyhemoglobin levels in the blood. Can produce delayed pulmonary edema. Because of its high volatility, airborne concentrations of methylene chloride can accumulate in poorly ventilated areas. Odor is a poor indicator of possibly dangerous air concentrations of methylene chloride.​

Chronic: Possible cancer hazard based on tests with laboratory animals. Prolonged or repeated skin contact may cause dermatitis. May cause reproductive and fetal effects. Laboratory experiments have resulted in mutagenic effects. Chronic exposure may cause lung, liver, and pancreatic tumors. May cause conjunctivitis and/or corneal burns.​

Thin CA is considered an irritant except when it bonds your eyelids to your eyeballs.

INHALATION Irritating to respiratory system. May cause damage to mucous membranes in nose, throat, lungs and bronchial system.​

INGESTION May cause discomfort if swallowed. May cause stomach pain or vomiting.​

SKIN CONTACT Irritating to skin. Prolonged contact may cause redness, irritation and dry skin.​

EYE CONTACT May cause severe irritation to eyes. Irritation, burning, lachrymation, blurred vision after liquid splash.​

MethylEthylBadStuff was always my favorite from Hazardous Waste Operators Class. DCM is best used in paint stripping and then only with the right protective gear.

 

[Ronz Rocketz]

MethylEthylBadStuff was always my favorite from Hazardous Waste Operators Class. DCM is best used in paint stripping and then only with the right protective gear.

I visited a helicopter maintenance shop years ago. They had buckets of methylene chloride open throughout the hangar. I took pictures of open MC cups next to coffee cups on their tool benches. They said they have to use MC because it's worked for decades so why should they switch to a healthier solvent. I told the Underwriter that these guys were nuts.

 

[Kelly]

I've used Minwax Wood hardener (which is essentially acrylic dissolved in acetone) to stiffen select areas of cardboard tubes - like the ends, around mounting holes, etc. I think acrylic actually has better mechanical properties than ABS; it would be interesting to compare your method with Minwax (or a homemade version) to see if there are any differences.

 

[jqavins]

I told the Underwriter that these guys were nuts.

Perhaps you meant to write undertaker?

 

[Marc_G]

Love this thread.

Similar to @RocketScientistAustralia 's method, I dissolve polystyrene (waste styrofoam) into either Acetone or MethylEthylKetone (MEK) and use for impregnating/stiffening purposes. Either super thin as described above for maximum penetration or thicker mixes for grain filling.

Mostly I just like melting plastic into solvents.

 

[OzHybrid]

From Wikepedia:_ ABS is a terpolymer made by polymerizing styrene and acrylonitrile in the presence of polybutadiene. The proportions can vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene.
Abs is basically a hybrid of all the plastics mentioned. So we're all using a version of the same thing. Funny we've all done the same thing independently. Who gets the patent? Obviously the strength you get is going to be dependant on the penetration into the cardboard you get and the total amount of plastic. As we're all using random cardboard tubes it would be difficult to get comparisons going. It added 1% weight to the tube I did and certainly gave a significant increase in hardness feel. Might even increase the paintability of the tube. So maybe the increase in weight is offset by the reduced amount of filler/ primer needed.
Norm

 

[jqavins]

OK, so, source a bunch of tubes, all of the same type and same manufacturer. Divide them into three or four groups. From the first group, set one or more aside. Mix up a single large batch solution using a small ratio of polymer to solvent. Apply that to all the other tubes in the group, and tightly seal the solution. Set one or more aside. After they have dried, do a second application to the remaining tubes, seal the bottle, set one or more aside. Repeat until all tubes in the group have been given their last treatments.

Weigh the tubes and measure their resistance to deforming, and subsequently to folding, under a transverse rod centered between two supports with unchanging spacing.

Repeat the entire process with the other groups, using a slightly higher polymer to solvent ratio each time.

Analyze the data, considering the stiffness, strength, and weight increases as functions of mixture ratio and number of applications. Consider, as well, stiffness and strength increase as a function of weight increase.

Please notice that the above is written entirely in the imperative tense. Meaning I'm not going to do it, I'm telling someone else to.

 

[OzHybrid]

Good luck with that. Let me know the results