Transformer Lamination Refinishing

[Ray Ivers]

I just wanted to pass on some info for anyone who might have to recoat or refinish transformer laminations (perhaps after rust removal, etc.) and wanted the end result to look similar to the original.

I had an '81 Marshall on the bench whose PT lams needed recoating, and after some trial and error I found that Minwax Polyshades 'Tudor Satin' tinted polyurethane was an almost perfect match to the dark-brown Drake lam coating (it seems to be a pretty good match to a lot of other transformers I have lying around here too).

Initially I stirred the can contents well before applying the poly; this was a mistake, the poly is far too transparent to cover well. I let the can sit for a couple of days, then scraped the tint sludge off the bottom of the can and transferred it to another small cup and used that instead; it worked quite well. I had areas of bare metal which I touched up first, then I coated the whole lam area.

The PT looks great now. I didn't touch the OT, and the two units now look identical; same color, same semi-flat finish.

Ray

[Amp Kat]

The stuff you scraped off the bottom was mostly flatting oil. The Minwax and Mc Closkey products settle to the bottom after being on the shelf for awhile. The only draw back to this is the driers in the poly are mostly at the top because they are lighter. Another way of doing color is to add some Minwax 211 provincial and 218 puritan pine together and mix it into a small cup of polyurathane as they are both mineral spirits based and are compatible with each other. The poly shades are cool products but they are quite transparent on woods mainly lighter ones like ash,maple,new cypress,ect... The Minwax Co. also has a product used on floors called Dura-Seal and the colors are much deeper and less transparent than the Polyshades. Benjamin Moore also has a product called Rust converter also by Klean Srtip that converts the old rust to it's original state then you can come back with the tinted urathane and it would work also. Ray could put a tad of Naptha in that mix if it doesnt' dry right but Japan drier would make it crawl . Sounds cool though and thanks for the advice now if I can just find someone to rewind them were coolo