Nozzle blowout due to waxed tubes?

[dagabu]

The issue is that you can cause some to 'misunderstand' and think that, "Hey, justvisiting says that BP motors dont loose the water content, I guess he has empirical proof because he waited 3 weeks!"

 

This IS important to us because there is a difference between your claim and the science that rules us all. "Wink" or not, your sarcasm about zero moisture content does not help those looking for answers based on facts.

 

Normalized moisture content is just that, for example, a slab of wood (like a freshly pressed BP rocket with moistened BP) may have a moisture content of 40% when cut from dead-fall. It goes into shed and the moisture content drops to its normalized content. Wood, not being hygroscopic, but absorbent, looses moisture and ends up about what the average RH is in the storage space.

 

BP does have absorbent and hygroscopic properties, one such white paper is here: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-77602016000400423

 

This means that indeed! If your BP was "dry" and you added moisture but the hygroscopic nature of KNO3 and C retains the added moisture because it has not yet reached its 'normalized moisture content' for the storage area, it will not "dry out".

 

And, no, BP does not have natural moisture content unless you provide standardized laboratory conditions.

Edited July 29, 2020 by dagabu

[justvisiting]

I DO have empirical proof that my motors lost less than a gram of moisture in 3 weeks. I used the emoticon because people online can infer bad intentions if something is not clarified as a tongue in cheek comment. Sometimes bad intentions are inferred anyway. I can't help that. I do believe that my motors are normalized for my conditions. That's why I said it, not to be smart. I'm all ears if you have any proof to the contrary. As I've said, even if my motors lose a titch more moisture (or ALL of it!), I don't see a problem. Do you see a problem? I don't understand your objection to this thread or the other one you popped into Dagabu. Do you have any information to show that following ANY of my instructions will cause a problem if followed? If so, I'd like to review your information. Thanks.

[SeaMonkey]

It seems that the "normal" moisture content of Black Powder is from

1% to 1.5% until exposed to greater than 75% relative humidity of

the air.

 

The drying of Black Powder has an interesting history.

 

Some Black Powder analysts have conjectured that the moisture

content of the powder is dependent upon the very tiny amounts

of Sodium and Calcium impurity in the Potassium Nitrate. Both

the Calcium and Sodium Nitrates are deliquescent while the

Potassium Nitrate, if sufficiently pure, is not.

 

Another possibility for moisture retention is the type of Charcoal

used. Certain charcoals tend to absorb more moisture than

others. Completely dry powder with 0% moisture has not yet

been possible.

[justvisiting]

The issue is that you can cause some to 'misunderstand' and think that, "Hey, justvisiting says that BP motors dont loose the water content, I guess he has empirical proof because he waited 3 weeks!"

 

This IS important to us because there is a difference between your claim and the science that rules us all. "Wink" or not, your sarcasm about zero moisture content does not help those looking for answers based on facts.

 

Normalized moisture content is just that, for example, a slab of wood (like a freshly pressed BP rocket with moistened BP) may have a moisture content of 40% when cut from dead-fall. It goes into shed and the moisture content drops to its normalized content. Wood, not being hygroscopic, but absorbent, looses moisture and ends up about what the average RH is in the storage space.

 

BP does have absorbent and hygroscopic properties, one such white paper is here: https://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-77602016000400423

 

This means that indeed! If your BP was "dry" and you added moisture but the hygroscopic nature of KNO3 and C retains the added moisture because it has not yet reached its 'normalized moisture content' for the storage area, it will not "dry out".

 

And, no, BP does not have natural moisture content unless you provide standardized laboratory conditions.

 

 

The last line of the quoted post appears to say that black powder has no natural moisture content. But that's not true. Maybe it says something else. Authorities like Sasse, Shimizu, and Dr. Hardt all acknowledge that black powder has a natural moisture content. They further state that black powder is hygroscopic and absorbs moisture in a humid environment. Dagabu has also provided proof that charcoal is also hygroscopic. Another thing that's hygroscopic is the white dextrin used to produce the NEP tubes. Dagabu's concern is moisture LOSS? Dagabu appears to have interrupted a productive discussion for no other reason than to stir up some trouble, with nothing to back up his position, a position which he hasn't even been able to make clear. I think Dagabu just had a bad day, pooped in a couple of threads, and left.

