Gluing MDF

[jim]

I have 2 pieces of 3/8" MDF that I would like to glue together to make a 3/4" board.
They are a 4X8 feet sheet and I need every square inch for an up-and-coming project so I cannot
do any experimenting. I was thinking about Carpenters Glue but that is water-based. Is this still OK to use or will this water-based glue
cause an issue with the MDF like warping?
Thanks

 

[PCustoms]

I have 2 pieces of 3/8" MDF that I would like to glue together to make a 3/4" board.
They are a 4X8 feet sheet and I need every square inch for an up-and-coming project so I cannot
do any experimenting. I was thinking about Carpenters Glue but that is water-based. Is this still OK to use or will this water-based glue
cause an issue with the MDF like warping?
Thanks

Even clamping across a 4x8 sheet will be difficult.

Any reason you wouldn't just go buy a 3/4" sheet?

 

[robin1731]

Cabinetmaker for 25 years. We used MDF quite a bit. We built cabinets for airport terminals. The water-based glue is fine. That is what we used on the edges. We usually used contact cement for what you are doing. But the carpenters glue will be ok. I would scuff up the mating surfaces first though.

 

[mike93lx]

A gallon jug of titebond 1 and a roller is what I would probably go to. But 3/4 is usually very readily available. Between all the glue, time and effort, I'd have a hard time justifying this one.

 

[pcmeiners]

Gorilla Ultimate, states it is water proof ( more like water resistant)......

Gorilla 18 oz. Wood Glue Ultimate 104406 - The Home Depot

Perform all your heavy-duty projects and repairing tasks at ease by choosing this Gorilla Super Glue Brush and Nozzle.

www.homedepot.com

Why are you using MDF ?, it ***** if hit with water, actually it just *****.

 

[PCustoms]

Why are you using MDF ?, it ***** if hit with water, actually it just *****.

I used to use it for speaker boxes, and really hated working with it didn't have great strength to screw on the edges, always put a ton of dust everywhere, couldn't even look at it if it was wet out, and of course a full sheet of it required two people to move.

 

[cgrutt]

Agree with others I'd just use a 3/4 sheet if that's what you need but wood glue will work. You didn't state if it was covered with a laminate face or not. I'm assuming you're talking about bare mdf I don't think wood glue would work on laminate. Contact adhesive might if that's what you're talking about.

 

[jar944]

A gallon of titebond and a 5x9 vacuum bag/press with a platten will do it.

Or just buy a 3/4 sheet for $50.

 

[Tom Sestito]

I've done that a bunch of times because sometimes you just have that material laying around and you want to use it up rather than spending extra.

You might consider diluting the glue a touch (or heating it) to increase the viscosity before you roller it onto the board. You want to avoid big blobs of glue and apply a nice even coat.

You'll need a flat surface on which to glue it obvioulsy. Good luck!

 

[DGersic]

Trowel out enough Tightbond II to cover the surface, then clamp it. How you’re going to clamp it will be the fun part. 5 gallon buckets filled with water would work, or bags of salt, cement, sand, something like that. I‘d plan to let it dry for a few days.

I did something like this with two sheets of 3/4” to make a desk top. Don‘t think I’d bother with two 3/8” when a sheet of 3/4” is readily available, but I can see doing it to use up what you have.

 

[carlaisle]

Clamping will be your problem, not warping. The only way you're going to get that to bond well is with a flat surface underneath and a bunch of weights on top. You could try cauls but the juice is rarely worth the squeeze at the length and pressure needed for this application. Don't thin the glue if you go this route. In a situation where you don't have a square inch to spare, the other caution is getting the two layers to align with each other. The glue layer is slick and the two pieces will slide around when you start to clamp them. A few pin nails can help with this if they won't cause a problem with your project. To echo others, I'd just buy a piece of 3/4" or cut everything to size first and then glue the pieces together.

 

[PoorUB]

I work with MDF every so often and I wouldn't try to glue two sheets of 3/8ths together and expect it to work out to my satisfaction, even if I had a mirror flat work table large enough to deal with it, the correct glue and weights to cover it.

Weigh it out, $50 for 3/4 MDF, or $20 of glue and two 3/8" thick pieces, A royal PITA glue job, and toss it all in the trash when done.

Just go buy a sheet of 3/4"

On the other hand, if you plan on cutting it up into smaller pieces, perhaps cut up the pieces, then glue them togther. You might have a better chance of it working out.

 

[Torque&Recoil]

I noticed that you are in Wisconsin, and this is February. Be aware that white or yellow carpenters glues will not cure properly in cold temperatures. I tried Titebond (normally a great glue) once in an unheated barn. The next day, the parts just fell apart. The glue turned to dust as it dried. Really. Check the label on the glue bottle for minimum temperatures. Of course, if your shop is heated, this is no problem.