From: Robert Bastow <teenut@home.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Thu, 28 Oct 1999 14:21:01 GMT

The price of Shamban's adhesive is a killer if , like most of us, you are only
in need of a small amount.

Here is one way to get around it...Contact your local or regional Shamban rep,
explain the situation and ask if he can help.  He may be able to put you in
contact with one of their larger users..who may be willing to let you have
enough for your needs from their "leftovers"  Once opened the cans have a
limited shelf life..or they may just open a fresh pack for each application,
simply as a quality control measure.

You have to find and talk to the right people.

Alternatively you can do without their adhesive!   My first aplication was on
the planer I built and using 1/16" material with a combination of thin film
double sided tape AND mechanical "entrapment" I had a very serviceable end
result.

On most applications the Turcite is fastened to the "Saddle" rather than the
"bed ways" so it is usually easy to arrange some form of mechanical
retention..anything that stops the "meat" sliding sideways out of the "sandwich"

Finally, you may try chatting with your local Loctite Rep. While it may be true,
that at one time, the adhesive had to be specially formulated by
Shamban..because nothing else was available,  I doubt that is true now and
several grades of adhesives, now available, will do the job.

8^)

teenut

Tony Jeffree wrote:

> Anyone suggest a suitable epoxy adhesive for Turcite? Busak & Shamban
> (who make the stuff) sell their own special grade of epoxy - but
> apparently only in 1 pint quantities (here in the UK at least) &
> charge 50 pounds a pint (75 bucks) for it.  More than three times what
> they are quoting me for a metre of Turcite strip.
>
> More expensive than good whisky...and not NEARLY as tasty...
>
> As a pint is probably a hundred times the quantity that I will
> actually need, this seems an expensive waste.  Anyone used regular
> epoxy adhesives with any success?  Which ones?
>
> Thanks in advance...
>
> Regards,
> Tony
>
> Website: http://www.jeffree.u-net.com/

From: Robert Bastow <teenut@home.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Thu, 28 Oct 1999 19:33:13 GMT

I wouldn't rely on it for material less than 1/16" thick and I have no
experience of anything as thick as 3/16".  Bearing in mind the tendency for
these type materials to cold extrude, I would be wary of it..and of using screws
through it.  Knowing my relationship with Murphy (He has it in for me as I have
challenged and cheated him far too many times!!)..I would Expect the screwws to
come in contact with the ways eventually!!

What I HAVE done is to use the aformentioned double sided tape simply as a means
to hold the turcite in place during fitting and assembly.  Eventually cutting
oil etc will degrade it to zero effectiveness.  Howerver, by adding retainer
lips, just like and incorporatin wiper seals, the turcite is trapped with no
place to go.

Before Turcite, the only teflon alternative was pure white teflon.  Many machine
tools..especially NC and CNC HAD to use teflon to overcome the bugaboo of
stick/slip.  In those cases, with glues simply not available, the manufacturers
used mechanical means of retention..the main one being as I detailed above..with
entirely satisfactory results.

Turcite and other teflon based slideway materials offer several advantages, some
of which may not, immediately obvious:

Reduced friction and massively reduced stick/slip differentials (The ratio
between static or "stuck" frictional coefficient and dynamic or "slip"
coefficient, are probably its best known and understood advantages.

Others include; Reduced sensitivity to lubrication (or rather, lack of it).
Reduction of wear on slideways..teflon tends to simply "swallow" abrasive
contaminate particles rather than simply holding the at the surface to act like
a lap.

Reduction of chatter..teflon tends to act as a damper.

To me, however, one other feature is, in itself, worth all the effort.  This is
what I call "Zero Clearance slideways

Hard metalic slideways always need a minimal clearance to opperate..without a
thou or two of carefully adjusted clearance, they become "clamps" rather than
slides.  Any wear, taper or other inaccuracy of the sliding surfaces makes this
controlled clearance difficult or impossible to set and maintain.

With resiliant, low friction teflon lined slides the need for clearance is
ZERO..indeed I set up slides, whenever possible with NEGATIVE clearance..a clamp
arrangement even!!  The low friction material makes a lousy clamp though..so the
result is a slide without ANT wobble or shake, and which can accommodate quite
large degrees of wear or taper.

The difference this makes to the "Feel" of the machine and the accuracy and
improved surface finish obtained, have to be experienced to be truly
appreciated.   As a bonus, given adequate power, the depth of cut and feed rates
can often be dramatically increased..Chatter is a thing of the past!

8^)

teenut

mulligan@advinc.com wrote:

> In article <38185CFB.6C92820E@home.com>,
>   Robert Bastow <teenut@home.com> wrote:
>
> > Alternatively you can do without their adhesive!   My first
> >aplication was on the planer I built and using 1/16" material with a >
> > combination of thin film double sided tape AND mechanical "entrapment"
> >I had a very serviceable end result.
>
> Hmm.  I could see milling a pocket under the saddle ways and making
> the wear strips a nice snug fit into them - how about also using
> screws in from above, if the material were thick enough - say, over
> 3/16 or so?
>
> Jim

From: Ted Edwards <Ted_E@bc.sympatico.ca>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Thu, 28 Oct 1999 15:59:25 -0400

First, a question.  What is "Turcite"?

