Cyanoacrylate (super-glue) fixturing?
Close
Login to Your Account
Results 1 to 19 of 19
  1. #1
    Join Date
    Oct 2010
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    5,083
    Post Thanks / Like
    Likes (Given)
    4325
    Likes (Received)
    1839

    Default Cyanoacrylate (super-glue) fixturing?

    We've got a one-off job coming up where we need to reduce the thickness of some stock 0.125" 6061 sheet to 0.098" and also cut some 0.050" to 0.070" slots the majority of the length of the part. My intention is to face off a sacrificial block held in the vise, then super-glue the sheet to the just-cut face, face off the sheet to the required thickness, then switch to a slotting cutter and cut through both the sheet and the sacrificial block. Release would be via industrial heat gun, possibly assisted by some (unheated!) acetone. Incompletely cut ends of the slots (due to slotting cutter diameter) would be finished by hand.

    Area of the part is 4 to 5 square inches, so I am not worried about shear. But peeling and impact resistance concern me, especially peeling from the slotting operation which might tend to pull up on the edges of the slot. Am I going to run into trouble if we use a toughened cyanoacrylate like Permabond 731, 735 or 737 (Black Magic)? Could this be done with simple methyl cyanoacrylate like Permabond 910, or am I correct that garden-variety Super-Glue doesn't have the impact resistance to hold up to milling?

    Thanks for any experience you can provide.

  2. #2
    Join Date
    Jul 2005
    Location
    central Illinois
    Posts
    233
    Post Thanks / Like
    Likes (Given)
    1173
    Likes (Received)
    86

    Default

    The kid at NY CNC on youtube has several videos of their journey sorting through what works and doesn't with those glues. Be sure to look towards their latest video on the subject, as they have kind of made it a mission of constant improvement and he shares freely.

  3. #3
    Join Date
    Mar 2001
    Location
    Switzerland
    Posts
    2,529
    Post Thanks / Like
    Likes (Given)
    2275
    Likes (Received)
    1088

    Default

    I and several folks I know have used Loctite 480 cyanoacrylate (black, rubber reinforced)for years, decades. It's fantastic for holding thin work down where no other fixturing would be practical.

    With two flat faces like that acetone would take days or more, heat is your ticket. Heat gun should work, when I need it I use a hotplate on the first setting.

  4. Likes BugRobotics liked this post
  5. #4
    Join Date
    May 2005
    Location
    Interior British Columbia
    Posts
    2,269
    Post Thanks / Like
    Likes (Given)
    235
    Likes (Received)
    689

    Default

    All the clock maker videos and books I see that use super glue for fixturing, recommend a series of slots in the base plate, to allow some air to access the middle portions (carries the moisture that 'kicks' the CA glue). It also allows the excess to go somewhere.

    Dunno how big your parts are, but would a vacuum plate work? Have seen several variations of that theme. Usually a big rubber o-ring and a checkerboard pattern of grooves to allow the ring to be strung in various directions.

  6. #5
    Join Date
    Dec 2005
    Country
    UNITED STATES
    State/Province
    Wisconsin
    Posts
    893
    Post Thanks / Like
    Likes (Given)
    11
    Likes (Received)
    124

    Default

    He is also using tape with superglue.

    Dave

  7. #6
    Join Date
    Oct 2013
    Location
    New Jersey
    Posts
    1,093
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    907

    Default

    I think Mitebite sells a heat release tape just for this purpose.

  8. #7
    Join Date
    May 2011
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    2,198
    Post Thanks / Like
    Likes (Given)
    198
    Likes (Received)
    1222

    Default

    I'd be more worried about it becoming a potato chip and breaking the bond.

  9. Likes MrWhoopee liked this post
  10. #8
    Join Date
    Nov 2017
    Country
    UNITED STATES
    State/Province
    California
    Posts
    257
    Post Thanks / Like
    Likes (Given)
    169
    Likes (Received)
    172

    Default

    I would also be concerned about it curling up when released. What's the thickness tolerance? Maybe get some "select" grade 10 gauge.

  11. #9
    Join Date
    Oct 2010
    Country
    UNITED STATES
    State/Province
    Oregon
    Posts
    5,083
    Post Thanks / Like
    Likes (Given)
    4325
    Likes (Received)
    1839

    Default

    Thickness tolerance is informally +- 0.002". In this particular situation, curling won't be an issue. The finished part will be restrained, and the customer is willing to hand-flatten if it won't initially go in the mating recess. Keeping in mind that we will have to "torch" the part to get it to release from the fixture, asymmetric stress relief due to milling one face is not my biggest concern. :-)

    The local Grainger has a bottle of Loctite 480 with my name on it for pickup tomorrow morning. We'll see how this goes.

