UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Cabinet and Chassis Restoration and Refinishing

Notices

Cabinet and Chassis Restoration and Refinishing For help with cabinet or chassis restoration (non-electrical), please leave a message here.

Closed Thread
 
Thread Tools
Old 26th Dec 2018, 1:00 pm   #1
stevekendal
Heptode
 
stevekendal's Avatar
 
Join Date: Mar 2004
Location: Kendal, Cumbria, UK.
Posts: 623
Default Plastic cabinet (drastic) repair

Santa sent me a nice red plastic Murphy U572, but failed to pack it adequately before sending via courier. The right hand side is a bit of a jigsaw, but I will make it look half decent eventually. Your suggestions please re glues and filling etc? Its a fragile piece to start with.
__________________
Knobs and tubes rule ok
stevekendal is offline  
Old 26th Dec 2018, 1:44 pm   #2
Boater Sam
Banned
 
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
Default Re: Plastic cabinet (drastic) repair

Edge stick it all together getting the best close fit for every piece with good quality superglue.
Brace it inside with plastic or thin wood and epoxy resin.
Let it set for 2 days then rub it down with fine wet and dry with superglue sparingly in the cracks so the dust fills them up. Polish to finish
I usually achieve an almost invisible repair this way but if all else fails its a paint job.
Boater Sam is offline  
Old 26th Dec 2018, 2:08 pm   #3
Guest
Guest
 
Posts: n/a
Default Re: Plastic cabinet (drastic) repair

If it is made of polystyrene or similar I would go with a solvent weld type of glue, available from model shops. It leaves the plastic the same, no differing material in the joints.
 
Old 26th Dec 2018, 2:28 pm   #4
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,738
Default Re: Plastic cabinet (drastic) repair

According to the article at the link below, the cabinet isn't plastic - it's brown Bakelite sprayed red, later also available in beige. If that is indeed so, an invisible repair is much easier as the whole cabinet once repairs, can be primed with high build primer, then resprayed the desired colour of red. There's such a wide variety of shades of red auto aerosols that an exact match should be achievable.

It will have been well towards the end of the valve radio era, having a printed circuit board:

http://www.classicwireless.co.uk/Murphy_U572.htm

Good luck with it.
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 26th Dec 2018, 3:30 pm   #5
stevekendal
Heptode
 
stevekendal's Avatar
 
Join Date: Mar 2004
Location: Kendal, Cumbria, UK.
Posts: 623
Default Re: Plastic cabinet (drastic) repair

It isn't bakelite, its red plastic and is reponding well to poly cement. Like making an Airfix kit really. Will just need strengthening later.
__________________
Knobs and tubes rule ok
stevekendal is offline  
Old 26th Dec 2018, 3:45 pm   #6
Guest
Guest
 
Posts: n/a
Default Re: Plastic cabinet (drastic) repair

It looks thin enough to be polystyrene or a close relative, when gluing with poly cement (it can be had in very usable dispenser types, better than tubes) ignore the bits squeezed out of the joints for at least a week, then rub down and polish. You can hand assemble the bits one by one, leaving a few minutes twixt operations, the glue remains slightly flexible for a while allowing one to do the whole job bit by bit and leaving a twiddle factor for final alignment. Practice on a broken CD case or the like. The "solvent only" glues are not very good for this job.

Last edited by Guest; 26th Dec 2018 at 3:45 pm. Reason: clarification of bits squeezed out
 
Old 26th Dec 2018, 5:47 pm   #7
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Plastic cabinet (drastic) repair

When I've had to rebuild [small] things made out of this sort of material I've drilled 1.5mm holes into the edges of the broken parts and used Superglue to embed short hard stainless-steel pins into one edge, then - with matching holes in the other edge - Superglued the two faces together. The pins provide the real mechanical fix and stop the join from parting when faced with temperature-cycling.

#1 advice - leave it for a week after glueing. Superglue may seem 'hard' after half an hour but it gets a lot better after a few days!
G6Tanuki is offline  
Old 26th Dec 2018, 8:01 pm   #8
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,191
Default Re: Plastic cabinet (drastic) repair

If you can find a solvent for the plastic (dichloromethane, sold as 'plastic weld' is a good one to try first) then what I do is :

Put the pieces together

Run a brush dipped in the solvent along each of the cracks. The solvent is drawn in by capillary action and will cause the plastic to weld along the cracks. DO NOT push the pieces together hard when doing this you do not want to squeeze out the softened plastic. Use a natural bristle brush, some of the synthetic bristles disolve in said solvent with unpleasant results.

Now take a piece of cotton fabic and cut it to cover the back of the repair area. An old cotton dress shirt will be fine, or a good sewing shop will have something (maybe an offcut, which iwll be cheap). Put that over the back of the repair area and 'paint' it with the solvent. When the plastic has softened, force the fabric into the softened area.
TonyDuell is online now  
Old 27th Dec 2018, 1:50 pm   #9
valveaudio
Hexode
 
Join Date: Feb 2006
Location: Diss, Norfolk, UK.
Posts: 386
Default Re: Plastic cabinet (drastic) repair

For adhesive try PLASTI-ZAP This is the best I have ever used.

Trevor
valveaudio is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 4:25 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.