Piano Black La Scala's

[Jeff_R]

Lacquer it is then. Thanks Michael, I would have hated to see it "alligator". I am already doing too much sanding due to my inability, as of yet, to lay down a nice even coat of paint. I am still waivering on Satin versus Gloss. The box is so hard and smooth now, gloss would look great. I fixed the dryer, and got back in time to finish sanding the one speaker entirely, inside the horn area as well. I will vacuum and blow it out tomorrow, and finish it, and then the other speaker.

No warm up predicted, and rain Monday, so it's design grill time. I have to go out and look up copper as Bruce found, see what I am up against there. I have done a lot of sheetmetal in aviation, so I will just apply that over to copper. I have the use of a brake at work as well. Really just a matter of figuring out the prettiest way to make the corners.

That's it for today.

Jeff

[michael hurd]

Jeff: I have used epoxy repair materials for fixing sheet moulded compound items... ( heavy truck hoods ) and have found that heat from a heat gun greatly decreases the viscosity and allows you to spread the material very very smooth. After it cools off a bit, the viscosity increases again. ( tip for next time playing with that product )

You had mentioned that it was like 90 w gear oil.... I know what that's like... when I use Fusor T-21, ( SMC repair product ) I put the twin tube cartridge in the microwave for about 18 seconds, this really really helps, otherwise it is so hard to squeze in colder weather... you would have forearms like Popeye.

In retrospect, you could heat both components in the microwave before combining them and spreading. This will also cause it to set up a bit faster, not a lot, as you won't have a lot of residual heat.

Also, get the largest trowel you have for spreading it evenly. I have a 8" drywall knife I have occasionally broken out for bodyfiller, like when I am blending a box wheel opening repair panel and have to spread a few feet of filler.

Re: Copper for grill edging. If you can't find what you want and you absolutely want copper... see if there is a chrome plater in your area or other metal plating services.

You could weld up an aluminum trim ( or machined out of one piece ), and have it plated with copper alternately. Of course, it has to be sanded smooth as glass first, but I am sure that you could do most of the work and have it plated for a nominal fee. Think outside the box.

[Jeff_R]

GREAT IDEA Michael!!!!

Where I work, we have welders, machinsts, name it. So there is always a wealth of experiance, inside out otside experiance to draw ideas on. As a matter of fact, one co-worked in my inspection group, his family used to own a plating shop, and still knows the current owners on good terms. All kinds of aluminum extrusions in different dimensions are available, at Lowes or Ace Hardware for example. I can wrap the grills in the cloth, cut and sand the extrusion to a perfect 90 degree corner, and get it tigged up for nothing. Then hand it to Mike, I think he will get it copper plated for next to nothing.

If I do a picture frame open to the back, I will either be glueing it on, or figure some other way to attach. Barge glue would hold forever, but I will come up with a mechanical attach method or read about one here this afternoon. [] Or maybe channel on the top, and sides, with the the back flange of the channel removed on the bottom. Then the extruded frame simply slides down over the grill.

Thank you for that idea. Aluminum extrusions would be a lot easier making up perfect corners as opposed to bending copper. That is going to be the plan for the frames.

I love forums and the suggestions that come out of lots of folks apporaching a task from a different perspective.

Gotta go sand for half a day at least. 56 degrees today, so I will likely be doing grill work and not painting.

Jeff

[gaspr]

After your frames are all plated with copper and are nice and shiny, you might want to give them a coat or two of lacquer....they won't stay shiny for very long unless you can keep the new copper from oxidizing...

Can't wait to see how these turn out...nice work!

[Jeff_R]

4 hours later the second one is sanded. I had ever so tiny a defect pop back out on one side of an inside corner of the horn area where there was a bit of bondo. Just a bit of it popped back out. So I filled that, and 4 uncovered pinholes with lacquer putty. I have every confidence the defect the one on the edge of the horn area will fail again when sanded. If that happens, I am going to round that area out with a file, drill some more #50 holes, surround it with clay, and use 5 minute 2 part epoxy there. I will peg the holes with toothpicks after the pour. When it dries, file, and sand smooth. These darn edges are so fragile. I am going to give the lacquer putty 2 hours as the tmeprature is so low and go see if it works.

As to the copper. Yes, I planned to seal the copper after doing the sand paper stroke thing for a burshed appearance, thanks. Of course if I could talk the wife into white La Scalas, and then put a false green patin on the copper badge and grill surround would be pretty wild looking. [] Okay, I get funny looks around here too on that idea, kind of thinking out loud.

