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Discussion Starter · #1 ·
So, I finally decided to build a little something up for the lonely AV15-H drivers I have waiting in their boxes. Here's what I've ended up with. Each enclosure should end up ~165L net. I plan to line the tubes with R13 backed fiberglass. I'm going to use 600W per driver. Testing will be done with a QSC PLX-2402. Assuming everything checks out I plan to get a miniDSP PWR-DSP1 amp and use that.



Obviously, they still need to be finished. I plan to spray black Duratex on the sonotubes and stain & clear the BB endcaps.
 

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Would love to try the Minidsp amp out so I look forward to your impressions and experience. Minidsp and AV-H drivers should be an awesome combo. Very jealous. :D
 

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Discussion Starter · #5 ·
So I'm still sanding (what a chore) :( I still need to hit all the wood pieces with 220grit. I've done 60/80 and 120. The 60/80 took a long time because I was sanding out some roughness and burn marks left by the router. I've been sanding the flat parts with a random orbital and the curves and roundovers with an oscillating multi-tool. At least the 120 grit went faster.

I'm also trying to figure out my finishing process. Here are two different test finish samples after pre-stain conditioner dye + stain (no clear coat).



I still have some work to do since the finish is uneven. I think I need a second coat of pre-stain conditioner or more dwell time with a single coat before wiping it off. I'll hope to work up more finish test samples today.
 

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Discussion Starter · #7 ·
Looks like a cherry finish. How are you going to finish the edges?
I'm going for a dark brown with a hint of red. The two samples look less similar in real life than in the photo. One is too red. I plan to finish the edges the same way as the flash surfaces. Pre-stain conditioner + dye + stain + clear.
 

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Discussion Starter · #8 ·
I got the first coat of dye on all my pieces. Here's what one looks like, and a picture of it with my 3rd test sample (that I'm after). The test sample has pre-stain conditioner + two coats of dye + stain + one coat of flat poly. Obviously I need more than one coat of poly (more like 3-4), but I didn't see much point in continuing to finishing the last test sample instead of starting in on the real deal. I was real happy with the look of 3 coats of poly on my other test samples.

 

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Discussion Starter · #9 ·
I got the 2nd coat of dye and stain on the various pieces.

This is my target test sample with a piece. One shot is with flash the other is under ambient light.

 

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Discussion Starter · #11 ·
Oddly the finish seems to have gotten a little lighter after putting 2 coats of poly on it. Oh well...



I still have a few coats of poly left as well as putting Duratex down on my sonotubes. I coated those with some flat exterior latex two days ago to harden up the exterior cardboard before sanding.
 

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Discussion Starter · #12 · (Edited)
A bit of progress to report. First, I have a stack of end caps that are done and waiting.



I made a makeshift "paintbooth" to spray Duratex onto the sonotubes.



I made a pair of PVC rotisseries so I could rotate the sonotubes while I was spraying them.



I needed a spot to hang the 2nd sonotube to dry so I set up a second set of rope to the side.



This is what the duratex looks like after 1 coat with the Harbor Freight texture hopper gun. I used the smallest nozzle, about 30PSI, and worked the tube fairly close. As you can see I didn't get perfect coverage. :(



Now this is where you get to learn from my mistakes. The outer layer of cardboard soaks up the moisture from the Duratex (it's a waterborne finish). It swells up quite a bit. This caused all sorts of problems. I had the tubes pretty smooth via some careful use of drywall joint compound and sanding. The cardboard swelled up and climbed up over the joint compound making a some nice ridges. I have no idea what will happen when it dries out. Here's a picture of the swelling on one of the sonotubes. It's almost 1/4 of an inch.



Here's a closeup of the texture after the second texture coat with a ruler for scale.



A zoomed out shot of the whole tube. This is the one without all the ridge problems though it still has a small issue on the right side with a ridge.

 

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Discussion Starter · #13 · (Edited)
If I were doing it all over again I'd use bondo, not drywall joint compound (despite what Duratex instructions say). I'd also use an oil based primer followed by a coat (or two) of black semigloss latex as a base layer for the Duratex (instead of "wasting" the Duratex on the base layer). I believe that would prevent / address the swelling issues. The Duratex would only be used for the texture coat since I don't need the enhance durability of Duratex vs. latex.

Edit: If these end up really ugly due to the cardboard shrinking back to size & opening up tears in the finish or if the ridges don't subside I'm probably going to trash them and try again with new sonotubes.
 

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Discussion Starter · #14 ·
So, after drying overnight there hasn't been any real improvement. Here are a few pictures of the sort of defects on the 2nd tube where I used drywall joint compound to fix a spiral gap.



Yes, the white "lines" in last picture are the joint compound peeking through tears in the Duratex.

I'm going to try to sand these down tonight to get them to a point where I can Bondo any gaps and then put down a coat or two of black semigloss latex until I have a very even and consistent base finish. The remaining Duratex I have will be used for applying texture over that. If I can't get these tubes reworked I'm getting new ones and starting over. I put too way too much effort into the wood portion to use these ugly things.
 

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Discussion Starter · #16 ·
In an attempt to get the Duratex to cure much faster so I can sand it down and get this disaster fixed I made a makeshift paint drying booth by putting them in the smallest room in my house (a bathroom) and stuffing two space heaters in the room running full tilt and a box fan running on low to stir the air. After a few hours the temperature in there is up to 120F and still climbing very slowly.

FWIW, I noticed the outer layer of cardboard has contracted significantly but hasn't quite returned to it's pre Duratex size.
 

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Discussion Starter · #17 ·
So I shut off the "drying oven" before I went to bed last night. Surprisingly the cardboard has returned completely to it's original size. The Duratex is noticeably harder than when I started. Hopefully I'll be able to get them sanded down tonight after work.
 

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Discussion Starter · #19 ·
First off, using Bondo indoors it a bad idea. It horrifically smelly and will stink up your house something awful. It's also remarkably tough to sand. :dumbcrazy:

Second, I'm still fighting the cardboard and it's expansion. I sanded them down yesterday and used bondo to fill the gaps and defects. I sanded that down and I got them pretty smooth. I rolled on flat black Behr Plus Ultra exterior last night and they looked real good while wet. This morning, after they "dried" overnight, there were some lumps under the paint in areas where I had sanded through the Duratex (presumably due to cardboard expansion). :hissyfit:

I've got them cooking (again) to try to dry them out. If they don't end up smooth I will be using some drywall joint compound and will sand super carefully as to not penetrate the paint / Duratex so I don't have to go through this again. Once they're finally smooth and sealed with the flat black paint the Duratex goes on.

At this point I wish I would have just built boxes and skipped the sonotubes.
 

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Discussion Starter · #20 ·
I think I'm finally done with the sonotubes (I hope). I followed the recipe I listed in my last post and smoothed out the tubes (again) with drywall joint compound. When sanding I was careful to not sand through the paint anywhere. I vacuumed them off and covered the filled areas with the flat black exterior latex. After that dried (with some heated help) I applied my spray grade Duratex with a stiff 3" paint brush to the entire sonotube and then used pieces of a plastic shopping bag to put texture on it. Basically I just followed the Duratex leather look instructions. I'll "bake" them some this afternoon / evening to harden them up so I can start assembly tonight or tomorrow.

Here's a quick shot of the texture:

 
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