[dagabu]

As typical in this site and others, we run into the member that regards themselves as expert, no credentials, no experiential data over time but bold, brazen, "in your face" rebuttal without data is expounded to beat down those that would dare to differ.

 

Perhaps IF there was the ability or willingness to conduct themselves in a manor that would edify, lift up, increase understanding without always insisting that they were right, we would all learn more, grow more, be safer and find solutions to issues without being shot down by ignorant, boisterous, blowhards.

 

Perhaps if one were to deflate their ego, the rest of us could learn and we could all prosper?

 

I DO have empirical proof that my motors lost less than a gram of moisture in 3 weeks. I used the emoticon because people online can infer bad intentions if something is not clarified as a tongue in cheek comment. Sometimes bad intentions are inferred anyway. I can't help that. I do believe that my motors are normalized for my conditions. That's why I said it, not to be smart. I'm all ears if you have any proof to the contrary. As I've said, even if my motors lose a titch more moisture (or ALL of it!), I don't see a problem. Do you see a problem? I don't understand your objection to this thread or the other one you popped into Dagabu. Do you have any information to show that following ANY of my instructions will cause a problem if followed? If so, I'd like to review your information. Thanks.

[dagabu]

Everybody, gather around, let me tell you the story of JV, "Authorities like Sasse, Shimizu, and Dr. Hardt all acknowledge that black powder has a natural moisture content."

 

Boys and girls, a "natural moisture content" is that which normalizes in the current conditions which it is present.

 

I call BS on you Justvisiting, please LEAVE US!

 

 

 

The last line of the quoted post appears to say that black powder has no natural moisture content. But that's not true. Maybe it says something else. Authorities like Sasse, Shimizu, and Dr. Hardt all acknowledge that black powder has a natural moisture content. They further state that black powder is hygroscopic and absorbs moisture in a humid environment. Dagabu has also provided proof that charcoal is also hygroscopic. Another thing that's hygroscopic is the white dextrin used to produce the NEP tubes. Dagabu's concern is moisture LOSS? Dagabu appears to have interrupted a productive discussion for no other reason than to stir up some trouble, with nothing to back up his position, a position which he hasn't even been able to make clear. I think Dagabu just had a bad day, pooped in a couple of threads, and left.

[justvisiting]

Dagabu- are you going to make a point sometime soon, or just run your mouth. I've shown my work. Let's see yours.

[dagabu]

Bottom line, everybody; moisture normalizes over time in hygroscopic, absorbent and non-absorbent materials.

 

Period.

[justvisiting]

So? What's your point? How does this enlightenment affect the subject being discussed?

[dagabu]

The point sir, is that you are a liar and make schidt up to serve your own ego.

 

Dagabu- are you going to make a point sometime soon, or just run your mouth. I've shown my work. Let's see yours.

Edited July 30, 2020 by dagabu

[justvisiting]

The point sir, is that you are a liar and make schidt up to server your own ego.

 

Name the lie. Explain what I made up. And don't post when you're too drunk to spell. Thanks.

[justvisiting]

When Dagabu came up with a new way to make rocket tooling, I did my best to promote it to anybody that would listen, because it was a good idea.

 

When Dagabu got hurt and somebody added insults to his injury, I stuck up for Dagabu.

 

When collections were taken up for Dagabu, I donated.

 

When Dagabu got himself in hot water with the crew at Fireworking, I helped him work it out.

 

This is the man that turns on me now, and sabotages my efforts publicly.

 

EDITED for spelling.

Edited July 30, 2020 by justvisiting

[dagabu]

I apologize for my harsh comments and I thank you for your support, I thank you for your donations, I appreciate all you do and have done, none of that changes and you do a lot of good work, you contribute much here and FW, I have no issue with your personal findings or observations.

 

The issue is in pushing a hypothesis that is unproven, I asked you not to do that but you insisted. In that light you started in with insults and carried that forward with insults on a PM as well. I bristled and fired back, I should not have done that.

 

As a final thought, then I will back away: There is no need provide examples or prove anything, this data is available in perhaps thousands of posts here and FW about drying of BP, charcoal bases stars etc. All I wanted to point out from the beginning is that water is a tricky little bugger and once bound into a compressed mass, it may take quite a while to leave the grain. Three weeks is only a sample of time, not the complete hypothesis.

