Advice on Black foamex signs please?

[Phill Fenton]

Black Foamex will absorb sunlight and heat up which is what causes the buckling. Proper sign trim allows for expansion of the panels which avoids this problem. If using an existing frame you need to make the panels slightly smaller to allow for this expansion. If however you are using an older 90 degree extrusion around a plywood backing then there is no allowance for this expansion hence the problem.
The solution is to engineer in some allowance for expansion when fitting the sign (e.g elongated screw holes or use proper sign trim)

[Kevin Flowers]

Malcom
has Phil said plus if its in a sign frame that it is on a hanging strip

Kev

[Malcolm Elliott]

Thanks guys, my head just couldn’t get round the problem! Makes sense now it’s written down!!

Oh well out with the scaffolding again…..

Malk

[David Rogers]

It will be fine if you can allow for 20mm horizontal expansion and about 5mm vertical in the frame at the size you gave. Any less and it will buckle as there’s no room to more.

It’s for this very reason that I haven’t touched PVC for ANY external signage for the last couple of years…and because it’s just too fragile for potential impacts.

3mm alu-composite costs £10 a sheet more than good coloured foam which is why I can’t understand why people even use it in for this sort of job nowadays

Lesson learnt eh!

[Matty Goodwin]

Hi!

I agree with David.

One question, how did you join the panels?

Matt

[Liam Pattison]

I made a small sign about 1m by 25cm out of black foamex type material and put it in the back of my 4×4 to deliver. It was a really hot day, the sign was leaning from the floor to the back of one of the seats, so it was at a 45% angle. It took me half an hour to get to the location and by that time the sun had come though the back window and totally warped the board.

I would never have believed this until i saw it! But it just showed me how susceptible this material is to warping.

Liam

[Graeme Harrold]

Ask your supplier for the material data sheet and look for the "Coefficient of Linear Expansion" figure, usually stated as m/deg C of change. When calculating you will have to use the surface temp of the panel to gauge who much it will expand.

Personally I would not have used black foamex outside in direct sunlight :lol1:

[Malcolm Elliott]

When I checked the job out I knew it wasn’t in direct sunlight so I thought it would be OK, am away today to check it out, see how bad it is!

thanks for all the replies, appreciated.

Malk

[Martin Cole]

We all live and learn Malc, you won’t do it again no doubt.

White Foamex is ok for exterior signage as long as it’s fitted correctly but coloured is a no go as the colour tends to drain pretty quickly And as David says composite with not a great deal of difference in price is the preferred choice.

I always when doing a fascia use my compass on my i-phone to see which way the shop is facing.

Martin

[John Harding]

Hi Malcolm

Don’t worry you’re not the first, also worth pointing out gloss foam warps less than matt and 10mm thick less than 5mm but to be honest I NEVER spec foam for outdoor as David said composite is not much more cost wise and so much better.

Martin

quote :

I always when doing a fascia use my compass on my i-phone to see which way the shop is facing.

Why? south facing = more light but surely the right material should be used regardless of direction or do you just like looking good with your iphone you poser 😀 😀 😀

[Chris Wool]

martin was not a boy scout then 😀
i heard somebody say hit man for the brownies more like it 😀

[Malcolm Elliott]

Hi all

Just come back and there’s nowt wrong with it!! If you stand underneath and look up then it slightly bows out but nothing drastic and it certainly wouldn’t come down.

Customer is fine with it now but you know when you doubt yourself…..

cheers
Malk

[David Rogers]

quote Malcolm Elliott:

Hi all

Just come back and there’s nowt wrong with it!! If you stand underneath and look up then it slightly bows out but nothing drastic and it certainly wouldn’t come down.

Customer is fine with it now but you know when you doubt yourself…..

cheers
Malk

No hanging rail then – just slipped into the frame? Will just be sagging under its own weight…

For PVC hangers – Gluing a 10mm strip of the same PVC to the sheet with superglue (bonds amazingly well) works a treat.

[Malcolm Elliott]

quote David Rogers:

quote Malcolm Elliott:

Hi all

Just come back and there’s nowt wrong with it!! If you stand underneath and look up then it slightly bows out but nothing drastic and it certainly wouldn’t come down.

