# Router Table Top Glue-up Question



## Greg60525 (Jan 9, 2014)

Ok, so I will be gluing up my first router table top using two sheets of MDF. Simple question: what type of clamps are the best for clamping two sheets of MDF together? I've read that parallel clamps are the best for keeping things square, but I'm not sure that clamping two sheets together requires a parallel clamp. I'm think that F-style clamps, probably the 6" length, is satisfactory. The only real advantage that I see of the parallel clamp for this application is that the clamp will also act as a foot to hold the sheets off of the surface during curing.

Another question: do I have to clamp the sheets to a flat surface or can I clamp the sheets between the jaws and still maintain a flat top when all done?

Thanks,
Greg


----------



## Mike (Nov 22, 2004)

Greg, for gluing up sheet goods you can set cans of paint or anything heavy on them and just use the clamps for alignment.


----------



## jw2170 (Jan 24, 2008)

I hope that propane bottle is empty, Mike.....


----------



## OPG3 (Jan 9, 2011)

Greg, It is important to assure that both faces you are going to glue are absolutely smooth. If they are identical in size you can build-up something to "confine" them - so that they will stay together, otherwise they are quite likely to slip apart. Use a plastic trash bag to make sure your glue-runout doesn't cause problems. Glue overspills on the MDF can be easily sanded away after the glue has hardened, but in some cases (without the trash bag), it could have bonded to something you did not intend to become part of your overall assembly.

I come from the "engineering world" and in design, we have no choice but to look at "worst case situations". This is often referred to as EXAGGERATION FOR CLARITY, now; *pretend there is a marble* between your two pieces of MDF - this will help you visualize why your two faces need to be perfectly smooth. Furthermore, this will help you realize WHY you need pressure in the middle (as Mike suggested above) and a good, solid, smooth surface to work from.

I hope this helps!
Otis Guillebeau from Auburn, Georgia


----------



## kywoodchopper (Jul 18, 2013)

Hi Greg, why are you gluing them? Could you not run screws up through the bottom one into the top one? If you do, don't forget to predrill the holes (the hole should be slightly larger than the screw threads) then counter sink for the screw heads. Malcolm / Kentucky USA


----------



## Wildwood (Aug 14, 2010)

I can't help feeling that gluing would result in a more rigid structure overall - or would there be no difference in this application? Just asking.


----------



## 64 ford (Apr 21, 2013)

Hi Greg
As said make certain they are both smooth so they bond all over. I would clamp them together using cauls to be certain they have clamping force distributed thru out the sheets.
I would also make them slightly over sized and trim them to size after wards so everything is perfectly flush. Even cutting pieces on a good table saw and then gluing them together don't always come out perfectly flush - at least for me.
Dennis


----------



## supercat (Apr 23, 2010)

Hi Greg - I wondered the same thing when I built my new router table in December (still working on the cabinet). I'm building a variation of Norm Abrams table. I decided to use screws as my "clamps" and this turned out to be a good choice. I cut both sheets of MDF (I used 1/2" and 3/4" to end up with a 1 1/4" top) roughly to size making sure I had a perfect factory edge along one side. I drew out the layout of the router table insert plate, slots for the bolts to secure the fence, and a miter track on the 1/2" MDF side (back or bottom of table). I then dry clamped this together and drilled my screw pilot holes about 4 inches apart and then countersunk each pilot hole (I used 1" screws) taking care to stay away from the insert, slot and miter location. 

This was probably overkill (probably used almost 100 screws!) but I ended up with a very strong and flat table top after I laminated the top and added 3/4" oak stripping around all edges. I used biscuits to install the oak edging.

I'm using the top now for some projects I have to get done and am working on the finished cabinet which will eventually hold the top and all of my bits, jigs and hold down. Good luck to you and welcome to the forum! These guys are the best and I have learned a lot here.


----------



## Greg60525 (Jan 9, 2014)

Thanks everyone for the great advice........greatly appreciated!

I plan to use Titebond II glue and a bunch of F-clamps. I only have a few, so I will be picking up some of these.........probably Bessey Tradesman F-clamps. I will use cauls or at least some propane tanks  to clamp the middle down. I'm not planning on using screws as the clamps. I will definitely protect the work surface with plastic or something.

One thing I plan on doing to make sure the top is square is to start with slightly over-sized panels and offset one panel in both directions leaving the factory edge of one of the panels proud. This way I can run those edges along the table saw fence ensuring a square cut on the other two sides and then use the cut sides to cut the other two sides square and parallel at the proper size.

I will be laminating both sides in Formica or equivalent. I plan on edge banding in oak, but may make the banding a bit wider and insert T-tracks into them. I am thinking of rabbeting the top and bottom of the router top and grooving the banding to give extra glue area and support.

BTW, I will be using an Hitachi M12V router with a Woodpecker PlungeLift.

Couple of questions:

- as long as I wipe the MDF panels down before gluing is this sufficient to provide a smooth surface for gluing or do I have to sand the surfaces?

