That Tape Thread

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lakeroadster

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I was looking to find some actual data on some of the 3M tapes that I use. More specifically to gain knowledge which would be best for motor retention.

I couldn't find any online Data Sheets so I contacted them via email to get some data, and had to call them for other data. I'm hoping to get the rest of the data to fill the chart below.

Updated 2021-05-21.

I stumbled upon this plethora of data.... you would have thought the good folks at 3M would have turned me onto their 64 page 3M Masking & Surface Protection Products brochure when I contacted them looking for technical data sheets? Go figure?

Here are a couple screen shots.

3M Masking Tape Specifications.jpg
3M Aluminum Tape Specifications.jpg
Peel.jpg
Shear.jpg
Tensile.jpg
 

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Funkworks

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I don’t quite see how these numbers help with motor retention.

However, I could imagine an experiment to measure friction coefficients. That might be fun and maybe practical.
 

mjennings

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Interesting. As far as retention goes I'd expect the shear and peel values to be more useful than the tension (for the thrust phase), although tension will be a player for the ejection charge
 

lakeroadster

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I don’t quite see how these numbers help with motor retention.

However, I could imagine an experiment to measure friction coefficients. That might be fun and maybe practical.
I added diagrams that help define the test methods to the original post.

Shear, Tensile and Peel are all factors that come into play with motor retention.
 

dr wogz

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I think it also depends on how & where this tape is being used..

I have 'friction fitted' motors, and I've used the regular white / crème crepe tape, but I wrap the motor; then it is held in place jut by the "interference" of the motor & motor tube (the tape is more of a wedge) I've also used the blue & green tapes for this (although they tend to 'ball up' when removing the motor)

I have also taped the outside of the motor to the exposed end of the motor mount tube. This is in shear. (and other I know have done this too..)

Shear also relies on the amount of surface area in contact: Using teh green tape will suffice, assuming you have 1" of motor and 1" of MMT to tape up; and are using a 2" wide piece. the same shear will be 1/4" for both, if using packing or duct tape..
 

Mike Haberer

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If you are using the tape for friction fit you don't care about shear or tension, you want the surface of the tape to be "frictiony". You wouldn't want to use packing tape! Crepe would probably be the roughest, hence the best.

If you are wrapping around the MMT and the end of the protruding motor, you want STICKY tape. Certainly not green painters tape. It is designed to be NOT too sticky. Same applies if you use tape to make thrust rings on BP motors. For thrust rings I would use Gorilla duct tape trimmed to 1/4" thick with a straight edge and a Xacto. Gorilla is the stickiest tape I've run across. It's the only duct tape I buy anymore.

I don't think shear or tension strength matter all that much. More important are the factors noted.
 
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BABAR

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If you are talking friction fit, cheap masking tape works great. Don’t just wrap it around, make a couple redundant “pleats” where the tape doubles back on itself and makes “flaps.” Uses LESS tape (less weight,if that is an issue), usually the hard part is getting the motor back out (I find paradoxically it is easier to do this while the motor is still “hot” after the flight.

if you have at least 1/2 inch motor mount sticking out, you can do great with Electrical (Vinyl) Tape.

first, prewrap the outer surface of the motor mount with either cellophane (scotch) tape if you want to save the original color. I use Mylar, it adds color. this protects the undersurface from the wraps of tape you will presumably be putting on and taking off with each flight. Wrap the tape the OPPOSITE WAY/direction from the way you plan on applying the electrical tape wrap. Best way to figure this out is grab the rocket and pretend to out it on, this is your “natural” direction, then for this tape layer go the OTHER way.

motor block should be positioned so only 1/2 inch sticks out.

when prepping, place the motor and do two wraps of electrical tape. Stretch it so it is tight. You may have a little hanging over the tail end of the motor, you can press this in and it will actually extend a bit over the motor base.

because of the stretch, this gives a really tight hold, but is pretty easy to remove, especially if you laid the base layer on the motor mount as recommended,
 

mooffle

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Tsmith may be onto something here. tape may do great at the 3 measurements mentioned but if the adhesive gets hot and slippery during motor burn then there may not be retention at burn out or worse blow the motor entirely and not the laundry, especially if wrapped around the mount.
 

