Material choices, thickness and others about building a case

[Farinorco]

I've seen that the material of choice for many people who builds a case from scratch is MDF. I can undestand why looking at its physical properties, but I'm considering another posibility: I'd really like to use a board with a melamine finish, and I can't find a place where I can buy melamine treated MDF, they use a board that I don't know how to call in english (gaaah, I hate this kind of language barriers... ), it's "aglomerado" in spanish, similar to MDF but with less density (I know, bad...) and bigger shaving (I think it's named so in english? hrrrrrrr ). On the other hand, in most places this board used with melamine, is a three different density layers material, with higher density edges and lower density core (and AFAIK this different density layers approach could be excelent regarding noise isolation), and the average density of this board would be 625-690 kg/m3 -depending on thickness-, when the MDF density is 750-760 kg/m3 -to the same thickness.
________________________
EDIT: Here you can see an image of this boards. The one I would use instead MDF would be the one labeled with "AGLOMERADO PLASTIFICADO", but the same board is used in "aglomerado sin cubrir" and "aglomerado chapado". Sorry for the spanish link, but if I knew the english name, none of these would be necesary
http://www.bricotodo.com/tipostableros.htm
-----------------------------------

My former question is... should I buy MDF board because the other is BS and think in a way to give it a decent finish (as self-adhesive melamine paper), or the other board is gonna be good enough and the difference isn't worth the headaches?

Regarding thickness... my design makes the case currently very tall, i wish i could reduce a couple or five cm of height, but it's absolutely impossible. That's with the originally planned 10mm board, that's it. But now I don't know if that's gonna be enough. What thickness would you use? I think the next thickness I can get is 16mm, and that would make the case another 1,2 cm taller...

And regarding noise dampening, I think I'm gonna use Copopren to partially cover the inside of the side panels (the closed sections of the motherboard -with the fans and pump- and hard drives, to be exact) and completely cover the front panel and door. It's this material:


http://www.isolplus.es/catalogue.php?cat=9

In the latter link you can see a closer image where it's open cell can be seen, sorry for being in spanish, I can't find nothing in english about this product. I would use the 20mm thick 150 kg/m3 dense variety.

Do you think it could do a good job, or should I look for an egg-shaped (waved) open cell foam?

Lots of thanks in advance for any help you could give me (and for reading all this bore... )

[jhhoffma]

There's two ways to reduce sound here. By using a dense (heavy) building material you "mass-load" the case, and prevent resonance vibrations from the moving components inside. But making a heavy case with flat walls also allows the noise (not resonance vibrations) to reflect inside the case. The foam (as long as it's open cell) will reduce vibrations by presenting and uneven surface for sound to reflect off of and essentially dissipate the noise more effectively after each reflection.

If you already have the stuff you have a picture of, I'd give it a try, as it's used for dampening inside many autos as well. If it doesn't work you can always go the "egg-crate" foam route.

[Farinorco]

There's two ways to reduce sound here. By using a dense (heavy) building material you "mass-load" the case, and prevent resonance vibrations from the moving components inside. But making a heavy case with flat walls also allows the noise (not resonance vibrations) to reflect inside the case. The foam (as long as it's open cell) will reduce vibrations by presenting and uneven surface for sound to reflect off of and essentially dissipate the noise more effectively after each reflection.

If you already have the stuff you have a picture of, I'd give it a try, as it's used for dampening inside many autos as well. If it doesn't work you can always go the "egg-crate" foam route.

Thanks for the answer. No, I don't have the stuff shown in the image, I found it using Google image search to show you what I plan to use

AFAIK, Copopren is an open cell foam (and it looks like it is as can be seen in the picture at the latter link I posted), I knew about it searching for damping materials in the web, but it's cheap (~15€ 2x1m) and I can buy it in a near shop. I don't know where I can find egg-crated foam, but I know it exists and its shape is more appropiated... so, do you think I should give a try to Copopren even if I have to buy it, or I should I look for the egg-crated foam?

And, what do you think about the MDF / the other board and 10mm / 16mm thick questions?

Lots of thanks for your help here...

[jhhoffma]

Start with the cheap stuff. It'll still be better than nothing.

As far as the MDF vs. pressboard (which is what I think you're talking about), it's really a crapshoot. Again MDF is easy to get here, and it's pretty much the densest material you can get. Plus many speaker cabinets use it. So it's known to work. That being said, many lower quality speaker cabinets use pressboard of much less thickness. As long as the case has more mass than a standard aluminum/steel case, I think you'll be safe. That's assuming that the material doesn't flex too much and cause sympathetic vibrations.

If it's cheaper get it, if not, you can always buy laminate finishes and glue it to the MDF yourself.

[Farinorco]

Start with the cheap stuff. It'll still be better than nothing.