- how much pressure do I need to apply? I don't want to squeeze all of the glue out.

- Know of any sales going on for Bessey F-clamps?

Thanks,
Greg


----------



## Salty Dawg (Jan 24, 2014)

I did mine like Super cat & screwed the 2 pieces of MDF together, I gave both mating surfaces a light sanding before gluing.


----------



## Mike (Nov 22, 2004)

Jay, "Norm's" table is from a design in Fine Woodworking magazine. Norm modified it to use Rockler parts since they were sponsoring the show. This table design was for sale 6 months before Norm started work on his as the RT 1000 by one of our forum members.

"Now you know the rest of the story..." (he said in his best Paul Harvey impersonation)


----------



## OldEd (Feb 4, 2014)

*My* question is *"Why MDF"*? I used two sheets of 3/4 baltic birch which were glued and then screwed together, and then topped with high grade Formica for a smooth nonstick surface. (I had the Formica applied by a commercial counter-top shop guy that I am friendly with.)

Then I could screw into the base with some assurance that the screws would bite into something solid, not that horrible dusty MDF stuff. 

I used it once, and won't have it in my shop. I'm still finding traces of the powder that sawing it generates.

Routing the hole for the mounting plate was a lead pipe cinch. Also routing for T-track was equally easy, as was fastening it to the frame of my router work station.


----------



## Mike (Nov 22, 2004)

Ed, the high density of MDF helps to reduce vibrations generated while routing. The added weight or mass helps to anchor the table down too. Several popular router tables use 1-1/2" thick table tops of MDF. This works.

I prefer a single layer of 3/4" Baltic birch plywood with Formica top and bottom. Properly supported this design is light in weight and trouble free. This is the construction method used in the Router Workshop table.


----------



## Greg60525 (Jan 9, 2014)

OldEd said:


> *My* question is *"Why MDF"*? I used two sheets of 3/4 baltic birch which were glued and then screwed together, and then topped with high grade Formica for a smooth nonstick surface. (I had the Formica applied by a commercial counter-top shop guy that I am friendly with.)
> 
> Then I could screw into the base with some assurance that the screws would bite into something solid, not that horrible dusty MDF stuff.
> 
> ...


I struggled with this myself! 
Things become much easier when you could just easily screw into the plywood. The main thing that I'm worried about is the flatness, so that is why I'm choosing MDF.


----------



## TWheels (May 26, 2006)

What about phenolic faced plywood? Then no need to laminate, etc.


----------



## Mike (Nov 22, 2004)

Tom, wood slides nicely over phenolic impregnated Baltic birch plywood. When you clamp to it you leave indentations; we found this out by trial and error with the economy table tops. Don't get me wrong on this, it is a good starting point but Formica adds a lot of stability and helps keep moisture out of the wood.


----------



## TWheels (May 26, 2006)

Mike said:


> Tom, wood slides nicely over phenolic impregnated Baltic birch plywood. When you clamp to it you leave indentations; we found this out by trial and error with the economy table tops. Don't get me wrong on this, it is a good starting point but Formica adds a lot of stability and helps keep moisture out of the wood.


Thanks very much Mike. Makes very good sense.
The Oak Park (Router Workshop) router table was phenolic impregnated Baltic birch wasn't it?


----------



## Mike (Nov 22, 2004)

Tom, the Router Workshop table top from Oak Park was built from 3/4" Baltic birch plywood with Formica top and bottom. James uses just the top in a Workmate for portability and easy storage.

My table spends as much time outside as it does in so at times it is clamped to saw horses and sometimes it is on a roller cabinet base. You can see how we built the economy table top to be as close to the Oak Park version as possible. The economy table top is phenolic impregnated Baltic birch plywood; this is an easy way to get started since you just cut the material to the size you need.


----------



## TWheels (May 26, 2006)

Thanks very much Mike. 
From the beginning I had been wrong!


----------



## fleetinglyshort (Oct 22, 2013)

I plan on using 2 18mm MDF pieces and edging it in hardwood. I usually use Titebond original (Red Label) stuff, Would I better using something thinner when laminating them together. What screws are best to use in MDF?

I plan on using a series of screws and heavy objects to laminate the sides once prepared smooth.

Any advice on the best adhesives/methods for laminating the Formica on top?\


----------



## masonsailor (Sep 20, 2013)

I am using melamine so gluing is not really an option. Very little sticks to it so screwing them together is best. For MDF gluing works well. One thing you can do to get the edge alignment perfect is to cut one piece about 1/4 to 1/2 inch bigger than the other and once the glue dries flush trim the edge of the larger one to match. This works well if you are going to edge band the table top when you are done. This method eliminates the need to have perfect alignment during gluing and ultimately gives you a perfect edge to glue your edge banding to. Another great trick is to throw two biscuits in opposite corners to keep things from sliding around during glue up. Paul


----------

