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  • working with turcite question

    first of all...Merry Christmas!

    i`m going to be using turcite on a lathe saddle to bring it back to original height following a bed re-grind.

    is there any reason why i can`t use little fixtures like the guys using Moglice make to locate the saddle on the bedways to maintain perpendicularity of the cross-slide ways to the spindle axis?

    ie- if i use the little fixtures on the ends of the saddle will the bond strength of the adhesive be compromised due to slight shrinkage of the adhesive while it cures?

    hopefully this question makes sense to you guys...

  • #2
    You mean like this....



    You may do this, but you should still machine accurately for the Turcite plus adhesive thickness so the adhesive thickness is not excessive. If you use the special 3m adhesive as recommended for the Turcite, be aware it has .003 glass beads in it so the the bond layer must be at least that thick and probably should not be greater than about .005 in.

    I added lock nuts to the brass screws and put scraps of Turcite under the ends of the ways along with a scrap of .003 shim stock and then adjusted the screws to just touch the ways (this was before I learned the adhesive had .003 glass beads in it). Then I checked the alignment and tweaked the screws just slightly higher to bring the saddle into perfect alignment. These scraps were then removed and the real Turcite and adhesive applied.
    TexasTurnado

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    • #3
      thanks TT!
      that`s it exactly!
      FWIW, i`m using the turcite/waylock adhesive as supplied from Devitt

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      • #4
        I would also cut it a little larger the what you need as it will creep if not captured. I have also seen where they pin it with a 1/16" nylon plug or flat head brass screw. I usually just cut the Rulon a little bigger. I use Rulon as it is the same product and is cheaper. I buy it from TriStar . You will still need to scrape it as both Rulon and Turcite only guarantee it to be +/- .003" flatness. Be sure to glue the dark and I usually scratch up the cart iron so the glue bond to it better. I have had better luck using acid-tone to degrease it then alcohol. Be sure to mark where the oil holes are. If your area is cool, you cn shine a heat lamp on it too. PM or call me if you need any other help 651-338-8141
        PS: Be sure to spray some release agent on the the ways your gluing too. Some use masking tape,wax paper, plastic wrap or newspaper.

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        • #5
          Originally posted by Richard King View Post
          PS: Be sure to spray some release agent on the the ways your gluing too.
          Important safety tip!

          Merry Christmas Rich and John (and everyone else!)
          "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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          • #6
            Originally posted by 1200rpm View Post
            hopefully this question makes sense to you guys...
            need some help there

            The moglice works as TT showed because its soft and then sets up.....is the turcite not in solid form to start with? If so how is holding the carriage as such going to work? my understanding is moglice is 'castable' where as turcite is scraped to fit.
            .

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            • #7
              The glue settles out and levels the Turcite.

              Not as much as a castable like Moglice, which is why Rich and John are saying that you have to machine the mating surface level before you apply the glue.
              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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              • #8
                I used to sell Moglice and use it, I am very familiar with it. I use Rulon / Turcite all the time and have been applying it for over 30 yrs. Both have advantages. If your going to use the Turcite with the Moglice method of alignment I would make a dry run or 2 to get your technique down pat.

                Do everything accept the glue, slide in the turcite and set it down, mae sure there is no binding, mark the locations with a Magic Marker, if your lowering it with a hoist mark the links of your chains. Have your glue and spoons ready on a clean area where your going to mix it. One for the Epoxy one for the hardener. In classes I use plastic, in the real world I use metal ones. I wear surgical gloves as the epoxy gets under your nails and a pain to clean up. I also use a clean piece of sheet metal or Plex-e-glass as a mixing board. I also use the fast dry electrical cleaner or brake cleaner to clean the metal and turcite. Be sure to clean the saddle really good, especially where the oil holes are before gluing. When the saddle or part being glued is really dirty I use a propane torch to heat the metal to wick out the oil soaked iron. Have to be careful not to get it to hot. You will see the oil come bubble out. Might take a couple of try's to get it clean.

                After you apply the glue to the metal (be sure to wet the dark side of the Turcite too) I use kitchen tablespoons and putty knife to measure the glue exactly instead of eyeballing it. Rulon sends along a serrated putty knife that lets the glue disperse more evenly (same as a tile trowel) Lazlo is correct the glue has the glass beads, but lets say the V way is ground 45 deg's. but the bottom of saddle was machined 43 degree's so the gap you need to fill may be tight at one side touching the glass beads, but isn't at the other side, say it is open .007", well the glue squeezes out and dries and saves time in the scraping.

                The Moglice makes a exact duplication of the surface and all you need to do is 1/2 moon it and scrape the middle low. With the Turcite you need to scrape it with bluing to get the fit after it dries, but I say it's more forgiving because if you have the alignments off you can re-scrape it. If you don't get the alignment perfect before you pour or putty with the Moglice you need to chip it off and do it again.

                Good night..
                Last edited by Richard King; 12-26-2012, 01:54 AM.

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                • #9
                  Richard's explanation is as I thought, thanks.

