Penetrating oil

[oldbikedavey]

As mentioned above, acetone and ATF works well. However if you want something in an aerosol can then Bulldog BDX is the best I've tried and it's the only stuff I use in the workshop because it actually works.

Whatever you use if thing thing you're trying to move is really stuck/corroded then heat is the only answer, and an induction heater is an absolute game changer.

Not soooooooo difficult to make your own induction heater, if you are so minded.....
Somewhere, I have a rather detailed book on the subject .....

 

[tigdlo]

I've found if I'm in a hurry which was 99.9% of the time in the motortrade then all the penetrating oils I've tried are next to useless for undoing rusted threads but ok as lubrication once things start to move with any engine oil being better.

For DIY projects with a bit of forward planing then repeated applications and plenty of time appears to work but as we can't undo the same thread in the same condition twice it's all a bit anecdotal.

Anyone know of a penetrating oil called Nimrod? I'm sure I've used it but can't find it online

 

[Gareth J]

Project farm YouTube channel did a DIY test. The outcome was that something is probably better than nothing and that heat is probably better than everything else. With price not a great indicator of usefulness.

Therefore I go with cheap, in order to not mind liberal application. Used atf and kerosene. And then end up heating it anyway normally.

 

[bricol]

When I was an skint student I found WD40 worked well . . .by spraying it liberally all over the seized fastener, then lighting it

 

[ajlelectronics]

Perhaps there is some confusion about "penetrating" oils? None of them can get through into a rusted and seized fastener, despite claims from the like of WD manufacturers to the contrary as there is nowhere for it to penetrate.
The value of them comes from the creeping lubrication effect once the fastener has been cracked slightly after wire brushing and the continued effect as the fastener is correctly cycled in and out, adding lubricant.
Sometimes a fastener just has to be cracked with heat before applying a lubricant which is not a hyped up Water Dispersant (39 failed attempts to make it do something). The Acetone and ATF works by diluting the ATF which is an excellent lubricant. In that dilution, it is better able to creep before the Acetone evaporates and so leaves a film of lubricant where it can.

 

[daleyd]

Back in the days when I was dismantling industrial dryers and thermal oxidisers for a living a squirt of "something" (Usually whatever the customer had lying around, usually WD40, occasionally PlusGas or some other proprietary can) and left for an hour or so before trying to shift it certainly gave better results than going straight in with a spanner. That was repeatable over hundreds of bolts, most of which had been in hot, dirty environment.

Bigger thermocouple fittings, especially stainless were great if someone had bothered to put high temp anti seize on before fitting, if not then it was a lottery whether they came out without galling. In those cases a squirt of some thin oil definitely helped, but there was no point if they already started galling - too late by then.

 

[piman]

Hello Alan,

I don't find that these fluids do much for really tight rusted fasteners but I am fortunate still having an oxy\acetylene torch which rarely fails.

Alec

 

[Smallfry]

I had something from the USA that worked well some years ago. Marvins miracle something or other. Can't remember now, and never found it since.

I have a 3/4 bolt on the front axle of my tractor that needs to come out. First the end with the nut snapped off, then going to the other end, the head snapped off, leaving both ends flush with the axle beam. Been soaking it for months to no avail. Even tried grinding down a steel for an electric breaker, luckily the bolt is vertical, and trying that. No joy either.
I don't really want to put heat on it, because I don't gave any oxy acetylene or gear now, and also the amount of heat that would have to go into the axle to make it hot enough worries me. Might affect the axle in some way, as the bit that is left is about four inches long.

 

[Smallfry]

On occasion following a run of exhaust studs I've considered a career change.

So what you are saying, is that the Bulldog BDX is not THAT good then ?

 

[8ob]

There is a certain feel to a bolt that’s going to fail when undoing, some have it and some don’t, knowing when to stop and change tactics can save a lot of grief.

Bob

 

[steveo3002]

I had something from the USA that worked well some years ago. Marvins miracle something or other. Can't remember now, and never found it since.

marvel mystery oil?

 

[Smallfry]

There is a certain feel to a bolt that’s going to fail when undoing, some have it and some don’t, knowing when to stop and change tactics can save a lot of grief.

Bob

That is true, but sometimes it doesn't work out, no matter what you do.

 

[tom2207]

acf 50 works really well ,,,,

 

[minimutly]

Not soooooooo difficult to make your own induction heater, if you are so minded.....
Somewhere, I have a rather detailed book on the subject .....

A detailed book, sounds like it might not be that easy??

 

[ajlelectronics]

There is a certain feel to a bolt that’s going to fail when undoing, some have it and some don’t, knowing when to stop and change tactics can save a lot of grief.

Bob

I refer to it as "going plastic".

 

[tom2207]

I refer to it as "going plastic".

turning to something ,,,,

 

[addjunkie]

turning to something ,,,,

An ah expletive of choice moment usually!

 

[Dapph2]

Well, there's no really meaningful data about any these products, so whether or not A is better than B is all very subjective. I know a lot of people are fans of Plusgas and my attitude is 'use whatever keeps you happy'. And in my garage, sometimes I'll reach for one and sometimes for another.
I'd love to try and do some sort of experiment on them, I know there are Youtube videos doing just that, but are they really convincing? I did do an experiment some time ago, using a microsyringe which can measure out very precise tiny volumes of liquid (a bit smaller than the head of a pin). I placed tiny droplets of all the products I had onto a flat sheet of metal which had a uniform layer of rust on it and watched to see how fast and how far they spread out through the layer of rust. After I'd done the experiment the first time, I could see ways of improving the method, but have never got around to doing it. Of course, if you want to argue that a rusty flat sheet of metal bears no relationship to a screw thread, you can. But, I do think it's an interesting experiment and does give some pointers, especially on the issue of which spreads quickly, but which might be best if you have the time to leave it. Acetone/ATF was really unimpressive in that test. A dark horse was 3in1, but that was slow. I'm also curious about whether using product A for the first squirt and product B for the next squirt might give a good outcome. First you need something to work as a wetting agent then you need something that lubricates and stops evaporation.

The Deep Creep is interesting; more than anything other product, it comes out of the aerosol can like a foam and it seems to be good at releasing stuff.

The best penetrating fluid will be the one that creeps between two well clamped slightly rusty plates the fastest or through the greatest distance . Brake fluid is very good for that reason but then it takes very gentle back and forth movement for the rust to turn to a slippery fluid enough so you can break the torque of the parts stuck . That's where the big hot ready to solder soldering iron comes in handy to expand the parts and let them take in brake fluid as they cool , it might take 1/2 an hour or more to get results don't be in a hurry . One job took 3 Days of frequent work like this before it finally yielded to me without causing any damage to myself or the bolts.

 

[Dapph2]

On occasion following a run of exhaust studs I've considered a career change.

Do you have a Rigid stud extractor set C/W precision drills , guides plus the drive nuts for the shaped extractor pins ? There used to be two sets one went down to 1/8 dia. studs , the other 1/4 dia. studs.
I've only ever seen one 1/8 " extractor pin part sheared by a knuckle dragging gorilla pretending to be a mechanic.

 

[MattF]

some have it and some don’t, knowing when to stop and change tactics can save a lot of grief.

Unfortunately though, sometimes the sneaky little sods can feel like the bond is breaking, around the same time the head/nut shears.

Admit it. We've all done it.