Question regarding laminating MDF

[Shawn Honeychurch]

Hello;

I am just about finished building myself a router stand and am wondering about the top. I was going to use 2 pieces of 1/2" MDF for the top, but I got to wondering which would be better:
2 sheets of 1/2"
4 sheets of 1/4"
8 sheets of 1/8"

Any thoughts?

Thanks
Shawn:)

[Chris Padilla]

Can you easily and for reasonable cost get sub-1/2" thick MDF? The stuff I've seen is almost or even more expensive than the 1/2" thick stuff!

I personally feel that with today's modern glues, laminations can be very, very strong but not everyone is convinced. I'd use something like Unibond 800 for such a glue up and I'd go to 1.5" thick top, or 3 sheets of 1/2" MDF. Then I'd laminate the top and bottom of the MDF with formica. How do you plan to treat the edges? Hardwood?

[Peter Quinn]

I'd use 1 piece phenalic coated 3/4" material (or melamine) with a hardwood frame attached from below, leaving a box in the frame to accomadate your router. Easier than trying to press multiple plies flat (unless you have a vacuum bag) and stronger too. MDF sags like granny at the nude beach!

[Shawn Honeychurch]

I have 2 big sheets of 1/4" MDF left over from a bed project. So that is not an issue.

It seems to me that a 1.5" top would be overkill, but I am very new to this so I will take the advice of the wise to heart. The formica is a great thought, make the wood slide nice and easy.

I was either going to use hard wood or steel channel for the edges.

[Lee Koepke]

i dont think 1.5 is overkill ... esp w/ mdf.

the plastic laminate would help the durability of the top as well. If you use a white PL you can have a permanent notepad !!

i use my white laminate top to write stuff down all the time.

[Shawn Honeychurch]

Hmm;

I was unaware that MDF sagged. I will have to made sure to brace the top. Maybe a few stringers (?) across the bottom.

[Peter Quinn]

MDF is flat but it can't even hold its own weight over any reasonable span. Throw in a 15# router and a lift (if you use one) and it will definitely droop in the middle. You can make the stringers into a frame (think tortion box with only one skin) to stiffen it up a bit. You can buy pieces of baltic birch with hot pressed phenolic (thermofused I think they call it) at places like woodpeckers and woodcraft. Not too expensive, get you there quick.

I'm using a piece of Borg melamine that cost less than $10 with a hardwood frame under it and a bosch 1617 with an extra base as my second router table for cope/stick set up. Stays flat, parts slide smooth, price was nice. Visually speaking it wouldn't make the cover of any magazines, except maybe 'CHEAP YANKEE DIGEST' but it works.

[Ron Bontz]

Shawn, I personally used 2 layers of 3/4" MDF with laminate on the top and Balance backer on the bottom. You can use the 0.05 or post form laminate on the bottom as well but a little more expensive. The "Balance backer" is important. Without it the MDF can and will warp. I made the mistake of leaving a couple of tops I made sitting for a couple of months without the balance backer. Big mistake.. I also edged mine with 1/8th" aluminum angle on all four sides avoiding the problem with movement of the wood edging. I also occasionally bump into things in my small shop. I use a router lift so that adds weight to the middle. It may seem like over kill but I use my 36"x27" a lot and it stays dead flat. Good luck.

[Shawn Honeychurch]

OK, new term.

What is a "Balance Backer"?

[matt dumney]

Shawn, I personally used 2 layers of 3/4" MDF with laminate on the top and Balance backer on the bottom. You can use the 0.05 or post form laminate on the bottom as well but a little more expensive. The "Balance backer" is important. Without it the MDF can and will warp. I made the mistake of leaving a couple of tops I made sitting for a couple of months without the balance backer. Big mistake.. I also edged mine with 1/8th" aluminum angle on all four sides avoiding the problem with movement of the wood edging. I also occasionally bump into things in my small shop. I use a router lift so that adds weight to the middle. It may seem like over kill but I use my 36"x27" a lot and it stays dead flat. Good luck.


What kind of glue do you use to glue this MDF together. Is it necessary to use laminate? Where can laminate be purchased?

[Tom Henderson2]

OK, new term.

What is a "Balance Backer"?

I believe he is using that term to describe the laminate that should be on the bottom of an MDF top if the upper surface is laminated.

If you don't do that, the unlaminated bottom surface will absorb moisture, but the top won't since it is sealed by the laminate and adhesive. This can lead to warpage etc.

Whatever you do to the top surface you usually need to do to the bottom.

I haven't heard the term "balance backer" before but I believe that is what he is referring to.

I'm sure somebody will correct me if I misunderstood.

-TH

[Tom Henderson2]

What kind of glue do you use to glue this MDF together. Is it necessary to use laminate? Where can laminate be purchased?

I don't think glue choice is a big deal -- any glue suitable for use with MDF should work. I had to build up a 1" MDF surface a while back and ended up laminating a piece of 3/4 and a piece of 1/4 to make it up. I used polyurethane glue and it seems to work ok (that application was for a TV stand)

Formica/Laminate is available from many home stores, or anybody that makes kitchen counters should be able to get it for you.

Hope this helps.

-TOm H.

[Tom Henderson2]

Hello;

I am just about finished building myself a router stand and am wondering about the top. I was going to use 2 pieces of 1/2" MDF for the top, but I got to wondering which would be better:
2 sheets of 1/2"
4 sheets of 1/4"
8 sheets of 1/8"

Any thoughts?

Thanks
Shawn:)

Hi Shawn-

As long as the glue bond holds, it shouldn't make any difference whether it is 4 thin sheets or 2 thicker sheets.

I'd suggest using 2 sheets of 1/2" just to minimize the gluing.

-TH

[Shawn Honeychurch]

Obviously there is more to router tops than I had thought.

I built mine based on plans from a wood working magazine. The base is great, nice strong and heavy, but the plans called for 2 layers of 1/2" MDF for the top and that is all.

[George Bowen]

Be carefull gluing up to keep the two board flat and paralel. If the glue isnt perfect between the two surfaces is will creat a ridge or bow, and if they sag while gluing it will warp the entire piece when dry.

I would do 3/4" and 1/4" on the under side. Glue it up upside down, so 3/4" on the table or floor, then glue then the 1/4", this way the surface that you will use and want to stay flat remains against a flat surface.

[Joe Spear]

My router table, with a Milwaukee 5625 in it, is made of two layers of 1/2" MDF, one layer of 1/4" plywood, and one layer of formica on the top and one on the bottom. I glued all the layers together with contact cement. the whole thing is slightly more than 1 1/4" thick. I glued on purple heart edging around all four sides with Tiebond. The top is supported on the outside frame of the stand (four edges) and on two cross braces under the top and attached to the frame of the stand. In two years I have had absolutely no sagging problems. If you're worried that your top isn't thick enough for the span, just put some braces under it.