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View Full Version : MDF trim. what is the deal with that?



customwoodworking
04-29-2010, 07:33 AM
I looked at a job a few months back where the building was unfinished. again some contractor went defunct and the poor guy i went to meet had purchased it for pennies on the dollar. He asked me to quote out the trim job and off I went. The bid got to him in a few days and was what i would call competitive being that it is so slow around here. Well of course the owner didnt think it was reasonable and told me no way. Well we got a call a few days ago by the same owner requesting labor only for all the trim he supplied. We got there and its all MDF that he painted with three coats of paint! Now i could understand the 8 inch crown because of the cost savings and its never gonna be touched except by me and the painter (again) but whats the deal with base, casing, backband, door jambs, stool, even the shoe!!! and this guys got dogs for christ sakes!!!! why this crap was ever brought into our industry is beyond me. We use it it limited amounts form job to job but never in this quantity. Been wearing dust masks but doesnt seemed to help. What percentage of homes use mdf vs wood do you guys experience? Guess im just ranting cuz the stuff sucks. Nails like crap, can hardly cope it, long lengths are like speghetti and break easily. Whats the deal?

Lavrans
04-29-2010, 09:37 AM
Well, you get better at working with it over time. It's brought into the industry for exactly the reason you mentioned- cost. Initial cost.

Really, it does hold up relatively well for casing and baseboard. Some high use corners can be damaged, but hey- it's cheap to replace, right?

Dust masks are pretty useless for anything anyway- they'll stop a little of the big stuff, but really a respirator works better.

FramerTK
04-29-2010, 09:48 AM
Don't worry about it - you get used to having brown boogers after a while :). Or you could just buy a Kapex and a CT33 and not have to worry about it.

Also, a lot of guys who cope everything don't cope MDF. I cope it iand it isnt too bad, you just have to be very careful at the thin edges. I usually cope it a little thick and touch up the edge with a utility knife.

Where I am, MDF is very common especially for crown, large base, and window casing. Prehung doors are usually cased with wood.

joseph
04-29-2010, 10:09 AM
well he did not like your bid -picks up cheaper material and thinks he got such a deal because he paid so much less then your material cost .he would probable settle for less quality instalation also . that is also just a rant .
but seriously what happens when you come up short -will he be able to get it easily? He may of saved you alot of running around picking it up and prepainting .mdf goes up fast , takes glue well and means you can hide mistakes . get one of these ,you will feel better http://www.dustbeegone.com/dustmask.html

MSLiechty
04-29-2010, 11:24 AM
MDF jambs? are you kidding me! No thanks,

ML

SteveC
04-29-2010, 03:05 PM
Hopefully he painted better than my HO. All the crown, casing, base, and shoe (FJP) had drips on the back that had to be scrapped off, as well as small remnants of cardboard. PITA

Tom Bainbridge
04-29-2010, 03:21 PM
MS

i worked with a young aussie chippie a couple of years ago, from perth i think. mdf door linings are standard in his area


MDF base and door casing, is a stock item in most builders/timber merchants here. its all pre primed.

at this level of quality, we call it house bashing, the painters get to fill rough coping

Kent Brobeck
04-29-2010, 04:21 PM
The biggest advantage to MDF other than cost is it reduces demand on real wood hence leading to lower costs. Plus once you get used to MDF It is easier/faster to install.. Try and use an 18 gauge nailer only. The bigger nails leave big holes. Get used to it because it's here to stay.

MitreIt
04-29-2010, 06:51 PM
I have always turned jobs down when I see the builder is using MDF. I hate the stuff. Has to be the most toxic thing a carpenter ever cuts into, totally pollutes the area you cut it in.

Guess I have been lucky in that the builders I work for mainly only use it for closet shelving.

Pretty much the only thing I use it for is making the raised panels for paint grade wainscot and built-in doors, an occasional column or two and also on some archways, etc.

