Read in another thread that using MDF for cab’s was recommended.
I hadn’t run across that. I do some built-ins on occasion. I believe the MDF in the other thread was to be used for kitchen cab’s.
What’s the concensus? I’d never think of MDF for the boxes……I’ve only used it for the door panels.
As a matter a fact…I have a fire place surround/wall unit on the drawing board right now……will have book cases on each side…bottom units closed with doors..tops open shelving…..trimmed with a face frame.
I’m planning 3/4 birch ply for the cases. Poplar for the FF and door styles/rails…and MDF…for the door panels….either MDF or ply with edge banding for the base cab top shelf…..probably ply with an edge.
Is MDF an acceptable material for the cases? I’m still thinking ply is better….
But always will to learn. Anyone else use MDF?
Jeff
Buck Construction Pittsburgh,PA
Fine Carpentery…..While U Waite
Replies
Jeff
We do cabinetry and architectual woodwork for high end homes and we use MDF all the time(after you carry it enough all the time is to much). MDF is fine for the carcase, painted or finish grade(we get MDF with the veneer of our choice on it)
I would not want to use it for base and case but it does have a use in many places.
If I could ever figure out how to post a stupid pic I would show you some of the MDF cabinets that we just installed, something to shot for this weekend.
Doug
the weight issue alone will probably keep me sticking with ply.
I could see the cost saving issues....but I don't make cab's everyday all year long...
and when I do.....99% of the time I'm there on a referal..or they really liked my pic portfolio...so I'm not in a bidding war....
so my materials cost of MDF vs ply really wouldn't add up to much on each project...and I'm not exactly paying for the materials outta my own pocket...
so the customer might end up paying a few bucks more for me using ply.
And definite "pro's" to using MDF over ply?
JeffBuck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
All I can say is let it get wet and it'l turn into something that looks like termite droppings
Twp other factors.
MFD shelves can not be used for as long a span. The Sagulator can be used to compute the deflection.
http://www.woodbin.com/calcs/sagulator.htm
If you are going with end stain grade the MFD with veneer has a flater surface then plywood with veneer.
I started that other thread (I think)
As I remember, Adrian uses MDF, and based on a post in knots, that's all they use in Oz (believe that's New Zeland)
those folks using MDF helped me decide to try, along with other reasons.
I might try finding confibre MDF, or light weight MDF.bobl Volo Non Voleo Joe's cheat sheet
Oz is not new Zealand. Oz is Australia
I think it was your post that got me asking.
I wish those that were on the "pro" side...as in..."in favor"..would give the opposing view.
Anyone know how to send this to someone's attention.....I'm thinking of getting Adrain's opinion......I'll listen to him on this...not like we're talking american politics!
So far what I've heard against is what I've thought in the past....heavy/not very strong/bad with moisture/etc...
the dust issue doesn't bother me...I grew up remodeling old mill houses.....used to be "row houses"..now their "condo living"! I've swallowed enough black mill soot/rat sh!t/bubonic plague to made me immune to any modern MDF dust...just put on a mask...hold yer breath...and look away as ya cough.
On an up side to MDF...sometimes it's the right material to keep annoying coworkes at bay for hours.
Jeff
Buck Construction Pittsburgh,PA
Fine Carpentery.....While U Waite
I did a series of tests a few years ago and concluded that MDF is at least as strong as plywood in the way we need it to be strong for casework. And I don't know what this "sagulator" is, but I found that a 12" wide x 32" long shelf of 3/4" 9 ply Birch plywood sagged more than the same sized piece of standard weight MDF when loaded with 30 lbs of books and measures over two weeks.
I tested joint and fastener strength and was surprised by what I found, too. I screwed two pieces of several different types MDF together with a butt joint and loaded the horizontal piece with 5 lbs at a time, observing and recording sag, and finally when the joint failed. Not only did MDF held together with Confirmat screws (failed at 60 lbs) way outperform plywood and drywall screws (failed at 30 lbs), MDF and drywall screws fared 50% better than plywood. The MDF and drywall screwed joint failed at 45 lbs. The only thing that proved stronger than the MDF and Confirmat screwed joint was MDF with biscuits and glue, which failed at 65 lbs, and looked like a train wreck as the MDF actually pulled apart before the glue failed.
MDF provides a more consistant substrate for paint, veneers, melamine, plam...did I miss anything you might put over it? It has no grain "direction" so you can use more scraps by rotating them 90 degrees. It machines much easier than plywood, is more consistant thickness wise and the difference in the potential for edge moulding is obvious.
It IS heavy. And different to handle and fasten than plywood. They tell me it's hard on cutting tools, but I haven't noticed much of a difference. And there IS a definate stigma about it being a "cheap" alternative. But in many ways it's BETTER than plywood. At less than 1/2 the price of Birch plywood, I finally had to stop rationalizing and give it a fair chance. I now offer it as a lower cost box in paint grade cabinetry, not always, but when I think it would be appropriate.
I'll try to attach some photos...this should be good for a laugh.
Brinkmann for president in '04
I use raw MDF (for painted stuff) or veneered particle core or MDF for stain grade almost exclusively for casework (except kitchen cabinetry, where it'e usually melamine), and so do almost every professional cabinetmaker I know. I only use plywood......which I hate....when backed in to a corner supply wise, like I can't get the veneer I need on the substarte I want.
