Advice About Disposable Wadding Alternatives in LPRs

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mh9162013

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I'm working on my next LPR project. It'll probably have a BT-20 or BT-50 body diameter, or maybe a combination of both with a BT-20 to BT-50 transition. I also want to avoid using disposable wadding. I dislike the idea of potential "litter" when I can't recover all the pieces used during a launch and I dislike even more the fact that I have to spend money on disposable wadding.

So it looks like I have two alternatives: resusable wadding (like Dinochutes 3x3 chute protector) or an ejection charge baffle. And now I have a few questions about these. Please note these questions are asked within the LPR context and with the use of a plastic or nylon parachute (12" or so) recovery system.

1. If using reusable wadding, instead of threading the shock cord through a slit in the corner of the wadding, could I use a snap swivel or small metal keyring loop to attach the protector to the shock cord, but still allow it to slide up and down the shock cord? I figure this would make it much easier to remove the reusable wadding for cleaning and transfer to another LPR rocket.

2. Will a 3x3 Dinochutes reusable chute protector work in a BT-20 model rocket? I wonder if it'll be too bulky and my only option is the an ejection charge baffle.

3. Does anyone believe the baffle or reusable wadding has an inherent advantage over the other when installed in a BT-50 or BT-20 main body tube? If so, why?

I've done some research on both, and it seems like no system is perfect in terms of fully protecting the parachute and payload (like an altimeter). I'm trying to decide which is better for me and if using both is also a viable option (yes, I know there'll be a weight penalty, but performance is a tertiary consideration in this rocket's design).

Thanks ahead for all your advice.
 
The 3x3 kevlar is too big and heavy

Baffles work well and are lightweight. Drill small holes in 2 BT20 diameter plates. if the holes don't line up, the ejection gas pressure will get through, but the burning hot particles will not.

Glue the plates above the motor, with some space between them, say 1 inch or so.

You can leave the space between baffle plates open, but also consider putting in a small piece of a stainless steel scrubber. Only use stainless steel, SOS iron wool type pads will burn!


One more option, a piston that slides in the airframe tube, between the top of the motor tube and below the parachute. I'm not a fan because the piston eventually jams on the particles left over in the airframe.
 
Dog barf works well and we have a bucket for everyone to use at every launch. As a solo LPR flyer it may take you a while to make a significant dent in a bale of blow in attic insulation, but it works well and is environmentally safe. It does produce "litter", but one rain and the stuff dissolves. Plus it comes out in such small pieces that no one really notices it on the ground.

Look for a damaged package at a home improvement store and make them an offer.
 
Dog barf works well and we have a bucket for everyone to use at every launch. As a solo LPR flyer it may take you a while to make a significant dent in a bale of blow in attic insulation, but it works well and is environmentally safe. It does produce "litter", but one rain and the stuff dissolves. Plus it comes out in such small pieces that no one really notices it on the ground.

Look for a damaged package at a home improvement store and make them an offer.
I can echo the dog barf endorsement. DART uses the stuff extensively and I’ve never had a problem outside of user error. Usually my problem is that I don’t use enough.

Make two slightly compacted balls of the stuff about the diameter of the body tube, loosen them back up into the material’s original density, then stuff the material in the tube.

You can even insert it from the rear if you wish. I find this trick valuable with cruddy tubes and uncooperative chutes.
 
I'm not a fan of dog barf either @mh9162013

Use a crepe paper streamer with a penny tape to it. You roll the streamer really tight so it's a slip fit into the body tube. Put the streamer in, set the penny on top and then shove it down the tube so it's sets right above the motor, then pack the chute in.

The streamer falls to earth after apogee, and you pick it up and reuse it. It also helps in tracking the direction of the rocket.

It won't work with an Estes tri-fold style shock chord mount that is near the nose cone though, you need to use a motor retained shock chord mount, or bury the Estes style mount down deep into the body tube.

You can get the crepe paper streamer @ Walmart and it's flame resistant. I'd suggest testing it's flame resistance.

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I have had Estes Recovery Wadding TWICE in the past year burn an ember all the way to the ground. I will ONLY use it when conditions are WET. I use "Dog Barf" more and I'm now installing Ejection Baffles on every rocket I now make. I've had Great results with a "Parachute Bucket" in my Estes V-2 made from a used small Yogurt Cup. I'm starting to experiment with the Nomex parachute "blankets" but haven't really gotten out with them yet. Great Post! Thanks for starting this topic!!!
 
