Building doors with MDF... anyone? Tips, details, etc?

[666666]

I'm considering building my own doors from scratch, especially since I need custom sizes.

One thought is to use two layers of 3/4" MDF, screwed together, perhaps with Green Glue inbetween the layers. Then glue 1/4" paneling to both sides (to cover the screws)... this would be 2.00" thick in total, just a hair thicker than a standard door, I'd hope that most standard hardware would fit nicely.

And 3/4" MDF... not sure of the exact PSF, but I believe it's about 3.0 PSF... so, the door in total would be about 6.0 PSF, would match or be of even greater mass than my walls... sweet.

Has anyone made doors of MDF? I've never used MDF before, just wondering if it will hold screws well (as in the screws that would hold the hinges from the sides). I know with other man-made materials (like OSB for instance), screws will NOT hold well when driven in at the sides... even plywood for that matter (the plys tend to separate if screws are driven in at the sides, etc)... I am hoping that MDF will take screws well from the sides (assuming proper pre-drilling and use of good long heavy-duty screws). Before I go out and buy several sheets of MDF, can anyone confirm?

If anyone has built doors of MDF from scratch, I'd love some details.... pics too if possible... OR, I'd surely welcome any other ideas in terms of DIY heavy-mass doors.

Thanks

[themaidsroom]

mdf is good when hidden. it wants to be covered with plywood or other wood. it is
great mass but will fall apart with any moisture or sudden collision....if you did
3/4 mdf/ 3/4 mdf and 1/2" ply on every face, you would have a solid door.
sheetrock can also be used in this fashion - i have found that where a website
or guide says use two sheets, use five or seven - mass is amazing - it is the
only way to stop sound.


looking at your post again, i have had trouble with mdf and screws - this changes when the mdf and plywood
are laminated with glue and the screw can hit both


be well


- jack

[jwl]

Make sure you do a good job with sealing it. Magnetic weatherstripping is good, and Rod Gervais recommends using GM type K trunk rubber in his book "Home Recording Studio: Build It Like the Pros." But the door has to be both massive and airtight to get any semblance of soundproofing out of it.

Another approach is to find a standard solid core door, and "beef" it up with a layer of MDF on each side, covered with some sort of veneer.

A closer is a good idea.

Also, think about what you will do to seal it up at the threshold.

Green Glue won't hurt either.....

[stuntbutt]

MDF will not hold screws well enough to support hinges. You would need solid wood on the jam side of the door.

I have used 3/4" MDF with birch veneer for cabinets. Using that would allow you to skip the 1/4" plywood and add a middle layer of MDF and a second layer of Green Glue.

Fabricating a door and hanging it are very tricky. It's probably better to try to beef up an existing pre-hung slab.

[666666]

Originally Posted by stuntbutt

MDF will not hold screws well enough to support hinges. You would need solid wood on the jam side of the door...

How about using "T-hinges", like these:

Stanley Hardware - 8" Heavy T-Hinge

If you screw hinges into the FACE of the MDF door panel, I'd think it might work... using three or four hinges minimum. What do you think? Side load on the screws would be way less of a problem than a load trying to pull the screws straight out (as with a conventional type hinge).

Or you could use T-hinges and run small BOLTS through the hinges / MDF... as long as the MDF doesn't outright tear apart like a sheet of paper, it should work fine.

In general, what would be better? MDF or particle board?

I can't believe no one has made doors like this, two sheets of 3/4" material screwed together covered with 1/4" paneling... for a door with total thickness of 1.75" like all standard doors. It's either the greatest idea that no one has ever tried, or it's a terrible idea.

Considering the super low cost and great STC that can be achieved (due to excellent mass), I'd think this would be a very popular door design. A good new fire-code solid door is like what?... $500 at least?... two sheets of MDF or particle board and some paneling is like... $60 maybe? With two layers of MDF you'd be looking as almost 6.0 pounds per square feet of mass... this outperforms two layers of 5/8" fire-code sheetrock and likely performs exactly the same as a brand new fire-core door of the same thickness that costs over 10 times as much.

Of course the SEAL (frame, etc) of the door is very important and that's where things get tricky.... but it CAN be done well by the DIY person if careful attention is paid to the details and careful workmanship is performed.... not TOO hard if you have patience. And if you are putting together a DUAL-door system, a tiny "leak" in one door is not as critical anyway as if you were just running one single door... not to say one should be careless, but with a dual-door system, overall success is much higher in the DIY realm.

[stuntbutt]

I think those hinges would be beefy enough, but it will probably look like a shed door.