 

Now, can we get back to the OP? I have a few hundred Cohetes to press and if there is a method I have missed, I sure would appreciate knowing of it before I start batching BP.

[wildcherryxoxo]

Prove it

 

Ok

 

Well thats not right

 

Ok

 

Its more complicated than that

 

Ok

 

Well really theres no need to prove it

 

Ok

 

 

 

Eat shit dagabu

[Bourbon]

Would a wax nozzle mix help stick to a waxed tube? Or, does that make it more prone to blow out?

 

I also have to ask. Does anyone here predry their ingredients for BP even if they appear to be dry "enough"? I have read in many places around the net that folks will do this ritualistically, no matter what, before weighing them up.

[davidh]

How the hell many waxed tubes do you have??? I think by now you could take donations to buy replacements, just to end this thread...

 

Wipe the wax out of the tubes, pound the nozzles hard (I never press black powder, even 6lb motors), and perhaps add some grog to your nozzle mix (which in my experience is hard on spindles). Ultimately you're just going to have to try and see what works.

Edited July 30, 2020 by davidh

[Bourbon]

I have "never" waxed a tube and never said I did. It was merely curiosity and happened to be what the thread was about.

 

You know the last three times you have replied to anything I say you have been a smart mouth, ass.

 

I'm trying to learn here and if that bothers you, Ignore me!

[dagabu]

A pleasure as always, good to see you have matured nicely.

 

Prove it

Ok

Well thats not right

Ok

Its more complicated than that

Ok

Well really theres no need to prove it

Ok



Eat shit dagabu

[dagabu]

Good question but sadly, no. Not that in small amounts would it hurt anything, several people have done just that and while it hasn't helped nozzle retention, the added wax does help with compaction as it does act as a lubricant and allows the clay to become more plastic when ramming/pressing.

 

Yes, I did 'predry' my charcoal and KNO3 before making BP but only because its hygroscopic and I store the raw ingredients in the pole barn where stuff can pick up a lot of moisture. "Wet" ingredients are more likely to lump up in the ballmill and make a mess out of your meal.

 

I am currently 'hyper milling' (Dave F) my ingredients separately and combining them damp, ricing and allowing to dry for rocket fuel. I add the dextrin to my charcoal if I am coating rice hulls or making burst/lift.

 

Would a wax nozzle mix help stick to a waxed tube? Or, does that make it more prone to blow out?

 

I also have to ask. Does anyone here predry their ingredients for BP even if they appear to be dry "enough"? I have read in many places around the net that folks will do this ritualistically, no matter what, before weighing them up.

[justvisiting]

Dagabu has requested that I acknowledge that leaving my "wet" motors to dry for 3 weeks is not a complete experiment. He has concerns about "wet" motors exploding, and also his other concern about motors drying out. So I will do so. I hereby acknowledge that's it's quite possible (AND quite likely) that my motors will lose some more moisture over a much longer period of storage. I never stated that this would not happen, and I don't believe it's an issue, even if it did happen. I made no claims of indefinite storage, but I don't see any evidence to lead me to believe otherwise. One thing worthy of note: whistle rockets are known to CATO on storage. It's a VERY common problem, and well documented. What's interesting is that when the experts tell folks how to make whistle rockets, they don't mention that. These rockets are WAY more powerful than black powder rockets. If the concern of rockets blowing up is so great, why not warn whistle rocket newbies about it? My rockets have not presented a problem on storage, and I don't expect them to. I wholly believe that if I said I stored my motors for 6 months, it would be said that they need to be stored for a year to be 'good'. The objective was to tear me down, and the weak point was my 3 weeks of storage. If a theoretical concern is the best criticism of my methods, I guess I did OK.

 

Dagabu has outlined his concerns by PM, and I won't violate his privacy by mentioning them here. I disagree with his position, and I see no evidence that his concerns apply to the way I do things. If anybody thinks they have a problem I can help with, they can PM me. I don't feel like being picked apart any more. If anybody wants to debate factual issues constructively and without ad hominem attacks, fine. Facts don't care about feelings.

[dagabu]

I agree, thanks for posting.

[mabuse00]

Somehow there's a tendency to boil things up lately... Is that new or has it always been this way and I did not notice...?