Where I am on paint. Beautiful weather outside, clear, no wind, and 45 degrees, maybe 54 degrees later. A bit cool for painting I imagine. I have noted I have just a more sanding inside the horn area of the first speaker. A tiny amount of "freckling" I call it, which is low spots. Today I remembered I had aBinks Suction gun. This really saved me a lot of time. I can blow at line pressure, 100 PSI, which means I sand 15 to 30 seconds, blow off dust on the block, blow off the area, sand some more. That is how i got finished in half the time today as to yesterday. All outer surfaces are as flat at they can ever be.

So now I have to list a few observations/issues, and questions.

1. I have some areas, small and only a few, where plywood is visible. However, it isn't the acutal plywood surface, it is high spots of epoxy now as level as everywhere else. That is from sanding the epoxy with an orbital, and not a big enough block like I now have that shows me everything. Oh yes, I did use my heat gun on the epoxy some Michael, and it helped. For examply, some of these areas now uncovered with my 9 inch block sanding are beautifully filled, which was my goal with the epoxy, relaminate and seal.

So the question is, can I shoot my color over the epoxy? Is that correct to do?

2. The vertical 8 to 10 inch flats along the woofer horn area. I have those areas 'mostly' covered with overspray from shooting past them to the back, and the outside

How do I get paint on those areas? Do I need to get an airbrush and load it 20 times per side or what? How did you paint those areas?

That's about it for now. I am going to run to Lowes for Masonite and goof for a while. I was just fed meatloaf sandwhiches and cornbread salad so I am too stuffed to work. Gives that lacquer putty stuff some time to set as well.

Jeff

[michael hurd]

You can put lacquer over the epoxy, no problems there. Not sure what you mean about the flats, it's been a while since I saw lascalas last close up. What I would use for close quarters is a small detail touch up gun, preferably gravity fed, and just concentrate first on getting those areas with color.

If you are shooting for a high gloss on the entire speaker, here's what I would do: I would shoot the entire inside with black and then clear it, with the outside masked, making sure you get the 3/4" edge of the ply well. THEN mask the high gloss area of the inside of the horn and make your paint break line @ the edge of the ply where it's not noticeable at all, sanding down the previously painted and cleared 3/4 edge.

If you do it in this manner, I would not try to buff the inside at all, just shoot for the best, taking care to tack it well with a tack rag after blowing it out well.

Mask the inside and shoot the outside, as well as the 3/4" lip, wait for cure and sand and buff to a beautiful high gloss finish.

[Jeff_R]

Michael,

Thanks for the reply. I figured I would be okay, I mean I am shooting lacquer primer on epoxy now. These boxes are as hard and slick as dominoes. What a job this has been so far.

Okay, below is a picture of the speaker upside down. The woofer horn area consists of the triangle facing forward, two "flats" one each side, then the back section with the 4" x 15" (or whatever dimension it is) slot for the woofer to fire through. Those side flat areas are about 8 inches by 24 inches. I have 3 inches of acess to try to shoot those flat areas of the horn, the back of th ebass bin, and the corresponding area of the bass bin on the sides. Now I have pretty good coverage on three of the four, but this all amounts to sanded over spray, as best I can tell. It really isn't that visible, but of course I want it the same color as everything else. I had thought maybe I need to get an airbrush for more access. If I can shoot my color through a 1mm tip, I do have my trim gun to use now.

Here is the picture;

I also pulled the trim off the plywood inside edges where the arrows point. These speakers must have been built on a Monday. I swear those two little cheap pieces of trim were cut with a hammer, and adull hammer at that. I sealed the edges they look fine.

Now are you telling me to tape along the sharp inner edge to paint inside complete first, then tape inside the bass bin along the same edge and paint the outside. I have idea, I am just trying to be certain you want me to tape exactly along that edge inside I left intact.

I bought a 2 x 2 piece of birch 1/4 inch plywood at lowes today, like $3. I also picked up 8 t-nuts, brass screws, and brass washers. The thinking now is that now matter what I do to attach a grill, it will be invasive to the front of the speaker box. So I am considering cutting the plywood grill, drilling a #10 hole in each corner. I will then locate and clamp the plywood grill plate to the speaker, and drill the corresponding hole all the way through the motorboard. I would then mount my t-nuts on the inside of the motorboard and insure they are slightly below flush. Just in case I get near the midrange horn flange, which I shouldn't. This would look pretty "old school" with brass phillips and countersunk washers on the grill cloth. I haven't absolutely decided on that method yet, but it is the easiest.

I can do all this, and take my time on the came or aluminum. Lowes has a nice selection of U channel aluminum extrusions too. I will also check the stained glass shops around town.

