[Boatanchors] [Milsurplus] Drying Out an Open Frame, Large Power Transformer.

[Richard Knoppow]

       FWIW,  when I worked for Hewlett-Packard we routinely washed 
instruments sent in for repair unless they were almost new.  The routine 
ended with baking in a temperature controlled electric oven set at about 
130F.  The minimum time was 48 hours but I preferred to leave stuff for 
as long as five days if possible.  Open frame transformers usually 
survived.  The ones we worried about and removed were hermetially sealed 
units.  That sounds odd but  the corporate experience was that these 
transformers often developed small leaks which allowed some moisture to 
get in but made it very difficult for it to leave again.  An oven of 
this sort would be ideal if available but in its absence one can make as 
sort of makeshift oven from a couple of cardboard boxes with 
incandescent lamps for heaters.  There should be a few holes cut in the 
cardboard to allow ventillation.   Gas ovens often produce a lot of 
moisture, it depends on how well the oven itself is isolated from the 
burner, but I think electrical heating is better.

On 5/8/2015 2:41 PM, n2lxm at juno.com wrote:
> Good afternoon David,
>
>          The low heat approach is slow but the way to go if you don't have
> anything else. I found any old electric oven, hooked up in my garage, set
> it to low (about 100 deg) and used it to dry out radios and magnetics.
> Once dry you should do an insulation test( sometimes called Hi-Potting)
> to see if anything has sorted or shifted in the core. If that passes then
> you should be good to go.
>
>
>                                                      Jeff N2LXM
>                                                        American
>                                                          Patriot
>                                      Proud Father of Two U.S. Marines
>
> ____________________________________________________________
> High School Yearbooks
> View Class Yearbooks Online Free. Reminisce & Buy a Reprint Today!
> http://thirdpartyoffers.juno.com/TGL3141/554d2dc0e116a2dc02ec0st03vuc
> ______________________________________________________________
> Boatanchors mailing list
> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Boatanchors at mailman.qth.net
> Message delivered to 1oldlens1 at ix.netcom.com
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL