Go figure...126 bucks

**bowtie427ss** · June 12th, 2012, 09:35 PM

Originally Posted by A7fan

I beg to differ AbG. See here......http://www.google.com/url?sa=t&rct=j...H7BxUw&cad=rja

Pretty sure he's referring specifically to the multicells highlighted in parentheses in AB's post.

**A7fan** · June 13th, 2012, 12:06 AM

Your right Bowtie, i misread the post.Sorry A_b_G

**Altec Best** · June 13th, 2012, 01:42 AM

Originally Posted by Audio_by_Goodwill

Those aren't cast horns, Though. They were made with sheet that was probably oiled while in the role. That oil may not have been removed before paint was applied.

Originally Posted by bowtie427ss

Pretty sure he's referring specifically to the multicells highlighted in parentheses in AB's post.

Yes I was using the Multicells as an example (Only). Now I have a couple 511E's right now that need to be repainted (internally).And they too have flaking paint,and light oxidation.They are Cast Aluminum Sectoral's.No oil here.The Cast Aluminum oxidizes and creates this white chalk like substance under the paint.But for simple paint removal you can use a paint stripper.But most people want to re-coat them with fresh paint and nothing prepares cast aluminum for repainting IMHO like glass beading.Glass bead is the way to go, especially if you decide to powder coat.

I have been extremely pleased with all my results from the glass beading...

In A7fan's case the paint looks to be in good shape albeit white.If he so chooses glass bead will be an easy and fast way to restore them to a paint free state...

Paint strippers,glass beading,etc... Are all good ways to remove paint, some are faster and cleaner than others. I just happen to prefer GB.As others prefer other methods.You really just need to do what works for you.

**bowtie427ss** · June 13th, 2012, 06:59 AM

Yes I was using the Multicells as an example (Only). Now I have a couple 511E's right now that need to be repainted (internally).And they too have flaking paint,and light oxidation.They are Cast Aluminum Sectoral's.No oil here.The Cast Aluminum oxidizes and creates this white chalk like substance under the paint

Die cast under high injection pressure. The dies are sprayed with a release compound before each shot. Oxidation needs oxygen to occur. Oxidation should not occur thru a sealed coat of paint. If you have paint lifting with powdery white oxidation underneath, i'd wager it was caused by leftover release agent eventually breaking down and releasing enough trapped oxygen molecules under the paint to cause the oxidation and paint separation that you see.

Any good body man will tell you that just a microscopic speck of the right contaminant can cause a major eyesore years down the road. There's some truth behind that old one liner "rust never sleeps".

**Altec Best** · June 15th, 2012, 01:51 PM

I took pictures in the dark with the flash (In A Hurry).And it didn't pick up the small scratches in the photos.These 511E's were in pro sound boxes.And in the inside of the horns there are some small scratches.I suspect that the paint was broken through in a few spots that allowed them to oxidize for 25+ years.These were bought for a Band.So it could be from either reason... Or a combination of the two..

I would imagine that the horns are dipped in solution to remove grease,release agents,dirt,etc... Before painting would they not ? They also use a paint booth to keep those contaminants to a minimum... Who knows ?

**Audio_by_Goodwill** · June 15th, 2012, 03:17 PM

Originally Posted by Altec Best

I would imagine that the horns are dipped in solution to remove grease,release agents,dirt,etc... Before painting would they not ? They also use a paint booth to keep those contaminants to a minimum... Who knows ?

In more recent times, yes I'd expect a wash, but back then maybe it was considered optional given the use of oil paint and not modern "eco" paints. An then of course there was the cost cutting*....... if there was a wash often was the stuff changed out?

Probably the biggest thing to consider is that to us, the finish is important, but for pro-sound back in the day, I'd imagine the finish wasn't so important as long as it was gray/black when it was sold........ a lot of installs they'd never be seen, and for touring it would get bashed up any way. That's a lot different than out living rooms.

*Don't know when these were made, or if that coincides with times of cost cutting.

**A7fan** · June 15th, 2012, 03:19 PM

Any recommendations on what type/color of paint?

**Altec Best** · June 15th, 2012, 03:43 PM

Dark Gray was original I think...

**bowtie427ss** · June 15th, 2012, 05:20 PM

I would imagine that the horns are dipped in solution to remove grease,release agents,dirt,etc... Before painting would they not ?

After a few tens of thousands were distributed and it eventually was brought to the company's attention that the paint was flaking off, and as the technology/methodology for painting aluminum improved.

Some of them there horns are old, so old that aluminum itself was still fairly new in industry............ wink wink

**Old Guy** · June 15th, 2012, 05:33 PM

Originally Posted by bowtie427ss

After a few tens of thousands were distributed and it eventually was brought to the company's attention that the paint was flaking off, and as the technology/methodology for painting aluminum improved.

Some of them there horns are old, so old that aluminum itself was still fairly new in industry............ wink wink

Back in my day dirt was fairly new. Transporting speakers made of stone was hard so we came up with bronze...men were men in those days...