Nitro Cellulose (Guncotton)

[Dean411]

Just recieved a pound from Hobby C.

 

My question is how safe is this to store?

 

How often should I check the dampness of it.

 

Storage temps and so on.

 

I've heard different stories and don't currently have a use for 4 gallons of

NC Laquer at the moment.

 

actually I still have a half pint or so,so I dont even need to open it right now.

 

Mumbles or Dag I am pretty sure you have both had or have it.

 

Any advise?

Edited December 16, 2011 by Dean411

[Peret]

I keep my NC well sealed in the freezer.

[allrocketspsl]

thanks for the thread i just bought some and was wondering same,freezer huh!

[Dean411]

Yeah I.saw something online saying not to store it but looking at the price of a pint versus a lb of NC had to buy it.

[Algenco]

A lot of people replace the water with alcohol, quicker to dry when you need it

[Mumbles]

I always stored it in a sealed container in the dark. Light will accelerate some of the decomposition processes. I do like the alcohol wet stuff. The stock I had came from Firefox. It comes in a plastic bag inside of a HDPE container. I took out what I needed, and typically stored the entire thing in a cardboard box or something just to keep the light out. If you notice it turning quite yellow or red, or smelling strongly of something resembling bleach, it's time to get rid of it.

[Dean411]

This stuff is damp with alcohol. I will keep my eye and nose on it thanks for the tips guys.

[FlaMtnBkr]

If the NC is dried out will it last longer? Does NC lacquer degrade over time? I know there is some really old NC based smokeless that still works as intended so I would think in a dry state it would have a long storage life if well sealed. Maybe the well sealed is the key and not moisture content? I had planned on ordering a few pounds but won't if it can break down with time.

[Algenco]

If the NC is dried out will it last longer? Does NC lacquer degrade over time? I know there is some really old NC based smokeless that still works as intended so I would think in a dry state it would have a long storage life if well sealed. Maybe the well sealed is the key and not moisture content? I had planned on ordering a few pounds but won't if it can break down with time.

 

 

it breaks down quickly if dry, keep it moist

[WSM]

A lot of people replace the water with alcohol, quicker to dry when you need it

 

I recall the first NC base I got was stored, moistened with isopropyl alcohol (probably 99%). After first drying it out, it took from a week up to a month to completely dissolve (with daily agitation) in acetone, but made a nice, clear (thin) gel. The best lacquer I ever made with it was by dissolving the NC base in amyl acetate (AKA "banana oil") and it has kept well in an HDPE bottle with a PTFE disk in the lid for over a decade. It appears to have broken down very little so far (slight yellowing). Amyl acetate (if you can find it) has the advantage of not absorbing moisture from the atmosphere (and is preferred for compositions containing magnesium), but lacquer made from it dries much slower than lacquer made with acetone.

 

The dry NC based smokeless powders don't break down (go bad) as fast as the raw NC because they are treated with stabilizers. I believe they are mentioned in Ellern's books.

 

WSM

Edited December 26, 2011 by WSM

[pyrojig]

I recall the first NC base I got was stored, moistened with isopropyl alcohol (probably 99%). After first drying it out, it took from a week up to a month to completely dissolve (with daily agitation) in acetone, but made a nice, clear (thin) gel. The best lacquer I ever made with it was by dissolving the NC base in amyl acetate (AKA "banana oil") and it has kept well in an HDPE bottle with a PTFE disk in the lid for over a decade. It appears to have broken down very little so far (slight yellowing). Amyl acetate (if you can find it) has the advantage of not absorbing moisture from the atmosphere (and is preferred for compositions containing magnesium), but lacquer made from it dries much slower than lacquer made with acetone.

 

The dry NC based smokeless powders don't break down as fast as the raw NC because they are treated with stabilizers. I believe they are mentioned in Ellern's books.

 

WSM

 

Huh,,,, I have had great luck with DBSP breaking down fairly easy.... Makes for a great NC laq. I too have had a fair NC laq. with ping pong balls in acetone . Of course nothing beats the real stuff. I have found Amyl acetate is quite hard to find as you describe...

[Potassiumchlorate]

I have made my own NC twice, but since sulfuric and nitric acids are hard to get in my country, and I don't like the fumes, I prefer buying it. The one I bought doesn't burn very well compared to the home made, but it dissolves in acetone in ½-1 hour.

[WSM]

Huh,,,, I have had great luck with DBSP breaking down fairly easy.... Makes for a great NC laq. I too have had a fair NC laq. with ping pong balls in acetone . Of course nothing beats the real stuff. I have found Amyl acetate is quite hard to find as you describe...

 

By breaking down, I meant having it go bad (not dissolving it in solvent). Sorry for the confusion. I wish I had several gallons of amyl acetate, it's great stuff.

 

WSM

Edited December 26, 2011 by WSM

[Dean411]

I made some NCL last week and it dissolved quite fast and work great with the eggs I made.

I think I prefer making it over buying it already made.

 

Also I hope it holds up well because I think it will take a while to use it all.

4+ gallons is a lot of NC

Edited December 26, 2011 by Dean411

[WSM]

I made some NCL last week and it dissolved quite fast and work great with the eggs I made.

I think I prefer making it over buying it already made.

 

Also I hope it holds up well because I think it will take a while to use it all.

4+ gallons is a lot of NC

 

With a few exceptions, I prefer to make it as I need it, but you need to keep the base material in such a way that it doesn't go bad. Keeping it wet with alcohol certainly helps (for a while). If you've already made up 4+ gallons of NC lacquer, maybe you should share it with your friends or sell the surplus (or paint a lot of furniture?!!).