I do see it becoming more common though... but I do my best to stay away as much as possible.

customwoodworking
04-29-2010, 07:40 PM
I do have the kapex and ct33 but keep it in the shop for "the good stuff" we use dewalt scms's on the jobsite. I did think about bringing the ct out there but wasnt sure how effective it would be in combination with the dewalt. Plus i wasnt sure how the mdf dust would effect the filters in the ct. I dont bring that crap anywhere near my shop becasue how it "pollutes" everything. I do a bit of finishing back there and have a hard enuff time with regular wood dustlet alone that pulverized dirt board.

Keith Mathewson
04-29-2010, 08:36 PM
I'm in agreement with Mitrelt, I've done I believe 2 MDF jobs several years ago. After that I've turned them down. I have done jobs where they wanted MDF but after talking to the HO was able to guide them away from it. I've found that if you put the cost difference between MDF and wood as a percentage of the cost of the house it becomes a pretty easy sale.

dbritt
04-29-2010, 09:14 PM
one great advantage of mdf is its never bowed or twisted so bad that it cant be used.easily installs. i have grown to love it for crown molding. consistancy is nice.
i still like wood for base though and i would never use it for door jambs. cased opening.....mmmaybe??

Tom Bainbridge
04-30-2010, 02:16 AM
the ct duxt extractors are happy with mdf, ive a mini and a ct22 for about 5 years

ive done a lot of mdf including cabinets

the bags are good for mdf, virtually nothing gets past them

ive only had to bang the dust out of the filters a couple of times in five years

once was for a bag split..... my fault not the bag

Tom Bainbridge
04-30-2010, 02:26 AM
slightly off topic

the only dust ive found that clogs festool dust bags is the sanding flour from two pack filler

the ct mini only gets half full before you need a bag change, ie loads of two pack filler work

clinkard
04-30-2010, 07:16 AM
We go through a couple hundred of sheets a year, only using it for door jambs, rip it to width and then sand. (3/4), and built-ins. We will usually do baltic birch drawers, and mdf carcasses pocket screwed together, and they hold together quite well. All of out trim is poplar, so easy to cope, and quite cheap 2$ a LF for 7 1/4" Base. We can use the clam clamps on poplar... not sure how well they would work on MDF.

It is very toxic stuff. Always wear a good respirator, I bought a good one with a silicone face mask so it is very comfortable to wear. I do alot of ripping with my TS55 hooked up to a shopvac, and it does an adequate job.

betterdrywall
04-30-2010, 07:44 AM
The biggest advantage to MDF other than cost is it reduces demand on real wood hence leading to lower costs. Plus once you get used to MDF It is easier/faster to install.. Try and use an 18 gauge nailer only. The bigger nails leave big holes. Get used to it because it's here to stay.

I have only seen MDF on the green homes. and not a lot of those built here. I would not even use it at all, if you want to conserve the wood, there is nothing wrong with just keeping things plain.

I should add material is what i am concerned about right now, Not sure, I have seen some HOers just go crazy with wood all over , and some with very little trim at all. On my next project I just want to get it right , with the flow . are you guys seeing a decline in the use of alot of trim in homes these days?

dave_k
04-30-2010, 08:29 AM
MDF's a good choice for large running trim like base and crown. I don't like using it for mitered casings unless I can at least get a biscuit in it. It works fine if you use corner blocks or entablature and don't have to miter it. I find using a hard wearing finish like tinted poly or CV has more to do with the durability of trim finishes in houses that the actual hardness of the material. The same whack that damages MDF will damage pine or poplar. Small mouldings like stops and 1/4 rounds in MDF are a bad choice, they're way to fragile for my liking and the obvious exposure to moisture is another area to be avoided. Never for door jambs. I have to admit MDF is often a joy to finish and I love spray the stuff, less nasty surprised when the light hits it.

