Any good alternatives to talcum powder?

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BRS Hobbies

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Any alternatives to talcum powder that work just as good at helping a plastic LPR parachute to open?
 
Chalk. I use the line marking chalk you can get in hardware stores but I've heard it can stain hands and clothes. You can get just normal white powder chalk instead. Calcium Carbonate.
 
Looks like you can get marking chalk in various levels of permanence:

https://www.keson.com/product-category/chalk/
Level one is least permanent. I assume it would help a chute open. I use billiard chalk which used to be talc, but the brand I use now uses cornstarch instead. With the recent lawsuits regarding asbestos in talcum powder, I suspect it will no longer be sold for human use.


Tony
 
I always have a gallon of chalk for the chalk box for doing construction. I have always just used that. It's red, so why not? Any Lowes, home depot, hardware store will have it. I only use it on cold days or really high fliers.
 
I've used corn starch.
Caution advised; cornstarch is combustible. I don't know whether there is a significant chance of the ejection charge igniting a cloud of starch powder. And I don't intend to find out. :)

Powdered chalk will work fine. Real powdered talc is still available from any number of online vendors. I got 5 lb---lifetime supply---from US Composites for $8 plus shipping. Works as a epoxy filler too, though it's rather heavy.

Best -- Terry
 
I didn't know corn starch was flammable. I haven't used it in a couple of years. I don't use plastic chutes any more.

Another seemingly innocuous, but highly flammable substance is Non-Dairy Creamer ( aka "Cremora" ).

https://www.youtube.com/watch?v=9pP7mTgX7iw


Any alternatives to talcum powder that work just as good at helping a plastic LPR parachute to open?

I believe that the OP asked this question, due to the possibility of being exposed to Asbestos in Baby Powder and other Talc products..

Asbestos & Talc can occur together in nature.

https://www.fda.gov/cosmetics/cosmetic-ingredients/talc

https://www.asbestos.com/news/2020/03/10/fda-asbestos-cosmetics-testing


Dave F.

Dave F.
 
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Caution advised; cornstarch is combustible. I don't know whether there is a significant chance of the ejection charge igniting a cloud of starch powder. And I don't intend to find out. :)

Powdered chalk will work fine. Real powdered talc is still available from any number of online vendors. I got 5 lb---lifetime supply---from US Composites for $8 plus shipping. Works as a epoxy filler too, though it's rather heavy.

Best -- Terry
You know, I think someone should find out. You are not putting a lot of talc/cornstarch on the parachute. It is getting ejected and therefore hitting air/wind......I would not worry about it. Time to test and try. Otherwise yes someone last month posted to a message back in Jan/Feb that it ..talcum powder, is available on Amazon..
 
It doesn't take much. All it takes is fine dust suspended in the air and a source of ignition. Ask anyone that owns a grain silo.

Dip your finger in wheat flour and snap over a lit candle. That cloud of flour dust can make a fireball almost a foot wide.
 
Ok, but you are still hundreds of feet up in the air, so I will say it will blow out....just like your ejection charge does not see the body tube on fire.
 
Yes, corn starch based body powders are flammable. However the amount you’re typically going to use to ensure that a plastic chute stays “slick” is highly unlikely to combust. There’s a concentration of any potentially flammable substance needed to sustain combustion along with a necessary ignition source at the correct temperature (in our case the ejection charge). If you’re dusting your plastic chute and then shaking off any powder in excess to what clings to the plastic the chance it’s going to ignite is pretty low, approaching zero. Now if you’re loading up your chute in the expectation that you’ll get a tracking powder affect from the “puff” of powder at apogee you’re could be taking a chance that the powder could ignite - though if it did, with everything exiting the body tube into the air (no containment of the flame or heat) it’s again very unlikely to sustain combustion (your rocket is not likely to burst into flame) but it is possible it could burn. I’ve launched hundreds of times using powder that’s at least partially corn starch with zero scorched or burnt rockets - but I’m just dusting the chute surface. If I flew rockets routinely in high wildfire threat areas I’d most likely buy pure talc since it’s worth minimizing the risk.

