Unable to get Formvar in UK (self-bonding poly instead?)

[22uf]

42 awg Formvar is ludicrously overpriced in the UK. Importing is uneconomical. Likewise PE.
So I have been using Elektrisola 42 awg poly. The regular gold coloured stuff. Works fine for my needs.
However I was wondering if - somewhat crazy idea I know - I could buy a spool of Self Bonding Poly 42awg.
This would be the same bare capacitance per ft as regular poly 42awg, but the additional bonding coating takes the OD to close to formvar/heavy build specs (0.028"/0.7112mm).
In theory (?) that should have the same practical effect as using havy-buil/formvar coated 42awg .. since the OD size is effectively the same?
I ask because bonded poly is actually very affordable and very available in 42awg..

[Antigua]

I think the dielectric values of those materials are close enough that the outer diameter is the dominant factor. I would bet that it would be a suitable stand in, if you're trying to get a target capacitance for it's own sake. If you don't already have a DE-5000 on hand, or a similar LCR meter than can test beyond 50kHz, to compare the capacitance, you'd most likely never be able to tell by sound alone, assuming the difference is no greater than 100pF.

[epizootics]

I assume you are talking about the self-bonding wire from Brocott/ScientificWire?
Just had a look at their website - the cheapest option is to buy a 2kg reel from their bulk website (Scientific Wire) and that still works out at £95.33 (including VAT) per kilogram.
Aren't you better off getting a 5lb spool of heavy build poly from Remington Industries? One of those costs $104, and even if you don't got for the cheapest delivery option (USPS international rather than 'ship by weight'), it still works out at about $220 / £160 shipped. And you get an extra 260g of wire, thanks to the imperial system

Not that there is anything wrong with Brocott's wire - I have bought from them time and time again - but as we say in France, a dime's a dime!

[Mick Bailey]

£160 shipped, plus VAT and import duty (3.5% IIRC,) as the combined goods+ shipping is over £135. Plus the courier/mail service handling fee - Royal Mail usually delivers USPS to me and they charge £8+ VAT. So expect to pay £207.20.