The Stacked Baltic Birch N2X Ideas and Assembly Thread

praedet · « **on:** 22 Aug 2010, 09:44 pm »

Well, this is kind of a continuation of this thread I created a long time ago. Lucky for me, and 8 other people, Danny tracked down getting some of these cabinets made.

Here are the pictures that he took

I thought I would start this thread so that the folks that picked up a set of cabinets could discuss building techniques and hints, and also so that everyone could offer ideas for finishing styles and techniques...

At this point I am personally trying to figure out how I want to finish them. I have thought about using something like a birds-eye maple veneer on the baffle, top, and bottom, and then doing the whole thing in clear. I also thought about doing the baffle in satin black and still doing a birds-eye maple top and bottom. Any thoughts or comments from other cabinet purchasers or anyone else?

jeffh · « **Reply #1 on:** 6 Sep 2010, 07:04 pm »

Anybody made any progress? I would love to see some picutres.

Jeff

praedet · « **Reply #2 on:** 10 Sep 2010, 03:28 pm »

Jeff,
I am about to start the gluing process. I am planning on just wiping the pieces down with a damp cloth to remove any dust, then spreading the glue on each side and in the holes, tapping in the dowels, then clamping the pieces together and wiping off the glue that squirts out. Does that sound about right to you? I'll take pictures as I go

praedet · « **Reply #3 on:** 12 Sep 2010, 01:31 pm »

Hmmm, just noticed there are 3 braces to try and evenly distribute between the 9 non-braced pieces and the top and bottom piece. Any ideas for the best spacing since it won't be even?

Vapor Audio · « **Reply #4 on:** 13 Sep 2010, 01:08 am »

I have a bit of experience finishing laminated Baltic construction cabs like this

All I can tell you is get ready to sand, sand, and sand some more. Then when you think you've sanded all you can, sand some more.

The real work comes from the fact that you can never get it totally flat sanding with a power sander, it has to be hand block sanded to get all the level sanded perfectly even. I use one of these, and suggest you order one as well in the right size to do the entire vertical height of the cab in one pass

http://dura-block.com/durablockline.html

Once it is sanded smooth, if you want to veneer the cabs you have to seal the BB end grain. What I use is West System 105 epoxy Resin, 206 slow hardener, and the Microlight filler. The first seal coat you don't need the filler because it'll soak in quite a bit. Apply using some disposable rollers, then sand again. Do another coat using the Microlight once that's set and a final block sanding. You'll need a bit of a scuffed surface on the final coat of epoxy sealer for the veneer adhesive to grab ahold of, so use 150 grit or so. The best veneer aplication is a Urea based glue and a vacuum bagger, but most don't have that availabe ... which means either contact cement or iron-on. Personally I'd go with contact cement, which means you need to use either backed or 2-ply veneer - I prefer 2-ply because backed veneer will always have a visible line at the edges.

With this construction I'd say you're going to want to veneer the baffle separately before attaching it permanently to the cab. That will pose some challenges as well, in getting the top/bottom and sides to end up perfectly flush when done.

Some people may say you can seal the sides using some sort of Fiberglass Resin, but I wouldn't trust it personally. I don't think it has the strength to hold up to veneer application and finishing, which can apply serious stress on the substrate.

It is a lot of work to finish of cabs with this construction, but it's worth the effort for the performance gains you get.

praedet · « **Reply #5 on:** 13 Sep 2010, 12:44 pm »

^^^Cool, thanks for the info!

I am planning on simply doing a clear coating over the end-grain to show that off. Any recommendations?

Also, any prep work that should be done before gluing the pieces together?

Thanks again for the help!

Peter J · « **Reply #6 on:** 13 Sep 2010, 02:15 pm »

When you're using any plywood there's endgrain every other ply, so getting a really glass smooth finish is a challenge, because of absorption rates and the way end grain machines vs. straight grain.

