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    Weber copper cap discoloring?

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    wgallupe

    Posts : 81
    Join date : 2014-05-18
    Age : 62
    Location : Central Mass.

    Weber copper cap discoloring?

    Post by wgallupe on Sat Oct 11, 2014 12:33 pm

    Hi, question to the group: Is it normal for the Webber rectifier to discolor? The copper color has faded (from heat I assume) leaving a mostly silver/grey appearance. I should add that I did remove the blue label and hand buffed it with fine steel wool before I installed it. I'm thinking this is a non issue but...confused

    ps: the amp sounds great. No operational issues other than the discoloration.

    Bob Latino
    Admin

    Posts : 2374
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Weber copper cap discoloring?

    Post by Bob Latino on Sat Oct 11, 2014 1:18 pm

    Yes .. In time the Weber Copper Cap will turn a silver/grey color whether you buff it or not. Copper oxidizes over time .. If this bothers you, then you can just buff it up with some metal polish ..

    NOTE - The reason Weber makes this rectifier out of copper is because copper dissipates heat very well. Once or twice a year I get an Email from someone asking why the Weber Copper Cap "gets so hot". There is a lot of current passing through this rectifier and it does get hot .. This is normal ..

    Bob

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sat Oct 11, 2014 1:46 pm

    wgallupe,
    If your Webers start giving you electronic grief, tmadden on this board has created an excellent fix for them that will cool them down.

    wgallupe

    Posts : 81
    Join date : 2014-05-18
    Age : 62
    Location : Central Mass.

    Re: Weber copper cap discoloring?

    Post by wgallupe on Sat Oct 11, 2014 2:50 pm

    Bob, Thanks for the quick reply. I feel better now.

    Deepee, Thanks for the tip. How will I know if/when I need that mod?

    Enjoying some great music with the help of my ST-120 on a cold and rainy Saturday afternoon in Massachusetts....

    Dale Stevens

    Posts : 76
    Join date : 2014-07-06
    Age : 67
    Location : Loris, SC

    Re: Weber copper cap discoloring?

    Post by Dale Stevens on Sat Oct 11, 2014 3:47 pm

    deepee99, wgallupe; what mod?? Dale

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sat Oct 11, 2014 6:52 pm

    Dale Stevens wrote:deepee99, wgallupe; what mod??   Dale

    Tmadden mods them with a bit of cooling and a beefier thyristor or thermistor, best just to ask him.
    I sent him a handful of ones I'd blown and he fixed them; I'm still on the first pair he sent back. A craftsman, to be sure.
    The Webers get VERY hot with a low-impedance speaker load, that's why I was blowing them. I've since rectified (pardon the pun) that problem as well, but it's good to have some confidence in the Webers now that I did not have before.
    I would just give Troy a PM for details. I'm a dunderhead at this stuff.
    Cheerio
    d


    ramon68

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    Join date : 2009-04-12
    Age : 75
    Location : naples fl

    Re: Weber copper cap discoloring?

    Post by ramon68 on Sat Oct 11, 2014 7:55 pm

    I hope tmadden's Weber Copper Cap mod gets put up in the "Sticky" section.

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sat Oct 11, 2014 8:04 pm

    ramon68 wrote:I hope tmadden's Weber Copper Cap mod gets put up in the "Sticky" section.

    Agree. He can fix broken ones, which I'd been tossing into the dust-bin. The Webers have a heat problem that can be fixed.

    MontanaWay

    Posts : 767
    Join date : 2014-02-06
    Age : 58
    Location : Cameron, Montana

    Re: Weber copper cap discoloring?

    Post by MontanaWay on Sat Oct 11, 2014 11:47 pm

    ramon68 wrote:I hope tmadden's Weber Copper Cap mod gets put up in the "Sticky" section.

    ditto on that, Mr Madden, if you could please put up a sticky on this, we'd all appreciate it, thanks!

    arledgsc

    Posts : 330
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Weber copper cap discoloring?

    Post by arledgsc on Sun Oct 12, 2014 12:00 pm

    The Webers are pretty neat but having the power resistor inside the can with the rectifying diodes doesn't seem like the best way to go for long-term reliability.  Makes for a nice, neat package but I'm still shaking my head as how long can it last before it blows.  