I still think the way to go is to add layers and seals to an existing door. Here's a basic exterior steel slab door for $105:

Product Information Error Page

There are plans for beefing up doors in "Home Recording Studio: Build It Like The Pros" by Rod Gervais

Amazon.com: Home Recording Studio: Build it Like the Pros: Rod Gervais: Books

Good Luck

[666666]

Originally Posted by stuntbutt

I think those hinges would be beefy enough, but it will probably look like a shed door.

Well, I'd add the hinges directly to the face of the MDF+MDF, and then add 1/4" paneling on top to completely cover all screws and hinges. You wouldn't see the hinges.

I still think the way to go is to add layers and seals to an existing door. Here's a basic exterior steel slab door for $105:

I do agree, I wish I could do that, but in my situation, I only have about 6.5' of height where the doors must go (door openings happen to be under a thick girder), so any standard doors I buy will need to be cut. Cutting those steel skinned doors (and included frame) is not impossible, but generally "messy"... then I'd have to deal with the edge that was cut, will have an open and weak steel skin edge with foam hanging out.

In my specific case, it seems to make more sense to make custom doors from scratch than to buy the steel skinned doors, cut them, and THEN add layers of material to them. Somehow it seems it that making custom doors will be about the same amount of work or possibly even less, and will yield a neater end result, at least if done with care.

I wish I had more height!

[jinksdingo]

I remember reading somewhere a long long time ago that piano hinge is the best for a studio door. You get a length the height of your door from your hardware store. Your door and recess have a thin portion chisled out to accommodate the hinge. there are plenty of screws required but when you open the door the hinge makes the opening gapless and more efficient for use with your door gasket.
Sounds like a proven wood for the core to screw into is the the go and laminate your MDF from there.
Good luck.
I luckily have a very thick laminated ply table top to make mine out of!

[Sen]

Originally Posted by stuntbutt

MDF will not hold screws well enough to support hinges. You would need solid wood on the jam side of the door.

Not sure about that if laminating multiple layers of MDF together, whic I think 6666 is interested in.
My doors are 3X18mm MDF glued and screwed together to create a door that weighs 65 kg . They're still hanging after 6 months , and provide some excellent isolation. (although double in each room)
here's a pic while they were being built. 4 heavy duty hinges though, note there are three hinges on upper half of the door and one on the bottom.


And after you paint it with MDF undercoat and enamel paint, they'll last for years and years.
Good luck

[Sen]

Andthis is what it looks like finished. (inner CR door, the other pic was of outter before sills and everything was finished)

[svart]

awesome, i was thinking of doing the same thing only I was going to sandwich two layers of drywall between two 1/2" layers of MDF. By sandwich I mean, MDF-glue-drywall-glue-drywall-glue-MDF with bolts around the perimeter. I was going to glue veneer around the edge of the doors too. The plan was that the drywall would lower the resonant frequency of the door. MDF has a fairly high resonant frequency. you can tell by tapping the board and hearing the short *ring*. sandwiching the drywall seems to give you a dull thud.

Any thoughts?

[shangoe]

when building doors with mdf keep slightly bending in mind that could ocurr when glueing parts together. you need something solid perfectly flat to align.

[gevermil]

I just built a ton of doors for a movie set using 1/2" MDF and 2x6s on face .
I was amazed at how well they actually turned out .

Make a simple frame like any panel door has then sheet it with 1/2" mdf .
Need to pick the straightest 2x6 . On occasion I had to bend the door as I was nailing
to keep it straight .
When " public enimies " comes out , check out all the doors in the bank robbery scenes
and building shots . All MDF . - my claim to fame .

[jinksdingo]

svart,
Not sure bout the drywall where you are, but here it is sandwiched with paper. Cardboard. I wouldn't use it as it might come away from the actual
gyp unless large washers were on your bolt right thru-funny looking door.

Similar to gevermil's doors would be the go. A frame that you fix MDF to on either side leaving a gap in the middle of frame which you fill with sand from the top plug you fill. Would achieve a similar result to what your after I think and a common design for a studio door.

[666666]

Originally Posted by gevermil

Need to pick the straightest 2x6....

This all sounds good, but for long-term use, the 2X6s could be a problem. First, it is really hard to find several super straight 2X6s. I was just at Home Depot and Lowes trying to find some... made several trips several days apart hoping to get better stock... no luck, almost every piece was a bit warped one way or another. In the past I've even resorted to just buying warped pieces and then "straightening" them with a table-saw, planer, etc... basically shaving them down until straight. But this is a pain.

