The Framers Forum

I need to stik a 1m by 1.6m 5mm sheet off Kappa onto MDF. Not sure if it is branded Kappa, but it's white plastic under a removable blue polythene protective coating.

I used some clear silicone from the local 'bits n bobs of everything' shop. IT did stuck but when tested it peeled off with little resistance.

What brand of silicone or adehesive would you recommend?

sticking smooth surfaces is always difficult - adhesive needs to grip onto something to adhere. The answer is normally to roughen the surfaces.

I take it the kappa board is plastic? If so I would use gripfil, that will glue most things. If the kappa is quite dense then you can also screw from the mdf into the kappa with appropriately short screws that with the glue would give a more secure hold.

is that the archival version of gripfil

Contact adhesive is maybe the thing. A bit dicey though as you got one chance to get it aligned spot-on.
It needs immaculate timing to let the solvent flash off and then you have a short window of stickness.
You also need to apply a good deal of pressure to get a firm bond.

I would also try a small offcut first.

Are there any sign makers near you. They have the kit to cope with large sheets.

Yes mark on the sense that it will last probably longer than the mdf that it is sticking to.

Are you sure this is Kapa (foam board with aluminium skins, skinned with paper), and not some sort of Foamex/ /Forex material (expanded PVC)? I've never seen Kapa with a release film, but all the Forex and similar that I've used has a release film.

From 3A composite info on Forex Classic PVC:
Bonding FOREX®classic to ...
 Wood, chipboard Contact adhesive / 2-component PU adhesive
 Metals (aluminium, galvanised steel, DIBOND®) elastic 2-component acrylate adhesive / some SMP adhesives
 Brickwork, concrete, glass Silyl modified polymer (SMP) adhesive / 2-comp. tile adhesive
 Thermoplastics, perspex double-sided adhesive tapes / 2-component PU adhesive
 Expanded polystyrene, FOREXsmart® 2-component PU adhesive / some SMP adhesives
 Rubber, elastomers, soft PVC (foam) Contact adhesive (plasticizer resistant)
 Paper, cardboard, textiles, leather Contact adhesive / dispersion adhesive / spray adhesive
 In addition, double-sided adhesive tapes can be used for bonding FOREX®classic sheets to entirely different materials. The best suited adhesive tape must be found by carefully matching the materials to be joined with the nature of the load.

Richard you absolute star indeed it is foamex. That's the problem with posting on a Friday afternoon.

Definitely put my mind at ease with your source of info.

Cheers