John Larson
04-30-2010, 12:07 PM
Like everyone else, I really don't care for it, but it certainly has its place. I built a craftsman style home in the Oakland hills fire area and used MDF for the casing, base, paneling, crown and box beams. I did not want to work with the stuff due the extremely fine dust it creates (jammed up the tubes on my SCMS on a previous project), so I went to a local cabinet shop that had extensive CNC equipment. I gave them my cut sheets for everything and they fed that into their system and everything came out in a package with the little ID/bar code sticker on the back. Since this was a craftsman, there were no miters and intersecting joints were not flush (5/8" base, 3/4" casing legs and 1" heads), so the trim-out went incredibly fast, produced very little job site dust and I made a pile. The house is about 12 years old now and it has been a couple years since since I was last inside and it still looked good. As has been said, it paints easily and looks like glass. Given the same parameters, I would not hesitate to use it again.

newman
05-01-2010, 02:38 AM
I don't care for MDF. Unfortunately, it's used around here all too often. It does take paint very nicely, and that's about it. I hate the dust and it eats your blades and bits quickly. MDF has its place, but its nice to work with REAL wood...

texastutt
05-01-2010, 07:55 AM
If I have a choice between thick MDF trim and finger jointed pine or, poorly run x-wood, I'll take the MDF, my opinion changed last summer when I had to take some jobs I would not normally have taken. My preference for paint grade is Poplar from Brenlo in Toronto. Brenlo makes some really nice MDF too. Homely and Desperate makes some really crappy MDF that's almost as bad as the 1/4" thick finger-jointed casing I had to install.

Kent Brobeck
05-01-2010, 08:49 AM
I used to turn my nose up to mdf too but no longer. For paint grade it's just to cheap to ignore. Say no to door jambs and keep it away from water but that's about it. It's great for base too. If I ran it all the time I'd buy a kapex. It would be worth it for dust control and plus the under powered kapex wouldn't bog down when challenged :)

Keith Mathewson
05-01-2010, 10:51 AM
MDF is cheap and is going to be around for awhile, just doesn't hold up well.

Tom Bainbridge
05-01-2010, 12:29 PM
there are more types of mdf than you might imagine

MR moisture resistant is one, there are other types

most of them are only a few quid more than standard sheets

here i look at the medite website for information, they are a european manufacturer

no doubt you have your own manufacturers

texastutt
05-01-2010, 11:11 PM
I know that store fixtures are built out of MDF because they take lacquer so good. I had to special order some light MDF which is about 1/3 the weight as regular, I have seen the MR stuff in catalogs.

But as far as trim goes I think its all "regular" MDF some is thicker and looks like real trim and others are so flat they might as well be. And I have see a lot of MDF door jambs in the last year and I don't see how that ever got approved for residential construction.

Tom Bainbridge
05-02-2010, 06:51 AM
texastutt

why do you think mdf door linings shouldnt be approved for residential construction ?

is there some building code that you think might not be met, or have you more general concerns ?

one that comes to my mind with standard mdf is fire resistance

medite make a FR (flame retardant) mdf

customwoodworking
05-02-2010, 07:25 AM
this stuff has its pros and cons but in my book the pro list is short.. What happens when i get to the bathrooms, laundries,basement areas? all of which would be high on my "moisture area" list. Stop and wait for the same profiles which are often too ornate because the low cost meant the h.o. could now dress it up. Wait for four to six weeks to get same profiles custom run in poplar then come back and finish those areas while the painters are caulking and filling right behind you. More than likely the floor finishers are there and the builder didnt tell you they were coming so you've shot a day in the ass getting there and now have to come back monday only to have to cut outside and take you boots on and off all day long. Sounds about right to me! Im glad he was able to save a couple of bucks cause it cost me a fortune just thinking about it. I dont know what to say but this stuff sucks.

texastutt
05-02-2010, 08:20 AM
Tom the MDF does not hold the screws as good as the FJ jam sets, and most of the MDF ones I've seen have been installed by a hack and the door's already falling off.

The other point of MDF jambs is they are so thin, the top member sags, and seems until trim is put on needs to be shimmed and tacked into place.

TOO many home owners & hacks out there... Plus I did one and its like hanging a noodle.

