MDF

[dmopar74]

I built a stand out of MDF in 2001, it has been moved a dozen times and now my friend has it. Still going strong holding the same 55g. I painted it with spray paint but that's it. The top was double layered of 1/2" or 3/4" so at least 1" thick. I think it was 3/4" though. Single layer sides and bottom. It has 3 small supports in the center area as well. The front is skinned with some very thin plywood type stuff. I had myself and 3 other people jump on it, didn't budge so I called it good. I am sure it's had water on it but if you wipe it up quick any damage is negligable.

Also I have a sheet of 3/4" MDF sitting on a night stand under a 29g, used to support a 50g hex as well. It's had water spilled ALL over it. I wipe it up sometimes. Most of the time I just let the little sheet of carpet I have sitting on top of it soak it up...

The wood hasn't desinigrated or degraded to a point where it's unusable or anything even remotely close. It has a few bubble type spots where you can tell some water was absorbed but it's just a slight rasied area. Nothing more.

No hear say, no I read it on the net, no oh I think this would happen...

Just real world experience. MDF is not *that* bad. Some of you act like it's paper mache.

having a stand built outta mdf or a sheet under a 29g is far from real word experience. i also have an old ass stand that is mdf and have had others as well and yes they are fine, but building a box that would potentially hold 200+g of water outta mdf is a bad idea. what are you goona do when you see a drop of water on the outside of the tank, just wipe it up? dont think so, because it would be coming from the inside out.
ever put mdf speaker boxes in an old car that leaks? let it sit in a puddle of water for a week and watch it swell to twice its size then fall apart.
mdf and water dont mix.

paper mache is paper and glue, mdf is sawdust and glue. not much of a difference there.

mdf is also placed under linoleum(sp?) in bathrooms and kitchens for some awefull reason. ever see what just an hour of contact with water will do to that flooring if it gets too the mdf? or inside a cabinet? it swells and theres no way to fix it other than rip up the linoleum, tear out the cabinets, and then rip out all the mdf and replace it all.

but im shure it will be fine

 

[polish]

Yep that is real world experience actually, because I did it.

I've also worked with MDF for about a decade now, I'm an MECP certified installer. Having built dozens of speakers box out of it and working at a custom shop for 2 years that used nothing but MDF I'd say I am experienced in it. I have seen some water damaged boxes too, but nothing like you say. The worst I have seen were pretty bad but had extreme water exposure, they were still together though. I won't argue with enough exposure it wouldn't finally give but it's not as bad as you make it sound. If that isn't enough experience for you then oh well.

I am not saying to go build a tank out of it alone, just sharing that it's not as weak as some make it sound. A lot of store bought stands are made of fiber board as well.

If built and coated correctly though I don't see why it couldn't be part of the structure. To each his own though...

 

[ErikFromNJ]

mdf is also placed under linoleum(sp?) in bathrooms and kitchens for some awefull reason. ever see what just an hour of contact with water will do to that flooring if it gets too the mdf? or inside a cabinet? it swells and theres no way to fix it other than rip up the linoleum, tear out the cabinets, and then rip out all the mdf and replace it all.

Just out of curiosity... where are you from? I'm a residential contractor for 22 years now and have never seen it used as an underlayment. I've renovated hundreds of kitchens and baths as well. It would fail inspection here in Jersey.

 

[greengiant]

I have seen what water will do to MDF first hand. look at alot of the DIY threads and you will see that alot of them had a leak along the build process. when the water is being foced through the MDF it will fail. the chances of failure are huge froma minor leak. unlike MDF being exposed to water being spilled on it whre the water is only on the surface a leak on a tank is forcing its way through the MDF. I had a box that was MDF it was left outside by a roomate and it rained in 1 day it was garbage. If someone wants to risk it to save a few dollars go for it but not a risk I would ever take. if you build it I hope that you get a perfect seal first time and around all your bulkheads otherwise it could turn really ugly

 

[greengiant]

it would fail home inspection up here to but that doesn't mean renovators won't use it their famous for cheaping out and cutting corners if no permits are pulled. ALWAYS GET THE PERMITS WHEN RENOVATING YOUR HOME!!!!!!

 

[cjohll]

Why not use OSB and double it up its strong,light and cheap.

 

[ErikFromNJ]

Why not use OSB and double it up its strong,light and cheap.

OSB is not that great either. We can use it for wall sheathing around here but once it has been exposed for a certain period of time it loses its structural capabilities.

I would use a wolmanized plywood. I mean how much are we talking in savings here? Its only a coupla sheets.

 

[dmopar74]

Just out of curiosity... where are you from? I'm a residential contractor for 22 years now and have never seen it used as an underlayment. I've renovated hundreds of kitchens and baths as well. It would fail inspection here in Jersey.

washington, been plumbing for 10 years and very rarely see a house in this state that doesnt use mdf for underlayment.

got a speaker box i just threw away because i left the shed door open, it rained for a day and a 1/4" deep puddle developed under the box, swelling the whole bottom of it.


anyways, not here to argue, even though it come across that way. just saying if a leak were to develop, i'd much rather have plain ol plywood over mdf.

 

[ErikFromNJ]

washington, been plumbing for 10 years and very rarely see a house in this state that doesnt use mdf for underlayment.

got a speaker box i just threw away because i left the shed door open, it rained for a day and a 1/4" deep puddle developed under the box, swelling the whole bottom of it.


anyways, not here to argue, even though it come across that way. just saying if a leak were to develop, i'd much rather have plain ol plywood over mdf.

I'm not trying to argue or disagree with you. It just surprises me that tradesman would use that junk under something that would get wet. Linoleum I could see, being there isn't a seam (unless its a really large floor), but under vinyl, linoleum or composition tile, you're an idiot if you think that it would last. Boy, you guys must build like sh|t up there!! j/k

 

[Dan F]

Our window trim is MDF. We had a small leak (actually the wind was blowing rain into the attic vent and then running down the wall) and the MDF swelled up to twice it's size and fell apart. It really is a poor choice for anything that may come in contact with water.

People do use it as underlayment for vinyl. I've worked in residential plumbing installation for close to twenty years ( dmopar!) and I've seen plenty of squishy floors. That's why I used surface-sanded plywood as subfloor in the bathrooms when I built my own house.