Next Project: Arc 40 CBT Array

[Kevin K.]

I build a nice dining room table for a customer, few years back.
Korelian likes a high gloss, high-build clear finish. Best is under french-polished shellac but a clear 2k will do it's justice as well. Oil may not be the best choice for it. All tho, the wood is so 3-dimentional in character that even a low build finish will do magic. Korelian Birch becomes more amberish in time and the contrast accentuates. I would stay away from any sorts of stains as well.
If you can spray a few coats of good old nitrocellulose lacquer on the speakers, I think it would look spectacular.

Spectacular looking Roman. Thanks for the advice. I sprayed lacquer on the Archers but the Texas heat was wreaking havoc on the finish, had a lot of orange peel. Tried a retarder but not much improvement. It's starting to cool off a little down here now, so could probably get away with it in the evenings or early mornings.

[donradick]

re: Roman -- wow, that's really special.

[r-carpenter]

Roman, do you have any experience with the Karelian Birch? What do you think about the Boiled Linseed Oil on it? Any negatives about it I should watch out for? Was still thinking about picking up some Tung Oil, not the Home Depot stuff, but the real stuff. Rocklers is about the closest place to me that carries it.

I build a nice dining room table for a customer, few years back.
Korelian likes a high gloss, high-build clear finish. Best is under french-polished shellac but a clear 2k will do it's justice as well. Oil may not be the best choice for it. All tho, the wood is so 3-dimentional in character that even a low build finish will do magic. Korelian Birch becomes more amberish in time and the contrast accentuates. I would stay away from any sorts of stains as well.
If you can spray a few coats of good old nitrocellulose lacquer on the speakers, I think it would look spectacular.

[donradick]

Thanks Don! I'll give your recipe a try on some of my cut outs. What's your favorite sheen when it comes to the Poly: flat, semi, or high gloss?

I used to dig high gloss, but then my (totally supportive) SO expressed a preference for satin/semi gloss, so that's what I use now.

[Kevin K.]

Thanks Don! I'll give your recipe a try on some of my cut outs. What's your favorite sheen when it comes to the Poly: flat, semi, or high gloss?

[donradick]

Kevin, I am in awe....

re: finishing.
I've recently moved to all oil based wipe on finishes.

I'm really digging a wipe on mix:
1/3 boiled linseed (or tung) oil
1/3 mineral spirits
1/3 oil poly

Give it try - I find that it really makes the grain pop, and it's foolproof.
Standard instruction is to apply liberably, wipe off after 15 minutes, then
repeat after 24 hours. After a few coats, if you let it dry for 7 days or
so, you can finish with 1 or 2 coats of full strength wipe on poly.

And, yeah, that Karelian Birch veneer is totally awesome.

[Kevin K.]

Thanks fellas! And Tom, that's high praise coming from a guy with so many incredible builds under his belt.

It's obvious you know a lot about the different wood species Roman. I honestly didn't realize it was that uncommon. Definitely pricey, spent almost as much for the veneer on the baffle as I did for a full sheet of Sapele, but IMHO, worth it. The Karelian Birch has a striking character that just has to be seen up close to be believed.

Roman, do you have any experience with the Karelian Birch? What do you think about the Boiled Linseed Oil on it? Any negatives about it I should watch out for? Was still thinking about picking up some Tung Oil, not the Home Depot stuff, but the real stuff. Rocklers is about the closest place to me that carries it.

[r-carpenter]

Karelian Birch,

MMMMM great choice!
Rotary cut variety of a norther birch. Only grows in some parts of Finland and Karelia (Russian territory, neighboring Finland,) Very pricey. Recently allowed to be harvested again. Historically, typical for Russian furniture manufactured for royal families of 18 and early 19 century by best shops in St.Petersburg. Best example are in Pavlovsk and Hermitage museums.

[Navy Guy]

We're not worthy! We're not worthy!

[tomzarbo]

This is probably one of the most incredible build logs I've ever seen. These things are going to be killer.
Incredible man.

TomZ

[Kevin K.]