Tom Bainbridge
05-02-2010, 08:49 AM
texastutt, that reminds me

the young aussie chippie i worked with said that mdf linings arnt stable until the door casing is installed and nailed to both the lining and the stud

ive got into the habit of foaming the gap between the lining and stud to reduce noise transmission

another advantage is that the foam glues the whole thing together. it means on hollow core doors i now rarely shim behind butts or the strike anymore. im only shimming badly warped jambstock

a few more 16 guage nails holds things firm until the foam goes off

but im not installing pre hungs, like you probably are

gburnet
05-02-2010, 02:50 PM
MDF is cheap and is going to be around for awhile, just doesn't hold up well.

Keith, do you know the story behind that picture? Were those MDF stops that were perhaps sprung a bit too tightly into place? I've never seen anything quite like that with MDF, short of moisture damage.

We've used a fair amount of MDF over the years & it's held up very well. I agree with what others have stated re. its shortcomings (nasty dust, too flexible at times, hard on tooling, etc.), but have also found that its positives more than make up for those issues in some situations.

cdatrim
05-02-2010, 09:07 PM
MDF is not bad with dust collection. I have my 717 hooked up to a CT22 with no dust mask. The problem exists when the builder starts having all the trim prepainted. What a touch up nightmare. Doesn't even make the craft fun anymore. If it wasn't so dead, I would run away, fast.

Keith Mathewson
05-02-2010, 11:24 PM
gburnet,

The pic is of a set of windows below a covered porch. One day a few years after the house was built a driving rain with high wind caused water to get under the door threshold and caused the damage you see in the pic. Now the trim needed to be replaced and then painted. So now the room needed to be painted....

My feelings when I hear about it being "green" or reducing the amount of wood being used is that it is a false promise. Things which were done well have a much lower chance of ending up in the dumpster during the next round of remodeling. I would be inclined to use it much in the same way that plaster was used in the past- in places where there is little to no chance of contact like, crown molding, etc. Everywhere else I doubt that anyone would expect it to still be useable in 100 or 200 years.

gburnet
05-03-2010, 08:51 AM
gburnet,

The pic is of a set of windows below a covered porch. One day a few years after the house was built a driving rain with high wind caused water to get under the door threshold and caused the damage you see in the pic. Now the trim needed to be replaced and then painted. So now the room needed to be painted....

My feelings when I hear about it being "green" or reducing the amount of wood being used is that it is a false promise. Things which were done well have a much lower chance of ending up in the dumpster during the next round of remodeling. I would be inclined to use it much in the same way that plaster was used in the past- in places where there is little to no chance of contact like, crown molding, etc. Everywhere else I doubt that anyone would expect it to still be useable in 100 or 200 years.

I agree with part of what you're saying, Keith. But I also believe it's up to the professional to select the correct material for a job, just as they would select the right tool. I would no more put MDF in a porch, covered or not (particularly in the PNW), than I would install Azek in a stain-grade application.

As someone once said: "The worst of work is done with the best of intentions." Seems the problem in the above situation isn't with the material, but with the poor judgment of the carpenter who installed it. This is a great example of where a little education would have gone a long way.

Keith Mathewson
05-03-2010, 09:59 AM
I don't think that I described the situation very well. That was a pic of the living room. Above is the master bedroom with a small tiled porch, almost a Juliet balcony.

This would represent a very typical application. If one were to suggest that MDF would not be an appropriate material to use there than the same would hold true for anywhere below a bathroom or kitchen or laundry room, etc.

I feel the the widespread use of mdf and products like it have contributed to the quality level of many homes being built now. Besides the durability difference the profiles lack crispness. The edges have been eased, perhaps to reduce handling damage. Who walks into a house from the 60's or 70's and thinks " That's some attractive fake wood paneling there"? My preference as to who should be targeted for a bit more education would be the architect, the builder and the homeowner more than the carpenter. In all likelihood the decision was made as to choice of materials before the finish carpenter was involved.