What adhesive for acrylic mirror?

[Chris Green]

I want to stick an acrylic mirror (quite tall and thin, 2m x 30cm 'ish) to a wall which is a sheet of MDF so nice and flat.

The 'recommended' adhesive is 'mirror mate' but this is gun applied, not easy to get smooth and not easy on such a large area.

Can anyone recommend a contact adhesive for this, preferably a spray one, or something else that would be suitable.

The problem with searching for 'adhesive for acrylic mirror' is that most of the hits are for adhesives which will bond/weld acrylic and I suspect they will damage the mirror.

[Martin Brown]

Masking tape around the edges to get neat lines?

Your problem is that anything that grips too strongly will pull the mirror surface off the back of the acrylic as thermal expansion flexes the bonded joint. Plastics expand a lot more than wood or bricks.

You want a relatively soft cure flexible adhesive and definitely not one that gives off acetic acid as it cures since that will also harm the aluminised mirror surface. You could probably make it stay put with four suitably sized blobs of adhesive at the corners and one in the middle.

It would just need supporting until the glue cured. That may be true however you choose to do it since wet glues make good lubricants.

[Jeff Layman]

I've no idea if it is suitable or not but something like double-sided sellotape might do the job without any possibly damaging solvents. Because acrylic mirrors are light, you would only need to space the sticky tape evenly; I'm sure it wouldn't be needed to cover all the mirror.

I think the main problem would be that you would have to get the positioning right first time!

[The Natural Philosopher]

In general the mirror glue is good and you don?t spread it everywhere - in this case I would proceed as follows.

First of all screw a batten to the MDF dead horizontal. This will support the mirror while the glue sets.Yes you will have fill the holes sand, and redecorate, but its the simplest way to do this.

Then use the gun to apply dobs of glue to the mirror - not too close to the edge - and not to big either. If its only acrylic its gonna be dead light - so not much stick required.

Then position the mirror on the batten against the wall and press all over with something like a towel to avoid scratching it until it won't squish any more. With luck there won't be any glue squidging out - if there is scrape it off carefully. I think the glue I used was water soluble until set so a wet sponge got the excess off.

Then LEAVE it at least 24 hours, glue behind a mirror doesn't dry quickly, although it its bare MDF it will absorb water.

Remove the batten sand down the holes fill with lightweight filler and if you are concerned about micro gaps at the mirror edges put lightweight filler in the cracks as well - or decorators caulk. Use that wet sponge to get a decent result without having to sand..

That should do the job. I'd mask up the mirror and paint the whole area again. I have a rule that whenever I do ANYTHING to a plasterboard wall I fill, sand and lick of paint over it. In my case sample tins of F & B emulsion are a fiver a time and that's not a bad price to pay for a perfect finish

[Chris Green]

Thanks, all very useful, the batten may be a bit difficult as the mirror runs down close to the floor of a wet room but I expect I can rig something.

[Brian Gaff (Sofa]

I never had any luck with plastic mirrors, they either separated where it was glued, or went a bronze colour at those points or slid down the wall or cupboard. Of course I have no need of any mirrors now, but in the end the only thing that worked were the good old corner brackets that you tend to use for glass, except they do not have to be quite as solid for a plastic mirror of course. Brian