DIY IKEA Lack Rack - Preparing the legs?


We are pulling together the parts to build my daughter her first audio rack on the cheap. Another post here about wooden racks brought to my attention some of you who have built racks from IKEA Lack tables, and I became very interested. I already have experience assembling an IKEA wall cabinet for my vinyl, so know that their composite materials are quite strong.

For the rack, you stack the tables up after cutting the legs to size that become your shelves. I want to spike the bottom of the legs, so that they stack up that way. The issue, is the core of the legs are hollow with inside dimensions of 1.75" x 1.75." Dimensional lumber like a 2"x 2" is only 1.5." My idea was using stock square lengths of turning wood that you can get 1.75" x 1.75.

Should I fill the entire length of the legs with the wood, or just insert a shorter piece into the bottom of the legs for the spikes? One of the benefits that's been said about the IKEA composite materials is low resonance even though it's strong. So, will adding a full length of wood to the core of the legs affect the resonance properties? I can go either way.
Kenny
kennythekey
Are the legs hollow? I thought they had fibreboard inside.

B

B,

From the pictures I've seen, just the bottom of the legs have fiberboard. Si if you cut them open they're hollow. Here's a link:

http://www.innerurban.com/innerurban/audio/labels/DIY%20Audio%20Rack.html

Kenny

Funny you put up that link.
That is exactly what I would do. 
B
B, Yup, that's what I have to do. So, if these legs were once filled with fiberboard, and now they're just fiberboard end caps, what's best to fill-in the legs with for resonance? So, that's the question.
Kenny
Gotcha.
If I were to undertake this project, I would try to find some wood with as close to the dimensions as possible. Fill the voids with some acrylic 2 part epoxy-It should come in a caulking tube that mixes as it gets pushed out.
Let it set up.
Drill out the holes for the T-nuts and put in some glue or more epoxy into the T-nut hole before installing.
Then get some spikes from Herbies.
I would also use some Herbies Fat Dots under the components or any other isolation product (Stillpoint, Synergistic, etc).
Are you sure you want to go with Lack? I use Besta for my components.
B
B, That's a great idea using epoxy as a filler. The only downside would be the amount required. I will have twelve legs that average 7" each. Except, for the fiberboard inserts at the ends there's probably 5" of cavity in each leg, so 60" total. That's a lot of epoxy. What do you think about using sand instead?

For the bottom base, we'll be using Herbie's Giant threaded Isolation discs, so that's where we splurged. The legs are getting spikes.

My daughter already got the IKEA tables, so we'll stick with those. Thanks for the Besta suggestion.
Kenny
Kenny, can’t you cut the fiberboard to be 1/8" smaller than the leg? That shouldn’t require too much epoxy.
I was thinking of filling the leg with wood or fibreboard.
Those legs should be pretty firm. Maybe put some in the shelf,too.
B
Hmm, I wonder if you could
 make an epoxy slurry with sand and fill the legs with that.
Now, I get ya B!

I wasn't going to try to find fiberboard to fill the cavities, because it only comes in sheets (I think). I was going to use wood turning stock that would perfectly fit the 1.75" x 1.75" cavities. That got me started to wonder if wood, like soft maple for example, would resonate more than the original fiberboard legs that were used in the past Lack tables. And, what the good reviews that I read are based upon.

Now, I'm pondering if just leaving the cavities hollow, but caped, would be just as good as anything you could fill them with. Obviously, I don't have much knowledge about resonating materials, so why I'm stumbling around.
Kenny
The fact that the shelves are filled with corrugated fiberboard seems to make having non resonating legs a non issue. 
As this is a quick down and dirty solution, I would try to get the legs to accept the threaded discs and then put some other isolation products under the components. 
It's never going to be as good as a purpose built rack, but it should do the job. FWIW, I try to not get too caught up with making things perfect. It might make a
 difference, but usually nothing earth shattering.
B
B, Yes it's easy to overthink this at this price point. Thanks, for your input.
Kenny
Let me know how it turns out.
B
Update - As it turns out, the IKEA shelves or table tops are not filled with fiberboard, so used only in the corners. Instead, they are for the most part hollow, but use a paper honeycomb structure for strength. Essentially, these tables are mostly air.
Kenny