If I use the rubber hole and plastic peg mounts, then no screws show through the grill cloth, but the huge rubber grommet things are still thereto look at.

I could do velcro, but the stick on always pulls loose, it might pull the paint, and it you take the grill off you still get to look at the velcro.

The most trick & invisible attachment installation I dreamt up was to use those small super magnets, neodine or something. One at each corner, counterbored and mounted from the inside of the motorboard to within an 1/8 of an inch of the outer face. Opposite for the grill plywood. I have seen these about the size of a quarter, and you absolutely cannot pull them apart, you have to slide them. This would be an invisible grill mount. I figured to put some velcro loop fabric only, no hook, along the mating side of the grill to pad them off the paint. I don't believe the magnets would have any effect on the midrange or tweeter. If that were a concern, it would be no problem to over counter bore, a 2 step counter bore, and cast 8 lead shields real quick. I used to cast my own bullets for competitive shooting so that would be a breeze.

Anyway, the wheels have been turning. I am going to look up the magnets, and decide. That is a solid 2 day project to mount those.

Jeff

[michael hurd]

Thin the color a bit more and shoot it inside with the small detail gun you have already. I would paint black the 3/4 inch wide edge that's exposed in whatever you have decided ( satin or gloss ), scuff the 3/4 wide edge back down, and tape the inside sharp edge ( on top of the cured paint ) this way you have double the coverage on the exposed ( previously raw ply edge ) and a much thinner line.

After the inside area was painted ( satin or gloss ) and cured, tape and paint outside. Get masking paper made for autobody work ( poly coated ) as it's not linty like newspaper... if you can't get a small roll of 18" for that... see if you can get some poly coated paper from a butcher / meat shop. It's not the best, but it'll do in a pinch. Oh, and make sure the masking tape you use is for autobdy use as well... I'd grab a $3.00 roll of 1/2 or 3/4" from the paint shop.

You can embed the neo magnets in the wood ( bore and epoxy in, cover over with epoxy... ) but now you have lacquer primer on them... epoxy isn't probably the best to apply over fresh lacquer... hmm... what about a couple pieces of steel brake tubing or other covered with rubber tubing that gently contact inside the very edge of the midrange horn.... they'd probably have a bit of a bend in them to make it a friction fit... just trying to brainstorm here. No need to shield the neo magnets at all.

[michael hurd]

The lacquer putty is um... well let's put it this way, I haven't used it since the second paint job I have ever done. I only use two-part materials, and hardly ever buy glazing putty of any kind. Mostly just premium lightweight filler. If I have a pin-hole or two, a quick scratch over with a razor blade and a tiny bit of filler before final sanding cures them.

[Jeff_R]

Michael, brainstorming is a blast. As to the putty, yeah I haven't had any in my hands since 1977, and thought it was pretty weak then. I am only concerned about that one edge. I will abuse it a bit before final color. If it isn't going to hold, epoxy repair., and spot primer.

As to the magnets, I am talking about mounting them 1/2 inch deep from inside the crossover/horn access. And 1/8 inch deep drom the grill cloth area. So no damage, no visibility from the outside or even the back side of the grill with it in your hand. I have extra 3/4 inch ply wood and will have scrap 1/4 inch so I can experiment. I may do some kind of very small alignment dimples or something.

Two reasons for mounting like this, one, those are so strong I was concerned they would pull loose from their bond, and of course second reason is invisibily of the mount.

So what did you think about 4 brass screws and the brass deco washers sitting on the grill cloth? I think it would be pretty much a period look. Seems a bit amateurish as it is so simple.

I have butcher paper, and will buy the correct light green (?) tape if my blue painters tape is something I shouldn't use. I will try the trim gun, and go get a swivel air conector to allow better access inside that box.

Gotta head to work

Jeff

[michael hurd]

Yes, please don't use regular painters tape for interior house paints. Buy the correct 3m autobody tape, it's pennies more but the glue will not dissolve with solvents. I think I would avoid using screws of any kind, and go with the magnets.

[Jeff_R]

Looks like clear and high 60's predicted for Wednesday, low wind if that holds. So maybe some spot primer on the repair & grill mount areas.

Here is my thinking on the magnets. The magnets are a neat idea, and will hold a lightweight 1/4 plywood grill I am building just fine. There is however an alignment being maintained issue I see. The grills will not necessarily stay on straight. So what I have thought about is using carriage bolts or button head screws in the plywood, screw threads facing forward. I will have to have #10 carriage bolts if that is what I use. I have ripped my plywood at work today, and am going to drill #10 holes 1 1/2 inches in from each corner. I am then going to mate to the front of the speaker, and drill through the motorboard. I will clicko them in place, and mark my midrange and tweeter cutouts. I also have to find magnets, only 4, and those mount on the inside of the motorboard.

