Has anyone built a flexi rack with lexan or lucite or plexiglass? (1 Viewer)

[RandyL]

MY wood finishing skills are... nonexistant I've seen a few sheets of 1/4" plexiglass that seem darn strong.
Anyone used this stuff for a rack?

 

[Bill Catherall]

I would go with 1/2" Lexan (polycarbonate). It's shatter proof. Plexiglass can break and when it does, it shatters. Also, you say your wood finishing skills are nonexistent. What about your plastic edge finishing skills? Raw cut edges look very bad and it's best to round them over with a radius cutting bit. They will have a white opaque finish unless you polish them with a torch. You can't buff it to a polish finish. But a white opaque rounded edge doesn't look bad. A local plastics shop can supply the material and do all the cutting, rounding, and polishing for you at a decent price. Look in your area for a TAP Plastics.
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Bill

 

[Bill Harada]

Also remember that Lexan/acrylic is pretty flexible, even in 1/2" thickness, unless you add bracing. Probably why you see component racks with tempered glass shelves...much more rigid.
Bill

 

[RandyL]

That's exactly what I may do! I figured I'd have whatever shop I bought the stuff at do the ripping/cutting, and I'd use a roundover bit in a router to finish it off.
Do you think 1/2" Lexan, with supports every 20", can support 100 lbs?

 

[Bill Harada]

If you mean like in a 40" wide shelf with rods at the ends and in the middle, then I think it'd be iffy. Add to the 100lbs the heat generated by the components and you're just asking for the shelf to bow. Adding bracing to the bottom of the shelf in the way of a 2-3" wide strip of 1/2" Lexan cemented down the center (width wise) might do the trick. I'd ask the people at the plastics store for advice on bracing specifics.
Bill

 

[Bill Catherall]

According to my calculations 1/2" Lexan will have a significant amount of deflection from 100 lbs. We're talking over 1/4" deflection. If you want to support it then I'd suggest a 1" wide piece of 1/2" Lexan glued on its edge under the shelf. If you have 3 supports on each side and one or two 1" x 1/2" pieces glued edgewise underneath running from side to side then this might help support it. But I'm not too sure the glue will be able to take the strain.
Something I should mention...if you are going to have the edges polished then it's best to use acrylic because it has a lower water content and won't bubble up when torched.
One other option that will look really cool. Have a local machine shop cut some 1/4" aluminum (have them put the holes in too). Then you can polish it up by hand with some aluminum polishing compound, then spray a clear glossy finish on it to keep it from oxidizing. I've seen aluminum that polishes up like chrome. It might make for a heavier rack, but not much heavier than if you used MDF. I think it would be very resonably priced too.
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Bill

 

[RandyL]

Wouldn't Aluminum flex more than acrylic/lexan? It's a fairly soft metal, isn't it?
It does sound like a great look though... but I may have my heart set on the clear acyrlic... Maybe if I did FOUR supports across the back (so every 10 inches) and then three in front (every 20 inches). Do you still think it would bow or bend?

 

[Bill Catherall]

Aluminum is soft as far as metals go, but is much stronger than Lexan.
With aluminum you'd have to have 20,000 lbs to get the same amount of deflection as you would with 100 lbs on Lexan! (Assuming it won't break first. Sometimes aluminum behaves like a brittle metal.)
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Bill

[Edited last by Bill Catherall on November 13, 2001 at 06:26 PM]

 

[Bill Harada]

You'd need to ask for hardened aluminum. Very rigid stuff. As for the bracing of the Lexan/Acrylic, Bill's right about the edge bracing. That's why an acrylic aquarium always has a top cap cemented to the walls. The additional rods along the back probably won't be enough as the front edge won't be supported and will still bow. The additional rods along the back in addition to a strip cemented along the bottom of the front edge would probably be enough, though.
Bill
[Edited last by Bill Harada on November 13, 2001 at 06:26 PM]

 

[Bill Catherall]

Well, I looked up the prices of aluminum and I'm wrong. It looks like it isn't as cheap as I thought. A 24"x24" plate of 1/4" aluminum alloy 6061 (the cheapest and most versatile alloy) is nearly $100. That would be a pretty expensive rack to get it machined too (although with the right tools and a little know-how you can do it yourself).
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Bill

[Edited last by Bill Catherall on November 14, 2001 at 10:44 AM]

 

[RandyL]

Well... it seems the best idea might just be to be "boring" (hehe, this is still a fun project) and use MDF painted a similar silvery grey as the TV plastic.
Would a piece of 3/4" or 1" MDF in this configuration be okay?

