[ARC5] [Boatanchors] Coils and the winding thereof

[Roy Morgan]

On Jul 3, 2009, at 5:09 PM, Michael Tauson wrote:

> On Fri, Jul 3, 2009 at 7:18 AM, Carl<km1h at jeremy.mv.com> wrote:
>> Hold the windings in place with Q Dope which is era correct. Even  
>> National had it in their
>> 1934 catalog ands its use in QST goes back long before that. GC  
>> sells it today.
>
> It's still available?  Ooooh, cool!  I gots ta gets me some!  Thanks!
...I used Q dope but not all the
>
> time.  It was a "special cases" material

It appears that "Q Dope" is the Genral Cement brand name for what we  
often call coil dope.

Q dope can be made at home with some polystyrene and the right  
solvent. A peek at a commercial container will tell, or poke around  
the net or the General Cement website for the MSDS.   I just did for  
you: See:
www.action-electronics.com/gcelect.htm

One other link,
http://www2.itap.purdue.edu/MSDS/index.cfm?letter=Q
Leads to:
Polystyrene Synthetic Resin
Methyl Ethyl Ketone 65%

So there you have the formula (I assume it means by weight.)

Also, a QST Hint and Kink entry reported many years ago that some  
clear toothbrush handles can be dissolved in the right solvent to make  
coil dope.  Try the MEK and report the results, will someone?  I think  
the cheapest type of toothbrush has been recommended.

I've heard that some packing peanuts are made from polystyrene, but it  
takes a LOT of them to make even an ounce or two of the coil dope.

Note that Polystyrene can be used at  microwave frequencies (radar)  
but not plexiglas.

Plexiglas cement is not the same thing.  If you try to repair a B&W  
coil with plexiglas cement/solvent,  you'll just make a mess. If  
you've made a coil with strips of plexiglas, you'll be fine.

With apologies to Rhome and Haas for not capitalizing plexiglas,
Roy


Roy Morgan
k1lky at earthlink.net
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Groton NY, 13073
Home: 607-898-3607
Cell: 301-928-7794