For now, I think I'm going to go with a 3x3 Dino Chutes reusable recovery wadding and see how that works in my BT-50 LPRs then go from there. Will probably try an ejection charge baffle next.
 
For now, I think I'm going to go with a 3x3 Dino Chutes reusable recovery wadding and see how that works in my BT-50 LPRs then go from there. Will probably try an ejection charge baffle next.

If you are doing research on baffles, Apogee's Peak of Flight has run several articles.

Here is the archive; search for 'baffle'. https://www.apogeerockets.com/PeakOfFlight/Archive

Issue 129 is a good place to start; it contains several different types of baffle designs.
https://www.apogeerockets.com/education/downloads/Newsletter129.pdf
 
I'm not a fan of dog barf either @mh9162013

Use a crepe paper streamer with a penny tape to it. You roll the streamer really tight so it's a slip fit into the body tube. Put the streamer in, set the penny on top and then shove it down the tube so it's sets right above the motor, then pack the chute in.

The streamer falls to earth after apogee, and you pick it up and reuse it. It also helps in tracking the direction of the rocket.

It won't work with an Estes tri-fold style shock chord mount that is near the nose cone though, you need to use a motor retained shock chord mount, or bury the Estes style mount down deep into the body tube.

You can get the crepe paper streamer @ Walmart and it's flame resistant. I'd suggest testing it's flame resistance.

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What is your problem with dog barf? It seems like a win win for everybody.
 
What is your problem with dog barf? It seems like a win win for everybody.

To add to what lakeroadster said, dog barf is also something you have to pay for when it runs out.

Engines are expensive enough. I see no reason to add another cost to each launch.
 
A lifetime supply for 5 bucks. Seriously?
Exactly, I have yet to fly with a club where dog barf is not allowed or even Estes/Quest wadding. Both are simply treated paper and break down completely and quickly in the environment (not instantly but they do breakdown quickly), we fly on our field monthly and see zero signs of either dog barf or Estes/Quest wadding and we live in a relatively dry area with little rainfall, the fields are irrigated though.
 
A lifetime supply for 5 bucks. Seriously?

Yes, I'm serious.

I'll tell you what. Go take a $5 and rip it up and throw it away. But before you complain, remind yourself that it's only $5 and nothing to be bothered about.

So there's the principle of paying for something that I shouldn't have to pay for. And don't forget how costs add up. If you take the "oh, it's only $X, so I can waste it" attitude, it's bound to apply to another situation where you waste money. Pretty soon, it adds up to a noticeable amount. Kind of like hardcare hikers who are gram weenies when it comes to their hiking equipment. Sure, 7 grams here and 90 grams there aren't a big deal. But that's just 2 items. You could be carrying dozens of items during a hike and pretty soon, we're dealing with a few kilos over the course of a few hundred miles.

But then there's the point I already mentioned about how I don't like the idea of having a few pieces of wadding or another parachute protection materials around the launch site and not properly disposed of. The only thing I'm recovering after a launch should be my rocket.
 
Another reason not to use wadding or dog barf besides cost and littering: there's the extra time it takes use it. No, it's not much time, but it's wasted time that can be avoided, so why not?
 
I use dog barf, but I find it to be a PITA. One, it's messy and gets all over the place if you are prepping at home. Second, it isn't the easiest to pack - too little and you get embers pushing through, too much packed too tight, you can get a failed deployment; I've had both. I use Qualman baffles on BT-50's to BT-80's if the airframe is long enough. I've even made a custom baffle for my 4" NCR Patriot when I needed to do a major repair. No wadding, no dog barf and no Nomex blanket in a 4" rocket is a joy.
 
Okay, to provide some context for the "nasty chemicals": very little (if ANY) of the sodium hydroxide, sodium sulfide, or bleaching agents remain by the time the newsprint is actually printed. In fact, any residual sodium hydroxide would have been long since converted to sodium carbonate, a milder base that is actually good for most soil; most soil needs "sweetening" with a base such as lime or limestone anyway. Sodium sulfide and bleaching agents are too reactive to remain on the paper except in virtually undetectable amounts.

The amount of ink in newsprint is pretty small compared to the weight of the newsprint. Nonetheless, any organic solvents have long since evaporated. I can't imagine that there's much of any of the materials except the borax and boric acid. Boric acid is an extremely weak acid and borax is nicely basic, so I doubt that they would cause any serious problem for soil---especially considering the amount of dog barf used at even the largest launch.

Bottom line: the amount of dog barf used by the largest launch in an entire launch season, or in a dozen seasons, is unlikely to cause any problems whatever with soil. Most of what's in the dog barf couldn't be detected in the soil except maybe with mass spectrometry or some other highly sensitive instrumentation.