                  I'm still left wondering how 1200's is going to use TT's moglice set up for turcite. Can't see it. Robert, you're suggesting the glue has enough gap filling ability that somehoe glue and turcite will accurately fill the void? What then holds the turcite firmly against the mating bearing surface? Have you used turcite and had success that way?

                  1200, if you want to go that route, and I agree it has appeal, why wouldn't you go moglice instead of turcite?
                  .

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                  • #10
                    Originally posted by Mcgyver View Post
                    Robert, you're suggesting the glue has enough gap filling ability that somehoe glue and turcite will accurately fill the void?
                    Re-read Rich's explaination
                    "Lazlo is correct the glue has the glass beads, but lets say the V way is ground 45 deg's. but the bottom of saddle was machined 43 degree's so the gap you need to fill may be tight at one side touching the glass beads, but isn't at the other side, say it is open .007", well the glue squeezes out and dries and saves time in the scraping."

                    That's why John was jigged-up the saddle while the glue on the Turcite dried.
                    "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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                    • #11
                      sorry i didn`t answer earlier-just got home.
                      to answer why i didn`t choose Moglice - my understanding is the minimum thickness for Moglice is .032"(IIRC) and the minimum for Turcite is about half that...i would have to remove more cast iron to make room for the Moglice.

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                      • #12
                        I see, thanks.

                        I think key to Rich's description is that it saves time in scraping....doesn't skip the scraping part like the pourable moglice. In the example given it seems the glue is pliable and gap filling but you're still not going to have a guarantee its in solid contact hence the need to scrape to finish the fit.

                        makes sense now.
                        .

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                        • #13
                          You can buy the thin Turcite but in my 40 years of using it the thinnest I have ever used was .025" because that was the thickness Okuma Howa put on their machine. The majority of factory built machines use .047". That is why I suggest you machine some material off the bottom of the saddle so you can use the thicker material. You can use the thinner stuff, but by the time you cut in some oil grooves and scrape it it is almost worn away.

                          Remember when you cut in the oil grooves both Turcite and Rulon warn you not to cut through the material as this increases the chance the epoxy will fail as your exposing it to coolants and oils. I suggest you cut the groove 2/3 the thickness of the material. So if you use .015 your only going .010. Not good. To let the glue squeeze out faster I set a chuck or some heavy bars of steel on the top of the saddle. Some C-Clamp it down, but if you do, use several all over. I prefer the weights. When you scrape turcite the normal depth is .002" so no need to 1/2 moon flake it.

                          It's Teflon and self lubricating, but will last a long time if it's oiled and kept clean. When you scrape it you need to sharpen your blade at a steeper angle and rounder tip. Say a 20mm rad. tip and a - 12 to 20 degrees neg angle on the blade. The normal 5 deg is good for cast but bad for Turcite / Rulon.

                          One more note my DVD will be available to download off the internet in a few months.

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                          • #14
                            And, in addition....

                            In the discussion above, I have not seen the importance of aligning the saddle (with apron) to the leadscrew - on both saddles I have done, the front prismatic way was not worn equally on each side. The back side tends to wear more because of the force holding the cutting tool against the work.

                            This means the prismatic way will probably be ground more on the backside to make it straight again and the matching backside on the saddle will also be worn more - so noticeably less needs to machined off the backside of the saddle way compared to the front. On the ones I have done, the end of the saddle way closest to the chuck is also worn more than the opposite end, resulting in the saddle actually being misaligned in both planes compared to where it should be.

                            The goal should be to not only machine the saddle to put it back in correct alignment wrt the ways, but to also position it correctly wrt to leadscrew. I use an alignment method that involves measuring the apron carefully for leadscrew position wrt to its front surfaces, and then transferring these to the saddle so I can determine where the saddle needs to be wrt the ways.

                            In the case of the Colchester, this was made easier by the fact there were small unworn portions of the original surfaces of the saddle ways left to indicate where it had been when manufactured. This allowed me to compare where the saddle should be for the leadscrew alignment to where the unworn areas indicated it was. Fortunately, the measurements agreed very well and validated the measurement method.

                            This proved critical on the SAG 12, as all indications of the original ways on the saddle had been worn away, and I had to rely on the measurements to calculate how much to take off each side of the prismatic way (taking into account the angle of these surfaces).

                            I tend to be cautious when approaching a problem like this, so I first machine off just enough metal to re-establish the saddle to be parallel to the ways in both planes, and then re-measure to decide how much more needs to be removed to put the saddle where it should be to align with the leadscrew while also being parallel to ways in both planes.

                            Aligning the saddle to leadscrew also aligns the pinion to the rack (presuming it was correct originally) that drives it back and forth, and thus should be carefully done to avoid having problems there at a later time....
                            TexasTurnado

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                            • #15
                              Originally posted by Richard King View Post
                              When you scrape turcite the normal depth is .002" so no need to 1/2 moon flake it.
                              I'm sure you remember that, despite your warnings, I managed to mangle the Turcite using a half-moon bit on a scraper, even at the lowest setting

                              As you showed us, it's dirt simple with the half moon bit on a hand scraper...
                              "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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