I've just obtained two dial gauges as part of a job lot, they're
absolutely filthy, one is minust the glass & the other is a bit sticky
but they look as though they should be decent gauges if they're
cleaned up.
Is it OK to just dunk them in my Aldi ultrasonic cleaner, or is that
the worst thing I could do?
Ta
TimL
Use a soft cloth with soapy water on to get the thick off, then use meths to
clean the rest of it. Don't use any oil on the spindle and if you need to
unstick it use plenty of meths. If you don't have meths use white spirit.
Oil attracts all sorts of nasty dust and metal shavings etc which will kill
a DTI in no time. Try to avoid total immersion as it will be hard to get
them 100% dry afterwards. I don't know of any DTI which is waterproof.
Though there probably are some out there which I have not come across.
Always try to keep them clean and dry and don't drop them ;-)
Andy
I reckon these will need *internal* cleaning, hence my suggestion of
the ultrasonic bath. Is there any fundamental reason why I shouldn't
take the backs off and put them in a suitable medium in the ultrasonic
bath, provided they're thoroughly dried afterwards?
Thanks
Tim
Take the back off, normally 3 or 4 screws, don't worry it won't 'explode'
out at you, unless it is well shagged and some numbty has packed it all back
inside. Have a look, if you still think they need a clean then have a go
with the worst one first, give it a clean in your ultrasonic bath and give
it a good dry followed by some time on a radiator or in an airing cupboard
or somewhere warm and dry but not too hot as some internal parts may be
plastic and might not last in an oven or some other great heat source. Once
dry lightly lubricate with the lightest oil you can get your hands on. DTI's
do not like thick oils, ideally you should be looking at something lighter
than WD40 but at a push that would be ok. Squirt some into a clean dish then
apply to the gears and gear pivots using a cocktail stick or matchstick.
Oiling must be kept to an absolute minimum.
If you decide to dismantle them keep the bits separated if they are
different makes. A good pointer removal tool can be fashioned out of an old
Alan key. I made one years ago from a 4mm Alan key with a bit of careful use
of an off hand grinder, a file and a hacksaw. Trim the small end of the key
to about 13mm then thin the outside edge of the short end with the grinder
to about half its thickness, use a file to thin the inside face so there is
about 1mm thickness, then use a hacksaw to carefully put a slot down the
middle to form a sort of 2 pronged fork, I still use mine on a regular basis
still.
At the end of the day its your call, do what you think is right, you got the
DTI's for nothing so what have you to loose? They are not that expensive to
buy if you really want one. It's a shame you didn't post this a couple of
months back as we scrapped off several large box full's of broken clocks at
work. We use them in modular gauges and they get broken almost on a daily
basis.
Out of curiosity what make are they? I might be able to get a used glass for
you?
Andy
Thanks for that. They're both Mercer, fairly modern metric, the one
with the missing glass is the 'small' size, 38mm glass, type 185.
They came in a job lot which I wanted for a couple of the other items
so they don't owe me much, but if I can get them useable with a
minimum of time & effort expended so much the better. I don't plan to
spend hours dismantling the 'works' and losing bits <G>
Cheers
Tim
I know nothing about DTIs, but as a clock repairer (and at one time a
chemist) I am used to small mechanisms and can assure you that WD40 is
almost the worst thing you could use. Its feeble lubricating power relies
solely on the solvent it contains, which once it has evaporated, leaves a
sticky gummy residue which will leave your instrument in worse condition
than it is now.
I suggest you use the lightest oil oil you can find (Mobil 1 synthetic motor
oil is good) and apply the tiniest amount only to the pivots. Leave the gear
teeth absolutely dry.
Cliff Coggin.
I suspect mineral terpentine is just another name for white spirit, which
itself is an oil-derived substitute for natural terpentine. (In fact I
recall it being called "terps substitute" when I was young.)
Cliff.
White spirit and Turps Sub used to be two slightly different products,
IIRC White Spirit was slightly more refined (and thus less likely to
leave a deposit), white spirit was OK for thinning paint but Turps was
best restricted to brush cleaning etc. I think you can still buy
solvents under both names but suspect it's the same thing with
different labels.
Tim
On Fri, 27 Mar 2009 08:36:42 -0000, "Cliff Coggin"
I have a supply of 100% pure Isopropyl Alcohol, bought 2 x 1 gallon
containers from my local chemical supply warehouse about 5 years ago.
I use this for all cleaning and (final) degreasing as it evaporates
off and leaves absolutely no residue. I also use for machining
Aluminium as I find it perfect for the nsame reasons as above. No
residue, stops chip welding, and it has an evaporative cooling effect.
Not that expensive either from what I recall, and after 5 years I
still have around a litre or so of it left.
Peter
Here's one for you.
did you know ......if you shop around ..
That windshield washer bottle additive is sometimes 100% isopropyl
alcohol
it's a cheap source I've used a several times.
all the best.markj
Cliff I would use anything but WD40 in this instance. The original poster
may not have access to anything but WD? I don't know? I said "at a push use
WD"... Even a drop of vegetable oil from the kitchen would be better than
WD. He plans on using his Aldi ultrasonic cleansing bath to clean these
DTI's, it will be totally void of any lubricant, a drop of anything on the
gears will certainly help in this instance surely?
I'm used to an environment (main work job) where spending anything more than
20minutes repairing a DTI is less than cost effective. As far as I am
concerned paying £20-£30 for a brand new DTI is worth every penny spent, no
sticking, clean, all screws there and stylus intact.
Andy
As I've said, I'm not planning to put a lot of time into these, which
is why the ultrasonic bath came to mind as a quick way to clean them
up. They don't owe me much, and my time is limited, but it would be a
shame to just bin them without some sort of attempt to make them
serviceable.
Thanks to all for suggestions
Tim
. He plans on using his Aldi ultrasonic cleansing bath to clean these
If a DTI is similar to a clock in which a small motion at one end of the
instrument (the stylus), is maginified by a gear train or rack & pinion into
a large motion at the other end (the hand), then no, absolutely not. Clock
gears (we call them wheels and pinions) should never be oiled. Oil in such
exposed mechanisms absorbs abrasive dust and increases friction.
Cliff.
Indeed, it is the main reason why clocks given to well-meaning model
engineers for repair invariably stop working after a couple of months
due to being gummed up by the sticky residues from "3-in-1" oil
adhering the teeth of pinions to the teeth of wheels!
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