Painting 511b horns

[ClassicComics]

I am going to spray paint my newly acquired 511b horns black... this is both for appearance and to dampen any potential ringing.... any recommondations on type of paint? I know they sell stuff with texture in it (like a stone texture etc...) would this be good or bad? Or just regular spray paint?

Also, any special concerns when spraying the interior of the horns? Special techniques or anything I need to tape off, or can I just spray away?

Any and all thoughts or hints would be appreciated!!

<font color="#FFFFFF" size="1">[ September 19, 2008 11:55 AM: Message edited by: ClassicComics ]</font>

[RonSSS]

Regular paint won't do anything for damping resonances.

A good color to use is Krylon 1613 semi flat black.
And just spray away.

Ron

[Vathek]

Not really an answer to what you're asking, but while you're working on your 511Bs and are going to paint them anyway, I'd recommend you cut the wings and insert some silicone, as Altec did with the later versions. It reduces ringing considerably and really does make a difference. I've heard both side by side.
Of course, all this assumes your horns are not of the later kind.

[ClassicComics]

If not spray paint then what? Brush on latex paint? Any suggestions would be appreciated.

[bfish]

There's no paint that will provide adequate damping on its' own. There are damping compounds that can be painted, and a plethora of alternate solutions. You're now at the "been there, done that, bought the t-shirt" point, where your questions have been covered ad finitum in archived threads.

How do you know when you've damped them adequately? When you can whack them with a stick and they don't ring like a bell.

How do you keep them from ringing? Don't whack them with a stick.

[GM]

To completely damp a 511 below its pass-band requires bonding stiffeners and mounting it in a well packed sand filled box or similar. In the early days they welded plates to create a small void around horns and filled them with tar.

Long ago I had two 511s coated with a very thick industrial insulating spray that turned them into an ugly blob that worked well, but about a year later the then new EPA took it off the market. It came back as a latex based system under a new name IIRC, but by then I'd moved on to experimenting with well damped constrained layer constructed wood horns, so never tried it.

Anyway, truck bed liner works OK as does the spray can undercoatings if you lay on enough coats, but the sand or similar filled box beats them both by a wide margin.

Tacking on some of the newer engineered composites used in vehicles to mimic a constrained layer construction seems the best bag/buck and is easily removable since it's just double stick taped on. Then again after just looking up pricing, the sand filled box is the best bang/buck.

All that said, most folks feel that damping the mouth bell curves is sufficient and it does kill the worst of it as does cutting the welds out of the vanes and installing rubber inserts or similar. Cutting out the internal brace also will allow all the stresses from welding to relax which lowers its Fs.

Note that all internal surfaces can't be too smooth, so nothing more than a nice thin coat of paint on the inside and ideally you'd fill all the seams, etc. and finish it like a show car.

GM

<font color="#FFFFFF" size="1">[ September 20, 2008 12:08 AM: Message edited by: GM ]</font>

[ClassicComics]

I have an idea I am going to try with window a/c unit foam and black a/c duct tape... I can remove it easily if it doesn't work... will let you know what happens.

Thanks for the suggestions.

[ClassicComics]

I was looking into buying some of that Quiet Kote spray on sound dampening material, but no one local seems to carry it. I was going to go ahead and order it on-line when someone at one of the places I called told me that the spray on car undercoating stuff would work. He said not as well, but close.... any experiance with using this stuff to dampen the resonance on horns?

[Audio_by_Goodwill]

Originally posted by ClassicComics:
..... someone at one of the places I called told me that the spray on car undercoating stuff would work. He said not as well, but close.... any experiance with using this stuff to dampen the resonance on horns?

<font size="2" face="Verdana, Helvetica, sans-serif">No, don't use that. I bought my 511B's cheap on Ebay because someone had sprayed that sticky undercoating on them. Some variations dry, but a lot of them stay sticky. I ended up having the garbage blasted off with walnut shells. I suppose it could have been done with paint thinner, but it would have been a big big mess.

I've never done it, but I'm thinking you'd be better off doing the latex paint mixed with sand trick, if you don't want to buy the real sound deadening stuff.

[ClassicComics]

When you say the real sound deadening stuff, do you mean the Quiet Kote or did you mean something else? I know a lot of the car audio places I called use to carry the Quiet Kote but now you Dyna Matte (sp?), which is like a peel and stick application of some kind....