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    Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

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    JD2
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    Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by JD2 on Sun Jun 05, 2011 12:59 pm

    And, can you repaint without pulling any of the screws?

    Bob Latino
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    Location : Massachusetts

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Bob Latino on Sun Jun 05, 2011 2:21 pm

    You can repaint without pulling any of the screws but if you do, the screw heads and the nuts and some screw threading on those screws that are on there now will get paint on them. You could "mask off" the screw heads with masking tape but it is better to remove ALL the original screws and use some other screws to hold the covers on temporarily. These temporary screws will get paint on them but the original screws will be free of paint. The transformer screws (IMHO) look better without any paint on them.

    Bob

    Scott R
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    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Scott R on Wed Jun 08, 2011 2:14 pm

    I have noticed high temp paints that require curing at 200 degree F for 20 minutes. If used on the tranformers in your kits it seems to me that as the transformers get pretty hot during operation this curing process wouldn't be a problem. Bob what are your thoughts?

    Bob Latino
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    Join date : 2008-11-26
    Location : Massachusetts

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Bob Latino on Wed Jun 08, 2011 2:27 pm

    Scott R wrote:I have noticed high temp paints that require curing at 200 degree F for 20 minutes. If used on the tranformers in your kits it seems to me that as the transformers get pretty hot during operation this curing process wouldn't be a problem. Bob what are your thoughts?

    Hi,

    I have never used any type of "heat curing paint" on any transformer on any amp that I have built and have never baked transformers in an oven before. The Krylon #1618 paint that I use is good to 1200 degrees Fahrenheit. The transformers never get any hotter than 140 to 150 degrees when the amp is on. The Krylon #1618 has never (to my knowlege) peeled or flaked off any transformer from the heat. This paint is a semi-gloss black paint that looks nice and is easy to apply.

    The transformers would probably survive 200 degrees F for 20 minutes but if you use the Krylon #1618 you don't have to worry about baking the transformers and the possibility of any damage that could be done.

    Bob

    Scott R
    Guest

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Scott R on Wed Jun 08, 2011 8:47 pm

    "you don't have to worry about baking the transformers and the possibility of any damage that could be done."

    Good point Bob ! I'll be starting on my kit in another week or so. I guess I'll leave the baking for food items. Laughing

    mantha3

    Posts : 298
    Join date : 2010-11-10

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by mantha3 on Wed Jun 08, 2011 9:47 pm

    Take your time with the build. Sand the transformers well and use a final 220 grit sandpaper... Use rubbing alcohol to clean them off to get the dust off.. Use the paint that Bob mentioned. You can get this in Lowes, Menards, Home Depot.. Semigloss.

    Have fun and do this in a few chunks time wise. You do too much and you get some potential mistakes.

    Take photos and report on the build. I built my ST120 in Oct and I wish I had to build all over again. A fun "project" and a rewarding one. Take your time is my advice... Read the step... Do the step... Re-read the step to make sure you did it right... put a check mark by the step.

    I miss the smell of a fresh build ST120.

    Have fun!

    Scott R
    Guest

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Scott R on Thu Jun 09, 2011 8:54 am

    Ahhh yes, the Zen of kit building. I too relish in the moment that is seeing the solder melt then harden. Each step taken with care and intent. I'll take some pictures and post later.

    Luddite

    Posts : 235
    Join date : 2009-02-04
    Age : 66
    Location : Texas

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Luddite on Thu Jun 09, 2011 12:30 pm

    mantha3 wrote:Take your time with the build. Sand the transformers well and use a final 220 grit sandpaper... Use rubbing alcohol to clean them off to get the dust off.. Use the paint that Bob mentioned. You can get this in Lowes, Menards, Home Depot.. Semigloss.


    Just a thought. Since rubbing alcohol contains lanolin it might leave behind a slight residue. To avoid that, I would use 90% isopropyl alcohol which should be readily available at most pharmacies.

    Best Regards,
    Charlie

    Scott R
    Guest

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Scott R on Sat Jun 11, 2011 10:32 am

    Lacquer Thinner and Xylene do not leave any residual at all. 90% isopropyl has 10% water.

    Tom

    Posts : 166
    Join date : 2011-04-04

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Tom on Tue Jun 14, 2011 10:13 am

    Xylene, like all the aromatic hydrocarbons, is a potential carcinogen.
    Avoid if possible or use appropriate protection.
    Good ventilation and nitrile (blue), not latex (tan) gloves would be the minimum.

    Ahhhh, remember the olden days (when we didn't know any of this stuff) and your Chem Prof would pass around the solvents to smell? "Note the 'bite' of the hydroxyl substitution on this aromatic. This scent is charactristic of the phenols."

    We're all going to die of something I guess....

    Very Happy Tom

    Scott R
    Guest

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by Scott R on Sat Jun 18, 2011 1:47 pm

    Good safety point. When I whip out the aromatic solvents, which I do most every week for one reason or another, I use nitrile gloves and a carbon respirator. Can't wait for the day when we find out nitrile gloves will make our hands fall off.

    I did end up finishing the transformers with Rustoleum (SP?) high temp semi gloss black paint. Used a belt sander with a silicon carbide belt to make the laminations smoother and get the crud off, then cleaned the stamped covers and laminations with lacquer thinner. Taped off the wires then sprayed away. Once reassembled they look pretty nice.

    j beede

    Posts : 328
    Join date : 2011-02-07
    Location : California

    Re: Painting the transformers in a ST120 kit. Why pull two screws and not all? Just curious. thanks.

    Post by j beede on Sat Jun 18, 2011 7:43 pm

    I can't imagine painting the transformers "in place". I wire brush the laminations to clean them and then use a very thin coat of flat black to achieve the look that is most original to my eye. I have a factory assembled ST-70 with the "dipped" transformers... not good looking in my opinion. They have "Dynaco" and the part number in white on top of the ugly runs in the coating, I am thinking that I should leave them this way.

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