Re: Garolite (G9, G10, G11) questions.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Parpp807-at-aol-dot-com>

In a message dated 6/8/02 9:51:49 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Sam, Terry,

Sam, nice to see you back on the list. As I recall, you were experimenting 
with 
ignition coils when I first lurked the list. Glad to see you posting again.

Lots of snips and my $0.015: 

Pictures of my use of G-9, G-10, and Delrin can be seen at:
http://hot-streamer-dot-com/temp/RalphsCoil/

> Even Delrin will break if you
> hit it hard enough, but Delrin IS my material of choice for "plastic stuff."
  
My various uses of Delrin can be seen on the SRSG. the spacers for the
helical primaries, and the side supports for the large 48" bipolar. Delrin is 
the white stuff. The 3/4" rods and tubes are all Delrin. It is strong and it 
is very easy to machine. It taps easily and neatly. The spacers for the 
solenoid primaries are
strips of Delrin with holes drilled to the proper spacing, drilled and tapped 
for 6-32
nylon screws, and then cut into two pieces on the band saw. After several 
tries
with the Wal-Mart plastic cutting boards, Delrin is far superior to the other
acrylics and Lexan. 

> GPO3 - That red stuff that is used in everything electrical.  It has
> amazing resistance to surface and electrical arcs but it is "soft" and the
> fibers in it are random.  Great electrically but I worry about the
> strength.  It is glass fiber in polyester resin?  Not good for a gap but
> great for other electrical insulating needs.

If you are going to dull your tools do it on Garolite, G-9, 10, 11.
In addition to being soft and difficult to machine, GP03 does not thread 
as neatly as Garolite. 

In my pictures, G-9 is brown in the SRSG, and G-10 is green in the static 
gaps.
G-9 and 10 are very similar. I can't see any difference in machinability, 
they are both very difficult to work with but the results is worth the 
effort. G-9 is supposed to have better resistance to arcing. Does anyone know 
what that means? For a RSG I would
use the 3/8 thickness. The 1/4 inch is OK for the other uses. Use zirconium 
drills
with a light oil such as WD-40 or turpentine. Drill in steps of small 
increments,
don't try to blast your way thru a 3/8 or 1/2 inch hole. I cut the Garolite 
on the band saw using a hardened, 4 TPI blade. I threw out the blade after 
cutting the 3/8 x 10 in
diameter disc for the SRSG. I use the shop vac to suck up the cutting dust 
from
the drilling and sawing operations. That dust is mean stuff.

McMaster-Carr is my favorite source for plastics and metals.
www.mcmaster-dot-com.

Cheers,
Ralph Zekelman
  
>  G10/FR4 is the common PC board material used in quality electronics.  Rock
>  hard and impervious to physical damage.  Flame proof, projectile proof,
>  chemical proof...  Woven glass fiber in epoxy.  It "can" be damaged but
>  everything else on the gap will disintegrate first.  Not too expensive
>  since it is so common and easy to find.  The material of choice for my
>  gaps.  You can burn it up but it is too hot then anyway.
>  
>  G11/FR5 - The new and improved version of G-10 with better chemistries.  I
>  don't think one would notice any difference over G-10 except for a
>  remarkable jump in the price.
>  
>  G5/G9 G-wizz :o))  Another version of glass epoxy.  it is supposed to be
>  stronger but I don't think it matters.  Only a little more costly than
>  G-10.  Melamine resin...  Might be fun to try.
>  
>  There is also a G-7.  Silicone is used instead of epoxy.  Great electrical
>  and heat properties but I am not sure how strong it is.  This price is
>  shocking...  I don't know much about this one but it looks interesting...
>  
>  I would avoid Teflons since they burn with wildly toxic gasses, cold flow,
>  expensive...  The glass filled is used at work now but I would not use it
>  for a gap.  Too weak really.
>  
>  There are "super phenolics" with like woven Kevlar, carbon fiber, arimid
>  (sp?) fiber... in them but the cost is not worth it unless you need a gap
>  than can go to war (with a similar budget and suppliers).  I think these
>  are known as military or ballistic grades.  Probably have to answer lots of
>  questions to buy them.  I think they are export controlled and all that...
>  If you are feeling lucky, I guess you can make them yourself for a fraction
>  of the cost.  "You" would probably have the skills and knowledge to do 
this ;
> -)
>  
>  So "i" would just get good o'l G-10.  If you want to get a little exotic
>  maybe G5/G9.  I think you would waste too much money on G11/FR5.  Really,
>  these materials are far stronger than you need and you will not have to
>  worry about them.  They are still much better than the canvas versions.
>  The glass filled stuff at greater than 3/8 inch will break the motor,
>  mounts, and electrodes before it breaks...  I have never known "thick" G-10
>  to delaminate unless you take a torch to it.  A high powered rifle round
>  "might" go through it but shattering is not an option.
>  
>  Of course, all the glass phenolics will eat tools like crazy!  Cut the disk
>  on a band saw with cheap blade you plan to discard.  Any cheap blade will
>  dull just as fast as an expensive one here.  Table saws with carbide blades
>  eat through it and survive for a one time thing just fine.  TiN drill bits
>  or even cobalt bit$ will drill the holes and survive too.  Don't even think
>  about milling it.  You don't need to anyway.  I just mount the disk in the
>  motor and use carbide sand paper and a hard surface to true up the circle.
>  Sort of a power sander in reverse.  Better than a lathe IMHO.
>  
>  The dust is nasty like finely ground fiberglass insulation.  Get a good
>  mask, gloves, and wash/clean up good afterward.  It never bothered me, but
>  check to be sure there is not anyone around that will not like such dust
>  since it is pretty irritating to some folks.
>  
>  
>  Cheers,
>  
>   Terry
>  
>