Cleaning Transformers?

[Chuck_Farlee]

I found several old transformers which were stored in a shed for quite a while. They all have a layer of dust, grime, etc. on them. What is the best way to clean them?

They were for a pretty high powered SS amp. Most of them are 70VCT@3.5A or so.

chuck

[Chuck H]

Don't rough up the lams any more than needed. You can wear off the original varnish. Or worse, you could cross hatch etchings across the laminates so they are in contact with each other.

What I've done with slightly rusty trannies in the past is just use a tooth brush and a small amount of naval jelly, scrubbing in the direction of the lams only. Then wipe clean with a soft cloth damped with paint thinner (not too wet) and allow it to dry for a day. Then apply a coat of Rustoleum rust inhibitive enamel. That will remove the oxide that is there now and slow down any further rusting.

Chuck

[Chuck_Farlee]

Chuck,

Thanks for the tips.

There is no rust on them, just caked on dirt/dust. How about using Simple Green or something like that to loosen the dirt? Obviously I don't want to submerse them in water.

chuck

Don't rough up the lams any more than needed. You can wear off the original varnish. Or worse, you could cross hatch etchings across the laminates so they are in contact with each other.

What I've done with slightly rusty trannies in the past is just use a tooth brush and a small amount of naval jelly, scrubbing in the direction of the lams only. Then wipe clean with a soft cloth damped with paint thinner (not too wet) and allow it to dry for a day. Then apply a coat of Rustoleum rust inhibitive enamel. That will remove the oxide that is there now and slow down any further rusting.

Chuck

[Bruce / Mission Amps]

Don't rough up the lams any more than needed. You can wear off the original varnish. Or worse, you could cross hatch etchings across the laminates so they are in contact with each other. ...
Chuck

Neither roughing up the laminations, a small amount of surface rust, scratches or cross hatch etching of the laminations will really effect the transformer to any noticeable degree so just clean it off with a brush and forget it.
This is a common fear of novice builders using salvaged iron and it should not stop you from using them.

[Chuck H]

"Neither roughing up the laminations, a small amount of surface rust, scratches or cross hatch etching of the laminations will really effect the transformer to any noticeable degree "

I know that. But it cant be good practice to ignore what the MFGs clearly tried to do when they built the unit. In truth I usually use a brass wire toothbrush to clean and then follow with spray paint.

We've all heard the reasoning behind not cross hatching, rust or otherwise creating continuity between the laminations. And while I can't imagine saturating a transformer enough for it to really matter in most amps, I have seen some marginal or maybe even under rated transformers in use on stock tube amps.

That, and I try to give advice on the cautious side.

Chuck