Gap staging with quickmatch?

Hello All,
I've been working on a scale PWN-10A (Super Loki-Dart) and trying to figure out a good method for gap staging. The first stage motor and second are
about 6 Feet apart so engine to engine are out of the question. I built one with an electronics bay and put together a simple capacitor discharge, deceleration triggered ignition system, but it added un-necessary weight and complicated what is otherwise a very simple rocket. I did some tests last night to determine if quickmatch could be used for a 6 to 6 cluster with very positive results, and that got me thinking perhaps that's the simplest solution to my gap staging problem. The length of quickmatch produces a nice ejection charge for the bottom stages recovery system also.
Before I reinvent the wheel I was wondering if anyone had any experience with gap staging with quickmatch?
-cat
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<reply to off list email>reguarding using AL tubing inside the body of the rocket.
I've been more worried about the rocket separating from the pressure before the top engine had come up to speed. I was thinking about porting the body tube maybe three 3/16" holes about midway up the tube? I really like the idea of adding a perm match tube, I was thinking taking a bt3 and soaking it in waterglass again with some small ports at the base this would (hopefully) push out the parachute (IE: gas pushed from the bottom into -> wadding -> out the top). Another good thing about that would be that I could channel the match along one side of the rocket leaving additional space for the recovery parts... hmm... so many ideas to try!
PS: Anyone ever try fire-proofing with waterglass? How does it improve the structural integrity of the tubing?
PPS: Anyone know of a supplier of the quickmatch piping? Is it used for anything else? That would be a great lead on tracking down a supplier. I have made my own, it's a pain, I have tried heatshrink tubing, and I don't like how it bends, I know one of the pyro suppliers sells short lengths but I'd rather buy a 100' or 1000' spool.
-cat
----------------------------

figure
one
and
simplest
nice
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What is waterglass, in this context? The only thing I found on the net was sheets of glass that looked like privacy glass for bathroom windows...
Eldred
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Eldred Pickett" wrote

Waterglass is a common name for Sodium Silicate. However I'm told that it will make the tube a bit to brittle though to be functional without adding some kind of plasticizer.
-cat
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Is this the old "sodium silicate solution" from my 60's Lionel chemistry set (that I still have of course)? Back then Estes or maybe Centuri sold a flameproofing solution to paint on things like swept fins.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
I'm not afraid of terrorists. I am terrorized by airport security. _george
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I've done it before, over a short distance (a few inches only), because I was worried about stage separation before ignition. I flew that rocket this weekend without QM worked just fine.
I would say go for it - the main thing to consider is that QM does generate a large amount of hot gas and leaves quite a lot of burning debris (depending on type). I find that often it comes apart at the bends if its been folded, but whichever way it often comes apart. If you can find a type of QM which tends to only eject gas from one end, with minimal number of breaks, you might be less likely to toast your rocket. Would it add to much weight to use a length of foil-lined motor tube from Totally Tubular? Perhaps you should try firing 6ft of QM in a tube and see how much toasting happens?
--
Niall Oswald
================================
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Weight is not that big of an issue, as long as it stays below 6oz added. The bottom cluster is 3x24mm to one 24mm. I have not seen this tubing but I will have to check it out. I was also thinking about just adding a thin wrap of AL foil to the match? I'll definitely need to do more ground testing.

Again, good point, and I don't know the answer I will have to try it out and report back.
-cat
v-- orignal below --------------------------------------
"Niall Oswald" wrote

this
generate
type
much
toasting
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.