Re: Tek Made Relays

stefan_trethan
 

Delrin burns with a yellow flame.

It could by Nylon with a blue flame, TPX (Polymethylpentene) or PE/PP
(unlikely).
My money would be on TPX, just because it is weird enough for Tek, but
that is transparent and I do not think they make it white?

So that leaves Nylon, or maybe the "blue flame" was not correct?

Delrin does degrade outdoors into the hard crumbling substance
described, more so the white variety.
I don't know if, given enough time, that will happen without light too.

ST



On Mon, Apr 24, 2017 at 11:14 PM, 'Dennis Tillman' @Dennis_Tillman_W7PF
[TekScopes] <TekScopes@...> wrote:
Hi David,
You co-worker might have been mistaken. That doesn't sound like Delrin at
all. Delrin is a wonderful plastic and as far as I know it is stable and a
dream to machine. One way to tell if it was Delrin is that Delrin is almost
as slippery as Teflon.

This is what one plastics provider said about Delrin
(http://www.sdplastics.com/delrin/delrin[1].pdf):

Delrin is a crystalline plastic which offers an excellent balance of
properties that bridge the gap between metals and plastics. Delrin possesses
high tensile strength, creep resistance and toughness. It also exhibits low
moisture absorption. It is chemically resistant to hydrocarbons, solvents
and neutral chemicals. These properties along with its fatigue endurance
make Delrin ideal for many industrial applications. Parts exposed to a moist
or wet environment, such as pump and valve components, are especially
appropriate. Other common uses for Delrin include gears, bearings, bushings,
rollers, fittings and electrical insulator parts.

Dennis Tillman W7PF

-----Original Message-----
Sent: Monday, April 24, 2017 1:57 PM
Subject: Re: [TekScopes] Tek Made Relays

When I was a newbie at Tek, a coworker referred to the material as Delrin.

He went on to say that Tek had discontinued that style of relay, replacing
them for safety and liability reasons with purchased parts. "They burn with
a beautiful blue flame," he said wryly.

Dave Wise
Information Display 1980-1995
________________________________________
From: TekScopes@... <TekScopes@...> on behalf of
Chuck Harris cfharris@... [TekScopes] <TekScopes@...>
Sent: Monday, April 24, 2017 12:10 PM
To: TekScopes@...
Subject: Re: [TekScopes] Tek Made Relays

The big problem I have seen with some tek made relays is they made an
unfortunate choice of plastics for the relay case. The plastic they used
breaks down into something that is fragile, and emits corrosive gasses.
The gasses corrode the relay armature, and make it stick open or closed.

-Chuck Harris



------------------------------------
Posted by: "Dennis Tillman" <@Dennis_Tillman_W7PF>
------------------------------------


------------------------------------

Yahoo Groups Links


Join TekScopes@groups.io to automatically receive all group messages.