What adhesive - that shrinks when it sets - do you recommend for melamine laminate sheets?

Dad used Formica stuck down with Evostik in Mum's kitchen in 1966. It was still all firmly fixed when we sold the house in 2005.

Nobody seems to have mentioned thixotropic cements like Thixofix and Timebond. They are similar to Evostik but are more forgiving of accidental touch-downs.

George

He has melamine faced board which I've only ever seen coated on both sides, if it were one sides it would not be balanced and warp all over the place. I use it regularly and often buy in a ton at a time.

OP would need to buy a belt sander to remove the LPL and as he wants a flat surface would need to be very carful to no sand to different depths, really wants a thickness sander to do it properly.

Yep, kitchen worktop, 32mm thick available but 1000mm wide?

Regards Ian.

Bit of plywood would be good enough to throw a cutting mat on top of. Comes any size you want pretty much.

900 x 2000 breakfast bar would come close if you went the worktop route but you would have to buy the whole 2m length

Melamine or Laminate top is nice if you are glueing up on it as it is easier to wipe off excess glue

One factor which needs to be considered, too, is the range of conditions in which the bonded parts will exist. Several clever adhesives are modified (or destroyed) by heat or cold, vibration, or by solvents, including everyday cleaning chemicals. Advice offered in the absence of detail like this may be nugatory. Or worse.

Cheers, Tim

The glue I used years ago was called "Cascamite", and it did exactly what it said on the tin [or sack, in my case ]

I t was cheap, simple to use, and never failed. I used it to bond plastic laminate to chipboard and mdf board and for wood -to-wood joints. For sheet work, I used a rubber roller, being faster and giving a better spread.

Dont know if it is still around, I no longer do that work, but it might be worth looking into.

As I remember, it was made by Borden Chemical Co.

Might not be what you are seeking, but worth a try.

No, Hopper, the whole point is that my sheets of MDF already come with melamine glued to both sides. And that is why I am needing to bond melamine to melamine. Single sided would warp all over the place, with every change in atmospheric temperature & moisture.

No, the MDF is definitely melamine (gads!)

...and it is 18mm thick and A0 sized and on the table I have it flexes just enough to be annoying.
No, I want a smooth & easily cleaned working surface, not plywood, for a whole variety of reasons.

It will need to withstand direct sunlight temperatures ranging from -5 (in storage) to +40C.

A lot of glues would work if only ONE side is plastic. "Cascamite" is a "Powdered urea/formaldehyde resin glue" so sounds like a powder which is activate by adding water. It sounds brilliant.

But I am keen if possible to use up some of my existing glues of which I now have quite a collection.

If my 2 tubes of J-B weld aren't going to be enough, maybe I'll just us some epoxy resin glue.

Donald

Another option would be Cyano, 50ml bottle of one of the "mitre" adhesives or bottle of ZAP would be enough to run a continuous straight bead every 50mm, don't do circles as you will bet air trapped. You would not need the activator.

I've used it enough times to stick various trims to MFC and NFMDF and it usually pulls the thin melamine layer off the substrate if you try and pull them apart

If 3/4” dual faced mdf flexes annoyingly on the current table I would suggest the current table is likely to be the issue.

Dave

Agree with Dave S. Like a building, it's only going to be as good as the foundations. (Waits for someone to come up with an example that disproves it... )

Rob

KISS Principle. Screw them together?

Buying a new table is definitely not KISS!

Not screws because:
A) I want to use the whole of the both of the top faces and any screws will be hard to flatten off.
B) I want to make sure that the centres does not bow out from each other.

But good point about using lines not circles, Jason. I shall definitely use that.

Don

I agree with Frances above ^^^^^  It seems like way overkill or overthinking on gluing two pieces of board together in order to create a surface on top of an existing bench for the very simple purpose of resting a cutting mat. If it is this difficult -- two pages of forum discussion with not one suggestion being "just right" -- something is wrong at basic principles level.

Edited By Hopper on 01/04/2022 07:30:17

It seems to me that the use of JB Weld in this situation is rather a waste of the product.

The thing to bear in mind once this gluing of two surfaces together - to provide a flat one - is the inability to part them if it does warp. Not suggesting it will but am saying it might - too late then.

NDIY's and others suggestion of screwing is to me the most logical. Correctly done the screws can be equally spaced to ensure even pressure across the area and the heads countersunk enough to either be flush or filled over. The original poster does say that for most of the time it will be used under cutting matts so screws shouldn't be an issue.

The environment would appear to present a challenge with -5 to + 40 and relevant humidity changes - another thing to be considered.

I have in my workshop a very flat bench top - MDF on top of MDF on top of Chipboard - all screwed together. It is checked for flatness and warpage each time I build a model - so far the stability has remained since I placed the last layer on

As always the pics are to assist the recommendation but what I do does require an absolutely flat working surface - the above has proved admirably successful for me.

Someone suggests this is probably being over thought, yes the question was about which glue type to use but it's time to think outside the envelope perhaps.

Regards - Tug

Edited By Ramon Wilson on 01/04/2022 08:04:11

Edited By Ramon Wilson on 01/04/2022 08:11:55

Ramon - not overthinking at all for your purposes where you are using it as a jig/fixture base for building large complex structures that must be dead flat/straight/true, such as airfoil sections as shown. But for resting a cutting mat as the OP describes -- not so much.

Hi Hopper,

Maybe so but the principle's the same - the object is to get two pieces of board together to provide a flat surface without it warping or delaminating. My approach is on the basis of once bonded it's bonded - if a warp does then ensue it rather defeats the object - atmospheric conditions can, and will, play a part in trying to do what you want to prevent..

FWIW all the MDF two layer bases I make for my plastic models are screwed together for the same reason but - 'yer pays yer' money etc.

Tug

Yes indeed good from that point of view. And as you say, screw holes could be filled with bog and filed/sanded down flat,

What kind of screws work best in MDF though? Ordinary wood screws? Chipboard screws? Or are there special MDF screws?

I use basic 'Screwfix' silver screws but I'm sure any 'modern' parallel thread screw would do. I would think an acrylic filler for the melamine surface would be best. If done with care they would be hard pushed to see let alone feel.

T