Aside from such obvious things as not using a metal capsules with HMTD and avoiding any metal but Aluminum or Tin with picric acid, are there any other compatibility issues between the metal of detonator capsules and the common primary or base charges, especially in longer term storage? Copper and brass in particular are both somewhat reactive towards oxidizers, and Copper catalyzes many decomposition reactions.

In the Blaster's Handbook there are several references to using one material or another for the capsule and lead wires of electric caps- But these are all from the point of view of what might be an unacceptable contaminant in the raw material being blasted. There is one thread here (that is, in the forum) that recommends Copper for fulminate caps and Aluminum for all others, but no specific reason is given.

Since lead azide was, and still is, very common in different kinds of detonators, I guess the reason why the Blaster's Handbook recommends only using copper for fulminate caps is to avoid the possible formation of copper azide.

O.K.- Starting to answer my own question...

First piece of information: Lead azide is not compatible with brass or Copper detonator capsules? Would Silver azide be similarly incompatible? How about Lead styphnate?
That would be inconvenient. Copper is such a widely available material and so easy to form, as I've learned while making my own 6mm benchrest bullets.

I'm sure there are more primaries and base charge materials that Copper is incompatible with besides picric acid or its salts, HMTD and Lead azide- Could someone with a bit of experience in these matters take a minute to post that information or suggest where I might find it in one place, rather than piecemeal?

I have a fair grasp of the chemistry of high temperature flames, but only as much knowledge of solution chemistry as has been needed to safely process waterbound compositions. Kind of the reverse of most of you chemistry types-

Thanks in advance-

I have read that my favorite primary, azo-clatrate, does not react to copper. It contains lead azide, but it is locked into the matrix of the clatrate and is not free to react. I plan on testing this myself before attempting any compound dets in a copper casing.
If you wanted to use a incompatible material, a coating of paint or wax could be used to protect the capsule. There would be some risk of the coating being damaged during pressing, so a compatible case would be preferable.

I am going to obtain a bag of those quite wonderful looking jackets and do some "bullet swaging" myself.

I've found several references to azo-clathrate (clatrate?) in the forum and on google. I've been unable to locate the preparation however- Could you direct me to that?

Bert,

have you got any stuff on the process you are using to form your copper benchrest bullets? That sounds like it could be fun.

e-mail me. It's not really on topic- It might belong in the tools, techniques & plans? Or water cooler...

Bert,
Here are the patent (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=3431156.WKU.&OS=PN/3431156&RS=PN/3431156) and the thread (http://www.sciencemadness.org/talk/viewthread.php?tid=501) referring to the azo-clathrate primary. I love this stuff, high performance, safe, stable, and easy to make. The only real concern is the toxicity of the precursors. The best part is you can make 24 grams of azo-clathrate with only 5.3 grams of NaN₃.

grendel23- Thanks!
I looked at the patent information. As they had mixed 25% ground glass with the various products for testing, the sensitivity information isn't too applicable to the straight product. Has anyone done drop hammer and/or friction shoe tests of this stuff? From practical experience, how does it compare to Mercury fulminate or Lead azide in sensitivity to handling?

Hey, why not just use plastic tubes for detonators, I dont think that any explosive will react with plastic.

Unless you have an explosive such as MEKP which is a solvent ^^ or nitromethane.

Oh shit why didnt i think of that. Sorry of that I dont have much of a brain.
Whats the VoD of MEKP? It is not a strong explosive right.?

Detonators can be made with plastic casing or even caseless without too much trouble. Caseless detonators have better initiation ability due to the more intimate contact between donor and receiver charge, but the problem is that they are somewhat less resistant to rough handling than the metal-cased variety.

MEKP is in the same range of VD as HMTD and AP around 3500-5000m/s

I want to make a cap with .1 grams of milled BP. That is kno3, sulfur, commercial charcoal, and trace contaminants of lead (from the milling process). The BP will be the first fire composition, .1 or .05 grams. Next I want to use .15 grams of double salts, and immediately after that 1 gram of PETN. I was also thinking about using .5 gram PETN and .5 to .75 grams of picric acid as well. I will do tests to see what is best.

I have some plastic casings but it just deforms all to hell while pressing. I am going to use some paper tubes, as these are actually stronger. After I can get into town, I will get some 1/4" ID aluminum tubing to use.

Does anyone see any chemical incompatibilities with my setup. I have done some research, but another set of eyes usually can pick up on something that might be right in front of me.

I will be doing tests against 1/8" steel sheet, and I will have pics.

I discovered the parfume sample capsules with volume of about 0.25-1ccm are wonderful and quaranteed without suspicion readily available small detonator cap shells that do not pose shrapnel threat like rifle shells do. They're made out of hard opaque plastic or even glass and can be pressed full with no fear of deforming. Probably one can obtain hundreds of them by taking a single trip to nearest mall or shopping centre. Usually they've given off free of charge.