 

I think this drying out or not drying out issue is hard to "prove" anyway, because everybody has somehow different raw materials, different grades or charcoal, different grades of KN (there are for example extra low sodium products in the HAIFA product range...)...

 

My belief is that added water will dry out over time. Maybe the time constant is very low... more so in a waxed tube...

 

 

But much more important is how the water content affects the burn rate and impulse of the motor.

 

I should also mention that the pre-densified stuff wants to cause tube compression wrinkles, unless the tube is waxed

I wonder why. You would probably not move downwards as long as you would with a lower starting density. Or in other words - the change of density within each increment should be lower (at least I would expect it to be...).

Well - thank you guys for kidnapping the tread with this wetpressing issue - I will gladly join in when my press is operational

 

 

Does anyone here predry their ingredients for BP even if they appear to be dry "enough"? I have read in many places around the net that folks will do this ritualistically, no matter what, before weighing them up.

As long as your not living in a rainforest area I dont see the point in doing that. If your ingredients are stored in a dry environment and of reasonable purity - no way.

 

 

Considering the original question -I'll try it when my equipment is ready.

On the long rung I'll be using a stopper to keep the nozzle area wax-free.

[justvisiting]

mabuse00, most of my black powder tests have been done with rockets or with 1/2" diameter X 2" thick pucks. The pucks were pressed to a density of 1.7 to 1.9, in general. The pucks were dried, and the weights tracked as they dried. After they dried, they were stored for probably a year before I pulled them back out again. When I did, just for a lark, I re-checked all the weights and all the dimensions. Part of the reason for this was because another (highly experienced) pyro suggested that the dimensions of the pucks might change as they dried out. He was right, kind of. The diameters all stayed the same. The thickness of all of them increased, by an average of .005". Strange! I've said it a hundred times that charcoal has elasticity, and it's been proven to me in my own life, as well as being documented in official studies on black powder.

 

With this in the back of my mind, my earlier concerns about shrinkage of a damp propellant grain evaporated. Even if I'm wrong, and they didn't 'grow'- they didn't shrink. What happens is that the structure of the black powder grain becomes more open instead. This is also documented information from published, available studies. I can provide references if anybody needs to see proof of these 'claims'.

 

When I damp-pressed my rockets, I fully expected them to dry right out. I expected it to happen slowly. But, with a core up the middle, and no nozzle, the weight didn't go down in 3 weeks. The surface of the propellant grain became dull rather than shiny, after a couple of hours. But no weight loss. I'm sure the water did move- it just didn't move out- in 3 weeks. I included this observation in my reporting, because my report would be incomplete without it. IF I had declined to include that observation, it would have been irresponsible. So I included it.

 

Dave Sleeter has written two books about black powder-type rockets. He's been hand-ramming damp propellant since the early 80s. For some reason, Sleeter's work has never really been accepted by the pyro community.

 

I think the chunky nature of the 'pre-densified' BP helped pull on the tube. It happened on 1lb motors. 1lb NEP tubes have the lowest amount of tube per unit of area of all the common sizes. Also, recently, NEP has taken away 10% of the paper from their 1lb tubes. The ones I have now fall through a rigid tube support like it's not even there.

[Bourbon]

 

As long as your not living in a rainforest area I dont see the point in doing that. If your ingredients are stored in a dry environment and of reasonable purity - no way.

 

 

I was wondering about that. I have never had a problem with my BP but I had heard several times that coal could have a substantial amount of water in it and never show signs. Reading around I had heard that it could throw ratios off by almost 2 grams. Thus drying being substantial for proper weights. I didn't see any estimations for the nitrate.

 

I don't have a drying box to experiment and I'm not firing my oven up with the 100 degree weather right now. I read a 175 degree oven at least for 12 hours would be sufficient. ( I think Not ) 12 hours, Holly Crap! Seems excessive. However, what do I know. Figured I would ask.

 

I apologize for throwing a bunch a debris in your thread. Thank you for your courtesy and opinion.

 

[davidh]

I have "never" waxed a tube and never said I did. It was merely curiosity and happened to be what the thread was about.

 

You know the last three times you have replied to anything I say you have been a smart mouth, ass.

 

I'm trying to learn here and if that bothers you, Ignore me!

WTF? I wasn't even referring to you. Hell, you posted after I loaded this page and started my post. I was referring to the OP.