Okay guys, sorry for the shouting but I'd really like to kill off the internet myth of the 50/50 mix acetone/atf being the best penetrating fluid known to man. It ain't no such thing.

One question; if it's supposed to be that good, why aren't the big companies selling such a mix? There's a fortune there for the making and they're not doing it???

The answer is that it's not acetone in the original mix but a rather more nasty substance -  trichlorethylene. The original article has long since disappeared (possibly available in the Wayback Machine but I haven't looked). See post 10 here:-

http://geometroforum.com/topic/5391292/1/

IME the best commercial penetrating fluid available is Kroil but it's damned expensive and not generally available in the UK. Kroil is designed to be a penetrating fluid and not a water dispellant like WD40.

Dai, I respectively disagree that 50/50 mix of acetone and ATF is not an effective penetrating oil. I have been using it for years with good results, just recently was called out to remove a sized pin on a piece of equipment that other mechanics had tried for days to free up and I had it out in two hours. I will not make the claim that it is the best but will say I have found it very effective.

I've been using it for years (30) and it has usually worked as well if not better than any other readily available stuff. Saying it "does not work" well I have found it to be effective most of the time. Also considering that for me it's easy to make because I will almost always have ATF and always have some acetone.

Dai wrote:. . .  I'd really like to kill off the internet myth of the 50/50 mix acetone/atf being the best penetrating fluid known to man.

In italics is an abridged extract from the introduction to the PBS (Public Broadcasting System in the USA) series, The Power of Myth:
Myths are stories that are based on tradition. . . . Myths are sacred tales that explain the world and man's experience. Myths are as relevant to us today as they were to the ancients. Myths answer timeless questions and serve as a compass to each generation. The myths of lost paradise, for example, give people hope that by living a virtuous life, they can earn a better life in the hereafter.. . .

The myths of perfect rust penetrants give people hope for reclamation of the clapped-out, seized pieces of scrap masquerading as a motorcycle projects in their sheds.

Here's what seems to be a well-designed evaluation of various mixtures for freeing stubborn fasteners:   
https://www.youtube.com/watch?v=xUEob2oAKVs

Every hack mechanic knows all you really need for stubborn fasteners is a blowtorch, a welder and a sledgehammer.

Okay, so saying 'it does not work' was a bit much but this question remains permanently unanswered:-

'(...)if it's supposed to be that good, why aren't the big companies selling such a mix? There's a fortune there for the making and they're not doing it???'

Laitch: Nice quote

If you want a really good range of penetrants, and protectants have a look at the LPS range LPS 1, LPS 2, LPS 3. Used by a lot of industries under extremely harsh conditions, however they can be expensive. Some of the US inmates should have come across it.  I was lucky enough to buy a US gal of LPS, 1 a pump bottle of LPS1 and a gal of LPS 3 for $20.00 Au at the local Saturday market. It should outlast me. But I have used the acetone ATF mix with success.
Regards Martin.

When ATF Acetone fails Kerosene wont!  Rust seized pistons were not persuaded by a month of  acetone but a 2 hour 4 cylinder BBQ did the trick. Trying to post bbq pic.

Well I have access to all the above in my work for a major oil company as a machinist/millwright/engineer. LPS 1 is fine for applications where WD 40 would be used , LPS 3 is more of a waxed coating to preserve. Kroil, is the go to for rusted together, fused, chemically or electrolysis enhanced issues where heat and kroil are used together to get ridiculously stubborn fits to to come apart like taperlock bushings in harsh environments. Acetones and atf, not so much. One, it's a msds nightmare. Two, these are hazardous chemicals your messing with. The original atf had sperm oil in it and trichlorethylene was the carrier that got the old formula ATF to the problem. Spem oil is incredible stuff. Once we quit using it in ATF the transmission repair business really took of. Taking a breath and sometimes opening our wallet is better and safer. Heat cycles and time. BTW, we buy kroil in 55 gallon barrels. It is expensive because it works.

Kroil and heat just got a stainless pin out of my front right caliper. It's a shame the stuff is so expensive over here: £20+ / 236ml.

We used to use LPS 2 offshore for frozen rusted bolts which seemed to work well. Unfortunately I haven't been able to get a cheap source of LPS 2. The LPS 1 is good for electrical stuff and every 12-24 months I fill and drain my centre stand with LPS 3.
Regards Martin.

Hey Chickenstrips, what did the sausages taste like?
That looks a great idea.

Must try it, maybe have a beer as well.

....and ponder Laitch's post.

Seafoam Deep Creep




From this video:
https://www.youtube.com/watch?time_continue=601&v=st8dkGzJWtg
(by the same guy of brickrider2's link above)