MDF and Glue Help

[Scott Berg]

Hello All,
I am a longtime reader, first time poster who is somewhat new to woodworking.
My question is probably pretty dumb so be easy on me. I am in the process of making a small(24" by 27") side table for my table saw. I am planing on gluing together 2 sheets of 3/4 inch MDF, using screws to hold it together even more, and then apply plasitc laminate to the top.

QUESTION: What kind of glue do I need to use for MDF? Can I use regular wood glue or is there a special glue that I must use?

Thanks in advance for your assistance.

[Jim Hinze]

Regular yellow glue is sufficent for gluing the MDF together. For the plastic laminate, use contact cement...

[Scott Berg]

Thanks Jim, I have never worked with MDF before so I wasn't sure how porous it was, etc.

[Chris Padilla]

Scott,

For face to face gluing (like the lamination you are considering), just about any glue will do and good old yellow is just fine.

Edge gluing MDF can be a bit tricky because the "end-grain" likes to suck up glue.

Check out John Lucas' demo of exactly what you wish to do:

http://www.woodshopdemos.com/wpkr-1.htm

Unibond 800 is also popular but I don't think it is necessary for what you want. Still, at least you know about it! :)

http://www.vacupress.com/veneerglue.htm

[john elliott]

A tip for this situation- examine the mdf carefully and you will find that it is slightly curved, like any other panel product it is never dead flat. Identify the two convex faces and glue those together (ordinary PVA is fine). Now all you need to do is to clamp around the edges, because the natural curves will push the middles together. I hope you see what I mean
John

[Mike Alagna]

Just another thought for you to consider...Instead of gluing up the 2 MDF panels and then laminating the top you might want to consider using a sheet of the white melamine and gluing it to a sheet of MDF. The melamine has teh nice smooth finish on it already and it will save you time and money and you will be sure to get a smooth top.

[Joe Mayo]

Hi Guys,

New to the forum.

I usually use contact cement to glue 2 pieces MDF together. I've heard that yellow glue never fully cures. MDF is so dense that there is insufficient airfolw to cure the glue. Anyone ever experience this?

[Jim Hinze]

Just another thought for you to consider...Instead of gluing up the 2 MDF panels and then laminating the top you might want to consider using a sheet of the white melamine and gluing it to a sheet of MDF. The melamine has teh nice smooth finish on it already and it will save you time and money and you will be sure to get a smooth top.


Melamine does have a nice smooth finished top, but it's thin and is not as durable as the formica. If you already have the formica, go that route... otherwise melamine is much less expensive.

[Jim W. White]

Gluing sheets of MDF I would turn to a spray on adhesive instead of the yellow glue. I've used 3M 'Super 7' on several of these type projects and it works very well.

You should be able to find it at any hardware store.

[Scott Berg]

Thanks again everyone for taking the time to answer a beginners question, I appreciate it. I already purchased some plastic laminate so that is what I will use for the top and then paint the bottom. This will be the first time working with MDF so it will be a learning experience for sure!

[Hal Flynt]

Watch out for splits when you screw it together.

A couple of hints:

Pre drill pilot holes and countersink as normal. THEN make a small counter sink on the other side. (This will allow the small amount of MDF that pulls up as you drive the screw home a place to go without creating a bump).

Something else I do, when I take the time, is a dry assembly with all the screws etc. then when I disassemble, I take the bumps of with a chisel or block plane.

I try to use a screw hand clamp (I'm not sure if that's the correct name or not, but I mean the wooden jawed ones with the 2 threaded rods with wooden handles) to help prevent splitting near the end of a board.

All the gluing info here is good, so follow that.

Now if you should ever find a split, all is not lost as you can glue it closed again. The trick is getting glue into the split and using a hand clamp (like above). If you force some glue into he pilot hole and run a screw in the hole w/o clamps, the hydraulic pressure will force the glue into the split. You may do this a couple of times to be sure you have glue in the split. Then put the clamp on to support the sides and glue the project up and screw it down again for the final time.


Good Luck.

[Keith Hooks]

I glued together two sheets of 3/4" MDF to make a router table top. I used contact cement and it's held up wonderfully. If I remember correctly, I coated both faces with the contact cement using a cheap foam brush and let it dry for several minutes. Then I flipped one over and laid it on top and pounded lightly over the surface with a soft mallet to make sure the adhesion was nice and even. There's no need to clamp it to dry. It was quick and clean without squeezeout. I also laminated a sheet of formica on the top using the same process. I think this would work great for you.

Specific information about drying time should be on the can.

[Lee DeRaud]

I glued together two sheets of 3/4" MDF to make a router table top. I used contact cement and it's held up wonderfully. If I remember correctly, I coated both faces with the contact cement using a cheap foam brush and let it dry for several minutes. Then I flipped one over and laid it on top and pounded lightly over the surface with a soft mallet to make sure the adhesion was nice and even. There's no need to clamp it to dry. It was quick and clean without squeezeout. I also laminated a sheet of formica on the top using the same process. I think this would work great for you.

Specific information about drying time should be on the can.I've been using a Titebond product lately that goes on blue and turns dark green as it dries: no fumes, no odor, takes about 20 minutes to dry. I'm putting it on pretty thick...can says 30-40 minutes, but I'm in a dry climate.

[John Hemenway]

I've been using a Titebond product lately that goes on blue and turns dark green as it dries: no fumes, no odor, takes about 20 minutes to dry. I'm putting it on pretty thick...can says 30-40 minutes, but I'm in a dry climate.

Lee, is this a contact adhesive? I've built a TS extension table I don't like and am going to reuse it to make a RTT (router table top ;) ). It has formica on the top now. My plan is to cut it into RT size and glue two non-formica faces together. Since the surfaces already have formica, I'm worried the glue won't cure. Seems like contact adhesive won't need to 'dry' like PVA would. (I could be wrong here :p )

Comments?

[Steve Clardy]

I USED to use the blue stuff from Titebond. But after having three major counter tops go sour, laminate coming loose, I switched to 3M laminate glue. Pricey at $60.00 a gallon.
Titebond went throught a major lawsuit on the blue glue just last year or before. They had a lot of suits filed on them by the major counter top manufacturers.
Steve

[Alden Miller]

First time using MDF? Make sure you wear a dust mask!

-Alden

[Howard Acheson]

In the shop I was involved with we laminated particleboard and MDF with solvent based contact cement. We probably did a couple of hundred that way. It's a lot faster than using an adhesive. Use the same adhesive to bond the plastic laminate to the MDF substrate.

I have found the solvent based to be more reliable than the waterbased contact cement.