Customer is fine with it now but you know when you doubt yourself…..

cheers
Malk

No hanging rail then – just slipped into the frame? Will just be sagging under its own weight…

For PVC hangers – Gluing a 10mm strip of the same PVC to the sheet with superglue (bonds amazingly well) works a treat.

Yep, just slid into frame already there. Glued a strip top to bottom to keep the centre in place, looks OK.

[Warren Beard]

quote David Rogers:

quote Malcolm Elliott:

Hi all

Just come back and there’s nowt wrong with it!! If you stand underneath and look up then it slightly bows out but nothing drastic and it certainly wouldn’t come down.

Customer is fine with it now but you know when you doubt yourself…..

cheers
Malk

No hanging rail then – just slipped into the frame? Will just be sagging under its own weight…

For PVC hangers – Gluing a 10mm strip of the same PVC to the sheet with superglue (bonds amazingly well) works a treat.

I use plumbers "pipe weld" haven’t tried anything else but comes in a tub with a brush in it for spreading, once bonded you will never separate as it melts it together.

The panels will slowly sag more and more so I would expect another call soon, be careful the panels are not too small and if sag enough will slip out the top of the frame, usually the panels are cut smaller, maybe 15mm off each edge to fit inside, then when inserted they sit flush at the bottom now making the top short by 30mm (if you understand that 😕 )

Just a thought as I have replaced a few that were on the verge of slipping out.

Cheers

Warren

[Tim Painter]

Malcolm how ever good it looks to you at the moment it won’t last.

The larger the sheet the great the expansion, Foam PVC (especially black)really isn’t the material to use for such a job.

Even composite in black installed incorrectly could give issues.

I would swap for composite panel and use a hanging strip. With a hanging strip correctly fitted the panel is suspended and can expand.top to bottom and left to right.

It also needs a frame with a large enough front face dimension.

Even if it’s not in direct sunlight it will absorb heat.

[Glenn Sharp]

Malcolm,

The other option would be to use 5 mm acrylic with a rebated join…use tensol or fusion to glue the hanging strip on and just so long as you have got your sizes right you shouldn’t have any problems at all

[Tim Painter]

Malcolm This link may be of help re frames

http://www.pako.si/sl/pokazi.asp?id=294

[Martin Cole]

quote John Harding:

Martin

quote :

I always when doing a fascia use my compass on my i-phone to see which way the shop is facing.

Why? south facing = more light but surely the right material should be used regardless of direction or do you just like looking good with your iphone you poser 😀 😀 😀

Correct…BUT…If south facing and the fascia is printed or part printed, it will not last as long and would advise against heavy yellow, even with a good UV laminate this I would advise the customer to cover myself also I use a lot more brushed ally composite these days for exterior signage.

I did some for a golf course, near their entrance doors which were south facing, fitted early morning I went to take a photo a couple of hours later and they had virtually turned into mirrors with the sun reflecting off them 😎 Also black composite can react to the sun, if not quite right as Tim mentioned.

hence I use my compass to determine which way the building is facing :tongue: so there :D.

I used to use the compass in the sole of my pathfinder shoes until I got my phone…you would have to be my age to remember the days when you got a compass in your school shoes 🙁

[Robert Lambie]

sorry if I’m covering whats already been said, just skim read through the last few pages…

I HATE FOAMEX of any description. we "have" used it in the past, and been stung to the tune of well over £40k as a result of false claims "in writing" from a large supplier that has since went bust.

Do not get me wrong, foamex has its uses, many many actually. but my view is it should be used for cheap "short term" or interior signage. YES, it can and does regularly get used outside on walls, shop fronts, you name it… but still…

Composite Board
Comes in many finishes and sizes.
from lightweight hoarding board type, to the higher end Rynabond and Dibond types…
is lightweight and easily cut, shaped.
come in many finishes and colours.
does not warp and buckle.
Is UV resistant for many years.
Printed or Cut vinyl graphics adhere excellent to composite board. which in turn, helps promote the life of the vinyl.

Foamex
will Buckle & Swell if not fitted correct.
Not UV resistant for any great length of time, i.e. will fade in the sun quickly
it will quickly become brittle
easily shatter/break if hit by some form of solid object.
holds dirt & grime in its porous face.
Cannot be easily cleaned "long term" due its face texture.
does not promote long term adhesion of vinyl, unless in "gloss form"
is not great for joining due to constant movement with varying daily heat temperatures.

