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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! |
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15th Oct 2021, 2:04 am | #21 |
Heptode
Join Date: Oct 2005
Location: Olympia, Washington, USA.
Posts: 664
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Re: Rusted in grub screw.
One of the DIY channels here had a great program on getting rusted parts loose.
Leah Bolden of YouTube "See Jane Drill" makes up her own penetrant using 50% acetone and 50% automatic transmission fluid- not the synthetic stuff. Shake up well, as they do not like to mix. They will separate after a while too. Shake up well before each use. She claims that she has never had a rusted part she could not get loose with that in decades. I suggest mixing a small amount and capping the bottle it is in, as the acetone is likely to evaporate away. |
15th Oct 2021, 11:21 am | #22 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
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Re: Rusted in grub screw.
Yep, i have seen the 1:1 ATF/Acetone mix used by Dom on BBC's The Repair Shop, i have a feeling Edd China or Ant Anstead may have mentioned it also.
On experimentation with blends of Kerosene/Diesel/Petrol etc, i found wd40 superior to all of them. Farming supplies even sell it here in unpressurized 5 litre cans! Immersion always wins out of course, if the part is small enough to immerse.. Dave |
15th Oct 2021, 11:45 am | #23 |
Heptode
Join Date: Oct 2015
Location: Gloucestershire, UK.
Posts: 720
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Re: Rusted in grub screw.
The only thing WD40 is superior to, is nothing. WD is a Water Displacer and it took 40 attempts to make it do that reliably. You will not find it on any true mechanics bench, the ATF mix though is proven to be one of the very best.
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15th Oct 2021, 2:49 pm | #24 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: Rusted in grub screw.
My favorite mix is ATF and Diesel in equal measures. Stinky but cheap and effective.
Plus Gas is the professional mechanic's choice.
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I'm the Operator of my Pocket Calculator. -Kraftwerk. |
15th Oct 2021, 2:54 pm | #25 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
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Re: Rusted in grub screw.
-Nope, have a re-read Scim. WD40 was only superior to Diesel/Paraffin/Petrol and all blends of same, on simple steel nut/bolt scenarios- and the results were repeatable enough to average out different levels of seizure within the test pieces. I don't believe or claim it's superior to plus-gas, heave ho or even ATF mixes, even if it were true it would rekindle a discussion that's been on and off for decades, to no-one's advantage.
..mine's not on the bench, it's on the doorpost! (Phew..) Dave |
16th Oct 2021, 8:26 am | #26 |
Hexode
Join Date: Apr 2017
Location: Buderim, Queensland, Australia.
Posts: 428
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Re: Rusted in grub screw.
I use WD40 as a coolant for jobs on my drill press, and for ... er,...ah, ... now let me think about it.
Hmmmmm, still thinking, ......... Last edited by Radio1950; 16th Oct 2021 at 8:49 am. |
16th Oct 2021, 10:36 am | #27 | |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
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Re: Rusted in grub screw.
Quote:
I think you might have to provide some evidence regarding your statement- " You will not find it on any true mechanics bench" What is a "true mechanic" and how are you qualified to say such a thing?? |
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16th Oct 2021, 10:50 am | #28 | |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,766
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Re: Rusted in grub screw.
Quote:
For fans of WD40, if you want to use their products for releasing rusted grub screws, why not use WD40s own version, the formulation of which is in itself, tacit admission by WD40 that traditional WD40 isn't the best product to use: 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'. Unquote. Most householder/DIYers will probably only have a can of WD40, and will continue to press it into service for any and every task, in part, encouraged by the blurb on the can. I'm in the camp that believes it doesn't belong anywhere near vintage radios. (I use it as a cutting agent when I'm turning aluminium on my little metalworking lathe and it works a treat, but I wouldn't say that on the UK Workshop Forum or the sky would probably fall in on me!). With stuck grub screws, after applying a release agent (WD40 if you have to), we only get one chance at the outset, and that chance is often squandered by reaching for the nearest screwdriver, as depicted below, rather than the best one for the task. If the slot is then damaged, the only way I've succeeded in removing the knob is by drilling out the screw by making a drill guide on the lathe to enable a 1.5mm drill bit to be accurately centred, then progressively using larger diameter drill bits up to the tapping size of the screw. At that point, the knob will twist off the shaft and the thread can be re-tapped. A lot of palaver and best avoided. Releasing grub screws must be one of the few tasks where 'coming unstuck' means a successful outcome!
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David. BVWS Member. G-QRP Club member 1339. |
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16th Oct 2021, 1:16 pm | #29 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
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Re: Rusted in grub screw.
(Post 28 Para 1) I've never quite resolved this in my head, David- something hydrocarbon based with low surface tension also tends to evaporate quickly- so i look at the offending article 30 minutes later and think- has it gone in or has it merely evaporated..? If i have the time to do so, it's sometimes the case that i'll use something a little more viscous like 3 in 1 provided i can wait a day, in the knowledge that it won't all have gone to atmosphere by the time torque is applied.
As to why i tried pump fuels experimentally, this was on a cost per litre basis compared to aerosol cans off the shelf. (Most of the Sulphur has been removed from Diesel so it's likely inferior compared to 20yrs ago anyway.) Dave |
16th Oct 2021, 5:07 pm | #30 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: Rusted in grub screw.
I wonder if anyone has tried the 'shock and freeze' sprays sold in places like Halfords??
They contain a liquefied gas which evaporates when the pressure is reduced, and can cool things to around -70 centigrade to break the adhesion between parts.
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I'm the Operator of my Pocket Calculator. -Kraftwerk. |
16th Oct 2021, 5:21 pm | #31 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: Rusted in grub screw.
Another trick I have used is an automatic centre punch fitted with a screwdriver bit.
Put it in the slot of the offending screw and give it a few pumps - the shock can be enough to break the adhesion between the screw and the knob.
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I'm the Operator of my Pocket Calculator. -Kraftwerk. |
17th Oct 2021, 5:14 pm | #32 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,108
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Re: Rusted in grub screw.
I have tried the freeze and release agents, inconclusive results thus far, likely due to the freezing effect being wicked away by the mass of metal involved. May be good on a grub screw though..
Dave |