Why's my lathe getting smaller!?

[Lurkio]

Hi all,

Anyone care to comment on the following?
While reading a book on Miniature Loco Construction by a well known contemporary author, I came across the following, and I quote: "sprays such as WD40.....contain solvents that attack cast iron."
I haven't come across this before. My own view is that it has to be an error, but perhaps some of you have an opinion on this.

Lurkio.

[houstonceng]

I know the book you are talking about and I read that as well. Don't know where Stan's information came from but, practically, guys down my club have been using WD40 in almost industrial quantities and injecting it into CI cylinders with no obvious detrimental effects.

Perhaps, like de-zincification in brass, the CI suddenly fails after a long exposure.

Any chemist care to enlighten us ?

[Tel]

What we found in the gun world with WD40 was that the airbourne, pressurised spray can pick up some moisture out of the atmosphere & force it into nooks and crannies, causing rust. No problem if the stuff is sprayed onto a rag, shirt-tail etc & applied thataway.

[SteveW]

Lurkio,

A long while back I used WD40 on my Myford, the aim being to keep out the moisture. In the event the tailstock end that gets the minimum of oil went all brown and cruddy.

I read somewhere that WD40 was mostly kerosene but once that's gone there's some form of oil left. The brown cruddy stuff was a devil to remove.

I now use slide oil I got from the Warco stand to provide the protection and it works a lot better. It's quite thick and gooey and coats the slides very well. Maybe why they call it slide oil.

[Shawki Shlemon]

I thought that WD40 was a penetrating oil generally used to free seized parts (correct me if I am wrong) . after I use WD40 for those purposes I always coat the parts with light oil .

[JohnP]

I thought the WD part was "Water dispersant", rather than "War Department", so I've always assumed it was ok.

Maybe it depends on the relative himidity at the time of spraying?

JohnP

[ron]

I've used Screwfix's equivalent [SX90?] on both machinery and the engines of layed-up cars with good results, and being in SW Scotland dampness and humidity in winter are a major problem. I always thought of WD40 more as a water dispersant [say for car ignition leads in the old days] rather than a penetrating oil, Lusol and Plus Gas are penetrating oils.
Ron

[Lurkio]

Thanks for the replies so far.
SteveW, I too have used WD40 on my Myford hoping to displace moisture and protect the slides (hence the topic title). It looks from your own experience as if this might be a mistake....thanks for that. It's just so easy to squirt everywhere!
Tel, your experience with the stuff is interesting, given that WD40 should displace moisture.
For those that are interested, WD40 claims to displace moisture, clean, lubricate and protect.
I believe some loco owners use it to lube cylinders and clear out water after a run, so let's hope it's effects, if any, are minor.

Lurkio.

[havoc]

I use it mostly to remove water from parts I crinse in water after brazing and pickle, or soldering (to avoid having to heat the part to boil off the water or let it dry a whole night). Then apply light oil to replace the WD. I use parafin based oil for that. Use the same oil for stuff like angle plates, drill stand etc.

[Uzzy]

I was told by my late father in law not to use WD40 as it makes things rust?

[Noddy]

Again from a gun point of view, i once read that it would remove bluing, but have never seen this happen in practice.

What I have found is that the stuff tends to wash off any existing oil film, leaving too little behind to provide rust protection. So now, older, posibly wiser and with rust spotted gun: I still use WD40 and halfords etc clones as solvents and water displacers, but give parts a nice thin film of 3 in 1 or one of the proprietry gun oils for rust protection.

That seems to work, but perhaps the parts are now so spotty that I don't notice the new growth.....

[cardiffpat]

WD 40 is so called because it was some guys 40th attempt to produce a water displacing substance.

[waggy]

I use WD40 as a lubricant for drilling and tapping. Not in spray form though. I spray the stuff into a small container and leave it to stand so the solvent can evaporate. This leaves a waxy deposit that I apply using a small brush.

Waggy.

[jackrae]

Now my 2-pence worth

I too found that things rusted like there was no tomorrow after using WD-40. I eventually came across Castrol WDF which is of a similar breed but , for me, has completely solved the post-evaporation rusting problem.

Now to how to really rot your lathe.
The other day I was turning some alumunium (colonialists, note the correct spelling) alloy of unknown specification - but it turned well. I used some Rocol drilling and tapping fluid to lubricate the tool. (from those little brown bottles) With things running a bit warm (heavy cuts - or blunt tool) smoke was issuing merrily. Job, done so packed in for the night. Next morning the lathe bed under the chuck, the chuck itself and the lathe mandrel all had quite a heavy coating of rust !
I presume the Rocol contains sulphur which, when heated burned off the oil, resulting in the sulphur converting to sulphuric acid and hence the rot - Comments from any chemical friends welcome. Liberal amounts of very fine wet and dry took it off but it wasn't a pretty sight.

[the_viffer]

alumunium (colonialists, note the correct spelling)

aluminium (pedants note the correct spelling)!

[jackrae]

that wos just two maik shoor yoo wer reeding it

[Lurkio]

All,

Having read your valued posts on this subject, I'll now play safe and avoid using WD40 for rust prevention on my precious bits.
Ta for the tips.

Lurkio.

[the_viffer]

Actually overheated Rocol gives off hydrogen chloride and nitrogen oxides. Both of which would rot a lathe bed mighty quickly and in cmbination even faster.

[chris vine]

Pedants in glass houses shouldn't throw stones or they might have to change their "cmbinations".

(have checked my spolling very carefully)

Chris.

[Lurkio]

Look, to keep the number of posts on this topic down, we're all allowed one spelling or grammatical mistake from now on, OK?

the_viffer and jackrae raise interesting points regarding cutting fluids....some unexpected harmful effects can be experienced when using them.
I remember being surprised to learn that soluble oil cutting fluids can contain bacteria harmful to both machine slides and humans...most of you will know that already.
If you've worked in engineering, there's a good chance you've already spent many hours bathed in all sorts of harmful liquid, and inhaling dubious gases and vapours!
Practice good hygiene to keep your machinery and yourself in good nick!

Lurkio.