55 replies to this topic

[karlfoxman]

Thats a nice long mill time, I mill mine for 4 hours in my milling jar with cylidrical media. Its very very fast powder, also I use alder charcoal for my lift for smaller items. Bigger items like shells use willow lift, I can get away with milling my maltese lift for 2 1/2 hours.

[portfire]

Thats a nice long mill time, I mill mine for 4 hours in my milling jar with cylidrical media. Its very very fast powder, also I use alder charcoal for my lift for smaller items. Bigger items like shells use willow lift, I can get away with milling my maltese lift for 2 1/2 hours.

Indeed. i thought if i milled all the components separately for a long time, (especially the C/S mix) that it would cut down the time the bp is milling. Works a treet in my eyes

Edited by portfire, 26 February 2007 - 02:44 PM.

[treefingers]

Thanks for the replys guys. As you mention Kitty litter I am assuming bentonite would be suitable too?

Anyway for this batch of lift I did indeed use a ball mill which is why im puzzled. I filled the mill half full with cyplebs and then up to about 3/4 full with my Charcoal (willow) Sulphur and KNO3. I wet with about 6/7% water and milled for a few hours but found it was sticking to the sides so dryed it out and put it back. Then suspecting my mill might be inefficiant, I milled for a further 24 hours to be safe.

For granulating my BP I mixed with 7%dextrin and pushed through a sieve which i'm guessing was about 10 mesh.

For testing I used about 1/4 of the weight of the star in lift and rammed into a 3/4'' ID tube with a small hole at the bottom for fuse. I then pressed a fairly tight fitting star on top and added a little meal around the sides. On lighting there was a whoosing sound and the star only reached a dissapointing 40cm out of the tube.

Any ideas as to why my lift is so poor?

[BrightStar]

Any ideas as to why my lift is so poor?

Try 75% coarse ground KNO3 (about 20-mesh), 15% coarse ground willow charcoal (10 - mesh to fines), 10% coarse ground S (10-mesh to fines) in the mill. Spray in 2-3% solvent in several squirts, mixing well, using 25% IPA in water. Run the mill (1/3 to 1/2 filled with media and maybe 1/5th with composition) for 6 hours. Every 90 minutes, stop it and squeeze and shake the jar to dislodge the caked powder from the sides.

Dry the meal powder, screen in 3-4% dextrin with several passes through at least 20-mesh, dampen it with the same solvent and grate through a 15-mesh screen into a large-ish plastic container to dry. This stuff is scarily hot... probably too hot for larger mines, but should be good for candles.

Edited by BrightStar, 27 February 2007 - 05:01 AM.

[treefingers]

Try 75% coarse ground KNO3 (about 20-mesh), 15% coarse ground willow charcoal (10 - mesh to fines), 10% coarse ground S (10-mesh to fines) in the mill. Spray in 2-3% solvent in several squirts, mixing well, using 25% IPA in water. Run the mill (half-filled with media and maybe 1/5th with composition) for 6 hours. Every 90 minutes, stop it and squeeze and shake the jar to dislodge the caked powder from the sides.

Dry the meal powder, screen in 3% dextrin with several passes through at least 20-mesh, dampen it with the same solvent and grate through a 20-mesh screen into a large-ish plastic container to dry. This stuff is scarily hot... probably too hot for larger mines, but should be good for candles.

Thanks looks like an interesting method, however is it that nessecary for the reagents to be of coarse mesh? Unfortunately all the reagents with the exception of my KNO3 were bought or have since been, ball milled.

[BrightStar]

Thanks looks like an interesting method, however is it that nessecary for the reagents to be of coarse mesh? Unfortunately all the reagents with the exception of my KNO3 were bought or have since been, ball milled.

No, the finer ingredients should be OK, if not better. This method is just one I developed over time to suit my own circumstances - everyone here has their own procedure.

Looking at your method, the problem may be that you have too much in the jar - I find it is better to have it not much more than half full in total. The loading makes a huge difference to the effectiveness, using even slightly too much of the ingredients seems to quadruple the milling time. You can probably afford to cut down a bit on the water and dextrin as well.

In the early days I used Benzolift for the small stuff (it works well...) but that always seemed like cheating

Edited by BrightStar, 27 February 2007 - 04:41 AM.

[seymour]

Treefingers, I may be misreading you, and if I have done so I apologise, but I am sure you said you rammed the lift into the tube, and then put the star in? That would crush the lift into a plug and prevent it from burning fast enough to launch stars to the desired height. You should only consolidate the delay powder.

[treefingers]

No need to apologise as you were right, I did make the mistake of ramming it, so I'll give it ago without. However after lighting some of my BP unonfined I suspect my problem is a combination of ramming and poor BP so i'll attempt again using Brightstars method.

One last question i've been thinking about though. Would it be better to use a cooled solevent when granulating the BP. My thought was using a colder solvent would lead to smaller KNO3 crystals and therefore a faster burnrate, or would the effects be negliable?

[Caramanos2000]

When granulating use water and dextrin. I must stink at this, but when I try to do the strainer part I make a mess of hanging doodads from the bottom. Maybe its too wet?

[BrightStar]

Maybe its too wet?

Yes, probably. You need to dampen the BP only slightly but evenly with your sprayer (just enough so it clumps together) and then consolidate it into a firm lump or ball with your hands. You could also use a star pump type thing. No need to chill the solvent or worry about crystallisation - the KNO3 isn't particularly soluble at room temperature and you won't dissolve much of it. Now just grate this ball of BP though your sieve (I use about 15-mesh) as if you were grating cheese.

The grains will generally look quite fine when they are dried, but they are real grains with plenty of air space for flame propagation and will make good candle lift.

Edited by BrightStar, 28 February 2007 - 03:46 AM.

[Zinginex]

When granulating bp does the mesh size matter? I don't know what mesh my seive is but it's pretty small not like a strainer. Sifts flour through with several knocks but i heard that you get better bp if your mesh screen is higher.