That method is used in amateur rocketry quite often as fiberglass-epoxy is
lightweight and strong. You do need some experience with the method.
Iâ??m guessing most coilers prefer to use premade forms for the simplicity.
On Thu, May 19, 2022 at 11:28 PM Tedd Dillard <tedd.dillard@xxxxxxxxx>
wrote:
> Is there any reason besides difficulty to use a cardboard tube or other
> material as an arbor and use fiberglass fabric and epoxy Resin to make a
> form?
>
> On Thu, May 19, 2022, 6:00 PM <pupman.com@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > US plastics sells extruded 4" OD acrylic at $71.58 for a 6 foot piece,
> > which isn't too bad. A local plastics supply house if you have one can
> > chop it up if they have it in stock. 24" might fall into the scrap
> > category too.
> >
> > Acrylic is pretty, and solvent welds nicely. It's free of compounding
> > agents that leak out too.
> >
> >
> >
> > On Thu, 19 May 2022, Joshua Thomas wrote:
> >
> > > " It can be noticed that PVC isn't used in the electrical industry
> > outside
> > > of low voltage wire insulation. It's not a great choice, especially for
> > > high voltage applications. We just use is as it's good enough, and at
> > > least in north america, very available, and at a reasonable price as
> it's
> > > the cheapest of all plastics."
> > >
> > > No kidding! I tried pricing 4.00" OD acrylic and polycarbonate - yikes!
> > 24
> > > inches of acrylic was over $225.
> > >
> > > On Thu, May 19, 2022 at 9:12 AM <pupman.com@xxxxxxxxxxxxxxxxxxx>
> wrote:
> > >
> > >> In general, PVC cannot be epoxied.
> > >>
> > >> There is nothing wrong with mechanical fasteners on a PVC pipe.
> Anybody
> > >> with internal arcing on the inside of secondary is doing something
> else
> > >> wrong. The voltage at the bottom of the secondary is zero. There is no
> > >> reason to overcomplicate something as simple as a binding post.
> > >>
> > >> PVC pipes are not clean when you buy them.
> > >>
> > >> Wash and scrub them, including the bore before use. You don't know
> what
> > >> release agents or plasticizers are on those surfaces. PVC pipes (or
> > >> anything made of "PVC") is a complex mix of additives as pure PVC is
> > >> completely useless as a final product.
> > >>
> > >> It can be noticed that PVC isn't used in the electrical industry
> outside
> > >> of low voltage wire insulation. It's not a great choice, especially
> for
> > >> high voltage applications. We just use is as it's good enough, and at
> > >> least in north america, very available, and at a reasonable price as
> > it's
> > >> the cheapest of all plastics.
> > >>
> > >>
> > >> On Wed, 18 May 2022, Joshua Thomas wrote:
> > >>
> > >>> Hi Jim,
> > >>>
> > >>> It looked to be the copper side that failed. I had cleaned both
> > surfaces
> > >>> with isopropyl before using the epoxy; perhaps I needed to wait a bit
> > >> long
> > >>> for the iso to clear up.
> > >>>
> > >>> I really not have had any great results trying to use epoxy (Bob
> Smith
> > >>> brand, in this case) with plastic surfaces; but most of my epoxy
> > >> experience
> > >>> is with amateur rocketry, which uses material like phenolic and
> woods.
> > >>>
> > >>> Joshua Thomas
> > >>>
> > >>>
> > >>>
> > >>> On Wed, May 18, 2022 at 8:14 PM Lux, Jim <jim@xxxxxxxxxxxxx> wrote:
> > >>>
> > >>>> On 5/18/22 4:43 PM, Joshua Thomas wrote:
> > >>>>> Hello Mads,
> > >>>>>
> > >>>>> Thank you for reminding me of your site, I had used it before as a
> > >>>>> reference. I have been sticking to the ?rules? of not putting any
> > holes
> > >>>> in
> > >>>>> the secondary, but I see you?ve gotten away with it on occasion. I
> > >> might
> > >>>>> try using a nylon bolt threaded from the inside to outside as a
> place
> > >> to
> > >>>>> terminate the bottom of the coil.
> > >>>>>
> > >>>>> On that note, do you have any recommendations for adhesives for
> > >>>>> plastic-plastic (pvc) and metal-plastic bonding? The epoxy I used
> to
> > >>>> hold a
> > >>>>> piece of copper to a pvc pipe was a complete failure.
> > >>>>
> > >>>> Which side of the joint failed? The copper or the PVC? You have to
> be
> > >>>> scrupulously clean.
> > >>>>
> > >>>> I use silicone sealer (like for tubs or aquariums) for a general
> > purpose
> > >>>> "glue" - it sticks to most stuff pretty well. It's not good
> > >>>> structurally, but for something that's not seeing a lot of loads it
> > >>>> works ok - good epoxy joints are stronger than the material in some
> > >> cases.
> > >>>>
> > >>>>
> > >>>> _______________________________________________
> > >>>> Tesla mailing list -- tcml@xxxxxxxxxxxxxxx
> > >>>> To unsubscribe send an email to tcml-leave@xxxxxxxxxxxxxxx
> > >>>>
> > >>> --
> > >>> Joshua Thomas
> > >>>
> > >>> My new email address is: joshuafthomas@xxxxxxxxx
> > >>> Please update your information if you have not already done so.
> > >>> _______________________________________________
> > >>> Tesla mailing list -- tcml@xxxxxxxxxxxxxxx
> > >>> To unsubscribe send an email to tcml-leave@xxxxxxxxxxxxxxx
> > >> _______________________________________________
> > >> Tesla mailing list -- tcml@xxxxxxxxxxxxxxx
> > >> To unsubscribe send an email to tcml-leave@xxxxxxxxxxxxxxx
> > >>
> > >
> > >
> > > --
> > > Joshua Thomas
> > >
> > > My new email address is: joshuafthomas@xxxxxxxxx
> > > Please update your information if you have not already done so.
> > >
> > _______________________________________________
> > Tesla mailing list -- tcml@xxxxxxxxxxxxxxx
> > To unsubscribe send an email to tcml-leave@xxxxxxxxxxxxxxx
> >
> _______________________________________________
> Tesla mailing list -- tcml@xxxxxxxxxxxxxxx
> To unsubscribe send an email to tcml-leave@xxxxxxxxxxxxxxx
>
--
Joshua Thomas
My new email address is: joshuafthomas@xxxxxxxxx
Please update your information if you have not already done so.