Now I plan to do this first on the leftover 1/4 birch plywook, and some 3/4 inch scrap plywood I have. I need to find out how deep or shallow I can set the magnets, and have them hold firmly. The reason for choosing #10 carriage or button head fasteners is for alignment. If the magnets hold the grill firnly on the front of the motorboard/scrap test piece, I will use a round rotary file to make a dimple where my #10 pilot hole is. This dimple is the nesting place for the carriage/button head screw. So when the grill is held on magnetically, the dimples and the carriage/button head fasteners maintain alignment.

If this works, after everything is painted, there would be four dimples, hopefully very smooth and even, to be seen with the grills off. I just think there is agood chance the grills might cant without some mechanical alignment device. I would prefer carriage bolts as the dimple would be shallower than with a button head screw. It all depends on the hardware available.

Easy to visualize all this, easy to do the woodwork. just have to make the magnets work, and then not have paint errors in the dimples.

Yes, I will buy the correct tape without a doubt. Every correct thing I can do as to the paint I have to, I need every advantage due to a lack of spray painting skills.

Jeff

[michael hurd]

I can't see you having alignment issues with the magnets at all.... I would make a template and then drill from the back and mount with epoxy. If you use good neo mags from say Lee Valley tools ( the 3/4" or 1" ) they should be still quite strong @ 1/4" away from metal, they have unbelieveable holding power.

If using magnets on both halves, make darn sure you label each magnet side as to what polarity. ( start with one and mark a + on one side... ) check the others carefully against it. Like poles repel, and opposites attract. Label them all so you don't get confused when you install them.

[Jeff_R]

I am searching for magnets now, found lots on eBay. I understand these magnets are very strong, still, to remove them you slide across, so I am not so sure about the grill remaining perfectly plumb and level without some mechanical alignment aid. I really think the dimple, or maybe something to guide the grill for alignment into the horn cutout needs to be done. What concerns me about something thin sticking into the horn cut out as an alignment guide is vibration into whatever I stick into that opening. If it is thin enough to be in the plywood cutout, is it thin enough to start picking up output from a horn and buzzing? I will have to think about this. It really only takes to pins, angles, dimples matching fastener heads, or whatever to maintain alignment.

There will be the loop side of velcro on the back side of the grill to prevent marring the paint when removing/installing the grill, that's a given. That will provide the soft pad. Ihave handled a 3/4 inch pair of these magnets, and they are pretty damn snappy when brought into close proximity.

Off looking around at painting techniques. Still unsure as to final appearance, but other paint schemes are coming to mind.

JEff

[Jeff_R]

Ok, the grills are cut out. I drilled to them match, and clamped them on the speakers and drilled the speakers. I couldn't find any clecos so my Honey Bun dutifully held them on the face while I marked the cut outs with a pencil from the back side. That done I cut them out bigger than the openings a bit, and then clamped them back to the speakers and pinned the corners with screws.

Now is where I am really glad I have taken so much care on the inner plywood edge of the horn cutouts. I grabbed my horrible plastic router, why it is horrible is another long story, and stuck my 3/8 rabbit bit in it. I dialed the router in until it appeared I was shy just few thousandths from going past the edge of a piece of 1/4 in ch plywood.

Here are the results;

Came out nice, plenty of gap between my plywood edges and the horn openings.

Speaker S/N 6

Speaker S/N 5

Thinking 1/4 inch by 3/8 inch long cylinder magnets now. 7 per speaker, each corner, the upper midrange horn area corners, and one low center of the midrange horn. I am going to use the Famowood epoxy on all exposed plywood edges of the grills to seal them forever.

I played around with the 1 inch magnet on the locker door at work today, I can't even pull it off. I think 7 magnets per speaker should be plenty of holding power.

I am not completely set on the alignment pins designe yet, but I believe them so be necessary.

Jeff

[michael hurd]

Jeff, that is looking very very good, and I am sure that you have put many hours in to get to this point. FWIW, Klipsch does not use anything for alignment on the magnetic grilles they use on the newer speakers. I would consider a clear stick on bumper pad, as the velcro soft pad still may scratch.

[Jeff_R]

A friend knew I was looking for rare earth magnets locally and found them at Woodcrafters. Thanks Mark.

