Thanks John! And everyone else who has donated! Both this project and my waveguide project are building enough money to push both projects forward through a couple rounds of testing.
I've received the NidaCore. Very soft, papery fabric covering what appears to be a plastic honeycomb mesh. My initial use will be using 1/4" HDF to skin it: basically inner HDF box, then a layer of NidaCore, then an outer layer of HDF. Basically a box within a box within a box. Still deciding how to handle the baffle. I figure with 1/2" combined thickness of HDF and 3/4" overall thickness, direct comparison to the previous MDF enclosures should be helpful. Also intrigued by the XPS foam, cheap and easy enough to test. Will be a couple weeks though, family is in town until the 30th.
My vote would be for Sikaflex 292i. Better yet would be Sikabond construction adhesive, since it has properties quite close to 292i but can be found for much cheaper and more easily at most HD stores. (not Sikabond sealant)
If you want to get fancy then you can buy a pail of 3M microballoons and mix them in 1:1. That's what Geddes did with his shore A two part polyurethane.
Shawn
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I'm curious how this would function as box lining:
F-1 Industrial Felt By Foot
– thefeltstore.com
F-1 Industrial Felt By Foot
– thefeltstore.com
Wow that is incredibly expensive!
I have some glass microspheres to test this later on.
I think that stuff is usually made from polyethylene. It's a pretty difficult material to bond with adhesives... good luck.
I'd like to suggest Sika flex11 instead of more expensive 291i. Sikafloor® Marine PU-Red looks good, but impossible to buy, which leads to Sika latex which should give viscoelastic properties to that kind of "mortar"? Maybe combine that with microspheres, or bentonite. Datasheet suggest not to use it as a bonding agent alone, but in thin layers it should work. Did I mention its dirt cheap?
https://irn.sika.com/dms/getdocument.get/b7c8e904-9f76-39a0-b547-06e4d0a1b88f/Sika+Latex.pdf
https://irn.sika.com/dms/getdocument.get/b7c8e904-9f76-39a0-b547-06e4d0a1b88f/Sika+Latex.pdf
I do want to investigate some cheaper alternatives to Sikaflex 292i, something anyone could run down to Home Depot and buy. My hesitation comes from previous discussions where it was mentioned silicone latex was not at all damping. So then I thought just cheap all latex, but all of those are sealants, not adhesives, though I'm not sure if that is much of distinction when talking about latex.
If anyone has cheap, widely available suggestions with some data indicating why it might be a good damping agent, I'd love to hear them. Meanwhile, next round of boxes about done:
If anyone has cheap, widely available suggestions with some data indicating why it might be a good damping agent, I'd love to hear them. Meanwhile, next round of boxes about done:
Everbuild Everflex AC50 Acoustic Acrylic Sealant - Everbuild Everflex AC50 Acoustic Sealant & Adhesive 380ml White | Sealants Online
Hi, I used this stuff for my tower build, to adhere lead sheet. Looks like it's ideal for sheet boarding materials.
Hi, I used this stuff for my tower build, to adhere lead sheet. Looks like it's ideal for sheet boarding materials.
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PL Premium is like Gorilla glue but comes in contractor grade caulk gun tubes. That stuff bonds everything permanently.
Plain white latex caulking also has great damping prosperities.
I recently bought large mirrors. They ship with this incredible cardboard based honeycomb panel that is 3/4in thick stiff and lightweight. I want to make some speaker with with them. They look like expensive composite aerospace panels used on airplanes except not made of nomex/aluminum but all cardboard.
Plain white latex caulking also has great damping prosperities.
I recently bought large mirrors. They ship with this incredible cardboard based honeycomb panel that is 3/4in thick stiff and lightweight. I want to make some speaker with with them. They look like expensive composite aerospace panels used on airplanes except not made of nomex/aluminum but all cardboard.
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