Rocket motors stink

[SolarYellow]

I did some big purchases awhile back when rocket motors were particularly inexpensive. Keep them in the rocket room in the house because it's temperature and humidity controlled. The garage gets to about 130 F or so and is stupid humid. I keep most of the motors in sealed ammo containers, but now I had more motors than I could fit in those. A mix of mostly BP and a few APCP. Noticed a pretty unpleasant stink in that room after a little while. It's gone up and down, sometimes clearing out completely, other times coming back, generally decreasing over time.

Sunday, I put all the motors that weren't in sealed ammo containers into heavy "ziploc" bags with silica gel packs.

Tonight, I went in there, and I can smell the pine boards that I used to make shelves back in September in the closet with a closed door. Success.

Yet another reason to keep your motor stash sealed up.

 

[J Blatz]

Many of my favorite things have a strong, distinctive odor. Rocket motors included.

 

[Hobie1dog]

Many of my favorite things have a strong, distinctive odor. Rocket motors included.

+1

 

[Art Upton]

APCP motors will have a stink after you fire them.
BP motors will have a wonderful smell after firing, so will the Rocket tube

I have a BP revolver 1858 reproduction. Each time it is fired with real BP it is like a D-12 cluster going off; both the smoke and smell.

 

[lr64]

SOME rocket motors stink. Mine don't, at least until I put a "prime" on them, or fire them. But I can't tell you what they're made from. You CAN get the ingredients from two types of stores that most of you live near and probably even buy stuff from.

 

[JackC]

“I love the smell of APCP in the morning. It smells like…victory.”

 

[Wayco]

If you don't like the smell of ACPC, you're in the wrong hobby. I do avoid the smoke when they are burning, but new propellant grains?

 

[GalantVR41062]

I used a vacuum food saver. This reduced the space needed to pack the motors by a little also.

 

[kjhambrick]

I've been keeping my motors in Container Store plastic bins with lids with an inch of kitty litter in the bottom since last summer

I recently bought a jar of this: JOANN > Panacea 1.5lb Floral Drying Crystals

It can be recycled in your oven like the expensive little Pelican Desiccant gadgets: Pelican > 1500D Desiccant Silica Gel

Too bad for me ... I cannot smell my motors in air conditioned garage office

-- kjh

 

[SolarYellow]

Silica gel kitty litter, 8 lb for $20 and free shipping.

https://www.walmart.com/ip/PetSafe-...g-Fresh-Scent-Silica-Crystals-8-lb/5108695295

 

[rcktnut]

I must have had a bad nose for the past 28 years, never noticed a smell from motors other than after being fired. They are kept in an air conditioned room in my workstation right above of where I sit.

 

[kjhambrick]

Silica gel kitty litter, 8 lb for $20 and free shipping.

https://www.walmart.com/ip/PetSafe-...g-Fresh-Scent-Silica-Crystals-8-lb/5108695295

I have to check this one out !

Thanks @SolarYellow !

-- kjh

 

[rcktnut]

I use ice melter (calcium chloride) for absorbing humidity. I don't use it for motors at all but it works very well for storing CA. The bottles in the pic. are 3 years old and the CA is in perfect condition. I change the calcium chloride every 6 months or so. This pic. I took before changing, notice the water in the very bottom of the mixing cup. Amazing how much moisture that is absorbed in 6 months time in a sealed jar in an air-conditioned room.

 

[smstachwick]

I did some big purchases awhile back when rocket motors were particularly inexpensive. Keep them in the rocket room in the house because it's temperature and humidity controlled. The garage gets to about 130 F or so and is stupid humid. I keep most of the motors in sealed ammo containers, but now I had more motors than I could fit in those. A mix of mostly BP and a few APCP. Noticed a pretty unpleasant stink in that room after a little while. It's gone up and down, sometimes clearing out completely, other times coming back, generally decreasing over time.

Sunday, I put all the motors that weren't in sealed ammo containers into heavy "ziploc" bags with silica gel packs.