The grills and alignment pins are all figured out. I am going to mount 5 pairs of 10mm x 5mm magnets on the speaker front from the inside counter bored to within 1/16" to the rear of the grill and front of the speaker box. The magnet holes are moving inward to make the counter boring easier. I can't locate my old sheet metal back counter bore, so I bought a new 10mm counter bore at Woodcraft for $5.

The existing 4 holes where you see screws installed are going to be where the hardwood toy axles will be intalled as alignment pins. I will install the pins in the speakers, and use my rotary file, which is the size of these mushroom head toy axle pins, to make the back of the grill the dimple. The wardwood dowels will accept paint, so no issue there that I know of. That is what will be visible with the grills off, a mushroom head painted thing.

Also, looking around on craigslist I spotted a pair of factory satin black La Scalas for sale. After viewing those, all I can say is satin black is out for me as a color. No slight to any satin black speaker owners intended, that just doesn't "do it for me" on these La Scalas. So its going to be gloss black, if not a paint an entire scheme.

We shall see on the color.

Back to work

Jeff

[Jeff_R]

Michael,

We are at crossed posting time here I see. Yes, I was concerned that anything might scratch the paint, particulalrly lacquer. I will find something like you are talking about. Lowes has the stuff in all kinds of thicknesses.

By now you have read the plan to use these hardwood axle things so that is the plan. I didn't know Klipsch used magnets, these I bought feel strong, but not that strong. I know these dowels will take paint, but I don't have to paint them. I could put them in last and just oil them. I kind of have this alignment thing locked in myhead, right to do or just overkill I don't know.

Now I am undecided on the final paint scheme. First question I have is to where you spoke about using poly over lacquer, but only after you are sure all the solvents have evaporated from the lacquer. How long a time frame are we talking on that process? Does it make any differance in the time frame that this is primer and not a finish coat?

I can do a lot more with one color with polyurethane as opposed to lacquer, given my limited painting skills versus my asperations to the final outcome. Or it sounds like it from talking with the paint guy.

Gotta get back to work, breaks over.

jeff

[Jeff_R]

Magnets in, lots of issues with this job. Having done this with 10mm x 5mm magnets, I would have gone larger diameter and bored all the way through the grill next time and do one glass cloth lay up. That would have insured the distance from the magnets to be at least even. Without a drill press I bored by hand, and a couple were a bit tipped, possibly from the first 5 minute epoxy glue in.They hold, but I don't know how tight they will be with the grill cloth on. I am concerned that everything I add increases the distance between the magnets, and weakens the force.

They hold very tight right now, no alignment pins. We will see what happens when I test the grill by increasing the distance. I may have a complete redo on the grill magnets. Whatever pad i use is going to be ultra thin as I am now trying to avoid alignment pins.

The speaker magnets will be okay, just loads more sanding to do on the face as they went in with the Famowood epoxy over everything.

Jeff

Update: I forgot to mention the grill cloth isn't going to be recycleable. Too bad I wanted to use it. Even with my grill smaller than th area originally covered where the trim lays, the cloth isn't large enough to make a wrap around the edges. I have to go to th eRuby Tube stie, I think, or maybe Handmade Electronics site. One of those has cloth, or one site I have anyway.

As to the magnet lesson, I would use 20 mm x 5 mm magnets were I doing this again.

[Jeff_R]

I am having weather delays now. There will be another coat of primer on the faces from the magnet installation. I knew this was coming as boring the 10mm and insuring the magnets were going to end up below the paint required an epoxy fill over them. That set me back a couple days waiting for the epoxy to cure enough to sand.

The plan is shoot primer on the speaker fronts, sides, top, & backs. On those areas I plan to try to shoot more where you see the grey than where you see the white or epoxy over the wood. They are very flat, but i would like them to be uniform grey prior to shooting color. I am only shooting primer into the horn area of the bass bin on one side, one repair area, and one part where a bit of grain still shows slightly. I will have a chance, very slim chance, to sand tomorrow if it dries up after I get off work, overtime. Supposed to rain early I believe. So I have another small window to get everything prepped for the final primer.

From the weather outlook I doubt I have anything to add until next week sometime, and only then if I get lucky. We often have some nice days during Thanksgiving week, and I am taking that week off, so maybe a shot that week if not this next one.

Lowes has quite the selection of wool fiber stick on pads. I hope to go with the thinnest, but the grill fabric and surround will determine that. If that all ends up as think as I think it might, I may end up installing magnets on the back side of the grill as well. That is a snap, but kind of shows I got out of order on this part of the assembly as I could have just waited on the magnets on the grill itself.

All for now

Jeff