There is very little in difference in cost 8×4 of Branded Foamex PVC in comparison to a Composite Board at the same size.
I simply do not offer foamex as an option for signage unless specifically asked for. even then i try persuade the customer to use Composite.

At the end of the day mate… you nearly found out the hard way, and that is your customer wanting it fixed at your expense.

Good to hear you got the problem resolved anyway Malcolm.

.

[Malcolm Elliott]

Appreciate all the advice, being someone who is used to just supplying the signs and not fitting them I was always destined to make mistakes so thanks to those who took the time to actually explain my mistakes and what I can do to sort them.

cheers
Malk

PS Rob what the hell are you doing up at 1.23am on a Thursday!!

[Phill Fenton]

I feel some one needs to defend Foamex as it’s got some good qualities too.

1/ Its soft texture means it is easy to cut just using hand tools
2/ Vinyl can be easily applied bubble free
3/ Minor bits of fluff or grit trapped under the vinyl can be hidden and "pressed" into the surface of the material which is not possible using composite boards or gloss plastics.
4/ Matt finish can be preferable on many occasions and avoids glare
5/ Gloss versions are UV resistant and look every bit as good as acrylic but at a much lower price
6/ Its light weight makes it easy to handle and install
7/ Available in 5mm thickness which makes it suitable for the vast majority of aluminium extrusions used for framing. When used this way the signs can be fitted with no visible fixings showing and any problems caused by expansion and contraction are alleviated

[Stephen Morriss]

I used to use foamex on some exterior signs but they always end up looking a bit naf after a while, I tend to use Acrylic or composite.

The self coloured foamex has very little UV resistance so looks faded after a year or so.

Steve

[Ezekiel Ikhinmiwn]

fomex or composite wow … that was a fair bit to take in.. I guess all materials have a use one way or another. Thanks all for the info

Eze

[Robert Lambie]

quote Malcolm Elliott:

PS Rob what the hell are you doing up at 1.23am on a Thursday!!

:lol1: :lol1: Malcom… I am online Sunday to Thursday most nights till around 2-3am mate. been that way nearly 10 years now. 😕 :lol1:

Phill, The job i did some years back now, was Bright Red Gloss Foamex.
In fairness, this was "Years ago" and i am sure products have become much more UV stable these days, but still… We were at the start of a national rebrand.
when Pricing the job we were offered a NEW Gloss foamex as an alternative to acrylic and given "in writing", it had a minimum of 5 year life. we did about 25 depots dotted around the UK and still had about another 30 to do when i drove by the Glasgow branch about 8 weeks later and to my horror it was no longer bright red, but bubble gum pink!
this was NOT a fascia board, it was just a router cut "logo" on part of a large fascia. so the whole warping scenario was not an issue here, just the colour fade.

[Peter Normington]

I just went to get a half sheet of hoarding board from my shed, it was liying long ways on edge, it has warped! by warped I mean a very noticable curve from top to bottom,
Anybody else had this. not seen it with dibond etc, just the hoarding compo..
but could an issue if just placing in an extruded frame.

Peter

[Chris Wool]

gave up with hording board to weak i use the intermediate stuff

[Mike Grant]

Hoarding board is a wee bit thinner and lighter and like any soft material should not be stored at an angle especially if you lean other board against it, time and pressure will take its toll.
I only use foam PVC for internal jobs.

[Robert Lambie]

Hoarding board is the cheapest composite board you can buy.
it only comes in white with a silver finish on rear. its basically for cheap signage. however, i would still use this over foamex any day and regularly do.
it shouldn’t be used as an alternative to the higher quality brands of composite, its cheap for a reason.

Peter sheet material of any description should only be stored upright on its end in a rack or flat out on a level surface. particulalrly if other smaller sheets or anything is leaned against them.

if you have left it any particular time to allow a bow to form, in a shed which would get very warm then cold in the days we have experienced recently, it is going to have some sort of effect on your sheet.
at only 2ft deep over an 8ft length, ide imagine you must have had other things leaning against it to create the bow?