MDF is porous??
05-07-2003, 09:10 AM
#1
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MDF is porous??
According to this article it is. Keep in mind though, they used 3/8 sheets...and Im not sure about the source. Just want to seek your opinions on this and see what you guys have to say! I know about 95% of the people put there are using this stuff...
05-07-2003, 10:53 AM
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Just take some Fiberglass resin and pour it inside the enclosure and move the box around and let it coat the inside, or use a paintbrush if necessary, and it'll seal the inside right up if you have any issues.
05-07-2003, 12:47 PM
#3
Yeah, it's porous, but I'll bet if you pressurize a box and see how long it takes for a measurable amount of pressure to bleed off, and then consider how much pressure your typical box sees, and what period of time it sees that pressure for, you'll find that worrying about it is a complete waste of time.
I undercoat most of my boxes to make my customers feel better that the box is well damped and that there's no chance of leaks due to its porous nature or a spot I may have missed with the silicone, but honestly you can't really hear a difference, and what difference is audible is just due to the undercoating providing extra damping on the larger surfaces.
BTW, that test they do with the vacuum is a crock of sh*t. You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it. If you glue or silicone a smooth glass ring to the wood for the surface of the vacuum to mate to (but still hollow in the center so the pressure vacuum is on the wood, not the glass) I'd be willing to bet the results would be different. There's air getting in BETWEEN the wood and the vacuum tube, not through the wood.
I undercoat most of my boxes to make my customers feel better that the box is well damped and that there's no chance of leaks due to its porous nature or a spot I may have missed with the silicone, but honestly you can't really hear a difference, and what difference is audible is just due to the undercoating providing extra damping on the larger surfaces.
BTW, that test they do with the vacuum is a crock of sh*t. You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it. If you glue or silicone a smooth glass ring to the wood for the surface of the vacuum to mate to (but still hollow in the center so the pressure vacuum is on the wood, not the glass) I'd be willing to bet the results would be different. There's air getting in BETWEEN the wood and the vacuum tube, not through the wood.
Last edited by Jim85IROC; 05-07-2003 at 12:50 PM.
05-07-2003, 02:19 PM
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Originally posted by Jim85IROC
You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it.
You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it.
:hail:
05-07-2003, 03:26 PM
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Originally posted by Jim85IROC
You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it.
You can't get a suction cup to stick to a turd either, but that doesn't mean you can breathe through it.
05-07-2003, 07:51 PM
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Good tip, I imagine fiberglass is water proof also. Now I can cover the whole box and water proof it, I had a leak that I recently repaired so just in case........
05-07-2003, 09:41 PM
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During a recent visit by Dave Gumienny of Phaze Audio in Arizona, he reminded me about the porousness of MDF. He told a story of one of the training courses they did at PPI where 5 small pieces of MDF, 3/8 thick, were stacked, and lifted by a vacuum into the air.
If they stacked 5 pieces and picked them up w/ a vacuum, wouldnt that mean that it was airtight because if air escaped they wouldnt be able to be sucked to the end of the vacuum...it would be like trying to suck up a screen. Am I right? or am I brain farting?
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05-08-2003, 02:29 PM
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Disturb, I think the idea is that the 5 pieces of MDF weren't stapled/glued/velcro'd/etc to each other in any way. So the vacuum was able to suck "through" the first piece of MSD to get to the second, etc...
05-08-2003, 07:54 PM
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really means nothing. for the price, mdf is the best material for boxes. you could do better, but the price/quality increase isnt worth it. and if it were so bad, pros wouldnt be using it.
05-08-2003, 11:56 PM
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Originally posted by TomP
Disturb, I think the idea is that the 5 pieces of MDF weren't stapled/glued/velcro'd/etc to each other in any way. So the vacuum was able to suck "through" the first piece of MSD to get to the second, etc...
Disturb, I think the idea is that the 5 pieces of MDF weren't stapled/glued/velcro'd/etc to each other in any way. So the vacuum was able to suck "through" the first piece of MSD to get to the second, etc...
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