Adhesive question ...

[Arfa Daily]

So, what exactly is the difference between "impact adhesive" and "contact adhesive" ? Or actually, is there any difference ? Both seem to sport broadly the same quoted characteristics. It has been years since I did any Formica work, but now need to do some on a large area. Back in the day, I seem to remember using an Evostik product that came in a screw-top tin with a brush built in, that was called contact adhesive. Until recently, I had a tube of Evostik in the workshop that called itself impact adhesive. As far as I can recall, it had the same smell and consistency as the 'contact' product used all those years ago.

Looking in the Toolstation catalogue, both types are listed, and both seem to have a pretty similar descriptions of characteristics, and uses. As I am going to be working with large sheets of laminate, I guess ideally, I am looking for something that is low enough viscosity to be able to be applied quickly with a paint brush. Anybody got any thoughts / recommendations ?

TIA

Arfa

[The Natural Philosopher]

None AFAIK ? Or actually, is there any difference ? Both seem to

Possibly one is a water based pale imitation.

If you are truly doing large areas and quantities a hydraulic press and a non contact glue is cheaper..

Polyurethane maybe.

Or a hot press and hot melt.

[Nightjar]

Originally, they worked exactly as the names suggest. Contact adhesive would stick firmly the instant the two surfaces came into contact. Impact adhesive stuck lightly, but needed you to go over the whole surface with a block of wood and a large hammer, whacking away until the two parts stuck fully. Contact adhesive was very unforgiving of misalignment, while with contact adhesive you could reposition the pieces until you started hitting; then along came repositionable contact adhesive to blur the distinction. It is a very long time since I used either and I have no idea whether they still work the way they used to.

Colin Bignell

[Tim Lamb]

It is an *under the counter* item at B+Q so it must have alternative uses:-)

regards

[Dave Plowman (News)]

Evostick changed its formulation in recent years - probably because of the original solvent being banned or whatever - and IMHO isn't as good as it was.

IIRC, the first contact adhesive to allow you some degree of re-positioning was Thixofix.

[Arfa Daily]

Ah yes - Thixofix ! Because it was thixotropic ?? whatever exactly that meant ...

'Unforgiving' shouldn't really be a problem with this job. It's for the front vertical face of this counter I'm building for our new burger joint. It is one large curved surface about 4 m long, and then a long straight, both in MDF. There's an upper 'customer side' to the counter, which will overhang the top edge of the MDF / laminate, so as long as the stuff is pretty flat to the floor, it doesn't matter too much at the top, as it will just be trimmed to match the top edge anyway. Biggest challenge, I guess, will be where there are any joins.

Arfa

[Terry Casey]

Ignoring any distinction between the two, the instantaneous nature of contact adhesive can be a drawback, particularly so when working with large sheets of laminate, as it only takes one slight slip and you end up with the laminate permanently stuck in entirely the wrong position!

What you need is a thixothropic glue - it is like contact adhesive but gives you a bit of latitude to adjust the final positioning, then you just apply pressure and it sticks.

Could it be that 'impact' is a dumbing down term for people who can't read or understand long words like 'thixothropic' ...?

[Andy Dingley]

Evo stik Timebond is the modern version. Very good stuff, although the price is steep. It also looks & feels like lemon curd, not the usual stringy contact adhesive that loves to dribble, I use it for leatherwork, just to avoid this risk.

[Terry Casey]

That should have read "What you need is a thixothropic adhesive ..."

Not quite sure what the difference is between glue and adhesive but something niggling away at the back of mind says that glue is adhesive but not all adhesives are glues ...

[Nightjar]

On 10/05/2011 10:22, Arfa Daily wrote: ...

It means it gets runny if you stir it - like non-drip paint.

Colin Bignell

[Dave Liquorice]

And all you need is a plastic bag.

[Arfa Daily]

Thanks Andy. Looks like that might be the favourite product. Do you have any indication what the approximate coverage of the tins are, or maybe you just use the small tube ??

Arfa

[Andy Dingley]

500ml tin claims to cover 2.4 m^2 (single side) or 1.4 m^2 if coating both. These cost =A38 retail, =A34 from Focus

[Arfa Daily]

OK, Andy. Thanks for that. When you think about it, that's a bit of an odd way of them putting it, as both faces have to be coated with a contact adhesive, don't they ? Or am I missing something here ... ?

The amount that I've gotta do, that's going to work out mighty expensive. Maybe I should go for one of the 'no-name' 5 litre tins of standard contact adhesive from Toolstation or wherever. About 20 quid, as I recall. Or maybe, I don't coat the whole surface. I guess I could go around the edges of each face, and then paint 'stripes' in opposite directions over the rest. That way, I save 50% of adhesive, and still get a bond point at each 'crossing'. :-)

Arfa