And here is this weekends progress:

Made a decision (really hard for me when it comes to veneer, I like em all) and the baffles will be out of Karelian Birch, rest of the enclosure will be Quartersawn Sapele. Ordered enough for the entire 7.1 system when ever I decide to make the rest to accompany these arrays. Glued the birch to the mdf and cut the two baffles this weekend. Really happy with em. Here is one of them laying on top of the Sapele Veneer.



This is one of the cut outs from the baffle with Boiled Linseed Oil on it. May pick up some Tung Oil this week and try that also.



Ok, last pic for the evening. This is where I left off. Got most of the 3/4" three layer damping foam cut and started one of the harnesses. Ran out of time, still have two more tweeter sections of the harness to go to complete the first harness. Then on to the second.



Hope you guys enjoy the updates. Not gonna lie, these things have eaten my sack lunch more than once. Progress seems so slow and for the longest the tunnel just looked pitch black to me. After this weekend, I think I might have spotted a little light at the end of the tunnel and have a renewed energy towards em. Still several more weekends of work to go, but I do feel a little closer to the finish than the start now.

[Kevin K.]

Time for some long overdue updates. The following pics are of the "full scale" versions. There have been a few small changes, mainly to the interior and how it was sub-divided.


After the spine and a couple of the ribs were cut, the first part to be glued and attached was the back panel. It's official, I have a new favorite clamp! Picked these up at Home Depot, about 15 bucks a pop, but worth every penny if you ask me. The red buttons are quick releases that allow you to adjust the clamps very quickly to the size you like, a very cool feature compared to the old fashion way of having to do it. Another nice feature on these clamps is the grip handle will actually break over 90 degrees if you really need to put some torque on em. Sorry I didn't capture that feature in this pic. Anyway, I needed the extra throat clearance these clamps offered to squeeze the back panel down to the spine. Worked great!


This pic was right after all of the ribs were cut and glued to the spine and back. Forgot to mention everything in the enclosure is 1/2" MDF except the spine and base, those are out of 3/4".


Here you can see the internal changes I was talking about earlier. In the previous enclosure, the subdivision was a flat front panel with two sidewalls that went back to the back panel and kissed off. After looking at that a little harder, I decided that was probably not going to be very friendly for the back waves and might create problems. This led to the redesign with the panels angled at 22.5 degrees from the center. At least this way, the back wave isn't being redirected right straight back at the woofers.


This photo show the lower divider in it's natural state, flat. I attempted to flex these into place but they were not having it. Ended up taking them back to the machine to cut grooves in the back of them to allow them to flex a little easier. The next couple of photos show the results.


Will probably back fill the grooves with an fiberglass epoxy resin before closing up the enclosures.




So here they are standing up on there own for the first time. The upper dividers are more of the same, so I didn't see the point to adding pictures for those. This pic was when they had the 1/2" bases, they have since been upgraded to 3/4".


Changed the base to 3/4" cause I didn't like how easily the base could flex after I cut the access hole in it. It's a fairly large access hole and I'm thinking about just leaving it open, makes these puppies a lot easier to carry that way.

[JavadS]

Good luck on your research Javad, I have a feeling there will be a new CNC in your shop somewhere in the near future. Nice website by the way. Is CariD one of your customers?

Hah yea, now I just need to justify the space and expense with a revenue stream! And they are not but they should be, hadn't heard of them, thanks Kevin!

Javad

[Kevin K.]

Hey Kevin we manufacture performance automotive products (034Motorsport.com) so they're all cutting metal, but I have been researching CNC routers, the thought of loading a file and cutting virtually anything I can imagine (as you've been doing) is so tempting. Javad

Good luck on your research Javad, I have a feeling there will be a new CNC in your shop somewhere in the near future. Nice website by the way. Is CariD one of your customers?

Were those cutouts made on a CNC? They're sooooo perfect.

Yes, it's all cut on the CNC. The model was created in an old CAD software I have on my laptop and then programmed to be trimmed on the CNC with MasterCam 10. It was all cut on a DMS router.

[xsundown]

Were those cutouts made on a CNC? They're sooooo perfect.