Robert Bastow wrote:

> Before Turcite, the only teflon alternative was pure white teflon.  Many
> machine tools..especially NC and CNC HAD to use teflon to overcome the
> bugaboo of stick/slip.  In those cases, with glues simply not available,
> the manufacturers

There is an etchant that will make the surface of Teflon bondable.  I
first encountered it in the late 50's.  The stuff I used was thoroughly
nasty - contained finely granulated Sodium metal among other
nastinesses.  It turned the surface of Teflon brown *and* bondable.  I
have not used it myself since the 60's.  There may now be other
preparations as effective and less noxious.

A few years ago, on a visit to Boeing Surplus, I was fortunate to find a
large piece of 3/16" thick Teflon sheet so treated on one side.  I
epoxied a piece about 5" by 10" to a piece of 1/8" Aluminum to hold it
flat.  This is very useful for glue ups where I want a flat but
non-stick surface.

Another use for this device is as a wrist rest when TIG welding.  I can
slide my hand along without the above mentioned stick/slip.

> Reduction of chatter..teflon tends to act as a damper.

> To me, however, one other feature is, in itself, worth all the effort.
> This is what I call "Zero Clearance slideways

Good idea!  Have to try that.

BTW, adhesive backed Teflon tape is available in various widths and
thickness.  The bond isn't as good as epoxy but for some applications is
adequate.

Ted

From: Robert Bastow <teenut@home.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Fri, 29 Oct 1999 04:44:44 GMT

Never have used teflon loaded delrin,

"Pure" teflon will cold flow more readilly than turcite, which is formulated to
minimise it.

On the applications where I used pure teflon I made sure the surface areas under
load were as generous as possible and never had any problem.

I guess there must always be a little cold flow..but it should be easy to nip up
the retaining clips to compensate.

very few applications would that affect machine geometry significantly..if it
does the machine aint designed right!!

(One of the principles of good machine tool design practice is the a machine
should first wear "More Accurate" befor it starts eventually deteriorate)

teenut

mulligan@advinc.com wrote:

> Have you used teflon-loaded delrin for any applications like this,
> and do you worry about cold-flow of the teflon eventually causing
> the saddle to 'sink?'
>
> Jim

From: Robert Bastow <teenut@home.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Mon, 01 Nov 1999 18:22:14 GMT

Jack is correct, the table should be a smidgin higher at the front than the
back..it takes account of weight and cutting loads plus eventual wear.

Sound machine tool design principal..the machine should get MORE accurate as it
wears...before it starts to deteriorate.

I would be tempted to leave the full 0.001" in there..ast least until the
machine has had time to bed in.  Turcice will bed a bit further than cast ron
slides will..even they will do so to some small degree.

Should you feel the urge..Turcite is scraped with regular scraping tools..same
shapes and angles etc., but they do need to be RAZOR sharp or you will just
float over the surface as the turcite "dodges" out of the way.

If you know how to sharpen and use a cabinet maker's scraper, you will find that
better for evenly reducing large areas before final spot scraping.

teenut


Jack Erbes wrote:

> Dave and Sue Erickson wrote:
>
> <snip>
> > The reason for the post is that there is a third problem; the
> > table is about .001" too high in the front.  My question: if
> > I plan on adding turcite, should I correct the .001" alignment
> > problem before or after adding the turcite?  If after, will I
> > be able to scrape it using the same tools and techniques that
> > are used on cast iron, or should the scrapers be sharpened
> > differently, or different tools used?
>
> Bridgeport manuals say that the front of the table should be .0005
> higher than the back.  They don't explain why, but I assume it allows
> for settling that occurs under load.  Maybe your Hardinge needs
> something there for the same reason.
>
> --
> Jack in Sonoma, CA, USA (jack@vom.com)

From: Robert Bastow <teenut@home.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: TURCITE - suitable adhesive??
Date: Tue, 02 Nov 1999 07:20:44 GMT

Your plan sounds fine, I still suggest letting it bed in a little befor taking
of that last five tenths...it is a lot harder to put it back on!

Sandpaper?  No!

A) I don't think it would cut the turcite...it is "harder" than straight teflon
but abrasives work best on friable materials.

B) Every piece of abrasive pulled off the sandpaper would finish up embedded in
the Turcite..it can absorb some..but that is just asking for rapid wear problems
later.

Try the cabinet scraper..you will be amazed how fast it will shift the
excess..just as it will remove wood a lot faster than sandpaper and to a
"cleaner" finish.

teenut

Dave and Sue Erickson wrote:

> Thanks for the suggestions; I'm aiming at .0005" high in front, which
> is also the amount the front relaxes if I unlock the knee.  The current
> measurement is .001" too  high, i.e. it is .0015" high in front, based
> on swinging an indicator around the spindle axis.  It is .0010" too high
> in front based on moving the table along the y axis.
>
> So if my math is correct, that means that if I take the full .001" off the
> table, I'll end up with about .0005" high in front, and it will all be in
> the knee, which is what I want, since the knee will wear towards more
> accuracy.
>
> I'd like to end up with a machine that I can use for surfacing (fly) cuts
> that remain parallel to the table, and at the same time keep the geometry
> with respect to the column correct, since boring on the Hardinge is done
> by raising and lowering the knee.
>
> So, reading between the lines, I guess that it makes sense to add the
> turcite then scrape it, rather than scrape the ways first.  Is sandpaper a
> no-no, due to embedding grit into the turcite?