BABAR

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Tsmith may be onto something here. tape may do great at the 3 measurements mentioned but if the adhesive gets hot and slippery during motor burn then there may not be retention at burn out or worse blow the motor entirely and not the laundry, especially if wrapped around the mount.
For low power, I don’t think the heat transfer is fast enough to heat up the tape BEFORE ejection, I know the outside of the cases definitely get hot by the time the rocket is recovered. (and I remember old Quest C Motors in minimum diameter rockets actually “browning” the white paint of the body over the motor). I think the old Quest motors had thinner cardboard casings.
 

shockie

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Tsmith may be onto something here. tape may do great at the 3 measurements mentioned but if the adhesive gets hot and slippery during motor burn then there may not be retention at burn out or worse blow the motor entirely and not the laundry, especially if wrapped around the mount.
seems to me that is the motor surface got hot enough, the adhesive of the tape may flow instead of actually stick..... this of course depends on the adhesive type... also seems that a plastic or vinyl tape would soften, melt or flow before a paper based tape like masking tape would. I've always used regular white/beige paper masking tape with no problems. But my experience is limited to LPR/MPR.
 

BABAR

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No argument electrical tape failed in this case. I find the charred bit of fin near the motor interesting. Wondering if the back blast off the deflector plate melted the tape. Suspect ANY tape other than aluminum tape might have suffered the same fate. I wonder what the deflector tape set up was (motor against flat plate without a standoff or something angled to keep the initial blow back gasses from frying the tape?)

each of us can only speak toward our own experience. I fly nearly exclusively 13 mm A through 24 mm D motors, and haven’t had a problem with electrical tape, although I frequently use masking tape. Interestingly, I have had a MOTOR HOOK fail and spit a 24 mm D casing.

last E I used was a single use E on my Interceptor-E, that had a motor hook, I added masking tape AROUND the hook and fortunately everything turned out okay.

in my experience with friction fit and the above motor hook failures, I think a significant factor was recovery gear packing. If the wadding, chute, and/or nose cone are tight, there is an increased risk SOMETHING is going to fail. As my signature block says, learn from your own mistakes and preferably those of others. Sometimes I will prepack my stuff before a launch if I have several rockets, I put tape on the nose cone body tube joint to keep them from popping out in transport. One launch I failed to take OFF the tape holding The nose cone on. Very public lawn dart with an 18 mm minimum diameter rocket, flown many times with friction fit without a failure. The motor spit (I guess alternative was ruptured tube, that nose cone wasn’t going to come off.)

I now purchased some pink masking tape, and when I do this, I double back and leave a 4 inch “tag” (my poor mans equivalent to a “Remove before flight, you idjit!” tag) that HOPEFULLY will remind me to pull it off before I stick it on the pad.

tape I think is fine for low power, due to higher stresses and maybe more heat, may not be best choice once you get into E and Above. IMO even motor hooks alone are not the greatest choice after a D.
 

caveduck

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The shear info is actually useful for a completely different purpose - superglue + tape fixturing for machining. Lots of people suggest the blue painters' tape for that, but the shear value is low and the adhesive flows rather easily. For me this has meant that I can't use the blue tape for small parts like 38/54mm avbay caps - any kind of aggressive cut will just push the part sideways off the fixture plate. So I'm interested in any kind of paper based tape that has an adhesive shear rating more like that of the packing tape.

For motor retention (wrap-around-the-outside flavor) I've used both Mylar and Kapton tape with good results for LPR. Electrical tape flows like crazy; I have a roll of it that turned into a cone just under gravity.
 

