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 24th Feb 2022, 8:12 pm   #1
Heyhey!
Diode
 
Join Date: Feb 2022
Location: Neston, Cheshire, UK.
Posts: 2
Question Plastic case & housing repair ideas?

Forgive me if this is the wrong place, but it felt the most suitable..

I picked up a very well worn Trinitron TV, some scratches on the tube but nothing mind blowing given its age. What I hadn't realised until after the fact, is that somebody has done a bodge repair on one side of the TV housing with what looks like the smallest amount of superglue I've seen!

It 'clips' back in somewhat once it's sat down and stationary, so all is not lost, but I'd prefer to have a more permeant solution given the voltage risks etc. I'm assuming the inner guides for the screws are cracked/missing given they've filled the entry holds to them with superglue also.

Only other thing of note is if pressure is applied to the top of the TV the colour can disappear, but returns once pressure is removed.

It's a heavy 20"+ unit, so the risk of forgetting about the case and shifting it one day can't really be ignored. Aside from that it's good, I want to preserve it, but at the same time I don't want anyone hurt either!

I can't lie I wish it had been made out of wood!
Heyhey! is offline  
Old 25th Feb 2022, 9:29 am   #2
FrankB
Heptode
 
Join Date: Oct 2005
Location: Olympia, Washington, USA.
Posts: 663
Default Re: Plastic case & housing repair ideas?

Since you didn't mention the type of cabinet, I will assume the case is plastic.
I have had excellent success in repairing broken out screw holes with 2 part epoxy.
Use coarse sand paper to roughen up the area and use a 2 part epoxy to repair it. I have found that the "stick" you knead works pretty good and does not "flow" like the liquids do.
If you can, coat the correct screw with grease and thread it into the epoxy. It wont stick to the screw and you avoid having to drill & tap a new hole. Works for me on Bakelite too. Silicone grease may also work, to coat the screw, but I have not tried that.
For repairing the cabinet cracks, I like the 2 part thick liquid.
Scruff up the inside of the cabinet where the crack is with like 80 grit sandpaper & clean it with denatured alcohol. (Acetone may discolor the cabinet)
Place the cabinet so the cracked side is down. Put on a layer of the 2 part liquid epoxy and let it set for a minute or two. then use a small piece of metal mesh screen door cloth over the cracked area as reinforcement, and add another layer of epoxy over that.

All that being said, don't use the "5 minute epoxy" Use the longer drying type and typically it will set in 24 hours. I did find a much better job will result if you wait 2 days or more for it to really cure up.

I am unaware of the brands of epoxy you have in the UK so I can't really recommend any specific one. Here I generally get mine at the car parts place or a "big box" hardware store. You might want to practice a bit before using the 2 part you must "knead" together stick type. I have tried several brands, and they all seem to act a bit different as to the time to fully set, and some have different characteristics.
Do stay away from the "liquid steel" type products or "liquid solder" ones. I never had any good luck with them.
FrankB is offline  
Old 25th Feb 2022, 2:36 pm   #3
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
Default Re: Plastic case & housing repair ideas?

If the case is a plastic like ABS or polystyrene, cracks can be mended using a suitable solvent such as methylene chloride, which can be obtained in small bottles from shops that sell plastic model kits or model railways under the name Plasweld. It is thin and rather volatile, and when applied to a crack with an artist's paint brush, will wick into the crack where it will dissolve the adjacent plastic surfaces and weld them firmly together. Where possible I apply reinforcement over the crack on the non-visible side using strips of styrene sheet that you can get from model shops, applying as many layers as seems appropriate. The Plasweld turns them all into a solid mass. But not all plastics can be solvent-welded.

Last edited by emeritus; 25th Feb 2022 at 2:38 pm. Reason: typos
emeritus is offline  
Old 25th Feb 2022, 7:12 pm   #4
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Plastic case & housing repair ideas?

In times-past places like Halfords used to sell 'plastic weld' glue designed to repair cracked car-bumpers.

Alternatively, I have used the brown version of Gorilla Glue to bond fine stainless-steel mesh [a kitchen strainer whose handle had snapped-off!] across cracks around the antenna-mount on the plastic cases of cheap-and-cheerful Motorola PMR446 walkie-talkies with great success.
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline  
Old 26th Feb 2022, 12:15 am   #5
Silicon
Nonode
 
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,152
Default Re: Plastic case & housing repair ideas?

Is it possible that the cabinet is made from polypropylene?

If so you probably won't be able to glue it.
Silicon is offline  
Old 26th Feb 2022, 6:18 am   #6
Heyhey!
Diode
 
Join Date: Feb 2022
Location: Neston, Cheshire, UK.
Posts: 2
Default Re: Plastic case & housing repair ideas?

Thanks for your replies all!

Yes, sadly it is your classic Sony black plastic I should have said.

If I end up having the nerve to sort it out, I'm concerned what screws to use too given their proximity to the larger side of the tube. I'm terrified of tubes as most hopefully are !

Actually wondering if it's worth me looking for someone on the NW of England to give me a hand, could possibly refurb the chassis that way too.

As a less secure fix the gorilla glue sounds like an option around the whole outside of the seal without screws. I'm conscious of not using something that actually melts/welds the surfaces together.

If it was anything else I'd go for it, but as I say, terrified of tubes! Most around here may laugh at me for it but it's a healthy respect in my mind,
Heyhey! is offline  
Old 27th Feb 2022, 10:49 am   #7
mark_in_manc
Octode
 
Join Date: Nov 2011
Location: Manchester, UK.
Posts: 1,872
Default Re: Plastic case & housing repair ideas?

We use methacrylate 2-part glues at work. They are expensive, and very, very strong. The brand we use is 'Plexus', which is available in small tubes on ebay. I don't like to splash out, but having used this stuff, I would give it a go in this instance. I have found online reports that it works with unusual plastics like polypropylene.

The glue is gap-filling and 'stodgy', and does not flow. It would work best to glue a patch on the back. One time I used some to glue a brick to an aluminium plate for work (!), and the only way to get it off was to slice the brick into thin slices on a brick saw, chip the slivers off with a bolster, and grind the remainder off the plate with an angle grinder and belt linisher. It's good stuff!
__________________
"The best dBs, come in 3s" - Woody Brown
mark_in_manc is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:07 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.