McIntosh 240 - can it be saved?

[Lo-Fidelity]

:thmbsp: Just going to clean it up. Too much family history to replace the old body with a jeweled case (but they are pretty).

 

[TR6man98]

Yes,
That might work, it would not look perfect but would improve current situation...
That bumblebee capacitor is really looking like its split... Hard to tell.
But then many say to replace them as they are "ticking bomb". I replaced them on my MC60 and it wasn't hard to do.
Good luck in your restoration...
Plese remember posting pictures.
Cheers

 

[SilverTpt999]

Warning: WD-40 is a solvent and will probably remove any/all remaining lettering on the chassis. Also, once removed or evaporated, it leaves no lasting protection against oxidation. Unless you apply some sort of protective layer afterwards, cleaning rusted items with WD-40 will make them rust more!

Terry recommends Wenol metal polish to remove all possible corrosion followed by Carnauba automative wax. Gentle buffing with these compounds and clean cloths will not remove lettering, will clean up the metal/rust as much as possible, and will protect the metal from further corrosion.

 

[Pio1980]

WD-40 may remove loosened lettering, it shouldn't bother it otherwise. As a solvent it's more a degreaser/wash than something really agressive like acetone.
Primary cleaning of something like this in this state should be done with as little abrasive action as possible to preserve whatever finish and details be salvageable.
Sent from my SM-N900V using Tapatalk

 

[CountD]

Warning: WD-40 is a solvent and will probably remove any/all remaining lettering on the chassis. Also, once removed or evaporated, it leaves no lasting protection against oxidation.

This is absolutely, positively, the most ridiculous statement I have read on here this month.

1) It will NOT remove any lettering
2) It was always on all of my chassis - both Mx110s that have a lot of lettering, a Mc225, a Mc2505, and a MR71 (that has a lot of lettering) for more than 5 years.
3) I lived in SoCal near the ocean for many, many years and my stuff looked new.
4) I 'painted' a light coat of WD on all the chassis, left it on and when I was in the detailing mood cleaned it off every year and put another light coat on. It completely preserved the chrome without any letter removal and without any harsh cleaners.
5) Wenol is OK but it leaves 1000s of tiny micro-scratches when looked at the right angle. That's the game.
6) WD is the least invasive and least harsh of anything. That's why I start here and work my way up.
7) In owning and cleaning more than 150 pieces, I can assure you it never removed a thing.

 

[SilverTpt999]

I'll freely admit I've never risked McIntosh chrome lettering by exposure to WD-40, so it's possible it won't react with the lettering.

However, here are the facts:

The WD in WD-40 stands for "water displacing." While the volatile carrier is in place, it does a decent job at keeping water and oxygen away from the base metal. Unfortunately, the carrier is volatile and nearly the entire formula evaporates. Regardless of how it gets applied, it ends up in the air - not on your part. The remaining thin layer does not protect against corrosion.

An un-corroded chassis in mint condition may not need protection if the metal isn't exposed. An already corroded chassis needs all the help it can get; once the oxidized regions are again in contact with air, they'll continue to react.

WD-40 is a good (great, even) agent against rust, and could be used as an initial pass on a corroded unit. But that had better be followed up with some actual corrosion protection.

This is all very well known in machinist circles.

Finally, regarding Wenol, that product leaves no microscratches when correctly applied with microfiber cloths/towels. You must move very often to clean areas of cloth, though, or the dust and debris you just wiped away scratches the chrome as it is dragged along. That sounds like your experience.

 

[Sam Cogley]

Carnauba wax would be a good choice for a sealant.

 

[CountD]

I'll freely admit I've never risked McIntosh chrome lettering by exposure to WD-40, so it's possible it won't react with the lettering.

However, here are the facts:

The WD in WD-40 stands for "water displacing." While the volatile carrier is in place, it does a decent job at keeping water and oxygen away from the base metal. Unfortunately, the carrier is volatile and nearly the entire formula evaporates. Regardless of how it gets applied, it ends up in the air - not on your part. The remaining thin layer does not protect against corrosion.

An un-corroded chassis in mint condition may not need protection if the metal isn't exposed. An already corroded chassis needs all the help it can get; once the oxidized regions are again in contact with air, they'll continue to react.

WD-40 is a good (great, even) agent against rust, and could be used as an initial pass on a corroded unit. But that had better be followed up with some actual corrosion protection.

This is all very well known in machinist circles.

Finally, regarding Wenol, that product leaves no microscratches when correctly applied with microfiber cloths/towels. You must move very often to clean areas of cloth, though, or the dust and debris you just wiped away scratches the chrome as it is dragged along. That sounds like your experience.