 

Better yet, maybe you should build a visco fuse spinner !!! Good luck and have fun .

 

WSM

[Dean411]

Its not all mixed. Sorry for the confusion its that

a lb of NC is able to make 4 + gallons so I hope the NC holds up.

[WSM]

Its not all mixed. Sorry for the confusion its that

a lb of NC is able to make 4 + gallons so I hope the NC holds up.

 

That's good. If you keep the raw NC wet (with absolute alcohol or water) it should keep for a fairly long time if kept away from heat and acidity.

 

I had a tub of it go bad. It was dry and in a closed plastic tub. After a couple years I opened the container to find a smelly, inert tar-like substance in the bottom of the tub that was totally useless . The dry material, if it isn't neutral, can out-gas acid which accelerates the breakdown of the NC, especially in a closed, non-breathable container.

 

WSM

[NightHawkInLight]

The one nice thing about winter weather is you can make NC outdoors without an ice bath. I've got a quarter pound soaking away right now.

[pyrojig]

The one nice thing about winter weather is you can make NC outdoors without an ice bath. I've got a quarter pound soaking away right now.

 

Nice! I wish I had time to do the same. Life can be busy at times.

 

What process are you going to take to wash and de-acidify the NC? Do you plan to use any stabilizers for storage or are you just gonna do the storage under water or alc?

 

BTW. ,

 

This got me thinking . I know that in the old days they used camphor as a NC plasticizer and stabilizer . I know they dont any more because they use Diphenylamine as a better candidate( lasts longer. ) I have wondered if it ( camphor ) would be fine if your storing only for a few years. Could make some of that nifty cordite

[NightHawkInLight]

I'll have this batch used up within a week. I just wash the NC in tap water a few times then a wash in hot sodium bicarb solution. After rinsing a few times with water first the bicarb usually doesn't bubble much. One final rinse to get that all out and I call it good. There's some salt contaminants left over from the tap water which makes the NC burn bright yellow.

 

I don't know why you would want a plasticizer in NC, it's plastic enough on its own. It can be cast or pressed into any shape you desire, and can be wound into string or rope just like the cotton it's made from.

[WSM]

I'll have this batch used up within a week. I just wash the NC in tap water a few times then a wash in hot sodium bicarb solution. After rinsing a few times with water first the bicarb usually doesn't bubble much. One final rinse to get that all out and I call it good. There's some salt contaminants left over from the tap water which makes the NC burn bright yellow.

I don't know why you would want a plasticizer in NC, it's plastic enough on its own. It can be cast or pressed into any shape you desire, and can be wound into string or rope just like the cotton it's made from.

 

I used to know a man who made his own nitrocotton. It was wonderful stuff for magic tricks and specialty items. After the nitration process and several rinses, he boiled the cotton in urea solution (agricultural urea should be fine, check the gardening section) to remove any residual acid and stabilize the finished product. It burned clean and fast when it was dried out and fluffed up.

 

Plasticizers are usually used to make the dry lacquer film pliable. They would be useful in Visco fuse coating so the lacquer skin wouldn't crack when bent; otherwise I wouldn't bother. Camphor is an old time plasticizer and suffers from the disadvantage of being volatile and will disappear after time (vaporize out). Modern plasticizers are usually "process oils" that stay put much longer. They make the final product almost nothing like the original. Think of the difference between clear vinyl tubing and PVC plumbing pipe; same base material but completely different characters. The primary difference is the plasticizers in the vinyl tubing.

 

WSM

[Potassiumchlorate]

I have only made NC twice, but I rinse it thoroughly in cold tap water first. Then I boil it in a 5% bicarbonate solution for one hour. Then I rinse it in cold tap water again. Edited February 3, 2012 by Potassiumchlorate

[NightHawkInLight]

I've heard many people speak of the urea nitrate stabilization process and read about it in some old texts regarding making colored flash paper. I'm not sure I understand what it does to stabilize the NC. I've had plenty of success with nothing more than sodium bicarb. I've even neutralized with clear ammonia on several occasions, which supposedly can damage the NC but I've had no trouble. Here's some NC made with my usual process:

 

http://www.youtube.com/watch?v=Nbt057a8Zzc

 

I typically react the cotton under sulfuric acid and potassium nitrate, which is how the above batch was made. For the one that I have going now I decided to try out ammonium nitrate instead. While everyone has been trying to tell me to do that for years, I never had trouble with potassium nitrate and so this is the first time for me. So far it does look to be superior in that there are no solid compounds that crystallize out of solution and block the flow of acids through the cotton. We'll see how the final result turns out.

[FrankRizzo]

I've heard many people speak of the urea nitrate stabilization process and read about it in some old texts regarding making colored flash paper. I'm not sure I understand what it does to stabilize the NC. I've had plenty of success with nothing more than sodium bicarb. I've even neutralized with clear ammonia on several occasions, which supposedly can damage the NC but I've had no trouble. Here's some NC made with my usual process:

 

Urea will scavenge free NOx, which can otherwise start a decomposition chain.

[Mumbles]

I suggest urea. It works by killing any nitrogen oxides present, and acting as a buffer to kill any that are formed subsequently. It reacts with both Nitric oxide, and nitrogen dioxide to form nitrogen, water, and carbon dioxide. Back in the day when this sort of chemistry was first being developed on the amateur scale and applicability, urea washings were the new thing I really brought to the table. It's amazing how much cleaner the NC gets, and how much longer it lasts.

 

For what it's worth, on a larger scale, your washing methods are rather inadequate. It's amazing how much more effort you need to put into cleaning up 50g of NC vs. 5g. It of course depends on the purity required, and storage stability. For what you're using it for, those are really not issues.