Even when you do find / create a super straight 2X6, it very well may warp over time, especially once in a new environmment. I guess this goes for ANY wood, but especially for "2-by" lumber from any given lumber yard. A friend of mine once showed me a stud in a wall he just built... he said all studs were very straight prior to construction... then afterwards, one of the studs, for whatever reason, twisted up badly, even though already installed... it was ridiculous... it must have had excessive moisture in it I guess... he had to pull it out and replace. That's an extreme example, but if this even happens to a small extent, it can cause your door to no longer fit properly.

I am planning on trying to build doors with just MDF only... no wood frame. I haven't ever worked with MDF before, but it appears to not be as prone to warping as wood. My plan is to get two sheets of 3/4" MDF, lay them against each other on a very flat concrete garage floor, then glue /screw them together on the flat flooring. Hopefully the glue / screws will help hold the pieces "straight". I suspect there will be some flex, but that's ok as long as the MDF pieces do not "warp" and take on a new permanent shape. In fact, it may actually be good if the MDF door "flexes" a little as it will then always conform well to the door seal stops... should help ensure a tight seal. Worst thing would be if the door was very stiff and then warp and thus no longer be aligned with the seals, creating gaps / leaks.

Just to recap, I know MDF will not hold screws well at the sides, I already purchased "T-hinges" that screw to the face, will cover the hinge legs with a final layer of paneling.

If I actually get through all this with any success, I'll surely post pics here, etc.

I already built the door jambs into the framing... came out well... used all 2X6s (which is why I was struggling trying to get straight lumber recently), but at least with door jamb framing, you have other framing members to attach to in order to help "straighten" warped pieces (via shims, screws, etc). With a door, the whole thing floats, no base points to attach to for straightening... the whole thing must simply be straight on its own... which makes door building difficult.

[gevermil]

I doubt over time the mdf will let the 2x6s warp , with the amount of glue and staples
in it . Most framing lumber will dance on ya unless you get the sheetrock up on it .
You could always buy poplar or silver maple .

[666666]

Originally Posted by gevermil

I doubt over time the mdf will let the 2x6s warp , with the amount of glue and staples in it...

That's a good point, I suppose with say two layers of 3/4" MDF screwed heavily to a 2X6 might just keep it inline... again, I have little experience with MDF, this will be my first MDF project... but otherwise "2-by" lumber can potentially warp very severely, can be hard to hold it inline.

In my case I wish to make the doors no thicker than 1.75" total. If I use a 2X6 frame (1.5"), I have only a quarter inch left to add paneling on top. Unless I route the edges of the 2X6s and try to add the MDF within the frame, but this starts to get laborious.

My limitation on thickness is surely making things tough for me, but I'll give it a shot. If dual 3/4" MDF with a 1/4" decorative panel on top (1.75" total) actually works, this will prove to be a fairly simple cost effective way of making a door with over 6 PSF mass (which in most cases is more than enough for a two door situation) but yet not be thicker than a standard fire-core door so that standard hardware will fit and standard sized jambs etc can be used, etc.

Who knows, my experiment here may not work out well at all... might turn out to be a big waste of time and MDF... I'll let y'all know either way. To me it's worth a shot to have 6 PSF doors that are just 1.75" thick for under $75 or whatever.

Side note... I built my custom door jambs 38" wide so that IF my custom efforts totally fail, I can always throw in some type of standard 36" door with jamb (38" is the typical rough opening for standard 36" doors)... trying to keep all options open. But I hope to build some effective custom 38" wide doors though... will try.

[andrebrito]

I just did a vocal booth for a TV studio and have used MDF x Green Glue x MDF x rockwool x MDF x Green Glue x MDF and 5 typical hinges. Worked Ok for the application

[Sui_City]

Originally Posted by andrebrito

I just did a vocal booth for a TV studio and have used MDF x Green Glue x MDF x rockwool x MDF x Green Glue x MDF and 5 typical hinges. Worked Ok for the application

Hey Andre,

What thickness of MDF were you using?

Doyou have any close-up pics of the door in assembly?

thanks

[svart]

I'm trying something new..

the panels are 1/2 MDF on either side of a 2"x2" frame(around the perimeter of the door) and filled with sand.

So far I have everything up and the door is about 2/3rds filled with sand..

It's insanely heavy.. estimated around 200lbs+.

The hinges are similar to the T hinges linked earlier but they aren't screwed they are bolted through the 2"x2" frame.

Anyone do something like this?