need advice

[scamlee]

hi,
Im trying to mount to 50 inch sheets of clear perspex to the wall but have no idea how to go about it. Does anyone know what would be best to produce a nice clean finish?
Someone mentioned mirror screws but im not sure what size i'd need.

Any help would be much appreciated.

x

 

[Scrit]

What thickness are you trying to mount? Also how tall is it (assuming it is 50in wide)? In sign case making acrylic and polycarbonate sheet is normally held in an aluminium profile, but before the ally profiles became widespread rebated hardwood was commonly used (still used on small jobs), but unless your acrylic is 5mm thick or more you'll be limited to about 30 to 36in in height on the frame - taller than that and the sign might pop out of the frame on a warm day

If you are screwing directly to the wall you'll need to make the holes oversize and use round-head screws with washers beneath to allow for expansion/contraction:

so mirror screw sets with the snap-over washer/cover would work quite well. If you want to use countersunk head screws avoid bugle-shaped heads (e.g. drywall fasteners and self-tappers) as they will propogate cracks. Also don't drill any nearer than about 1in in from the edge if you can help it. Personally I'd avoid them as you can still get cracks propogating from the if the acrylic gets stressed

If the wall isn't flat (and mosty masonry isn't) you'd be well advised to make-up a ladder frame from something like 2 x 1in battening, attaching that to the wall then hanging your acrylic on that

Scrit

 

[scamlee]

Hi,
Thanks so much for replying. Im using two lots of 4mm sheets, 50inch by 50inch, that is gonna have some art work sandwiched in between. All the advice you've given has been so much help!

sam
x

 

[Scrit]

I'm using two lots of 4mm sheets, 50inch by 50inch, that is gonna have some art work sandwiched in between.

Hi Sam

If you haven't already done it I'd suggest dry mounting your artwork onto something like a sheet of hardboard or the like and just using a single layer of acrylic at the front as two layers of acrylic 50 in square will probably belly out in the middle and won't support the art work at all well - it may end up in a crumpled pile at the bottom unless it is adequately supported. If this frame is going into a public area where vandalism or theft can be a problem I'd recommend using polycarbonate sheet rather than acrylic as it is almost unbreakable (although cigarettes will damage it as badly as acrylic), also for public areas you might want to consider screws with Torx or security drive methods, such as Tri-Wing or the like. Both Spax and Reisser do Torx-head screws which can be bought from mail-order outlets such as Screwfix

Scrit

 

[Newbie_Neil]

Hi Sam

Welcome to the forum.

Cheers
Neil

 

[Green]

two sheets of 50"wide 4mm will warp like hell and will not look good.
As Scrit says it would be best if artwork is applied to a good solid substrate and then faced with clear acrylic.
Usual method of fixing acrylic to walls is with alloy 'stand-offs'. I can send you some addresses of good suppliers if you want?

Cheers

Ben (signmaker)

 

[scamlee]

thanks for all the replies - definately raised some goo things to think about. Ben - if you could give me some addresses of suppliers that would be fab.

Unfortuantely i do not have the option of dryfreezing to hardboard - it has to be see through im afraid. Hopefully with enough support around the edges it should bow too much and it only needs to be in place for about four weeks.

cheers guys - much appreciated

sam
x

 

[Green]

Hi Scamlee

Of the top of my head i'd try http://www.fairfielddisplays.co.uk/. They are the UK leaders in this sort of thing.

I think this is the sort of thing you need http://www.fairfielddisplays.co.uk/products.asp?recnumber=166
The pocket stops the image/poster sliding out the bottom. You dont have to buy the fancy supports, a couple of stand-offs . http://www.fairfielddisplays.co.uk/products.asp?recnumber=219 top and bottom would do.