Thanks for all the great information. Let me know when you've dedicated your life to the brand, owned almost every piece, restored almost every Mc pre and amp, and almost lost your marriage over too many Mc-branded items, built a Wall Of Sound in your beach house with 7 Mc2300s and collapsed the floor, drove the entire continental USA to gather information and to collect historically important McIntosh paraphernalia in order to prove that the USA still stands for truth, justice and the American way.

Again, thanks for everything and your input is greatly appreciated. I hope your stay here is fruitful, and I appreciate your input so don't be scared away as this is a great board with a tremendous amount of great people, but I've moved back to New England now and I get salty.

Taking Care of Business in a Flash...as usual.

 

[Lo-Fidelity]

The old 240 was sprayed with WD this afternoon. Unfortunately some of the rust is pretty bad. Not sure how much time I'll have to clean on it this 4th of July weekend, but I'll post some before / after pictures next week.

 

[seta1]

I do warranty work for McIntosh at a shop I work for and at my home shop I refurbish the older ones. Unless the transformers are electronically unsound, the amps can be made to work again. You would not believe some of the cosmetically challenged Macs i have refurbished. Once done, they may not be pretty but they sound excellent. I presently have a couple McIntosh 60's from the late 50's that look horrible, pitted chassis, scrapes and dents and such, but they sound amazing. I drive them with a MX110. To me, any Mac is worth refurbishing. I have yet to find a McIntosh amp I don't like. Yes, some sound better then others, but in the world of amps, McIntosh never made any junk, And I have worked on everything from MC30's to MA8000's.
Take that 240 and get it working again. I just finished recapping a 240. Those things sound amazing. I actually prefer that one to the 275.

 

[Lo-Fidelity]

I've worked on a lot of different things in my life and have never been afraid of a challenge. I rewired my 1890s house from the top of the pole to the last outlet. Done framing carpentry, trim carpentry, made cabinets, refinished floors, and spread enough paint to cover a battleship. I've repaired various automobile problems including Corvette half shafts, radiator replacement, brakes, shocks, etc. However, the only electronic work I have ever done was to put new lights in a Marantz 2235B receiver (if that counts), and my soldering skills are limited at this time. I say this because I would like you guys to lead me through the restoration process and I want you to know that while I am as green as they come today, you are not wasting you time on someone who can't get it done at the end of the day.

First of many basic questions? How do we test the transformers? Is this really the right first question?

 

[SilverTpt999]

I believe for transformer checks none of the wires should have 'continuity' or near-zero resistance with any other wires. That would indicate a short. Someone more familiar with the 240 than I could tell you the specific resistances expected between sets of leads for a better test.

Soldering electronics can be a great or terrible experience and this is largely due to the equipment used. I strongly recommend purchasing a temperature controlled Weller or Hakko soldering station. One Hakko soldering tip can be particularly useful for careful lifting of leads; I don't know if Weller has anything quite like it. I'll dig up the part number if you like.

Then you need the ability to remove solder. A $6 Teflon - tipped bulb from Radio Shack does wonders; use some desolder wick to clean things up after the bulb. You don't need a $300 desoldering gun for this.

Finally, the solder. You'll get some mixed recommendations here, but I always strongly recommend Kester 44, which is a eutectic 63/37 type that has long been the industry standard. Eutectic means it has an exact melt point, making it easier to work with, and its flow is borderline psychic. Silver solder, unleaded or RoHS solders, and other mixes of tin and lead do not share these properties. I've used them and they make the entire experience a pain in comparison. Silver is just not worth the trouble, and I've never heard a difference. Quality work with good solder is almost definitely better in the long run. I really, really recommend against the unleaded solders, as they all form tin whiskers. This is the reason NASA and the military still demand leaded solder!

The guy from the EEVblog has a trio of great how-to videos for electronic soldering worth watching on YouTube.

That will at least get you heading in the right direction!

 

[Pio1980]

I do warranty work for McIntosh at a shop I work for and at my home shop I refurbish the older ones. Unless the transformers are electronically unsound, the amps can be made to work again. You would not believe some of the cosmetically challenged Macs i have refurbished. Once done, they may not be pretty but they sound excellent. I presently have a couple McIntosh 60's from the late 50's that look horrible, pitted chassis, scrapes and dents and such, but they sound amazing. I drive them with a MX110. To me, any Mac is worth refurbishing. I have yet to find a McIntosh amp I don't like. Yes, some sound better then others, but in the world of amps, McIntosh never made any junk, And I have worked on everything from MC30's to MA8000's.
Take that 240 and get it working again. I just finished recapping a 240. Those things sound amazing. I actually prefer that one to the 275.

What's your opinion of the early SS Macs, specifically the MC50, 250, and 2100?

Sent from my SM-N900V using Tapatalk