    I have a spare Weber but have been wondering how to open the Weber copper cap for repair.  Anyone know? But I would definitely like to hear more about tmaddens mods.

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sun Oct 12, 2014 12:15 pm

    arledgsc wrote:The Webers are pretty neat but having the power resistor inside the can with the rectifying diodes doesn't seem like the best way to go for long-term reliability.  Makes for a nice, neat package but I'm still shaking my head as how long can it last before it blows.  

    I have a spare Weber but have been wondering how to open the Weber copper cap for repair.  Anyone know?   But I would definitely like to hear more about tmaddens mods.

    I don't want to expose any of Troy's trade secrets as I was sort of his guinea pig, but basically it involves drilling some strategic ventilation holes in the case, and beefing up one of the internal parts. There's a lot of heat build-up in that little can and nowhere for it to go, exacerbated by its proximity (on the M-125 at least) to the xformers.


    TMadden

    Posts : 99
    Join date : 2011-12-22

    Re: Weber copper cap discoloring?

    Post by TMadden on Sun Oct 12, 2014 1:04 pm

    Hey everyone, this is what I did to David's Weber rectifiers. I drilled 4 evenly spaced holes towards the top and bottom of the copper case to let some of the heat escape. Most of them had shorted diodes, I replaced them with 1N4007's. Several of the thermistors had completely "burned up", I replaced them with Ametherm Inrush Current Limiters, Mouser P/N 995-SL12-12102. I glad to hear David is having good luck with them!

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sun Oct 12, 2014 1:09 pm

    Yep I am. I would highly recommend Troy's mods to these things. IMHO they'll last as long or longer than NOS Mullard GZ-33s (2-3k hours) and perform just as well. Not as pretty to look at as the tube rectumfriers, but they do the job. So don't throw your burned-out Webers away, send 'em to Troy. Never had any but the best help from him.

    TMadden

    Posts : 99
    Join date : 2011-12-22

    Re: Weber copper cap discoloring?

    Post by TMadden on Sun Oct 12, 2014 3:46 pm

    This may be another  solution to keep the Webers cool. I haven't tried one, but it looks like it should fit.
    It's made by Pearl.


    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Sun Oct 12, 2014 5:06 pm

    I like the cooling holes better. That's real ventilation.

    Pillo69

    Posts : 104
    Join date : 2012-04-11
    Location : Granada (España)

    Re: Weber copper cap discoloring?

    Post by Pillo69 on Mon Oct 13, 2014 5:38 pm

    Copper can be cleaned with flux to be used in plumbing for welds.
    Put on the tube and then rub with a cotton cloth. If the patches are too deep one has to heat the flux to copper until the dough begins to bubble.




    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Mon Oct 13, 2014 7:22 pm

    Philo,
    One of those pictures would not pass movie PG ratings.
    There's also Brasso, and Noxon if you can find it.

    DarthBubba

    Posts : 81
    Join date : 2012-05-05

    Re: Weber copper cap discoloring?

    Post by DarthBubba on Wed Jun 24, 2015 11:57 am

    deepee99 wrote:Philo,
    One of those pictures would not pass movie  PG ratings.
    There's also Brasso, and Noxon if you can find it.

    Try catsup (Ketchup) or vinegar.  Likely household items, non-toxic, and very effective for cleaning copper.  Very Happy

    NOT for use on TMadden modified Webers, however.  No

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Weber copper cap discoloring?

    Post by deepee99 on Wed Jun 24, 2015 12:58 pm

    DarthBubba wrote:
    deepee99 wrote:Philo,
    One of those pictures would not pass movie  PG ratings.
    There's also Brasso, and Noxon if you can find it.

    Try catsup (Ketchup) or vinegar.  Likely household items, non-toxic, and very effective for cleaning copper.  Very Happy

    NOT for use on TMadden modified Webers, however.  No

    Actually, I wouldn't sweat the discolouration. The Webers are there in the back, yes, copper will get some heat treatment over time, doesn't affect their performance.

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