It would be an interesting experiment to see if very small amounts of starch based powders could sustain combustion from a typical ejection charge - the experiment rig should be a rocket body tube and an ignition charge with a nose cone to provide temporary containment...
 
I used cornstarch baby powder on my Estes plastic chutes and got a some pinholes and minor melting. I'm planning to switch to nylon but have to get some sewing time with dear wifey.
 
I still have enough talc to last a while - I made sure to buy a bunch of J&J talc baby powder before they took it off the shelves.

However, I used to be an avid rock climber and have a bunch of magnesium carbonate - "climbing chalk" - and have tried that as well. It works great and is not water soluble, so it works even when it is humid or wet out. You can usually find it in bulk even cheaper than calcium carbonate. Heck, if you belong to a gym, they may even let you take a ziploc bag with you.

I am not so worried about cornstarch combusting, but on a hot humid day, I have seen it turn gummy. Not so great on a parachute.
 
20 Mule Team Borax may be a possibility. It is a fine, absorbent powder, odorless, and an excellent fire retardant.

Some things to consider with the suggested materials in this thread:

- Borax is soluble in water and becomes more soluble as the temperature increases. When dissolved, one of the products is Boric Acid. This is a good property for washing clothes clothes, etc, but may be detrimental to the use-cases in rocketry. US Borax, Inc (makers of 20 Mule Team) notes that at temperatures above 85 deg F and humidity above 45%, Borax has a tendency to "cake" up. This tendency gets worse as the temp and humidity increase. In the summer months, that describes most launch sites in the US. You probably don't want to use this on your rocket unless you are using it to clean it after the launch.

- Corn starch is not soluble in water, but it's particles are very hydrophobic. This is why corn starch gets pasty in humid weather. The particles tend to clump up when wet and form a gummy consistency. Not the properties you are looking for when trying to dry lube your parachute or piston eject system. Avoid corn starch.

- Calcium Carbonate is closer to ideal - it is generally insoluble in water and its particles are hydrophilic. For most rocket applications, this is a good product. The only issue is the "generally insoluble" - in pure water, Calcium Carbonate is insoluble, but if the water has dissolved Carbon Dioxide in it (like rain water, ground water, etc), the Calcium Carbonate combines with the Carbon Dioxide to form Calcium Bicarbonate, which is soluble. This is probably not an issue with rocket applications, but it is a consideration. When Calcium Carbonate gets wet, it tends to feel "slimy".

- Magnesium Carbonate is both insoluble in water and hydrophilic, making it a great choice because it can absorb moisture without getting clumpy or pasty. It can absorb quite a bit of moisture while retaining its powder like properties.

- Talc is interesting because it is hydrophobic as a solid, but when it is ground into a fine powder it becomes hydrophilic, which is why it has been prized as an absorbent body powder for at least the past 100 years. Talc is also insoluble in water. Another interesting property is that talc powder particles form into "platelets" which easily slip along each other in layers. This is why talc forms a dry, low friction layer between surfaces like plastic, rubber, nylon, etc. Finally, talc is completely inert and flame retardant (in fact, talc powder makes a pretty good fire extinguisher). This makes talc the most ideal substance that is easily available for dry lube on various rocket parts.

There are some other materials you could consider, like graphite powder. Graphite powder is a superb dry lubricant and would probably work quite well in that capacity, but it is not absorbent at all, so moisture would remain an issue. It is conductive, so would not be good near your electronics. It is very messy and hard to clean up. Your rocket would eventually be black, whether you wanted it to be black or not. In addition, graphite powder is expensive compared to the other products noted. I suppose if you were launching a black rocket with no electronics, graphite powder may be a consideration if that is all you had on hand, but I wouldn't recommend it.
 
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