As far as the MDF vs. pressboard (which is what I think you're talking about), it's really a crapshoot. Again MDF is easy to get here, and it's pretty much the densest material you can get. Plus many speaker cabinets use it. So it's known to work. That being said, many lower quality speaker cabinets use pressboard of much less thickness. As long as the case has more mass than a standard aluminum/steel case, I think you'll be safe. That's assuming that the material doesn't flex too much and cause sympathetic vibrations.

If it's cheaper get it, if not, you can always buy laminate finishes and glue it to the MDF yourself.

Lots of thanks again. That board is a little cheaper than MDF in the places where I can buy it but the difference is not worth it if its going to be much worse. The only reason I considered it is the fact that I can buy it with a good melamine finish, and the MDF not (easy to get here too, every shop selling board has it, just not plastified with melamine). So I think I will buy MDF board and glue some laminate finish (I supose that is what I wanted to mean with "melamine paper", or something similar with real wood) if I can't find a shop where I can buy melamine finished MDF.

I only hope that I can give it a decent look with my clumsy hands

And decide between 10mm (~2/5" ~0.4") and 16mm (~2/3" ~0.63"). If I can think a way to not end with something like the Eiffel tower with the thicker board, that's it . And thinking about it, 10mm costs ~20€/m2 and 16mm ~30€/m2. I believe the difference is smaller between different thicknesses with the cheaper board... ah, decisions, decisions...

[scdr]

EDIT: Here you can see an image of this boards. The one I would use instead MDF would be the one labeled with "AGLOMERADO PLASTIFICADO", but the same board is used in "aglomerado sin cubrir" and "aglomerado chapado". Sorry for the spanish link, but if I knew the english name, none of these would be necesary

If it helps any, I think the term you want is particle board.
(At least that's what the picture looks like.)

[Farinorco]

If it helps any, I think the term you want is particle board.
(At least that's what the picture looks like.)

Yeah, thanks. Any help to improve my chances of communicate with others is welcome . Now I've 2 different names to these , and both seems logical to me: pressboard and particle board. I'm gonna try to know if both are the same thing or which is the one I am referring to.

---------------------------------------

Anyway, I've been making a few calcs, and...

As long as the case has more mass than a standard aluminum/steel case, I think you'll be safe.

MDF seems to have roughly 1/10 density of steel, and 1/3 density of alu. That means that a 10mm MDF panel is roughly the same mass than 1mm steel panel or 3mm alu panel.

Does that mean that its acoustic properties are going to be more or less the same, or are there other factors in all this like thikness, type of cellular structure, I don't know, other things...

Would 10mm MDF be any better (or worse...) than 1mm steel or 3mm alu in any way? Or at least it would be enough to build a quiet case with it?

[JoeWPgh]

We get Melamine here, but I'm not sure if you could get it in a desirable thickness. What we get is Melamine laminated to the front and back of a sheet of 3/4" particle board. The problem with this material is that you need to conceal your edges or else they will chip and leave painfully sharp edges as well as voids in your melamine finish. If I was going to make a case from lumber products, I'd either go with a solid hard wood or a laminate over mdf or particle board.

[jhhoffma]

Now I've 2 different names to these , and both seems logical to me: pressboard and particle board. I'm gonna try to know if both are the same thing or which is the one I am referring to.

What I call pressboard is laminated particle board, which is particle board that has had a veneer or laminate skin glue and pressed onto the surface.

Would 10mm MDF be any better (or worse...) than 1mm steel or 3mm alu in any way? Or at least it would be enough to build a quiet case with it?

Most high-quality quiet cases are built with 1mm steel. It's strong and heavy. Not that you can't improve on it. You may want to go with 1/2" or 5/8" MDF instead of 3/8" MDF, if you wish to improve on that. However, I don't think you'll need it if your components are quiet to begin with and you use proper isolation techniques. As far as cellular structure affecting noise...it certainly won't transmit noise any more than a steel panel...

[Farinorco]

Well, now its absolutely obvious that "aglomerado" = "particle board", and I know exactly what is "pressboard", but I don't know if there is there is a spanish term for it aside "plastificado" or "chapado" (more or less "laminated")

Lots of thanks to everybody here, you are being of an incredible help to me . Specially jhhoffma, not only in this thread, in the end I'm going to have to include him in the credits of my project

I think I finally will use 10mm (~3/8") MDF if I can't find 12mm (~1/2") MDF by here. The usual thicknesses I can find are 10mm, or less, or 16mm (~5/8"), or more.

With my current design the tower is 67cm (!), or 26", tall, which I think is enough . You're surely thinking "bah, from 67cm to 68cm tall, it's the same", but I think a 68cm tall tower doesn't fit under my desk . I should take a new set of measures to be sure though...

[jhhoffma]

I should take a new set of measures to be sure though...

Standard rule of carpentry: Measure twice, cut once.

As for the pressboard, I wouldn't say that it's an industry-standard term, I've just seen it used at some of the home-improvement stores in the US. But if you wanted everyone to know what you're talking about, I'd call it "laminated particle board".

Props are always nice to get, but not necessary. We (well, most of us) are all here to help.