I am modifying some DSS satellite feedhorns for use at 10 GHz.
Wondering if JB Weld is electrically conductive after it sets up. I was
thinking I would use JB Weld to build up the outside of the "waveguide"
since after boring it out to 3/4" will only leave a wall thickness of
about 1/16". That doesn't leave much meat for the two machine screws
that will be used to mount the panel mount SMA connector to screw in to.
That's only about 2.5 threads if I use 4-40 hardware or 3.5 threads if
I use 2-56. Not sure what size holes are in the SMA, which will dictate
which hardware will have to be used. God forbid if it takes a 6-32
screw to do the job (2 threads). The mounting screws can not penetrate
into the waveguide. Any other ideas?

Something else I just thought of...once the JB Weld has set up, will I
be able to tap threads into it?

Scott
N0EDV

Nevermind...I found the technical data sheets on the web. Is is NOT
conductive after set up. It has iron filings in it, but since it is an
epoxy, it is not conductive. The good news is that it CAN be drilled,
tapped, machined, etc., just like any metal could be...the mounting
screws should provide the "ground" connection once they are screwed into
the waveguide itself.

Scott
N0EDV

Scott wrote:

I am modifying some DSS satellite feedhorns for use at 10 GHz. Wondering
if JB Weld is electrically conductive after it sets up. I was thinking
I would use JB Weld to build up the outside of the "waveguide" since
after boring it out to 3/4" will only leave a wall thickness of about
1/16". That doesn't leave much meat for the two machine screws that
will be used to mount the panel mount SMA connector to screw in to.
That's only about 2.5 threads if I use 4-40 hardware or 3.5 threads if
I use 2-56. Not sure what size holes are in the SMA, which will dictate
which hardware will have to be used. God forbid if it takes a 6-32
screw to do the job (2 threads). The mounting screws can not penetrate
into the waveguide. Any other ideas?

Something else I just thought of...once the JB Weld has set up, will I
be able to tap threads into it?

Scott
N0EDV

Nevermind...I found the technical data sheets on the web. Is is NOT
conductive after set up. It has iron filings in it, but since it is an
epoxy, it is not conductive. The good news is that it CAN be drilled,
tapped, machined, etc., just like any metal could be...the mounting
screws should provide the "ground" connection once they are screwed into
the waveguide itself.

Scott
N0EDV

THAT ought to provide a little inductance at 10 GHz.

W4ZCB

The SMA is 1/4-36. How about tapping for that and screw in a barrel mount?

On Sat, 10 Jul 2004 10:39:56 +0000, Scott
wrote:

I am modifying some DSS satellite feedhorns for use at 10 GHz.
Wondering if JB Weld is electrically conductive after it sets up. I was
thinking I would use JB Weld to build up the outside of the "waveguide"
since after boring it out to 3/4" will only leave a wall thickness of
about 1/16". That doesn't leave much meat for the two machine screws
that will be used to mount the panel mount SMA connector to screw in to.
That's only about 2.5 threads if I use 4-40 hardware or 3.5 threads if
I use 2-56. Not sure what size holes are in the SMA, which will dictate
which hardware will have to be used. God forbid if it takes a 6-32
screw to do the job (2 threads). The mounting screws can not penetrate
into the waveguide. Any other ideas?

Something else I just thought of...once the JB Weld has set up, will I
be able to tap threads into it?

Scott
N0EDV

Magic stuff, It will take tappings without problem, so long as there
is the material around it sufficient to hold it.

Strangely, here in UK, JB Weld is no longer available. I have a few
spare tubes and was asked if I would sell them to a local engineer
because he could'nt source the stuff anywhere.
atb Mike W.

"Mike W" wrote in message
...

Strangely, here in UK, JB Weld is no longer available. I have a few
spare tubes and was asked if I would sell them to a local engineer
because he could'nt source the stuff anywhere.
atb Mike W.

See http://www.jbweld.co.uk/

Maybe you can become a distributor?

73,

"PM"

I can't find it here in Milwaukee, WI either.

jw

"J999w" wrote in message
...
I can't find it here in Milwaukee, WI either.

jw

Do you have Home Depot stores in WI? HD carries it locally, and I would
think it would be there since Home Time on Public TV is a big supporter of
that show. Isn't that show out of Wisconsin? I hope JB Weld hasn't been
discontinued. Gosh, I'd miss that stuff badly.

Jerry

I can't find it here in Milwaukee, WI either.

Do you have Home Depot stores in WI? HD carries it locally, and I would
think it would be there since Home Time on Public TV is a big supporter of
that show. Isn't that show out of Wisconsin? I hope JB Weld hasn't been
discontinued. Gosh, I'd miss that stuff badly.

It's also available at Orchard Supply (owned by Sears) here in the SF
Bay area.

The home page at http://www.jbweld.net/ shows no suggestion that it's
been discontinued. They list Autozone, Pep Boys, Home Depot, Ace
Hardware, and Western Auto among their national dealers.

A boating-supply store might be another option, for their "Marine
Weld" version.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

They're very much alive & kicking.

I just had an email exchange with them giving my testimonial about how I
fixed massive crankcase-housing damage on my lawn tractor engine with it,
saving myself over $500. They responded by sending me a bunch of goodies,
including a free package of the product, some trinkets, and a $2 dollar
bill.

Great product and nice folks!

Joe
W3JDR


"Dave Platt" wrote in message
...
I can't find it here in Milwaukee, WI either.

Do you have Home Depot stores in WI? HD carries it locally, and I would
think it would be there since Home Time on Public TV is a big supporter
of
that show. Isn't that show out of Wisconsin? I hope JB Weld hasn't been
discontinued. Gosh, I'd miss that stuff badly.

It's also available at Orchard Supply (owned by Sears) here in the SF
Bay area.

The home page at http://www.jbweld.net/ shows no suggestion that it's
been discontinued. They list Autozone, Pep Boys, Home Depot, Ace
Hardware, and Western Auto among their national dealers.

A boating-supply store might be another option, for their "Marine
Weld" version.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Actually, Home Time is out of Minnesota (the Twin Cities). Robin did
spend some time working in Eau Claire, Wisconsin (not far from where I
live now...wish I'd have known that then!) meeeeeow!!

Scott


Jerry wrote:

"J999w" wrote in message
...

I can't find it here in Milwaukee, WI either.

jw


Do you have Home Depot stores in WI? HD carries it locally, and I would
think it would be there since Home Time on Public TV is a big supporter of
that show. Isn't that show out of Wisconsin? I hope JB Weld hasn't been
discontinued. Gosh, I'd miss that stuff badly.

Jerry