Funnels for Filling small tubes.

[pyroman2498]

Ok,

So about a year and a half ago at my last club dinner and shoot, i built a 3" Glitter to Ring of Reports which in my eyes failed miserably ( My timing may have been off a bit because i had 2 timings of time fuse next to me so i might have added the wrong timing to it ... oops silly me ... )
But the biggest problem was filling those tiny ass tubes. One member , who is a pretty well respected member was discussing with me about putting flash into a small mustard bottle with the thin tip and filling them that way but that just makes me feel uncomfortable doing that....
Too get on with the point of this , i was wondering if there were any small funnels that would help me fill them quickly and more accurately than just dumping it over the tube and hoping that the powder goes into the small opening ? I was looking at small Al Funnels but i would like to avoid metal at all possible and plastic too.

Stay Safe and Stay green

 

~Steven

[chuckufarley]

Im no expert on the matter, but I find small funnels don't work to well with raw flash powder. One device I have seen, but not used myself, is a board with holes drilled into it to snugly hold the tubes/cap plugs. You insert the tubes so they are flush with the top of the board, you then put some flash on the board, and using a credit card, or piece of paper/cardboard,you move the flash over the holes letting it drop into the tubes. You can tap the frame to settle the flash into the tubes, and refill as necessary.

 

I hope this makes sense in writing, as I sometimes have a hard time explaining my thoughts in words

[OldMarine]

Somewhere on here is a pic of a jig a member built to fill cap plugs with flash that was identical to the setup Chuck just described. I'll look for it.

Danny Creagan has some good ideas on filling cap plugs in his article:

http://www.wichitabuggywhip.com/fireworks/rockets/capplugs.html

Edited March 1, 2017 by OldMarine

[lloyd]

Patrick, (and more-importantly, Pyroman),

 

Yes, there ARE small funnels, and they work extremely well with small tubes. They work well-enough that we used them in dozens of sizes in commercial production.

 

More important to your endeavors is this: You have BUNCHES of them, just "lyin' around", waiting to be used!

 

Clean, then cut a full sheet from a soda can. Cut out a piece large enough to WIND your own funnel. Then, without actually bending the metal to the point where it loses its 'spring', simply 'spin' it into a funnel shape, and tape the outside seam with good masking tape (or better, aluminum refrigeration tape). Trim either top, bottom, or both to the desired size with sharp scissors.

 

The inner edge that's not taped will fit tight and cleanly to the inside curve, and the shape will be held with the tape on the outside.

 

Yeah... it'll take you a few tries to get the master piece the right size for any particular funnel, but you have LOTS of sample material to play with, be it soda cans or beer cans.

 

The lacquered finish on the insides of those cans is slippery as heck. Stuff just slides down them like they were greased.

 

Once you get the knack, I'll bet you'll make a dozen of them for different jobs. You can make them sharply tapered (wide at the top and small at the bottom), only slightly tapered (long, tall, and small-diameter), or anywhere in-between.

 

Lloyd

Edited March 1, 2017 by lloyd

[chuckufarley]

That's a great suggestion Lloyd!! I would have never thought of using a aluminum can as a funnel. I always tried a plastic, or rolled paper funnel, with less then satisfactory results.

[OldMarine]

Those little otoscope attachments suck. The static on the plastic grabs everything. I haven't tried cap reports yet so haven't needed anything smaller than the stainless mini-funnels Caleb has for small rockets etc..

[calebkessinger]

I've made little brass ones for those cap plugs before. Never heard back how slick they worked or if they were junk..

[mikeee]

The facilities I work at process large quantities of fine powders, you need to address each

type of product with different mechanical solutions to move these products. Vibratory methods are

used quite often on fine mesh products like FP and BP.

Vibratory frequency could be anywhere from several strokes per minute to several hundred strokes per minute.

We use air powered systems, electrically powered systems, and cam driven systems to keep these fine powders

moving in the process flow.

Using a wood dowel and tapping on the side of your funnel keeps the fine mesh powder moving most of the time.

Adapting a vibrating mechanical source to your table or tool being used is a common approach to this problem.

We also ground and bond all components in the system to prevent static build up, this is another issue that

cause fine powders to attach themselves to surfaces and then slowly plug up a system.

[FlaMtnBkr]

It seems to me that as fine powder moves down a funnel it gets slightly compressed and stops flowing and needs to be either slowly sprinkled in the funnel or the funnel tapped like Mikeee mentioned, or a funnel and rod process which I don't think you would want to try with flash!

 

Something that seems to work good is a scoop that is open on one side. Take a wooden dowel that is slightly smaller than the tube you want to fill. If you lacquer it they can last a long time and won't get stained from the grain getting powder in it. Then take Lloyd's beer can, but only once he's done with it, and cut a piece to wrap halfway around the circumference of the dowel. Then lash it on with some string which you can lacquer for a more permanent scoop or not if you want to be able to adjust the size for different applications. Then adjust the length to hold more or less powder and then trim the corners to put a nice radius so it's rounded and not sharp.

 

You can then dip into a container of powder and give it a tap with your finger to knock off any extra and with a little practice you can get a pretty consistent volume. Tilt your tube to the side, slide in the scoop, turn back vertical and give it another tap to fill it up.

 

You can make them for all kinds of things and they work great for filling rockets with fairly consistent increments. Just have to experiment with the length to get the volume you want.

 

If I remember when I get out to the shop I will try to take a picture of one but hopefully that all makes sense.

[lloyd]

Fla,

We use both the beer can funnels AND the beer can scoops. And usually, together. The scoop makes for "just the right amount", and the funnel makes sure it goes in the tube, and not on the table. (Fiber-reinforced or a narrow strip of duct tape works well to first assemble the scoop to the dowel, but a turn of twine as you recommended doesn't hurt to make sure it stays forever.)

 

Lloyd

[mabuse00]

I use an otoscope funnel made from metal for this task. No static problems with these. Give it a few knocks with something not to soft (depending on how paranoid you are - something non metallic) - tap tap tap - goes relatively smooth...