Model Railway Forum

Firstly, I have contacted the supplier of these backscenes and not received a reply. I contacted him again on another email address asking if he did internet shopping during lockdown and got a reply very quickly so clearly he is about and has presumably decided to ignore my initial query.

This is the problem. I purchased some Premium backscenes from art-printers and carefully read the instructions before applying them. They are printed on "very tough polypropylene film" and Foamex was recommended as a mounting board and it was stated that MDF and chipboard should not be used unless glossed or varnished. I chose to use 6mm beech faced plywood that I primed and glossed. The backscene was applied with the board flat on the floor and it went very well. No blisters at all. This was about 6 months ago and I used the self-adhesive backing. Everything went well and I was very happy with the result. I was then distracted from modelling for about 6 months and on my return to the loft the backscenes had blistered, some very badly. See attached photos.








Interestingly one sheet has blistered much worse than the other despite conditions being identical when they were applied. Does anyone have any idea what has gone wrong or have any suggestions as to how to remedy it or prevent it happening again? At the moment I'm tempted to tear it all off and use blue and green emulsion but I have no artistic talent at all so that is not likely to be successful.

Does your loft get very hot and cold?

It does look like temperature variation has caused localised expansion and contraction resulting in the wrinkles. After 6 months or so I think you will be unlikely to get any recompense, I would have expected a response though. You might find it difficult to remove them now from the boards if the material is self-adhesive.

If you want to have another go I can recommend Gaugescenes back scenes applied with doubled sided 3M tape. I put it along the top edge and any vertical edges and let the back scene mounting board attachment to the baseboard hold the lower edge in place. Not a wrinkle in sight. My backboards are very thin [3mm I think] ply.

R-

My backscenes in the loft used to get wrinkly then flatten out depending on the temperature extremes. That was mounted on ply.

Probably why they recommended Fomex as it a stable product unlikely to be affected by heat unlike timber.

I used a self-adhesive Premium range backscene - and I have air-bubbles. Mine are mounted on birch ply and screwed to the wall in the spare bedroom where my layout is. The boards were primed with several coats of diluted PVA before the backscenes were fitted. Obviously being in the house, the temperature fluctuation is normal, as in any house. I got rid of some of the bubbles by pricking them with a pin and then carefully smoothing the backscene down with a cloth. Probably now two years on the bubbles/creases are still there. I may change them at some time. They were fitted as per the instructions. BB

Thanks for your responses, very helpful,the temperature certainly varies a lot. Looks like the whole lot is going to have to come down and I'll start again. I'll have a look at gauge scenes, possibly buy one to try.

Try to fix them to something that isn’t affected by temperature fluctuations if it is in the loft.

Walking the dog.

I take your point but the backscenes were flat in the cold and now blistered in the heat. Therefore the plastic has expanded relative to the back board (plywood). I wonder what would have happened if I'd mounted them in the heat, would they have stretched in the cold or pulled in from the edges? Also, it's odd that one sheet has blistered a whole lot worse then the other. I've not heard back from the supplier and to be honest I've pretty much lost faith in the product. Having been a professional decorator for 17 years I do know how to get paper installed flat and once flat it should stay that way, not have to be kept in a controlled environment to suit the product. I'm going to try and peel the plastic off the backing, perhaps I'll be able to apply another product without having to replace the backing board?

I would have thought that the bubbles would be the result of trapped air expanding in the heat. Using a porous backing, notwithstanding the paint treatment, will still allow gases within the timber to get under the backscene.
The manufacturer recommends foamboard, I think, so it’s unreasonable to expect a different material to behave itself.

Thank you Steve, very valid points, but if foamboard is the only suitable back board why didn't the supplier simply say so? Also, can you please explain why one sheet has blistered much worse then it's neighbour? They were both adhered to the same piece of ply!

I do have one good thing to say about the premium backscene however, the plastic sheet is stronger than the adhesive so simply peeling off the backscene is a viable option, now I have to find out if it has left any residue that will cause me problems when I try again with a simple paper backscene and avoid exotics in future.