The tolerance to which I try and build cabinets, and the extremeley sloppy specs on plywood (and I've done this with students....measure the thickness ina bunch of places, and they are always amazed at how much variation there is), make them pretty much incompatible. When I do use ply, I'm always disappointed with the end result, even if the clients don't notice. Apart from weight, I can't think of a single advantage to ply, and that is reflected in the AWI and AWMAC specs (the commerical case quality standards). Plywood is either disallowed or specifically warned against for most applications in cabinetry. My opinion is, it's basically obsolete, especially with all the new combination cores around.
As far as moisture goes, that's in the design; if you consider that before you build, no problem. Never had a call related to moisture damaging a cabinet in my entire career (did see a set get damaged once on a commercial job, but a huge plumbing leak and two days of sitting in water before it got noticed counts as exceptional in my book). I make sure my cabinets are never in contact with the ground, or I take other measures.
As far as sag goes, again, design. and the typical way of dealing with it on painted built ins is to upsize the shelves to 1" MDF from 3/4"....looks better and more substantial, adds back in anything lost in strength.
I still wouldn't use it for common residential cabinetry, because of weight and cost; melamine, white or patterned is what I mostly use there, or some of the combination cores. Butit's great stuff for lots of other applications, just know your material. My opinion, anyway.cabinetmaker/college instructor. Cape Breton, N.SWAY too conservative to be merely right wing
Jeff,
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Edited 12/7/2002 3:58:03 PM ET by Joe Fusco
Bill,
Very interesting link. It definitely shows that MDF sags more than plywood.
One thing that I found kind of funny -- the list for MDF sheet goods inclues LD, MD, and HD, which I assumed to mean low-, medium-, and high-density. I thought MDF was medium density! ;) Any idea as to what a "regular" sheet of MDF is?
At "Bobls" other post, lots of people are talking like MDF for shelves and cabinet boxes is no big deal. But I'm with you -- it's too heavy and too weak for any structural components. I use is for trim only.
Thanks again,
Ragnar
IMHO. Smooth, holds paint well, cheap. Enough water exposure and the best tool is a pitchfork to toss it into a dump truck so you can take it to a commercial composter.
Ragnar
"-- it's too heavy and too weak for any structural components. I use is for trim only."
Too weak for structural components, I think that its compresive strength is at least as good as ply if not better.
Ive seen entertainment units that were 10' high and 25' wide and they certainly arn't "weak".
I agree that shelves will sag but thats as easy as doubleing up two pieces or adding a front edge, of course that depends on the lenght of the shelf.
As for MDF not holding screws, use the right ones, we use centrex and you have to use a special bit for them, but holds well.
All that being said I still like to use plywood but since working for my current employer I have seen that MDF does work well for some applications, and I personaly will never use it for base and case, JMO
Doug
Edited 12/6/2002 10:15:33 PM ET by Doug@es
Doug,
I wasn't talking about "compressive strength"; I'm talking about bending strength, which is the most important thing for building. And like you said, you need to double-up or otherwise modify shelves made of MDF to get them to function adequately.
Anyway, I think it's got it's place -- I don't want to beat a dead horse arguing about it! ;)
Regards,
Ragnar
All I have to say about the strenght of MDF vs. Ply is:
Take a piece of 3/4 ply and mdf and put them on a set of saw horses with a few feet span Now take your hammer and take a good wack right in the center of both of them. The MDF will crumble and crack possibly in two. The Ply will have a dent in it and be ready for more.
CAG
Im not sure that I would agree with you there, I'd have to try that to believe it, but not sure thats conclusive proff of anything other than how it takes a sudden impact.
Doug
Yup......it's all in the design. If your clients are likely to walk about trying to break your cabinetry into bits with hammers, maybe you should pass on the job. Anything else can be addressed through design.cabinetmaker/college instructor. Cape Breton, N.SWAY too conservative to be merely right wing
I guess your material testing crteria/methodology pretty much excludes ceramics, granite, etc. What do you do about glass ?.
Phill Giles
The Unionville Woodwright
Unionville, Ontario
I guess your material testing crteria/methodology pretty much excludes ceramics, granite, etc. What do you do about glass ?
Do you usually build your cabinets out of any of those materials? Different materials for different applications, Personally I think MDF is a cheap way to build cabinets, I worked in a cabinet shop where it was done, It doesnt take screws as easily as ply, its subject to blow outs and cracking far easier then ply, the dust it makes is nasty, but people use it not becase its beautiful, not because its stronger, it is used because it is cheaper.
CAG
I'll buy that the use of MDF is used because of cost in some cases but when you are talking about veneered MDF you arn't saving but a few bucks per sheet over ply, so I dont think cost has as much to do with it as the fact that you can get a much smother finish on venereed MDF over ply. As I think it was Adrian said, if you are building the cabinet for someone that is distructive than nothing will do, I havn't seen any of our cabinetry falling apart and I have been back to some houses that have had them in for quit a few years. Its how you build the cabinet that counts, maybe you should look there!
Doug
I am not sure. I know that there are some "light weight" MFD.
I was hoping Adrain would comment on that as he has the connections.
I know that there is a very wide range of particle boards. Look at the RTA bookcase from wally world that is make with vinyl cover partical board. Then compare it with the "industrial" particle board used for counter tops.
I don't use it for anything other than panels unless I need to veneer, because;
1. Waaaay too heavy
2. Low moisture resistance
3. Doesn't hold screws all that well
4. No real stuctural strength
After installing cabinets in many high end homes it seems that no matter how hard they try and no matter what method of fastening they use MDF in my opinion is junk, for the reason that they all fall apart usually before they get into the house. however once the cabinet is installed and properly cared for the box material is of little consequence.