Best -- Terry
PS: Lakeroadster, I'm not hollering at you, you've merely quoted a couple of sentences. But here you see an example of how the original source's carefully phrased (mis)information, or limited information, can go around the world while the truth is still getting its pants on. It takes a lot of explanation to overcome a bogus claim, especially in chemistry where one can induce fear simply by naming chemicals. (Remember: EVERYthing that you can see, smell, taste, or touch is either a chemical or is made of chemicals. No, that is not in any way an exaggeration.)
 
To add to what lakeroadster said, dog barf is also something you have to pay for when it runs out.

Engines are expensive enough. I see no reason to add another cost to each launch.

That's kind of absurd. Nomex blankets and materials to make baffles are going to cost you more than dog barf. Like jimzcatz said, lifetime supply for $5. A dinochutes 3x3 blanket already costs more than that with shipping.

Another reason not to use wadding or dog barf besides cost and littering: there's the extra time it takes use it. No, it's not much time, but it's wasted time that can be avoided, so why not?

It takes no more time to use than a Nomex blanket.

You do you and if you would rather use baffles and nomex than dog barf, that's fine. I just find your reasoning to be a bit shaky.
 
Okay, to provide some context for the "nasty chemicals": very little (if ANY) of the sodium hydroxide, sodium sulfide, or bleaching agents remain by the time the newsprint is actually printed. In fact, any residual sodium hydroxide would have been long since converted to sodium carbonate, a milder base that is actually good for most soil; most soil needs "sweetening" with a base such as lime or limestone anyway. Sodium sulfide and bleaching agents are too reactive to remain on the paper except in virtually undetectable amounts.

The amount of ink in newsprint is pretty small compared to the weight of the newsprint. Nonetheless, any organic solvents have long since evaporated. I can't imagine that there's much of any of the materials except the borax and boric acid. Boric acid is an extremely weak acid and borax is nicely basic, so I doubt that they would cause any serious problem for soil---especially considering the amount of dog barf used at even the largest launch.

Bottom line: the amount of dog barf used by the largest launch in an entire launch season, or in a dozen seasons, is unlikely to cause any problems whatever with soil. Most of what's in the dog barf couldn't be detected in the soil except maybe with mass spectrometry or some other highly sensitive instrumentation.

Best -- Terry
PS: Lakeroadster, I'm not hollering at you, you've merely quoted a couple of sentences. But here you see an example of how the original source's carefully phrased (mis)information, or limited information, can go around the world while the truth is still getting its pants on. It takes a lot of explanation to overcome a bogus claim, especially in chemistry where one can induce fear simply by naming chemicals. (Remember: EVERYthing that you can see, smell, taste, or touch is either a chemical or is made of chemicals. No, that is not in any way an exaggeration.)

Your statement "I doubt that they would cause any serious problem for soil" is reason enough to not use it, well unless you're launching on your own property, then do as you please.

Would you be ok with your dog eating it? Or wildlife? I'm not ok with either.

Again, for me, I follow the mantra of "Pack it in, Pack it out." There is a low-cost alternative, I choose that option.

When I was a kid, we launched in Dad or Grandpa's hay fields. Anything in that field ended up in the bales of hay. We used crepe paper streamers for wadding way back then. It worked then, it works now.
 
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That's kind of absurd. Nomex blankets and materials to make baffles are going to cost you more than dog barf. Like jimzcatz said, lifetime supply for $5. A dinochutes 3x3 blanket already costs more than that with shipping.



It takes no more time to use than a Nomex blanket.

You do you and if you would rather use baffles and nomex than dog barf, that's fine. I just find your reasoning to be a bit shaky.

A 3v3 Dino Chutes protector is about $5-6. If ordered with something else, the shipping is free. Larger protectors will be more expensive, but then they'll be used in rockets that require more dog barf.

When you use dog barf, do you keep a pouch of it on you at the launch site? I presume you take your rocket to you range box and in addition to loading an engine you go into your range box to grab a handful of dog barf. Then you have pack it into your rocket. Then you pack up your parachute and shock cord. I've never used parachute protectors before, but with a 3v3 sheet in a BT-50 rocket, I'm betting $5-$10 that it'll take longer to get out the dog barf, pack it into the BT-50 tube (or maybe a BT-60 tube), then pack the parachute and shock cord and put those into the tube.

With a parachute protector, the only extra work your'e doing is making sure it's as close to the body tube as possible (by just sliding it down the shock cord in 2 seconds), then when you're reading to pack in the parachute (something you have to do no matter what), you're at least partially wrapping the parachute with the protector.

