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I thought the white part is made of Delrin, but so far it has shrugged off every glue and solvent I threw at it.
MEK, dichloromethane, hot glue, cyanoacrylate, plastic bonder epoxy, nothing affects or sticks to it.


How can I be sure the material is Delrin, and not say, Nylon?

Hi,

I'm not sure what parts you are referring to, but I discovered "Gorilla
glue" some time ago. This works really well on lots of materials and
requires a little water, clamping and about 2 hours to set. Don't confuse it
with Gorilla super-glue, which is a cyanoacrylate. The info on the package
has the caveat that it is not recommended for use on polyethylene and
polypropylene. Since Delrin is polyoxymethylene, it should be ok, I think.
Try it first on somewhere hidden, as the saying goes.

Good Luck, Colin.



From: TekScopes@... [mailto:TekScopes@...]
Sent: 22 March 2016 01:25
To: TekScopes@...
Subject: [TekScopes] Those funny 311-0603-00 pots





I thought the white part is made of Delrin, but so far it has shrugged off
every glue and solvent I threw at it.
MEK, dichloromethane, hot glue, cyanoacrylate, plastic bonder epoxy, nothing
affects or sticks to it.


How can I be sure the material is Delrin, and not say, Nylon?

For anyone needing to glue polyethylene or other tricky plastics, I think there are special adhesives meant for that. I bought some a while back at an auto parts store, but haven't tried it, so don't know if it actually works. As I recall, it had an extra bottle of a surface-activating chemical that had to be applied before the adhesive. It should help to roughen up the surface too, with an abrasive.

Ed

Hi Snapdiode,
There is a slim chance it might be Teflon which is white and almost
impossible to glue. One way to tell if it is Teflon is that it will feel
extremely slippery to the touch. Another way to tell is that Teflon has a
very high heat resistance. If you hold a soldering iron to it nothing
happens.

Dennis Tillman W7PF

I'll try... I'll also try ammonium bifluoride, if it won't touch it, it's Teflon...

Of course the paradox is, what keeps the grey end cap glued to the pot?

Hi Snapdiode,
There actually is a glue or adhesive (I'm not sure what the difference is in
the terms) for Teflon. I have a roll of Teflon tape with glue on one side of
it that I can stick down on a surface. It is the only time I have ever seen
something stuck to Teflon.

Dennis Tillman W7PF

It melts quite nicely at a temperature that Nylon melts at. I wonder who told me it was Delrin.
Anyhow, I'll try glass etching cream, there's a local store that has it in little bottles.

The idea is still to etch the surface so epoxy will grab it.

Chromic acid will etch Delrin and Nylon, but I don't see how I can make the acid easily locally.

The grey end cap is glued to the white part, so I'd guess it isn't Teflon...

That would depend on how "Butch" the soldering iron is... ;-)

Mitch
N4MF

On Tue, Mar 22, 2016 at 7:48 PM, <snapdiode@...> wrote:

It melts quite nicely at a temperature that Nylon melts at. I wonder who told me it was Delrin.
Anyhow, I'll try glass etching cream, there's a local store that has it in little bottles.

I'm sure Chuck Harris will be posting any minute, but that's the last
thing I'd use. The active ingredient is HF, which will etch glass and
your fingers, but not most plastics.

Hi Mitch,
It is not clear which message you are responding to about melting points -
Snapdiodes or mine.

Teflon won't melt with any soldering iron I have ever had in my 45 year
electronics career. I have Thermal Wire Strippers that melt the Teflon
insulation off wire but the blades on that wire stripper glow cherry red.

Dennis Tillman W7PF

According to the MSDS, etching cream is actually ammonium bifluoride and some other weird chemicals. This has a "severe effect" on Nylon and Delrin.



I wouldn't go near HF with 15 space suits on.

Try Devcon Plastic Welder II. It's a methacrylate structural adhesive. It does not require any etching or special cleaning. Link:

Sounds good but at 45$ for 47mL it's eating into my scotch budget...

It's about $20 with shipping on Amazon.

Or even better: $6 with shipping on ebay:

On Tue, 22 Mar 2016, snapdiode@... [TekScopes] wrote:

Ammonium bifluoride + _ANY_ relatively strong acid => HF + ammonium salt of
that acid. It is simply more convenient and safer to store HF in form of its
salt.

According to the MSDS, etching cream is actually ammonium bifluoride and some other weird chemicals. This has a "severe effect" on Nylon and Delrin.



I wouldn't go near HF with 15 space suits on.




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Posted by: snapdiode@...
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Why don't you save yourself the trouble and buy a new one for $12?



Malcolm

On 23 March 2016 at 04:15, snapdiode@... [TekScopes] <
TekScopes@...> wrote:

Sounds good but at 45$ for 47mL it's eating into my scotch budget...

Because it's probably just as cracked as the three other ones I already have.

Thanks but they don't ship to Canada.

On 03/23/2016 12:15 AM, snapdiode@... [TekScopes] wrote:

Sounds good but at 45$ for 47mL it's eating into my scotch budget...

A man has to have his priorities.

Mark

Oh and I had a moment of sanity and remembered that ty-raps are made of Nylon. Doesn't melt at the same temperature as the pot so I'm back to believing they're Delrin.