Gluing together Formica clad mdf

[jimk04]

I have some offcuts of from a new kitchen installation. It is mdf covered with what I'm calling formica but it may be something different nowadays. It is hard, has a very fine texture and is satin in finish. It wasn't glossy kitchen.

It will make quite nice speaker cabinets but I'm unsure how well it will join. It will be butt jointed and so was considering an impact/contact adhesive.

Any experience with this?

Thanks
James

 

[dtaylo3]

No, but since it is mdf I would suggest using 3 or 4 dowels per butt joint and that will ensure a great hold.

 

[jimk04]

Oh yes of course. And i realise i have a biscuit jointer so that may be the tool for the job!

 

[jerrymchill]

Miter joints - this way you will have nice seamless look/surface and you can then finish formica in any veneer or paint or just leave it alone... Butt joinery is for amateurs!!!

 

[chrisb]

If you can’t see a thin brown line between the core and surface, the material is more likely to be “melamine” - although that technically refers to the chemistry of the resin that is the base of top surface layer.
This type of sheet good material is designed primarily for cabinets/casework, and wouldn’t be my first choice for speaker boxes in which you want not only structural intregity, but also - unless you’re building an open baffle - air tight joints as well.
You’d be best to at least dado/ rebate joints to ensure all glue surface areas are raw core, or consider cleats, low-root wood screws, and lots of silicone. In commercial cabinetry work, when cases built from melamine need a skin of high pressure plastic laminate (Formica, etc), or real wood veneer, the top surface needs to be scuffed off with belt sander to ensure adhesion of either contact cement or veneer glue.

 

[jimk04]

melamine.....that's the stuff!

I don't possess the tools to mitre along the edge of a board. But yes being air tight is an issue for consideration

 

[chrisb]

Another consideration with both melamine and HP laminate lay-ups is that the surface layer is very brittle, and getting a chip-free miter joint would be quite tricky to both cut and assemble.

 

[JMFahey]

Just thinking aloud, I think you may set up a router to just shave a melamine strip along joining edge, same width as wood thickness, so being able to use conventional gluing.

Or even better, improve it to a dado/groove joint.