Tonight, I went in there, and I can smell the pine boards that I used to make shelves back in September in the closet with a closed door. Success.

Yet another reason to keep your motor stash sealed up.

I got the Wanderer 2.0 in the mail the other day and showed it off to a friend that I had over at the time. I’m quite fond of the smell of burned black powder, so it took her commenting twice that she could smell it for me to take her meaning (dude, it STINKS!) and move it to the garage. Same story played out at least once in my youth, where my dad commented on my room smelling like stinky rockets and I had to figure out a new home for the fleet.

I haven’t had a problem with unburned motors or newly built rockets, but as soon as it experiences rocket-powered flight, the smell isn’t going anywhere.

My take: Black powder smells like a low-key, thoroughly un-demanding day at my home low-power club. APCP, and I think it’s the rubber binder specifically, smells like I just got absolutely insane performance on the most powerful motor I could stick in the mount.

 

[terryg]

After the launch, I have started to leave the rockets outside for a couple of days. Remove the spent engines and clean any reloadable cases. Get all the dog barf and wadding out. Leave the disassembled rockets in the sun for a couple of days and most of the smell disappears.

 

[J Blatz]

Many of my favorite things have a strong, distinctive odor. Rocket motors included.

APCP motors will have a stink after you fire them.
BP motors will have a wonderful smell after firing, so will the Rocket tube

I have a BP revolver 1858 reproduction. Each time it is fired with real BP it is like a D-12 cluster going off; both the smoke and smell.

If I fly a few BP clusters I'll leave them in the cab of my truck for a couple days just for the eau de BP lol...

 

[Joekeyo]

I keep my unopened motors and engines in a latched plastic container with kitty litter in the bottom and 1 layer of newspaper. Stored in an air conditioned space. It has a noticeable odor when I open it. Seems like burnt BP smells different than it did 45 years ago.

 

[Art Upton]

I keep my unopened motors and engines in a latched plastic container with kitty litter in the bottom and 1 layer of newspaper. Stored in an air conditioned space. It has a noticeable odor when I open it. Seems like burnt BP smells different than it did 45 years ago.

I think it is the cardboard that has other chemicals in it that cardboard did not back in the day.

 

[SolarYellow]

I keep my unopened motors and engines in a latched plastic container with kitty litter in the bottom and 1 layer of newspaper. Stored in an air conditioned space. It has a noticeable odor when I open it. Seems like burnt BP smells different than it did 45 years ago.

Just one container?

 

[kramer714]

blame the dog... that's what I usually do....

 

[lr64]

blame the dog... that's what I usually do....

Must be interesting to have a fire breathing dog.

---------
BTW, I understand that clay, as found in the cheapest kitty litter and rocket nozzles, can work as a desiccant. We used to use it inside oceanographic buoys. Maybe it was cheaper or something. I dimly remember that it wasn't supposed to absorb as much water in total, but could maintain a lower humidity level. At least compared with silica gel. I don't know about with calcium chloride.

 

[teepot]

What smell? I don't smell anything until they have flown and it isn't much then. Our humidity is single digits in the summer and not much more in the winter. I keep the motors in plastic tool boxes. Don't need a desiccant. The garage has heat and a/c. It is dry as a bone in the desert in here. After a rocket has flown I take the parachute out. It doesn't smell either and hang the rocket back from the ceiling. Still don't smell anything. My wife on the other hand has a nose that would put a bloodhound to shame. She is always asking me if I smell something. No dear I don't smell anything.

 

[BrendanH69]

I have a BP revolver 1858 reproduction. Each time it is fired with real BP it is like a D-12 cluster going off; both the smoke and smell.

Art, that reminded me of this old photo from 2009. This was me firing (if I can recall the details correctly) an 1880ish reproduction of an 1850s BP revolver at the British Airways Rifle and Pistol section's firing range about 2miles from Heathrow airport. First time I smelled BP up close, along with burnt semolina that was used as filler. Photo taken by a maintenance planning colleague on a mobile phone of the day.

