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 > Hints, Tips and Solutions (Do NOT post requests for help here)

Notices

Hints, Tips and Solutions (Do NOT post requests for help here) If you have any useful general hints and tips for vintage technology repair and restoration, please share them here. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

Closed Thread
 
Thread Tools
Old 20th Mar 2021, 11:18 am   #1
vinrads
Dekatron
 
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,737
Default Rusted in grub screw.

I had two small knobs both with rusted in grub screws, I filled the hole that the shaft fits into with wd 40 left it for an hour or so ,applied heat to the screw with my soldering iron tip , inserted a good fitting screw driver, managed to to turn it a little then with a rocking motion whilst giving it a squirt of wd got it free, this worked well on both knobs , Mick.
vinrads is online now  
Old 20th Mar 2021, 1:12 pm   #2
Julesomega
Nonode
 
Julesomega's Avatar
 
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 2,085
Default Re: Rusted in grub screw.

I rely on penetrating oil for almost every mechanical job: must be about a decade since it inexplicably disappeared from the hardware shops and market stalls, but I found it is now exclusively sold online as Omega 636.
For jobs like grub screws, a squirt is far too much so I pick up a minute drop with fine tweezers
Attached Thumbnails
Click image for larger version

Name:	Omega 636.jpg
Views:	338
Size:	62.5 KB
ID:	229649  
__________________
- Julian

It's good here
Julesomega is offline  
Old 20th Mar 2021, 2:32 pm   #3
Guest
Guest
 
Posts: n/a
Default Re: Rusted in grub screw.

After a bit of soaking I use a left hand drill bit, worst case it drills out the screw, best case it jams and unscrews it.
 
Old 20th Mar 2021, 4:48 pm   #4
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
Default Re: Rusted in grub screw.

Petrol lighter fluid is almost as good as penetrating oils like Plus Gas and easier to buy.
emeritus is offline  
Old 22nd Mar 2021, 5:39 pm   #5
Mike Phelan
Dekatron
 
Mike Phelan's Avatar
 
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
Posts: 4,609
Default Re: Rusted in grub screw.

A mixture of diesel fuel and white spirit is what I use.
__________________
Mike.
Mike Phelan is offline  
Old 22nd Mar 2021, 10:08 pm   #6
DonaldStott
Octode
 
DonaldStott's Avatar
 
Join Date: Aug 2015
Location: Glasgow, UK.
Posts: 1,840
Default Re: Rusted in grub screw.

Thanks to this Forum I am now a convert to PlusGas for any job of this kind.
__________________
BVWS Member
DonaldStott is offline  
Old 23rd Mar 2021, 2:30 pm   #7
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
Default Re: Rusted in grub screw.

PlusGas has been my 'go-to' for the last 45 years - the biggest problem I find with it is the tendency of the solvent-component to evaporate from the can whilst in storage. I never seem to use-up a can of the stuff, it escapes into the wild when my back is turned.

The heated-screwdriver-tip is another technique worth remembering: I've got a couple of old screwdrivers here whose tips I'm happy to heat until red-hot in order to put some heat into a tight grubscrew.
G6Tanuki is offline  
Old 24th Mar 2021, 9:20 pm   #8
Bazz4CQJ
Dekatron
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,923
Default Re: Rusted in grub screw.

Hee Hee - Our periodic "let's bash" WD40" thread . The reality is that the best releasing agent is time-dependent. If you only have 10 minutes, product A is best, but if you have 3 days, product B is best. I find my hand goes to the WD40 can, but there are always quite a few alternatives on the same shelf.

B
__________________
Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.
Bazz4CQJ is offline  
Old 28th Mar 2021, 7:56 am   #9
Mark1960
Octode
 
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
Posts: 1,264
Default Re: Rusted in grub screw.

WD40 is great as a water dispersant, but plus gas is better for penetrating rust.

Did it really take 40 attempts to come up with the best formulation?
Mark1960 is online now  
Old 28th Mar 2021, 10:06 am   #10
David G4EBT
Dekatron
 
David G4EBT's Avatar
 
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
Default Re: Rusted in grub screw.

The main shortcoming of WD40 as a release agent is that as a water dispersant (it's original purpose) it has high surface tension - the opposite of what is needed for freeing stuck screws and nuts, which is capillary action to penetrate. WD40 (the company), have tacitly accepted that whilst WD40 has for decades been seen as a 'toolkit in a can' for everything from stuck screws to oiling hinges - even for arthritic knees, it doesn't do most of the tasks for which it's pressed into service all that well. That's why they introduced their 'Specialist' range of nine products, one of which is their 'Fast Release Penetrant Spray', about which WD40 says:

Quote:

Our Specialist Fast Release Penetrant spray specifically targets corroded or rusted components and mechanisms. It’s [sic] formula loosens stuck or seized parts quickly and easily. The penetrant has an extremely low surface tension, meaning it can cut through rust, seams and tightly-bonded threads to easily saturate and lubricate seized fixings. The Smart Straw and 360° valve allows it to be used precisely at all angles, and the capillary action of the formula means it can reach tight and hard to reach spaces. Highly water resistant, Fast Release Penetrant can also displace moisture that may be disrupting smooth movement and can be used as a preventative to prohibit the build-up of rust and corrosion in the future. Use in temperatures ranging from -20°C to +90°C, on materials such as metal, rubber, plastics, alloys and most paints.

End quote.

