Epoxy resin mixed with enough ground silica to make a stiff paste then rammed into the hole
Robin
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On 19 Aug 2018, at 05:45, ¸é±ð²Ô¨¦±ð <k6fsb.1@...> wrote:
plastic is fairly soft compared to metal, normal thread is 70%, you can use a smaller tap hole to approach 95% thread, use a good sharp tap. plastic threads will hold better and longer with more thread contact.
I have used heli-coil in a few cases. moved to 5-40 or 6-32 in others.
¸é±ð²Ô¨¦±ð
On 2018-08-18 04:27 PM, Bill Riches wrote:
Is the knob large enough to use a 6-32 set screw? If so make sure you use a correct numbered drill with the tap.
73,
Blll, WA2DVU
Cape Mah
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Paul Koretko
Sent: Saturday, August 18, 2018 5:55 PM
To: [email protected]
Subject: [TekScopes] Machinable Potting Material ???
Greetings,
I'm trying to save a couple old plastic knobs that have stripped set screw threads, that don't have brass inserts. I remember reading someplace about a machinable potting material that is easily flowed into a mold. I've tried JB Weld, but it doesn't flow well. It has a tendency to leave void areas. I want to drill a new set screw hole and hand tap it for 4-40 set screw.
I remember seeing some discussion on potting material on one of the groups I read, so I'm asking for help. Any advice will be appreciated. I will also post this to some of the other groups I read.
TNX es 73 de WABAG ..
Paul K.
