Re: Toroid Building

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "D&M's High Voltage, Inc." <dmshv.davmckin@xxxxxxxxxxx>

Gerry,

The taping (paper, masking tape, or even Aluminum foil tape - tried 
that too but forgot to mention it) was to make a smooth surface to 
start with (which also cuts down on weight) by eliminating having to 
fill up the corrugations of the duct.  It's well worth the time 
spent.  I would suggest covering the toroid first with one of 
mentioned tapes, and then apply one (thin) layer of resin (hot or 
not, just so it doesn't run).  Sand the rough part down, then apply 
another layer of resin. Sand the rough parts, then fill in the large 
indentations with bondo, smoothing out as much as possible.  Sand 
them down. Then apply another layer of resin.  Sand down the rough 
parts, and then fill in the indentations with bondo.  Apply another 
layer of resin, etc.  Keep repeating until you have a smooth surface 
(should be a few layers and will require less with 
experience).  Using masking or aluminum foil tape will stiffen the 
toroid quite nicely.  Start sanding with large grit (I was limited to 
60 Grit, but 30 if you can get it for your sander).  Then when you 
get to the last fiberglass layer / sanding operation, step down to 
get a smooth surface without deep sanding swirls.  I finished with 
150 and 220 (final) paper.  Make sure you use a vacuum system when 
sanding, or do it outside!  Use acetone to get a very clean surface 
so the tape will stick really good.

Best regards,

David L. McKinnon
D&M's High Voltage, Inc.




----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Sunday, August 21, 2005 12:14 PM
Subject: Re: Toroid Building


> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
> Hi Tim,
>
> I will probably try either the bondo or the redevil "onetime" 
> product on this toroid.  I will eventually make a 10x40 toroid after 
> I learn from this one.  David from D&M suggested, I think, paper 
> taping the duct first (I presume to save weight), applying the 
> bondo, and then doing the fiberglass resin coatings for 
> strength.  I'm thinking of applying the bondo and filling the 
> corrigations, sanding, varnishing, and then adding the AL tape.  I 
> suppose, I will find out how heavy it becomes and alter the process 
> for the 10x40 toroid.  Dont know how heavy bondo is compared to the 
> redevil product nor how much filling the corrigations will improve strength.
>
> Gerry R
>
> > Original poster: Timjroche@xxxxxxx
> > Gerry R.,
> >     have you tried bondo...easy working, stable, and cheap....or 
> > even the fiberglass bondo for rigidity.....good luck... i'd like 
> > to know what you do... i'll be doin te same in 2-3 weeks.....tim