If they had a proof-reader to check the above text, they overlooked the 'Grocers' Apostrophe on the first line 'It's formula'. (There's a lot of it about!).

https://www.google.com/search?q=groc...iSi3xN67hTNkZM

The Specialist range of WD40 products (as well as their Motorbike and Bike Ranges), can be found on their website, here:

https://wd40.co.uk/products/wd-40-specialist/

I guess most of us use WD40 for all sorts of things, myself included - removing labels, degreasing, oiling locks, whatever. About the only thing I don't use it for is freeing stuck grub screws or anything else to do with radio restoration. Why would I want to use WD40 on grub screws when a can of Plus Gas lasts for a decade or more?

For those who prefer WD40 products, their Specialist 'Fast Release Penetrant' is widely available and not all that expensive. EG:

https://www.toolstation.com/wd-40-sp...waAsrUEALw_wcB

https://www.screwfix.com/p/wd-40-pen...B&gclsrc=aw.ds

Pic 1) Why not? It gets used for everything else!
Pic 2) Engineering Flow Chart.
Pic 3) I even use a can as a radio!
Attached Thumbnails
Click image for larger version

Name:	Suez Canal Job.jpg
Views:	241
Size:	62.6 KB
ID:	230343   Click image for larger version

Name:	Engineers flow chart WD40.jpg
Views:	306
Size:	71.9 KB
ID:	230344   Click image for larger version

Name:	WD40 Novelty Radio2.jpg
Views:	220
Size:	166.4 KB
ID:	230345  
__________________
David.
BVWS Member.
G-QRP Club member 1339.
David G4EBT is offline  
Old 28th Mar 2021, 1:17 pm   #11
Guest
Guest
 
Posts: n/a
Default Re: Rusted in grub screw.

I want one of the radios!
 
Old 29th Mar 2021, 4:52 pm   #12
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: Rusted in grub screw.

I respectfully disagree with David's flowchart, and offer this alternative.

Click image for larger version

Name:	flowchart.jpg
Views:	337
Size:	46.5 KB
ID:	230444
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 29th Mar 2021, 4:58 pm   #13
vinrads
Dekatron
 
Join Date: Feb 2009
Location: Chesterfield, Derbyshire, UK.
Posts: 3,737
Default Re: Rusted in grub screw.

All I can say it worked for me the wd oil turned a dark brown after a while ,and it helped to loosen the screw, Mick.
vinrads is online now  
Old 18th Apr 2021, 10:45 pm   #14
Oldcodger
Nonode
 
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
Default Re: Rusted in grub screw.

I once heard of a penetrating solution based on paraffin with graphite grease dissolved in it.
If the screw is really stuck then perhaps it's time to look at a more extreme engineer solution- helicoil. Drill the screw out, re tap and fit.
As for #12, I tend to use blue locktite.(you never know when you need to get that screw undone)
Oldcodger is offline  
Old 19th Apr 2021, 4:21 pm   #15
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Rusted in grub screw.

Blue loctite also tends to inhibit future rusting.
The Philpott is offline  
Old 21st Apr 2021, 2:14 pm   #16
telstar
Octode
 
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,588
Default Re: Rusted in grub screw.

I once heard of someone using a hot soldering iron to heat the rusted grub screw (Bakelite radio knobs only, of course).
Maybe this could work?
Mike
telstar is offline  
Old 21st Apr 2021, 5:13 pm   #17
The Philpott
Dekatron
 
The Philpott's Avatar
 
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
Default Re: Rusted in grub screw.

Most certainly heat works where other methods fail, (although with the example of a steel screw going into timber..it works by carbonising the wood!)
Dave
The Philpott is offline  
Old 3rd May 2021, 8:08 am   #18
G.Castle
Heptode
 
Join Date: Dec 2020
Location: Swaffham, Norfolk, UK.
Posts: 582
Default Re: Rusted in grub screw.

Hi.
My "go to" now is Loctite "Freeze and Release" not sure about the freeze part but an excellent penetrant and safe on plastics.

I prefer Duck Oil for lubrication and protection as it's wax based and doesn't evaporate away completely.
G.Castle is offline  
Old 3rd May 2021, 11:25 am   #19
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
Default Re: Rusted in grub screw.

Heating or cooling will work best where two different metals are involved, making use of their different thermal expansion coefficients (TEC). The approx. TECs for brass and steel are 18-19 and 11-13 respectively. So for a steel screw in a brass bush, heating will enlarge the hole on the bush by more than the increase in diameter of the steel screw, making the fit looser. Conversely, for a brass screw in a steel bush, cooling in a freezer would be required, as applying heat would make the brass screw expand more than the bore in the bush, making it tighter. In the latter case, or where screw and bush are of the same type of metal, if corrosion is present, there might be an advantage in heating due to differential expansion of the corrosion products loosening them, but it would be necessary to cool it down before trying to unscrew. Differential expansion will be much greater when one of the items is aluminium (TEC = 21-24). Replacing a cracked alloy piston in my car involved heating to about 140°C in an oil bath, whereupon the steel gudgeon pin dropped out under its own weight. At room temperature it was an immovable interference fit. Thus heating is likely to work with a steel or brass screw in an aluminium bush.

Last edited by emeritus; 3rd May 2021 at 11:39 am. Reason: typos
emeritus is offline  
Old 8th May 2021, 6:00 pm   #20
clockman
Pentode
 
Join Date: Jul 2020
Location: Borehamwood, Hertfordshire, UK.
Posts: 216
Default Re: Rusted in grub screw.

I also find that penetrating oil helps in removing those cabinet spring clips. AND is there a tool for doing this without braking the plastic stems ?
clockman is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:00 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.