Painting the K400 horns in my La Scalas

[wallflower]

I'd like to paint the inside of the K400 horns on my La Scalas (for purely aesthetic reasons). Other than pulling them out of the cabinet and taking off the K-55V drivers, is there any thing else I should consider? Is there a particular type of paint that would be preferred over another?

Thanks!

Jeff

[kumayama]

About 25 years ago I had a friend who owned a body shop paint my midrange and tweeter horns. He first smoothed them of the sand cast and mold marks (these were the aluminum horns) with sand paper, filled all the irregularities with body filler, then cleaned them, and finally sprayed them with gloss black epoxy paint. Before reinstallation I wrapped their exterior with mortite and used a couple of cans of satin finish black paint over the Mortite (which makes it very easy to touch up if this is ever required). They were then front mounted to the original baffle (a little router and file work was required on the baffle) which had been been covered in black felt on the outside. Then everything was covered with the stock grill cloth. The baffle and entire cabinets both upper and lower had a layer of 1/8 inch sheet lead  laminated to them. From the outside, there was no evidence any of this 

At the time I thought it made a considerable sonic improvement, and looked nice visually as well. Since several things were done at once, it's hard to know to what to attribute the sonic improvements. Alas, the two Klipshorns and center Belle were lost in a forest fire about five years later.

Anyway, regardless of any actual sonic differences, I think you will find the outcome satisfying (assuming you have aluminum horns), if you sand, fill and prep the surfaces as if they were autobody surfaces, then spray with epoxy, which should last forever.  I suppose too, if you wanted to be really high tech, you also could have them powder coated, but I'd ask around first if their was any chance the heat involved in the powder coating process could result in any warping of the horn. 

[Daddy Dee]

The factory paint on the horns has a gloss to it. When I painted mine, I found just a shot of spray paint in each one did the trick.

[ajsons]

Jeff,

I sent you a p.m.

AJSons

[Wrench722]

How about power coating them.[*-)]

[Groomlakearea51]

Many, many otions: Powder coating can get expensive. Another option is to have your local "rhino-liner" dealer coat them on the outside. It's thick, dampens any ringing (some say there is, some say not...), and is very durable.

Glass beading and filler is a must on some of them due to casting imperfections. Some 400's I have are nice, but one pair looks like a major acne attack..... (sounds ok though).

If you have them out, and are comfortable with using cans, the old spray paint method works fine. Pick a semigloss so you can wipe them down without leaving cloth thread pieces.

If you use, say a semi-gloss epoxy from Krylon (don't laugh, they make good paint), you can put them in your oven at 200 degrees (won't warp the metal) and bake them for about 4 hours and the paint will get really hard.

When you have them out, use a straight-edge and make sure the flanges are "straight", so when you put them back in they are perfectly flat against the motor board. Cross tighten the screws to avoid any warpage.

You can also use a thin (1/16" - 1/32") rubber gasket to isolate them from the cabinet. Use a small thin (1/16 - 1/32") gasket between the bottom flange of the metal rear vertical brace and the bin floor also. The gasket material can be had in pieces from an irrigation pipe/ well/ type industrial supply place. It's usually about $3-$4 a foot but is about 18" wide.

Hope that is some assistance.