About scraping and painting a power transformer

[Colas LeGrippa]

I am transforming a solid state MarkBass guitar  amplifier into a small tube amp that I will try to sell. The power tranny I have in stock is kinda rusty and needs to be painted for a better look.
I know the bells can be painted, sanded even drilled with no prob. but what about  the laminations?


Thanks.


Colas

[PRR]

Don't scrape so hard you deform the steel.

Wire brush and Rustoleum should last forever indoors, 5 years in a damp garage.

[jjasilli]

Checkout some hits on this page:  https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=rusty+transformer+laminations&*


Laminations are a problem.  They must be insulated from one another, so they are individually coated with varnish.  If the varnish is scraped away and the laminations make physical contact with one another, the performance of the tranny is degraded.  There seems to be more than one school of thought on what, if anything, to do about rusty transformers.

[frankenxtein]

I've got a bit of rust on a real nice Thordarson , I don't have a steel brush , lucky me If it moves salute it , if it doesn't paint it. lol

[Beezerboy]

air is a poor conductor of flux lines, the laminations are there to focus and "guide" lines of flux.  the chemistry of the steel they use the plates is designed for high permeability and resistivity... it conducts flux lines well and electricity not so well, both characteristics reduce eddy currents. the steel has a natural oxide coat, sometimes they add other coatings.  even if there were no coatings at all.... the effect would still be there simply because the stacked plates are not homogeneous.... the only way to totally eliminate that effect is to weld it all into one monolithic block.

soooooooo........ surface rust on the outside... I seriously doubt there is any detectable difference even with lab equipment. rust on the contact surfaces of the plates down through the core maybe, but I don't see how thats even possible

as for rust making it better.... I doubt that too
 

[kagliostro]

A piece of rough woolen fabric and paint diluent, strong rubbing on the laminations

when is dry you can paint it newly

Franco

[frankenxtein]

Guess I shouldn't put any cleaners , oils , solvents or "Red Lead" primer on , this Thordarson 26R46 , the only transformer I have with a bit of rust. A little flat black Krylon on the two sides effected would make it look nice again and , shouldn't make it weigh much more.  LOL

Some of the articles "High Temp Paint" lol , If your getting this stuff that hot , rust is the least of your worries eh?     

[uki]

What about some WD or the likes to kill that rust ?!

[shooter]

If it moves salute it , if it doesn't paint it. lol

I got a little frustrated with a Midshipman that ordered me to put together a crew and paint the deck at 2am, in a nasty squall, so when the ship pitched, he got painted, I got Captains mast, I won

[kagliostro]

If you use WD or other oil based, a small part will fall inside the laminations and also if you use diluent after that

you are not sure all the oil comes out and if you paint on oil ..................

--

BTW, on the old times, lamination were abandoned to rust before to be used on transformers

rust was used as a form of isolation between laminations

Franco

[frankenxtein]

If it moves salute it , if it doesn't paint it. lol

I got a little frustrated with a Midshipman that ordered me to put together a crew and paint the deck at 2am, in a nasty squall, so when the ship pitched, he got painted, I got Captains mast, I won

Those Midshipman never came near us , V2 division (Cat Crew) CV42 & CV66, the MAA wouldn't even come around. I've always lived in a rough neighborhood , I still do.   

[pompeiisneaks]

I was infantry, in the army, where we were, nobody wanted to be... and as soon as we made it livable, they kicked us out and took it over, and sent us to some other shithole :P

~Phil

[Beezerboy]

wire brush or sand, don't worry if you don't get it all. hit it with naval jelly if you like... it has phosphoric acid that converts the remaining rust into a phosphate. then paint. there are other rust killers but mostly all the same.... acid conversion. there are also rust killer paints that have the conversion coating built in.... one I use is Marhide. another good line of products is POR (rumored to stand for Paint Over Rust) which they say you can do. kinda spendy but wow does that stuff stick. or... as mentioned, BBQ grill paint, it seems to be the toughest of the common rattle can paints

[frankenxtein]

I was infantry, in the army, where we were, nobody wanted to be... and as soon as we made it livable, they kicked us out and took it over, and sent us to some other shithole :P

~Phil

+1  Phil
Probably didn't have to paint a lot .... eh? 

This same topic
http://el34world.com/Forum/index.php?topic=14251.0

 Another even gets to High Temp BBQ paint.
http://www.tdpri.com/threads/painting-transformers.144447/

Unless you gouge the lamination's cleaning one of these up a bit , I can't see how you could damage it , short of , dinging the winding. That varnish is in between the lamination's ?

I have two different spray cans here:
 One is the MalWart $1 gloss black enamel  (alphatic hydrocarbons Ketones, and tolulene) 4 hours between coats ..... Gloss paint dries slow and , this stuff would bond to the varnish ?

The other is Krylon Dual Superbond Paint and Primer  flat black (Acetone,propane,n-butyl acetate,butane,alphatic hydrocarbons,ethyl 3-ethoyxpropionate , xylene) 6 hours between coats 25min dry touch , handle in one hour $4 at MalWart Not sure what effect this would have.

Only one end on this Thordarson has varnish , the other three sides are bare metal.

The Essex transformer , I'm fixing to use has been painted the same color , you see in photo's , of some Stromberg Carson amps. Not heavy enough to , not see the separations between the lamination's.

I'd guess you could clean off what you can and put a single light coat of paint on it? Maybe transformers dissipate heat through the pretty much unpainted sides. The Japanese transformer I have is painted , not heavy , but you can see it's painted all the way around.   

I only have one transformer with rust and the only reason the others aren't painted , I'm lazy  ...  Mature iron is all I have so , this is of interest to me , not cosmetic so much but , ........ rust being okay ........... , sounds like a used car dealer claim.

[pompeiisneaks]

+1  Phil
Probably didn't have to paint a lot .... eh? 

Actually I did have to paint our battle signs on our Bradleys before we went in for the big drive across Iraq to Baghdad, and that wasn't fun in the Kuwait heat :P

~Phil

[HotBluePlates]

Probably didn't have to paint a lot .... eh? 

Actually I did have to paint our battle signs on our Bradleys before we went in for the big drive across Iraq to Baghdad, and that wasn't fun in the Kuwait heat :P

Having been in the Navy and the Army, painting Bradleys wasn't painting.  Not like the Navy guys mean it, anyway.

(All in good fun; though I did gut & refurbish nearly 300 spaces on a carrier undergoing half-life overhaul.  Navy is forever chipping paint or painting what they chipped.  But Kuwait in the summer is a ..... special experience. As I found out in the Army.)

[shooter]

forever chipping paint or painting what they chipped

For some reason every time the paint cans n needle guns came out my radar system went down

[frankenxtein]

forever chipping paint or painting what they chipped

For some reason every time the paint cans n needle guns came out my radar system went down

Worn Out Needle Guns made more noise than chipping anything , Bug Juice ..... Coffee with an oil slick , JP5 showers ,  Palma Majorca 

[Beezerboy]

"For some reason every time the paint cans n needle guns came out my radar system went down "

not all paint is radio transparent

[John]

I think Shooter meant he would "find a problem" he had to work on instead of chipping and painting.


I would have, anyway.

[shooter]

"find a problem"

Yup!
The cool thing was, Wayne and I were "tweaking" the receiver one "paint day", then did some testing on the tomcats and found we had increased the effective missile lock range of the Radar by almost 30miles over the OEM spec! We couldn't do anything about missile flight time but we could see 'em coming sooner