If you want to achieve that glass smooth surface and still show the plys, you could coat with epoxy or polyester resin, but grain filler is somewhat easier and designed for the purpose. It needs to be clear, not the traditional opaque filler. Here's one you could use as well a short tutorial:

http://www.rockler.com/blog/index.cfm?mode=entry&entry=7F490E9A-1372-6771-F60F68E2C3DB5112

And for some great products and advice:

http://www.homesteadfinishingproducts.com/

Quote from: praedet on 13 Sep 2010, 12:44 pm

Quote from: praedet on 13 Sep 2010, 12:44 pm
^^^Cool, thanks for the info!

I am planning on simply doing a clear coating over the end-grain to show that off. Any recommendations?

Also, any prep work that should be done before gluing the pieces together?

Thanks again for the help!

Vapor Audio · « **Reply #7 on:** 13 Sep 2010, 02:32 pm »

Quote from: praedet on 13 Sep 2010, 12:44 pm

^^^Cool, thanks for the info!

I am planning on simply doing a clear coating over the end-grain to show that off. Any recommendations?

Also, any prep work that should be done before gluing the pieces together?

Thanks again for the help!

Glad I can help!

If putting a finish directly over the end grain laminations, don't use stain ... it'll absorb into the layers in very different amounts and give a splotchy look. If you want to color it, use a dye instead and spray it on. I know what you're thinking, "I don't have a spray booth or an HVLP sprayer". No problem, just use a normal airbrush. Sure you'll have to refill your airbrush cup a few times, but it doesn't take much dye mixture to cover the cabs. Of course you couldn't spray on a poly with your airbrush, it takes a LOT of poly to cover and you'd have to refil your cup 100 times ... but dye goes a long way. Just mix up enough in a bowl for the whole job and refil the airbrush from that.

No prep needed before gluing the pieces together, just make sure and use plenty of clamps on the stack when it's glued and drying ... you'd think they would sit flat on each other and glue together easily. But there's enough moisture in yellow glue to cause the layers to warp just enough to cause gaps if not clamped every 4"-6".

One good thing about this shape is that it's open enough on the inside that you could easily 'paint' the inside with a seal coat ... and that's something I would certainly do. The voids in the ply will pass moisture very easily and can cause problems down the road, also some of the layers even is this good 13-layer ply are very porus and pass moisture. Probably the easiest way to seal up the inside would be to just paint on a few coats of diluted yellow glue after the stack is glued up. Although if you do that you're probably going to want to let it sit for a week or two, let the moisture in the yellow glue evacuate. Better would be to use something not water based, like the West Epoxy ... but that's much more expensive and harder to work with. You could also use a fiberglass resin or epoxy filler to seal the inside.

WGH · « **Reply #8 on:** 13 Sep 2010, 03:00 pm »

I would use a polyurethane glue because you get a real long assemble time. Gorilla Glue will work but I prefer Excel http://www.excelglue.com/. Polyurethane glues dry by reacting with water vapor so slightly dampen one side of the plywood. Keep the coats very thin and because plywood is porous apply the glue to both sides of every piece. Be prepared for a big mess, wear disposable rubber gloves, have rags and a container of acetone handy for cleanup. Wear old clothes because this glue will get on everything, it is amazingly sticky.

The glue line on some yellow glues like Titebond II & III will raise during humid weather so these glues are not the best choice for a smooth surface.

I don't know how tight the dowels fit but clamping long 1x2's along the sides could help with alignment. Wrap the 1x2's with clear packing tape and the glue won't stick.

Wayne

praedet · « **Reply #9 on:** 13 Sep 2010, 03:44 pm »

Thanks for the recommendation Wayne, I had some good ole' wood glue ready to go, so I will make sure to pick up some of the excel. Do you recommend Excel One or Excel Structan?

So, I would
1. Wet one side of each layer and wet all the dowels
2. Brush a thin coat of the glue on both sides of each layer, into the holes, and on the dowels
3. Assemble the pieces together and clamp.
4. Clean up the sides with the acetone.

Would you use a thin coat on the inside of the speaker also?

I also like the 1x2 recommendation as I don't have a huge number of clamps that go large enough so I was trying to figure out what to do!

Vapor Audio · « **Reply #10 on:** 13 Sep 2010, 03:51 pm »

Poly glue is great stuff if you need the gap filling ... but for this application I can't think of any upside to using it. It's messy and expensive, and tests over and over have shown that on 'glue ready' surfaces, plain ol yellow glue gives the best bond. The faces of ply that are being bonded are plenty smooth and glue ready to be ideal for yellow glue.

