Coating Iron powder

[PyroMan LTU]

Hello,

 

I have few questions about coating iron. I have mine 100mesh powder and have tried making stars with it, I failed, obviously the reaction accoured and the stars cracked.

Then I runned some tests. The only thing I had was universal spray oil - WD40

http://www.wd40.com/products/

 

I tried coating Iron and magnesium powders. And it seemed successful with iron since droped in the water and in light acetic acid, no reaction accured. Even in few days, while in acid uncoated iron produced little bubbles, in water just oxidised. However, Mg reacted in bought water and acid(duh), even coated, just coated Mg and acid reaction started a bit harder, water as well.

 

Then I made few BP/iron stars just for test, binding with dextrin and water. The stars dried and turned realy hard. Seemed that no reaction accured. Few days later I cracked few stars with a knife and hammer. They seemed fine, just now after a week or so, I see some brown spots in it, is it rust? The star was the same hard though.

 

So to conclude, is this a reasonable coating material? Is it okay to roll stars with this coated iron? In worst case sanario, I could buy Linseed oil, is it worth to try using it, or this silple WD40 is enough?

 

Best Regards

 

PyroMan

[dagabu]

Yes, the brown spots are rust and soon you will not have any more iron at all. The KNO3 eats the iron up pretty fast when its uncoated. Next time try this, add 1% candle wax, parafin or bees wax to the iron and heat in a steel pun just until all of the wax melts. The iron should suck up all the wax and the pan should be wiped clean while still hot.

 

If you get the temperature just right, you can crumble the iron by hand. If it gets to hot to handle, let it cool some and try it again. The final step is to place the mix on a hard surface you dont like very much and place a flat board like a cutting board over the top and slide it across the pile until all of the clumps are broken.

 

I finish my iron by using a hot air gun and remelt any wax back into the iron and scrape it up off the surface with a dough cutter.

 

D

[PyroMan LTU]

Thank you! That's a good sugestion!

 

Just one question, this counts for all coating methods, and this one ofcourse. Does physical forse, such as rubing (separating particles), pressing stars damage the coated surface? and if it does is it potentialy dangerous? You mentioned that you use hot air gun to get wax back into iron. For example, if you skip this operation, will it still remain usable?

 

PyroMan

[dagabu]

If you can powder the iron without removing too much of the wax then you would be fine but you will have to test it in any case. Interestingly, it seems that you cant overcoat it if you try.

 

Try the easiest way you can think of and try it, stay with the method that gives you the results you want with the minimum fuss.

[Lagrange]

if you want tought coating, use very hare wax like the one found on top of meaux mustard pot (the seal). Find this at your super market http://www.worldsfoo...ge/DSC00845.jpg

It also taste very good!

 

there's also a method consisting in boilling iron in nitrate solution with additives to create an blue oxide layer.

 

read this

http://www.substech.com/dokuwiki/doku.php?id=black_oxide_coating

Edited April 29, 2010 by Lagrange

[dagabu]

I am sure that would work too!!

[PyroMan LTU]

Alright, thanks! I'll try the wax technique, probably Will inform about results.

[PyroMan LTU]

Yes, the brown spots are rust and soon you will not have any more iron at all. The KNO3 eats the iron up pretty fast when its uncoated. Next time try this, add 1% candle wax, parafin or bees wax to the iron and heat in a steel pun just until all of the wax melts. The iron should suck up all the wax and the pan should be wiped clean while still hot.

 

If you get the temperature just right, you can crumble the iron by hand. If it gets to hot to handle, let it cool some and try it again. The final step is to place the mix on a hard surface you dont like very much and place a flat board like a cutting board over the top and slide it across the pile until all of the clumps are broken.

 

I finish my iron by using a hot air gun and remelt any wax back into the iron and scrape it up off the surface with a dough cutter.

