(no subject)

[Edward R. Wendell IV]

Those weren't legal at the last shop I worked at mainly because the  
aircraft manufacturer (Bombardier Aerospace) didn't approve of them. We  
instead used a crimp butt splice also made by Raychem. It was a two  
part item: one part was the inner copper barrel that got double crimped  
with the correct Raychem crimper and the other part was an outer  
insulating shrink sleeve with hot glue in each end (woe to the person  
who, after trimming the wire to the precise length required, forgot to  
slide the shrink sleeve on the wire before crimping). We did use solder  
sleeves for attaching jumpers to the outer braid on shielded wires and  
we used heat guns exclusively because the infrared guns were "too  
expensive". A nozzle that wrapped around the wire was required,  
otherwise the solder ring would only melt in spots and you'd end up  
with a cold (poorly conducting) junction. I must say that the one time  
I got to use a infrared gun it worked a lot better. No burning of the  
fingers and the solder melted right away without the danger of melting  
the plastic.

It should be noted that aircraft manufacturers in general shy away from  
soldered connections but I believe that it has as much to do with  
quality control and lower training requirements as it does with any  
concern with the strength of a soldered joint. Wires at any connection  
point must be mechanically supported in any case. If a technician is  
using the correct calibrated crimper with the correct terminal there is  
almost a guarantee of having a proper connection both electrically and  
mechanically. Soldered joints require much more care on the part of the  
technician and proper technique that only comes with a combination of  
classroom and practical training. When I took a high reliability  
soldering course in the Air Force it was a two day affair. Even though  
I had owned and used a soldering iron since age 9 I had a few failures.  
Particularly important was the application of a heat sink on the part  
of the wire between the end of the insulation and the terminal so the  
solder could not wick up the wire under the insulation and cause a  
stress riser that could lead to fatigue failure.

> From: Richard J Lebens <rick-l at rocketmail.com>
> Subject: Re: crimping technique??
> To: quattro at audifans.com
> Message-ID: <20041025210945.80401.qmail at web12508.mail.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> I've was a spectator through the solder - heat shrink - crimp debate
> for your O2 sensor but how do these Raychem splices work?
>
> http://www.raychem.com/US/datasheets/REVISED32004/Sec_8/8-006_8- 
> 011_SolderSleeve.pdf
>
> The aerospace industry seems to be in love with them.  I know you're
> supposed to shrink them with an IR gun but I was playing around and a