Gluing together the stack is the easy part. Just use the dowel alignment holes and it'll line up just fine, and use plenty of clamps like I mentioned above. A pin nailer is nice to have, but not necessary.

Vapor Audio · « **Reply #11 on:** 13 Sep 2010, 03:54 pm »

Quote from: praedet on 13 Sep 2010, 03:44 pm

I also like the 1x2 recommendation as I don't have a huge number of clamps that go large enough so I was trying to figure out what to do!

You'll probably only need 6 clamps per cabinet ... 2 on each side, one in the middle back and front. If you don't have 6 clamps, seems like a good time to buy a couple more. The bar clamps from Harbor Freight are dirt cheap and work very well.

WGH · « **Reply #12 on:** 13 Sep 2010, 04:29 pm »

I use Excel One. Dampening one side is probably enough but here in the desert I usually dampen both sides. Oh yes it is messy but I like to take my time during glue-ups. The foamy squeeze out is easily sanded off, the acetone is for your tools, workbench, telephone, and floor. I use waterless hand cleaner for my hands. Since TurboFC3S says the good 'ol yellow glue works then I would go that route.

If you are new to this then look for Titebond Extend Original Glue
http://www.titebond.com/IntroPageTB.ASP?UserType=1&ProdSel=ProductCategoryTB.asp?prodcat=3
Titebond Extend Wood Glue is a slower setting version of Titebond Original Wood Glue. It is particularly useful in complex operations that require more time to align.

Actually the gaps filled with polyurethane glue have absolutely no structural properties. The only glue that does does have structural properties is epoxy.

Wayne

BrianH · « **Reply #13 on:** 13 Sep 2010, 08:16 pm »

To understand better when and where to use poly glue vs yellow glue I found this article full of good information.
http://www.popularwoodworking.com/article/The_Truth_About_Polyurethane_Glue/

For my project needs even beyond speakers I find the various flavors of yellow glue meet my needs. The various Titebonds are not the same, Titebond I = Elmers = good all around, Titebond III = long assembly time, Titebond II = moisture resistance is the way I use them.

And I use Titebond II for heat veneering.

One guys opinion anyway.

nrenter · « **Reply #14 on:** 29 Sep 2010, 11:30 pm »

I was really hoping this build thread would take off.

How many kits did you sell, Danny? Has anyone reported back on their progress (that hasn't posted here)?

Danny Richie · « **Reply #15 on:** 30 Sep 2010, 02:59 am »

I think I have 7 left. I am actually a little bit surprised that I still have them.

face · « **Reply #16 on:** 30 Sep 2010, 01:36 pm »

What's the cabinet's internal volume?

Danny Richie · « **Reply #17 on:** 30 Sep 2010, 01:38 pm »

Half of a cubic foot.

praedet · « **Reply #18 on:** 2 Oct 2010, 05:28 pm »

Well, no one else who is building these is posting here, so here is my progress. I finally got some time to work on these.

I am using Titebond III wood glue. This gives me 10 minutes of working time. What I found this morning was that I was not able to get all of the pieces glued in 10 minutes, especially with trying to set up the guider dowels. I actually only got the bottom piece and the 3 above it together before I figured I had better clamp and take a break

So, some notes so far.
1. The dowels seem to be more than double the thickness of the individual ribs. This means that over time you will not be using 4 dowels for every piece of wood. Seems trivial but it takes time to get them hammered in and figure this out

2. Some of the pieces require quite a bit of force to get them together between an excellent fit and the dowels. I recommend doing a quick clamp to press the new piece on in between each added layer.

I guess that is about all. Here are 2 pictures of my progress. The outside is still wet where I wiped off the glue and I did a roughly 2-3 part water to glue layer on the inside using a brush to seal it. This was recommended above...

And thanks for doing these Danny, sorry they did not sell fast

eclein · « **Reply #19 on:** 2 Oct 2010, 06:54 pm »

Looks like an excellent build so far...keep us posted!!