 

D

 

Dagabu, I have tried this wax technique and coating went without problems! Today I made some bp stars with iron, alcohol and dextrine binding. They're drying around three hours and no rection, wet star burns fast though and nice. Droped in acetic acid the reaction, however, accured overnight. I wasn't sure some brown spots were visible, but it might be a mistake, since it was a dirty test plate.. Anyway, the results will be visible soon with the stars

 

PyroMan

[GalFisk]

I can vouch for the wax method - I used 2.5% (by weight) candle wax (100% paraffin) to coat a kg of iron powder, which then sat for 2 years in a non-airtight box in a shed in moist climate without showing any signs of rust. I used a teflon coated frying pan, heated the iron powder until it was hot enough to melt the wax, and stirred until the was was evenly distributed. I then let the mixture cool, and ran it through a sieve to remove clumps (they were loose and crumbly).

[PyroMan LTU]

Well, that should be stronger coat than 1%..

[WSM]

"The only thing I had was universal spray oil - WD40"

 

WD-40 has a special purpose. The "WD" represents "water displacement" and it serves well to displace water (from a wet distributer cap in an auto for example), and then the light oil carrier evaporates.

 

The classic way to coat iron (besides wax) was to coat it with boiled linseed oil. I don't mean you boil the oil and add in the iron, but you buy it from the paint section of the big box hardware store as "boiled linseed oil" and use it cold. To thin the oil, camp stove fuel makes a good solvent. Work out doors away from any ignition sources and avoid breathing the fumes.

 

The preparation takes time and when it is done, the iron needs to sit, spread out (do this on a metal surface, the oil heats up [exothermic] as it dries and can cause a fire on a paper or cloth surface) for several weeks so the linseed oil can air polymerize and firm up. The process can be accelerated by adding a couple drops of Japan drier (also available in the paint section) to the linseed oil and solvent mix before adding to the iron (the three to four week drying time can be cut down to a few days that way).

 

Warming the coated iron also accelerates the polymerization of the oil, but be careful not to get it too warm (try less than 200^oF or 95^oC for no more than a couple hours, less if possible). The amount of linseed oil to use doesn't need to be very much (try 2-3%) and the coated iron should keep on the shelf for many years if done right (mixed, I'm not sure how long it will last, depending on too many factors. Your milage may vary).

 

Besides iron, the process works for fireclay or bentonite nozzle mix, too. Have a great Independence day.

 

WSM

Edited July 4, 2010 by WSM

[PyroMan LTU]

Thanks for Idea WSM

[WSM]

Thanks for Idea WSM

 

You're welcome. Glad you liked it.

 

My favorite source for iron powder is brake drum turnings, by the way. Take a container to your local brake shop and ask if you can have some of the turnings. When they ask why you want it (they always do), tell them how sprinkling iron powder on the ground around your Wife's roses makes the blooms larger and more beautiful (this is true, I'm told; roses are supposed to take the iron up through the roots, systemically after chelating in the ground). I haven't coated many of them but they store without rusting for a long time, possibly due to something in the process of turning the steel. I do tend to sift out the various mesh ranges for different applications. Great stuff and the price only gets better if they pay you to take it.

 

WSM

[Twotails]

I have used the break turnings as well, it seems that theres a film of oil or some such residue the the metal, washing them in a solvent(i've used goo gone, as its main component is i think touline, and it was just sitting in my workshop) you can get it finer by soaking them in liquid nitrogen( i've brought a thermos to a welding shop before, told them what i was going to use it for, and to find out the shop owner is into pyrotechnics also! great, someone thats close to talk to! still got to pay for the nitrogen, but keeping in good i just dropped off a box of good quality soft hardwood charcoal to owner I made a few weeks ago, attract more bees with honey than vinigar.) then crush the iron firther with a hammer or the like, or run it through the meat grinder(seems to work on the largest setting, just on open grates, no second teeth attached)

[WSM]

Another method I've heard of to coat iron involved using "Thomson's Water Seal" product in the US for coating wood outdoors (Like a wooden deck or fence). I was told by a friend a long time ago about this process:

 

Take a quantity of the iron powder to be coated and put it in a filter or sieve. Dip the sieve with iron powder in it into a pan of the Thomson's till the liquid covers the metal. Lift the sieve and drain well; pour the coated iron out on a metal tray to dry. I'm told Thomson's is basically emulsified linseed oil and should coat similarly to the treatment with boiled linseed oil, described earlier.

 

I never tried this method so if someone does, please report back to us if it works or it's bogus. Thanks.

 

WSM