[ARC5] Tape

[Robert Eleazer]

In May 1986 we lost a Delta booster due to wire chafing through the teflon insulation, which produced a short circuit large enough to kill the engine.  

Experimentation showed that in a chafing situation with teflon insulation you will get a large short, followed by a couple of smaller shorts, after which the charring of the insulation leads to no more shorts in that spot.  Of course if its the wrong circuit in a rocket it may have been all over at the first short circuit.   

Some years ago I built a 2M 5/8 wave antenna out of 300 ohm twin lead.  SWR looked good.  Then I stuck it in a piece of PVC pipe and sealed it with RTV.  SWR went to hell.  Aside from that, the usual RTV available commercially evolves acetic acid during curing and sealing it inside something with no venting leads to corrosion.

I made some multisection caps by sticking radial caps inside some pill bottles and bringing the leads out via some feed throughs.  Then I pumped a bunch of hot melt glue gun glue in.  Subsequent cap leak checks are a bit worrisome..  Anyone know how that stuff does?

Wayne