Coating rice hull question again

[Fly]

OK fellows is there a formula on how much BP to use in coating rice hulls?Most of the stuff I read just

suggest the process & nothing more.

Fly:rolleyes:

[Cookieman]

OK fellows is there a formula on how much BP to use in coating rice hulls?Most of the stuff I read just

suggest the process & nothing more.

Fly:rolleyes:

 

Fly,

 

Generally most people use a ratio of 6:1 for damp hulls. 600g of comp. to 100g of hulls. I've even heard of some people using 4:1 on rice crispies.

[Algenco]

From what I've read 7/1 seems most common 5/1 for larger shells

 

 

[jwitt]

The weight of hulls is dry weight, just to be clear.

 

A scrap of window screen is great for spinning 'em dry after soaking, by the way.

Edited August 9, 2010 by jwitt

[jimbo]

I use a 1:1 ratio on grass seed with willow or balsa b.p and havent had any drama's as of yet

[mfstraydog1]

i just coat the rice hulls unil they are completly covered. but a 7 to 1 sounds about right. i will have to weight it out next time so i can be a little more consistant with my burst charges.

 

 

[Gunzway]

As you can see, it's dependent on the application; what you're going to be using it for. I use 4:1 on grass seed for my small shells where as you would probably use something 6:1 for larger shells.

[jimbo]

I find it strange using such high ratio's, how do you have 4-7:1 ratio's and not have them like small stars, my 1:1 ratio completly covers my grass seed perfectly.

[Peret]

I find it strange using such high ratio's, how do you have 4-7:1 ratio's and not have them like small stars, my 1:1 ratio completly covers my grass seed perfectly.

Grass seed is quite dense compared to rice hulls, so it may be that your spoonful of 1:1 coated seed has as much powder as the next guy's 4:1 coated hulls. I weigh mine out and aim for 5:1, but generally the hulls don't take it all, so I probably end up with 4:1 or a little over.

 

As for the star effect, you could be right. Looking at some of my vids, I can see a dim orange ball of burning hulls for a frame or two after the break. I figure anything still burning after the break is wasted.

[jimbo]

yeah true,there might be twice as many rice hulls to cover than grass seed to cover per 100g

[jwitt]

Probably more than 2x as much volume for rice hulls. It's been a long time since I've touched grass seed, but a 2 pound bag of rice hulls is roughly the size of a box of copy paper. Maybe a bit bigger. Hulls really seem like they're made for the job.

 

I guess there's a question as to whether it's worth coating more powder on hulls for small shells, since a booster is generally used to even out the break and give it some punch.

 

Then the question is if Peret's video is actually showing burning BP post-break. I'd think all the BP would be consumed in the inferno inside the shell. If a camera shoots 24 frames per second...hmm...I'm over my pay grade now. It could be that the burning things are smoldering hulls, and not actually BP.

 

 

 

Another tip for coating hulls- don't put any dextrin in a small increment of powder. Save that for last, and it will give the hulls a non-sticky surface as they're drying, preventing them from sticking together. You don't need much for this operation, maybe 1/2 the amount of your other increments.

[Peret]

Then the question is if Peret's video is actually showing burning BP post-break. I'd think all the BP would be consumed in the inferno inside the shell. If a camera shoots 24 frames per second...hmm...I'm over my pay grade now. It could be that the burning things are smoldering hulls, and not actually BP.

They probably are smoldering rice hulls. I separated out 8 frames of a break, you can be the judge. I picked this one because it has slow starting stars with a dark prime that don't obscure the break. I think frames 2-3 are BP, 4-5 are the hulls burning off; 6-8 is the beginning of the star burn. They don't really light up until about frame 15, when they're already well separated in the sky. It wasn't an effect I planned but it was interesting in its own way to see a ball appear ready formed in the blackness. 30fps.

[jwitt]

I think frames 2-3 are BP, 4-5 are the hulls burning off; 6-8 is the beginning of the star burn.

 

Yeah, the intensity of the light looks like there's still bp burning in 2 and 3.

 

Did you see that high-speed video of a shell going off?

(Shells start at about 3:00)