Any Professional Painters (Decorators) Out There

May be a l long winded post so please bear with me. I purchased a long time ago (8 years-ish) 2 second hand garage doors (aluminium) They were painted cream at the time. I rubbed them down and painted them to my colour, white, no problem. Changed colour around 4 years ago to Wickes External Oxford Blue (solvent based) again no problem.

Since we now only have one car, one door is never used and you men folk will well know there is NEVER enough room in the garage, I was running out of shelf space. I decided to use the garage door not in use as more shelf space.

Built a 2 x 3” wood frame around the door which left a gap of about 5-6” inbetween the frame & door. I then filled the space with polystyrene sheets then covered the frame in 18 mm mdf (sealed with varnish). Filled in gaps around door in & out so not damp air could get in, perfect.

All was fine for about 1 year or just over then I noticed the paint was staring to peel off on just that one door. I re painted the peeling paint and 6 months later started peeling again.

Now at this point I was beginning to suspect something was happening due to me building and sealing the door from the inside as the other door which I get my car in & out was perfect.

I stared by removing the polystyrene to let more air circulate as I was thinking perhaps the door is getting too hot, no difference. Next I cut in air vents every 9” in the mdf to let air in, again no difference, paint still peeling. Last resort I removed the bottom bit of mdf which was width of garage door and about 2 foot high, surely enough air circulating, no difference.

I have no taken down all the mdf, left the frame and hung shelves off the frame. There is plenty of air getting to the door now but paint still peeling. To be honest the paint peeling might be from before I took down mdf but the process has started.

The paint has come off in varying degrees, some just top coat and other parts down to original cream and in some cases down to the aluminium. Whenever I have rubbed doors down foe painting I always clean off dirt & dust with white spirit and let it dry.

The thing is the other door that has no frame is still perfect so somehow it is linked to me building frame & sealing the door air tight. To be honest I do not know how to proceed to paint again. Do I use the same wickes exterior solvent paint or would any exterior paint be ok.Would a general purpose exterior undercoat be ok. Most important is sealing the aluminium that is showing can I use red oxide or is there a special sealer for aluminium.

Any help or clues as to what would make this one door start to peel once I sealed it or how to proceed with repainting would be a great help. I have uploaded a photo but bear in mind the peeling has got worse over winter as I decided to leave it till this summer to paint. I suppose 6 months to peal to the state it is in.It is mostly bad at the bottom but small peeling near the top.Have not taken photo of other door that was painted the same and perfect.As you can see from picky of inside I now have plenty of air circulating so may do the trick??

Thanks

 

Hi All.
I have put a post in Off - Topic Discussions in the hope a member who is or was a pro painter may have some suggestion for my problems, it is titled as above.
Must admit I rarely go on that particular part of forum so I am hoping a pro (painter) might pick this up
Thanks

 

I think the polystyrene has helped to heat the door and with the whole area sealed the door has 'sweated' and condensation has been forming to make the paint peel. The reason it is continuing to peel is either because there is still damp underneath the surface of the paint or a chain reaction is occurring......when it starts to peel the rest will follow suit.

I think the only cure is to strip the whole door and start again.