Is MDF stronger than particle board?

[Packard]

I read recently, while researching the Formica product, Fenix, that MDF is the preferred substrate under Formica. 

They (Formica Corp.) said that MDF is harder, stronger and will make a better bond to Formica than particle board.

But…

In my entire life I have never come across Formica laminated over MDF.  I did once laminate Formica over plywood to extend the life of a beat up chest of drawers, but other than that, I’ve always seen it over particle board.

Is the lower cost of particle board the driving reason for its dominance as a substrate for high pressure laminates?

 

[Crazyraceguy]

Stronger is a relative term. If you are just talking about countertops, there isn't enough difference between them to matter.
Particle board will take nails, staples, or screws into the edge far better than MDF. So, if you are building some kind of structure, it might be a better choice.

I have laminated thousands of square feet of plastic laminate over all kinds of substrates, and I wouldn't choose one over the other, for the laminating process.
It is much more about what you are trying to create.

 

[Packard]

On the subject of screws into the edge of MDF, here is an easy way to get strong results.

Drill a pilot hole large enough that the screw threads just barely engage the MDF.  Then, using the slowest setting epoxy (I used to be able to find 60 minute versions), fill the screw hole and then gently drive the screw home. 

You need enough thread engagement to fully pull the screw into the hole.

The slow set, allows the epoxy to soak partially into the MDF, improving the bond.  This is a permanent, non-removable solution. 

Confirmats are probably a better solution (and I usually have plenty on hand) but the expoxy method is effective too.

 

[Sparktrician]

MDF is the substrate of choice for most of the semi-custom cabinet doors and drawer faces that are covered with high-pressure laminates, including melamine. 

 

[Packard]

If I take 1/2” thick MDF and laminate on both sides with Formica or equivalent, how do I find the resulting strength?

Formica has almost no resistance to bending, but it’s tensile strength is fairly high as well as its compressive strength.  Will this lamination behave like a torsion box?  It seems it should, though I have no idea about creep with contact adhesive.

 

[Steve1]

They (Formica Corp.) said that MDF is harder, stronger and will make a better bond to Formica than particle board.

An online search shows Janka hardness of MDF as 1000 - 1500.  Could only find one result of Janka hardness of particle board, but it was showing 530 lbs.
Strength spec would first need to specify the type of loading, compression, tensile, shear, bending... or even why strength of the substrate would matter.
Better bond is believable.  Very smooth surface on MDF.

In my entire life I have never come across Formica laminated over MDF.

I have done it.  On my entertainment center.  Seemed to work fine. 

Is the lower cost of particle board the driving reason for its dominance as a substrate for high pressure laminates?

Cost is always an important factor.
And you forgot 'weight". 

 

[woodferret]

Depends on your MDF really.  The orange box store one is typically the lowest grade you can get. 

For lamination, use something suited for it, like HDF ultra.

eg.https://www.weyerhaeuser.com/applic...WEY-HDF-Ultra-Core-Product-Specifications.pdf

Typically the glue is homogenously through the substrate, unlike the paper-backed fluff you normally get.  As for laminating a 1/2" MDF, no - it's not going to act like a torsion box.  Laminating glues, and adhesives are designed to have slack, to tolerate expansion of the substrate.  That makes it less than idea for structure.

 

[smorgasbord]

Depends on your MDF really.  The orange box store one is typically the lowest grade you can get. 

Yeah, I use MDF sparingly, mostly for trial cuts on my CNC. As you will it down, you realize that the big box store MDF is really nothing more than thick cardboard. It's amazing it holds up as well as it does in some applications.

 

[Packard]

Thanks for the replies.  I did notice a substantial reduction in quality on MDF since the pandemic.

It used to be that MDF tool paint amazingly well, with only the machined edges needing sealing. 

After the pandemic, I get “grain” raising when using water based paints even on the non-machined surfaces.

The local lumber yard won’t carry MDF.  He says he can’t make a profit on it.  Home Depot and Lowes showing low prices for their stuff.

 

[Cheese]

As Sparky mentioned...MDF is the substrate of choice for custom finishes. It's extremely smooth and will prevent the telegraphing of surface irregularities when bonded to thin substrates.

FWIW...the veneers on JBL's studio monitoring speaker line in 70's-90's was all adhered to MDF and the MDF panels were all joined by lock mitre joints. JBL chose MDF because of its dampening properties and the lack of resonances. The material cost more to purchase, the construction method took more time but the results warranted the additional expenses. Somethings just work.