Strobe

I use 15g of 3FA Equiv for 2.5" shells. 2FA I would use 20g. 2Fg is finer and faster so 10g might be about right. KP needs to be well confined to work. I would use BP first to burst and use fibreglass strapping tape to get as good a break as you can then try KP with strapping tape to see what difference there is

Ok thanks, that seems to be general area I was thinking of. The O.D. of the casing is 1.75 inches which is a little smaller than yours, so I may try a smaller lift charge like 5-8 grams. I'll try it out on a shell loaded with dog food pellets and see how long it stays up.

What kind of altitude should I be looking for in terms of burst height for this size of shell?

Hi,

I'm at a point where I want to try making my 1st shell and I have a few questions. I'll be using a 2 inch plastic cylinder casing for my 1st attempt.

Lift Charge
I have Geox FFg and home made BP available ( Sulphur and Hardward Charcoal ball milled for 30 hours prior to combining with KNO3 using the CIA method). I havent tested the homemade stuff yet so I'm not sure if its appropriate for lift.

Is the Geox FFg ok to use? Its a finer granulation than 2FA, 16 - 30 mesh for FFg versus 4 - 12 mesh for 2FA. I've seen various posts about the recommended ratio of lift powder to shell weight but I'm not sure how to account for the fact that I would be using FFg instead 2FA.

I realize it will take experimentation to fine tune it, but i am just looking for a reasonable starting point to work with.

Burst Charge
I have the FFg and home made available or I could use a KP burst if that is advisable. I'm not real clear on which would be best to try with this size of shell.

I'm curious about the consistancy as well. Here's what the website that sells it says:

(Chlorez 700, chlorinated paraffin resin) Cream colored powder

Used as a chlorine donor (70% chlorine). -50 mesh, 97%. Solvents are xylene, acetone and alcohol.

It runs about $8.50 US which is a lot cheaper than Parlon, but the only formulae I see using it are the Baechle system ones, which also use a couple of things I dont have like copper oxychloride and stearic acid. So maybe there isn t much point in buying it to save money.

Sorry, your probably right about this wanting to be in the Pyro chemistry forum but I'm not sure how to move it.

Yup, can't see any fault with your sums there. You should of course remember that the "missing" 1.9% in the PVC was in fact carbon/hydrogen i.e. fuel, so it might be wise to increase the amount of red gum by the same amount to keep the heat output up.

Thanks Pyrotrev. It hadn't occured to me consider the non-chlorine part of the chlorine donor as contributing as a fuel.

Judging from the lack of responses on the chlorowax question, I guess its not in very wide use.

As a follow up, I tried out the sweet gum seed which had been soaked in Strontium Chloride solution for about two weeks. I dried the seed out and then coated it in as much of the powdered Strontium Chloride as I could followed by dipping the seed in candle wax. It burned well but I really didnt get any red out of it other than when I pointed a butane torch lighter at it. When burning on its own I got a rich orange color.

I didn't get a chance to try disolving some in alcohol and burning it but I suspect I will get similar results. I'm thinking it may require a higher tempurature than alcohol or something like wax and a pine cone would provide since it did produce some red when I put the butane torch lighter to it.