Straightening a warped back - UK Vintage Radio Repair and Restoration Discussion Forum

Ian B · 17th May 2008, 12:34 pm

Hi folks,

I bought a GEC Mains 3 at the NVCF which is now working well (as well as you could expect for a 2 valve set anyway), but the back is very concave and almost touches the speaker magnet! At present I have the back weighted down with large & heavy books on the floor, but 3 days of this don't seem to have made much improvement. Should I try steaming it and then re-pressing? I'm a bit nervous of causing any irreparable damage to such a fragile thing.

Thanks,

Ian Blackbourn

samthelemming · 17th May 2008, 1:12 pm

Perhaps an idea, not sure if it would work, but place greece proof paper over the back and then use an old iron to warm it?
Not sure where you'd go from there but it might be a less risky option than steaming,

Sam

HamishBoxer · 17th May 2008, 1:14 pm

Think it needs to be dampened a bit

Nickthedentist · 17th May 2008, 1:40 pm

Quote:

Originally Posted by HamishBoxer

Think it needs to be dampened a bit

Yes, try leaving it in the bathroom while someone's having a leisurely, steamy bath, then put something heavy on it to press it flat.

Ian B · 19th May 2008, 6:34 pm

Well, I held the offending item over the saucepan in which we were steaming the cabbage one evening. This made it nice and damp feeling. Left it pressed under several bound volumes of Wireless World for a couple of days, and Bingo! - almost completely flat. Let's hope it stays that way.

Nick's idea of the steamy bathroom sounds even better, but we always have showers, and our bathroom doesn't get very steamy - I've never seen the mirror steamed up!

Thanks,

Ian

chipp1968 · 19th May 2008, 7:39 pm

I took a drastic action with a radio back that was badly warped .I have a wood burning stove , the top can boil a kettle . I ran water from the tap over the back sat it on the stove with a weight from a dumbell for a couple of mins , then did it again ,and it was just about perfect with a little scorch mark , so I recon a slightly more gentle option would certainly work ok

Andy Day · 19th May 2008, 8:55 pm

Last time I had this problem I soaked the back in the bath for half an hour, then stuck it on the bench in the shed between two sheets of aluminium with a couple of bricks on top. Didn't stick and came out pretty flat. I then touched the blinges and scratches up with some of my Humbrol enamels mixed to match and was quite happy with the result.

17th May 2008, 12:34 pm	#1
Ian B Hexode Join Date: May 2006 Location: Arlesey, Bedfordshire, UK. Posts: 401	Straightening a warped back Hi folks, I bought a GEC Mains 3 at the NVCF which is now working well (as well as you could expect for a 2 valve set anyway), but the back is very concave and almost touches the speaker magnet! At present I have the back weighted down with large & heavy books on the floor, but 3 days of this don't seem to have made much improvement. Should I try steaming it and then re-pressing? I'm a bit nervous of causing any irreparable damage to such a fragile thing. Thanks, Ian Blackbourn

17th May 2008, 1:12 pm	#2
samthelemming Retired Dormant Member Join Date: Nov 2007 Location: Carmarthenshire, Wales. Posts: 80	Re: Straightening a warped back Perhaps an idea, not sure if it would work, but place greece proof paper over the back and then use an old iron to warm it? Not sure where you'd go from there but it might be a less risky option than steaming, Sam

17th May 2008, 1:14 pm	#3
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,932	Re: Straightening a warped back Think it needs to be dampened a bit

19th May 2008, 6:34 pm	#5
Ian B Hexode Join Date: May 2006 Location: Arlesey, Bedfordshire, UK. Posts: 401	Re: Straightening a warped back Well, I held the offending item over the saucepan in which we were steaming the cabbage one evening. This made it nice and damp feeling. Left it pressed under several bound volumes of Wireless World for a couple of days, and Bingo! - almost completely flat. Let's hope it stays that way. Nick's idea of the steamy bathroom sounds even better, but we always have showers, and our bathroom doesn't get very steamy - I've never seen the mirror steamed up! Thanks, Ian

19th May 2008, 7:39 pm	#6
chipp1968 Rest in Peace Join Date: Jul 2006 Location: Somerset, UK. Posts: 2,356	Re: Straightening a warped back I took a drastic action with a radio back that was badly warped .I have a wood burning stove , the top can boil a kettle . I ran water from the tap over the back sat it on the stove with a weight from a dumbell for a couple of mins , then did it again ,and it was just about perfect with a little scorch mark , so I recon a slightly more gentle option would certainly work ok

19th May 2008, 8:55 pm	#7
Andy Day Pentode Join Date: Aug 2005 Location: Hemel Hempstead, Hertfordshire, UK. Posts: 154	Re: Straightening a warped back Last time I had this problem I soaked the back in the bath for half an hour, then stuck it on the bench in the shed between two sheets of aluminium with a couple of bricks on top. Didn't stick and came out pretty flat. I then touched the blinges and scratches up with some of my Humbrol enamels mixed to match and was quite happy with the result. __________________ The older I get, the faster I was!