But you all keep missing the big picture. It's not cost. It's not litter. It's not time (packing and picking up the pieces of wadding or dog barf on the field). It's all three. Then there are other reasons.

1. Something extra to forget. If your protector is already attached to your rocket, the only thing to forget is the rocket itself.

2. Something else to carry around and store. For an LPR, I have no idea how much volume of lifetime supply of dog barf would be, but I imagine it would be at least the size of a queen-size pillow case. Just another thing to store. As for carrying it around, I imagine most people don't carry around their entire supply of dog barf to their launches, but that still something to take up extra space in your car, range box or bag.

3. It's messy.

4. Availability and ease of purchase to buy what you need. Yes, dog barf is sold by various online model rocket venders. But not at the price of $5 for a lifetime supply. Ok, so go to your local harwdware store. But then you're paying more than $5 for dog barf in an amount you don't need.

Any single one of these is reasons enough to choose something else over dog barf. If you want to use it, that's fine. Yet with so many reasons not to use dog barf, I don't understand why it's being pushed SO HARD.
 
Your statement "I doubt that they would cause any serious problem for soil" is reason enough to not use it, well unless you're launching on your own property, then do as you please.

Would you be ok with your dog eating it? Or wildlife? I'm not ok with either.

Again, for me, I follow the mantra of "Pack it in, Pack it out." There is a low-cost alternative, I choose that option.

When I was a kid, we launched in Dad or Grandpa's hay fields. Anything in that field ended up in the bales of hay. We used crepe paper streamers for wadding way back then. It worked then, it works now.
Whatever works for you is good, no worries. However, I strongly suspect that you'd find that the same chemicals that go into newsprint and dog barf are used in crepe paper. The paper is creped near the end of the manufacturing process by adding sizing. But if you collect the crepe paper afterward it's not a problem. And certainly crepe paper, especially streamers, are a lot easier to find on the field than used dog barf.

Best -- Terry
 
Wondering: does anyone know whether today's parachute protectors are made from nomex alone, or from a nomex-cotton blend? Most of what I've seen on eBay is nomex-cotton cloth. It's quite inexpensive, though some is obviously too heavy-weight for parachute protectors.
 
Whatever works for you is good, no worries. However, I strongly suspect that you'd find that the same chemicals that go into newsprint and dog barf are used in crepe paper. The paper is creped near the end of the manufacturing process by adding sizing. But if you collect the crepe paper afterward it's not a problem. And certainly crepe paper, especially streamers, are a lot easier to find on the field than used dog barf.

Best -- Terry
MSDS for #11208 - CREPE PAPER (dick-blick.com)

SECTION 1 – PRODUCT AND COMPANY INFORMATION (greenfiber.com)
 
Wondering: does anyone know whether today's parachute protectors are made from nomex alone, or from a nomex-cotton blend? Most of what I've seen on eBay is nomex-cotton cloth. It's quite inexpensive, though some is obviously too heavy-weight for parachute protectors.

The ones I'm interested in are from Dino Chutes and they are not made out of Nomex...at least not completely.
 
"Yes, I'm serious.
I'll tell you what. Go take a $5 and rip it up and throw it away. But before you complain, remind yourself that it's only $5 and nothing to be bothered about"


I don't mean to be contentious here but you just spent ~$3.96 per motor, (I dont fly much LPR, but a 3-Pack of C6-5 is $11.90 on Amazon) and which are used only once. Assuming you fly the entire package, that is <2x the $5.00 you mentioned. (HPR gets a just a tiny, little-bit, not worth mentioning really.... more expensive!) And one is litterally lighting those $$ on fire!

Envronmentally, BP motors generate combsution gasses, and I am sure those can't be somehtning you'd want to breathe? (Althouigh I am a non-smoker so I dont get that whole concept in the first place!) and lets not even talk about AP motors, which are available in 18mm... (I am a EE, not a Chem E, so I am not an expert on the properties of the smoke/compbustion gasses, but they cant be as healthe as fresh. clean mountain air !)

So while I understand, and don't disagree with your "Leave No Trace" flying, Dog Barf & Wadding are biodegrable and prehaps not such a concern?

Oh and by the way, I have a few rockets that use baffles with the Stainless "scrubber", an HP as well, and I am always surprised that they work as well as they do!
They add weight of course, so in LPR, maybe not useful, but MPR and up, they may be an option. (I still use a blakent though)

Anyway Happy flying!
 
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