Buzzing dobro, unusual source.

[Bryan Bradfield]

I've fully torn down one of my dobros twice trying to find an annoying buzz. I checked all of the usual common causes. The actual source of the buzz: a small dust bunny, made primarily from intertwined small threads that had fallen out of my ragged old string wiping cloth through he cover-plate, and had gathered together on the outer edge of the cone. Obviously, that cloth is now history, and the new cloth is more tightly woven.

[Lee Holliday]

Microfibre dusters are the way ahead.

If only the wife knew I was talking cleaning products on a guitar forum!!!

Lee

[Dave Thier]

Once a year I carefully disassemble my resonators and clean the cone and insides. There is noticeable dust after a year that acts like a blanket muffling the sound. I occasionally find a dead insect or two. Use care when cleaning the cone, no chemicals, just a damp cloth.

[Bryan Bradfield]

Dave Thier - I certainly would not use acid to clean the cone, but I do use liberal quantities of isopropyl alcohol and a paper towel.

[Dave Thier]

Many household cleaning agents can be harmful to the aluminium. Windex with ammonia is certainly a no-no.

[Bryan Bradfield]

OK, I googled. Mixing hydrogen with ammonia produces hydrogen gas, as well as causing accelerated corrosion of the aluminum.

From personal experience, I've not observed any physical or tonal degradation from the use of rubbing alcohol as a cleaner.

However, with your advice, I will limit any further experimentation in cleaning.

[Greg Booth]

I put mine through the dishwasher... clean like new.

[Mark Eaton]

I put mine through the dishwasher... clean like new.

I agree, the dishwasher works great.

On the other hand, on my one trip to Nashville in 2010 to the Rob Ickes led ResoSummit, I took a Sunday morning dobro setup class from legendary luthier Tim Scheerhorn.

I suppose if you have somehow managed to accumulate a serious layer of grime on the surface it could effect the sound, but I posed this very question to Tim about dust on the cone and he shrugged it off as no big deal and said that he didn't believe it made any noticeable difference.

[Greg Booth]

Mark, you may have heard this story on another board because I know I've told it, but it was a mystery that was finally solved years later regarding cone crud. I was at Rockygrass before I had gotten my Horn and I was trying other folks' guitars in the RG Academy. I tried a guy's Beard MAS and it was a cannon. HUGE sound and loud! Then I tried his buddy's identical MAS. Weak! And quiet! Such a difference that you couldn't attribute it to normal differences between guitars. I suggested he send it back to fix whatever was wrong. A couple years later I was chatting with Paul Beard at ResoSummit and somehow that guitar came up. The guy did finally send it to him. Apparently it had been outside in Texas during a dust storm. Paul took it apart and the cone was caked with about a 1/16" of dust and dirt. A good cleaning and it came back to life.

It's true though, never use Windex or anything with ammonia or harsh chemicals. Aluminum is very reactive.

[Mark Eaton]

...I tried a guy's Beard MAS and it was a cannon. HUGE sound and loud! Then I tried his buddy's identical MAS. Weak! And quiet! Such a difference that you couldn't attribute it to normal differences between guitars. I suggested he send it back to fix whatever was wrong. A couple years later I was chatting with Paul Beard at ResoSummit and somehow that guitar came up. The guy did finally send it to him. Apparently it had been outside in Texas during a dust storm. Paul took it apart and the cone was caked with about a 1/16" of dust and dirt. A good cleaning and it came back to life.

An extreme example, and I doubt you'd get any argument from Tim Scheerhorn on that one regarding crud effecting the performance of the cone.

A resonator guitar usually benefits from periodic maintenance and setup work, but I'm surprised the the owner couldn't figure out the part about the caked on crud on his own.

[John Billings]

What Dave T says is gospel! Don't get anything with ammonia in it near aluminum. I use California Custom Purple Polish. Nothing better!

[Steve Schell]

Most cones are still coated with petroleum based lubricants from the spinning process. I have removed this with naptha and sometimes acetone with good results. Clean both sides!