Joekeyo

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I twist the engine ( think "unscrew") when I remove the engine. This seems to reduce the "bunching up" problem mentioned earlier. I use blue Tape exclusively and have many scratch rockets that use friction fit. Usually my recovery problems are not spit motors. Sometimes I use pliers to remove used motors. My $ 0.02.
 

mooffle

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I twist the engine ( think "unscrew") when I remove the engine. This seems to reduce the "bunching up" problem mentioned earlier. I use blue Tape exclusively and have many scratch rockets that use friction fit. Usually my recovery problems are not spit motors. Sometimes I use pliers to remove used motors. My $ 0.02.
I do this too with masking tape, along with wrapping it in a helical pattern. It ends up almost 'threaded' that way.
 

rklapp

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No argument electrical tape failed in this case. I find the charred bit of fin near the motor interesting. Wondering if the back blast off the deflector plate melted the tape. Suspect ANY tape other than aluminum tape might have suffered the same fate. I wonder what the deflector tape set up was (motor against flat plate without a standoff or something angled to keep the initial blow back gasses from frying the tape?)

each of us can only speak toward our own experience. I fly nearly exclusively 13 mm A through 24 mm D motors, and haven’t had a problem with electrical tape, although I frequently use masking tape. Interestingly, I have had a MOTOR HOOK fail and spit a 24 mm D casing.

last E I used was a single use E on my Interceptor-E, that had a motor hook, I added masking tape AROUND the hook and fortunately everything turned out okay.

in my experience with friction fit and the above motor hook failures, I think a significant factor was recovery gear packing. If the wadding, chute, and/or nose cone are tight, there is an increased risk SOMETHING is going to fail. As my signature block says, learn from your own mistakes and preferably those of others. Sometimes I will prepack my stuff before a launch if I have several rockets, I put tape on the nose cone body tube joint to keep them from popping out in transport. One launch I failed to take OFF the tape holding The nose cone on. Very public lawn dart with an 18 mm minimum diameter rocket, flown many times with friction fit without a failure. The motor spit (I guess alternative was ruptured tube, that nose cone wasn’t going to come off.)

I now purchased some pink masking tape, and when I do this, I double back and leave a 4 inch “tag” (my poor mans equivalent to a “Remove before flight, you idjit!” tag) that HOPEFULLY will remind me to pull it off before I stick it on the pad.

tape I think is fine for low power, due to higher stresses and maybe more heat, may not be best choice once you get into E and Above. IMO even motor hooks alone are not the greatest choice after a D.
Perhaps the tape caught on fire after landing and the flames went upward toward the fin...
 

KC3KNM

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The shear info is actually useful for a completely different purpose - superglue + tape fixturing for machining. Lots of people suggest the blue painters' tape for that, but the shear value is low and the adhesive flows rather easily. For me this has meant that I can't use the blue tape for small parts like 38/54mm avbay caps - any kind of aggressive cut will just push the part sideways off the fixture plate. So I'm interested in any kind of paper based tape that has an adhesive shear rating more like that of the packing tape.

For motor retention (wrap-around-the-outside flavor) I've used both Mylar and Kapton tape with good results for LPR. Electrical tape flows like crazy; I have a roll of it that turned into a cone just under gravity.
I use the green 3M 401+ tape for fixturing. I get it in 4” wide rolls. I machine with TSC and full flood coolant and haven’t had issues holding smaller stuff. It does help to leave a small .005”-.008” membrane around parts to maximize the surface area of the tape, and not typically a huge pain as you’re going to be deburring that area anyway.
 

David Schwantz

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None of your given choices are the best. I use aluminum tape. the sticky is way stronger. You can fold it over the rear of the thrust ring. Never had it fail. I hold 54 mm in place like this. The 3M # I use is 425. I do not use it as friction though, on the inside.
 

lakeroadster

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Tsmith may be onto something here. tape may do great at the 3 measurements mentioned but if the adhesive gets hot and slippery during motor burn then there may not be retention at burn out or worse blow the motor entirely and not the laundry, especially if wrapped around the mount.
For low power, I don’t think the heat transfer is fast enough to heat up the tape BEFORE ejection, I know the outside of the cases definitely get hot by the time the rocket is recovered. (and I remember old Quest C Motors in minimum diameter rockets actually “browning” the white paint of the body over the motor). I think the old Quest motors had thinner cardboard casings.
See updated post #1, now includes temperatures.

None of your given choices are the best. I use aluminum tape. the sticky is way stronger. You can fold it over the rear of the thrust ring. Never had it fail. I hold 54 mm in place like this. The 3M # I use is 425. I do not use it as friction though, on the inside.
"The best"... is subjective.

I searched for the data and added the al-you-min-e-um to the list. :computer:
 
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