That puts supports along the back at about 13" intervals, and 16" intervals along the sides. (About 38" spacing on the front, really don't want a center support in the front)

 

[Bob Sorel]

Why no support in the front center? I made a rack that is 44" wide and 16" deep out of 3/4" MDF (one sheet, and Home Depot will even cut it up for you), 36" high, with 6 shelves. I used six 5/8" rods for supports placed in the four corners, middle front, and middle back, and then mounted the entire flexy on six 2" casters. Since most components measure only 17" in width, and very few are deeper than 16", there is plenty of room to mount 12 items. This configuration is ROCK solid, cheap to build, and if you use a 1/2" roundover bit on all the shelves, top and bottom edges, it looks quite professional. Also, if you don't like the look of the painted threaded rods, you can buy 3/4" PVC tubing (I think that's the size....I didn't buy it) in the plumbing section, cut it to length, and then cover the threaded rod with it as you install each shelf. (I preferred the "macho" look of the threaded rod...hehe.)

 

[RandyL]

It's for a TV rack and thus I don't want anything in the middle front. I'm putting the edge of the bottom of the TV flush with the front for the best aesthetics.
I'm thinking it may be best to use 1" MDF (or double up two 3/4" sheets) for the top shelf. I want it sturdy, but 100# ain't THAT much and it won't be moved much.

 

[James Mudler]

Hello, On the finishing the edges question. Sand with 220 grit. The I use a blow torch to polish the edges on Lexan and plexi. Also jewlers rouge and a buffing wheel works great.
Just a idea to help you with your project.
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Luke, I'm your father

 

[Brian Bunge]

Randy,
I'd definitely consider doubling up the top shelf. TV's are heavy, especially in the front (I should know, I spent 4 years in the Electronics Dept. at Wal-Mart during college). Seeing as you will have no support in the front, the shelf could easily flex. Also, you never mentioned what size TV we're talking about. I assume from the size of the rack that we're talking around 32"-36". If so, I don't think I'd consider anything less than 1.5" worth of MDF.
Brian
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[Bill Catherall]

Randy - The supports for the front of the shelf can go underneath so they won't be in front of the TV.
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Bill

 

[Bob Sorel]

It's for a TV rack and thus I don't want anything in the middle front.

Then you could just cut off the bolt sticking out of the top middle front so that it wouldn't get in the way of the TV. As long as you have a nut and washer underneath the middle front support, it would still hold the same amout of weight. I have sat on my flexy and jumped up and down on it (I weigh almost 200 pounds) and it has not even flinched. I feel that the threaded rods offer the most in the way of support, and as long as all six rods (or casters) contact the floor, the weight will be distributed evenly. Oh well, it's your TV, so if you don't mind it crashing to the floor for the sake of aesthetics, then I don't mind either. Good luck!

 

[RandyL]

Your point is very persuasive (love the visual of my TV falling over... )
I'm going to give this more thought and more design work. Perhaps I can design a setup where the shelves are supported at 6 points.

 

[Bob Sorel]

Sorry, Randy, I don't mean to alarm you, but I have already had this happen to me once (though it was only a $600 set). Since then, aesthetics has always been second to functionality for me. I like things to look good, too, but not at the price it cost me last time. That's why I built this flexy like a tank.

 

[Greg_R]

Installing a hardwood strip (~1.5" high, 3/4" thick) across the front edge of the MDF will greatly increase the shelf's strength.
Greg