Ah! you didn't state it was a toroid.
The taping would make it pretty impervious to penetration.
The taping would make it pretty impervious to penetration.
You could try cutting part of the tape to let varnish in, it does not much matter if a 2 x 2 cm or so piece is removed, does it?
Antek transformers have a fairly loose tape. Not the vacuum-sealed shrink wrap you sometimes see. Varnish will penetrate, but have a devil of a time drying. It gets under and stays liquid because not enough air can get to it. I have experimented and it didn’t go well - I just had to un-tape, let it dry, then re-tape. Has anyone tried baking to see if that situation would improve? Just a heat lamp didn’t do squat after three days.
Try my trick, insulating varnish and under load.
It works...the hum causes heat and vibration, helping the varnish penetrate.
Insulating varnish takes a longer time to dry compared to furniture varnish, which might dry, and block new flow to the gap too fast if used in this application.
Think in hours, not minutes and seconds for this to work.
And internal heat would be more efficient than heat from a lamp, I think.
It works...the hum causes heat and vibration, helping the varnish penetrate.
Insulating varnish takes a longer time to dry compared to furniture varnish, which might dry, and block new flow to the gap too fast if used in this application.
Think in hours, not minutes and seconds for this to work.
And internal heat would be more efficient than heat from a lamp, I think.
I was giving some thought to a similar issue how to insulate a 1KVA toroid that runs at 2500v and hit on the idea of an old saucepan and sand. I'd use the fine sand as used in block paving, for extra insulation damping some sort of epoxy could be pored in.
Andy.
Andy.
Epoxy will be hard to pour, unless it is a thin one, and it will set in minutes.
You won't get enough pot life, you need it to flow into the deepest recesses. and the air displaced needs to flow out of the transformer.
You will mix sand in the epoxy, or use it to support the toroid?
Varnish is better suited for this application, at least in my opinion.
The vibration and heat on load make the potting compound flow nicely to where it is needed.
And insulating varnish is easier to remove, and more compliant at heat than epoxy, which cures to rigid, so your air gap may move to a place where local heating causes the winding to break, so your effort goes waste.
You won't get enough pot life, you need it to flow into the deepest recesses. and the air displaced needs to flow out of the transformer.
You will mix sand in the epoxy, or use it to support the toroid?
Varnish is better suited for this application, at least in my opinion.
The vibration and heat on load make the potting compound flow nicely to where it is needed.
And insulating varnish is easier to remove, and more compliant at heat than epoxy, which cures to rigid, so your air gap may move to a place where local heating causes the winding to break, so your effort goes waste.
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@NareshBrd thanks but I think that ship has sailed. There's just no way I'm going to be cutting out that polyurethane at this point. 🙄
@Demonkleaner Yeah 18V secondaries aren't common in the 1000VA category. Was looking at these guys here Amplimo - Toroidal Transformers - Largest Supplier Toroidal Transformers but same problem. They do custom orders but I think at this point I'm going to wait and see if the Alephs will be suitable amps for my future speakers or if I need to build something else anyway. And if they are suitable I'll try and get away with 800VA units which have 18V secondaries available in spades.
@Demonkleaner Yeah 18V secondaries aren't common in the 1000VA category. Was looking at these guys here Amplimo - Toroidal Transformers - Largest Supplier Toroidal Transformers but same problem. They do custom orders but I think at this point I'm going to wait and see if the Alephs will be suitable amps for my future speakers or if I need to build something else anyway. And if they are suitable I'll try and get away with 800VA units which have 18V secondaries available in spades.