 

[kjhambrick]

blame the dog... that's what I usually do....

Me too ... or... 'the baby'

We have neither anymore

-- kjh

 

[prfesser]

Must be interesting to have a fire breathing dog.

---------
BTW, I understand that clay, as found in the cheapest kitty litter and rocket nozzles, can work as a desiccant. We used to use it inside oceanographic buoys. Maybe it was cheaper or something. I dimly remember that it wasn't supposed to absorb as much water in total, but could maintain a lower humidity level. At least compared with silica gel. I don't know about with calcium chloride.

FWIW silica gel, anhydrous calcium chloride, and anhydrous calcium sulfate all have different capacities and equilibrium vapor pressures, but for rocketry work any one of the three is adequate. CaCl2 can absorb enough water to dissolve itself, so avoid a mess, replace it before it gets to that point.

As SolarYellow pointed out, crystal cat litter is silica gel. It's quite cheap, available in grocery and "superstores" even here in PartsUnknown, KY. Even has blue CoCl2 to tell you when to change it. Chemically more inert than most substances----silica gel is just silicon dioxide (sand), properly treated to absorb moisture. It's my go-to for desiccant.

And to move back on topic: BP motors do indeed stink after use. But they stink really, really GOOD!

 

[beeblebrox]

Art, that reminded me of this old photo from 2009. This was me firing (if I can recall the details correctly) an 1880ish reproduction of an 1850s BP revolver at the British Airways Rifle and Pistol section's firing range about 2miles from Heathrow airport. First time I smelled BP up close, along with burnt semolina that was used as filler. Photo taken by a maintenance planning colleague on a mobile phone of the day.

View attachment 645528

Those are awesome! I have an 1858 Pietta revolver and an 1830's replica .45 cal single shot underhammer muzzleloader boot pistol... both are fun to shoot.

 

[beeblebrox]

These are awesome, don't get the metal ones from Harbor freight tho. (Crappy handles, poorly made) The tactical one is perfect for Motors up to Low J range as long as they aren't long... (About 11" max.) The .50 Cal plastic boxes are great for 13-29mm or short 38mm. They have a watertight seal. You could throw in some desiccant bags... I get desiccant beads and put them in little cloth tea bags available on Amazon dirt cheap. You can bake them in the oven to dry them out periodically. Great for 3D printer filament storage too. (The desiccant, not the ammo cans...)
https://www.harborfreight.com/tool-...elts/utility-cases-ammo-boxes/ammo-boxes.html

 

[Joekeyo]

Just one container?

Unopened motors stored in single plastic container on right as discussed above. Open engines/motors in ammo box on left (same cat liter/paper). I don't keep a large motor inventory. We have a reliable launch day vendor. I usually buy only enough for about 6 launches.

 

[ksaves2]

I've stored APCP motors commercial and research for years without a stench. Seal them in plastic containers with tight lids along with putting the grains into zip-loc bags if research or original packaging with commercial loads . Yeah, if I open them up, especially the research grains, I get the hint of a smell. But then again, "I like the smell of burnt and unburnt APCP in the morning!!" The research grains might have some uncured reagents or additives in there that smell but mine burn fine with CATO's rarely. I don't worry about it as long as I have a good reliable mix formula that has good Burnsim numbers. Though at the time the B.S. numbers might be that, simply b.s. if there wasn't enough testing done. Some of the research loads don't smell after they've cured and it only indicates to me the mix was fine tuned by others over time. The "A" and "N" factors in the equation are the important variables for that prediction.
Some mixes have better "numbers" than others. Plus research folks might not "be able" to get the very pure reagents that the certified motor makers can get due to their "higher demand". Gotta to make do with what's out there and "adjust" the numbers to avoid overpressurization at launch.

 

[Rocketjunkie]

APCP motors smell good before you fire them. It's the HTPB that you smell. They stink of burning phenolic or inerts afterwards. BP motors don't smell until fired, then they smell good. Just like a pot head loves the smell of marijuana, the better the quality, the better the smell. It's an acquired like