  12. #10
    Join Date
    Dec 2008
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    10,127
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    2628

    Default

    some use thin double sided foam tape cause it has some flex to it
    .
    some super glue has some flex to it. but be aware of glueing different metals like steel and aluminum which expand at different rates.
    .
    had a steel part glued aluminum block slightly warm from milling and took to sink under cold water. they broke or fell apart in my hands from temp change. just saying if glue bond suddenly breaks it can be a problem especially if during machining.
    .
    thin foam tape like .030" thick will flex more than .001" at times but many times thats much better than bond breaking suddenly.

  13. #11
    Join Date
    Jun 2015
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    456
    Post Thanks / Like
    Likes (Given)
    955
    Likes (Received)
    161

    Default

    I use Loctite 380 and this tape from Mcmaster: 7630A43. I use these in conjunction with a freshly faced plate and clamps. Surface prep is everything to ensure good tape adhesion. Once you get it right though it's pretty secure. I always try to respect the setup and keep cuts relatively light.

    Here are a few shots of a thinner part using this process from a few weeks ago. In this case I used some dowels in the subplate to ensure alignment when flipped which also contributed to the security of the setup.

    2019-10-21-13.23.44.jpg

    2019-10-21-12.37.22.jpg

    2019-10-21-16.28.36.jpg
    Last edited by BugRobotics; 11-21-2019 at 04:19 PM. Reason: Had Loctite number incorrect

  14. #12
    Join Date
    Jul 2006
    Location
    rochester, ny
    Posts
    1,895
    Post Thanks / Like
    Likes (Given)
    380
    Likes (Received)
    521

    Default

    That's three thickness tolerances stacked up - 2 tape and 1 glue line. What is the typical thickness variation of the finished part?

  15. #13
    Join Date
    Jun 2015
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    456
    Post Thanks / Like
    Likes (Given)
    955
    Likes (Received)
    161

    Default

    Quote Originally Posted by richard newman View Post
    That's three thickness tolerances stacked up - 2 tape and 1 glue line. What is the typical thickness variation of the finished part?
    Great question. The thickness varies 0.0014" over a length of 240mm (~9.45in). Less than 0.0003" over a width of 191.5mm (~7.54in). Certainly not the quickest method as a vacuum plate would be better but for my work, typically one off parts to verify a design for my clients, works pretty good.

  16. #14
    Join Date
    Mar 2009
    Country
    UNITED STATES
    State/Province
    California
    Posts
    5,047
    Post Thanks / Like
    Likes (Given)
    91
    Likes (Received)
    922

    Default

    Quote Originally Posted by sfriedberg View Post

    Thanks for any experience you can provide.
    Many times I have been disappointed with super glue on bonds with all kinds of materials. The only thing that it does good on is skin, which is what it was originally developed for.

  17. #15
    Join Date
    Apr 2007
    Location
    mays landing NJ
    Posts
    504
    Post Thanks / Like
    Likes (Given)
    451
    Likes (Received)
    139

    Default

    Hot hide glue. removes with a heat gun. Residue cleans up with hot water . Brush on face plate ,stick part on, or let the glue cool, use heat gun on part to adhere it. I have heard but not tried shellac to adhere thin parts to a face plate. Alcohol is solvent for shellac.
    I had to thin 140 brass discs to .025 for a machine shop that did not want to bother with it. I installed an MDF scrap to a 10" face plate. Brushed hot hide glue on, stuck the pieces on and rolled them with a laminate roller while heating them with a heat gun. When faced to dimension the brass came off by heating them and scraping them off. Residue came off with hot water and paper towels.

  18. Likes BugRobotics, richard newman liked this post
  19. #16
    Join Date
    Jun 2015
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    456
    Post Thanks / Like
    Likes (Given)
    955
    Likes (Received)
    161

    Default

    Quote Originally Posted by mike 44 View Post
    Hot hide glue. removes with a heat gun. Residue cleans up with hot water . Brush on face plate ,stick part on, or let the glue cool, use heat gun on part to adhere it. I have heard but not tried shellac to adhere thin parts to a face plate. Alcohol is solvent for shellac.
    I had to thin 140 brass discs to .025 for a machine shop that did not want to bother with it. I installed an MDF scrap to a 10" face plate. Brushed hot hide glue on, stuck the pieces on and rolled them with a laminate roller while heating them with a heat gun. When faced to dimension the brass came off by heating them and scraping them off. Residue came off with hot water and paper towels.
    Ah, I've never tried hide glue but I'll have to now. Thanks!

  20. #17
    Join Date
    Jan 2011
    Location
    PA
    Posts
    420
    Post Thanks / Like
    Likes (Given)
    136
    Likes (Received)
    121

    Default

    I have had pretty good luck with carpet tape. I will admit though I have not needed to do anything tighter than +/-0.005

  21. #18
    Join Date
    Aug 2006
    Location
    Cape Cod, Ma
    Posts
    457
    Post Thanks / Like
    Likes (Given)
    177
    Likes (Received)
    96

    Default

    I've used the nycnc method. It worked awesome. saved me from making fixturing for a bunch of 1off parts.

  22. #19
    Join Date
    Sep 2019
    Country
    UNITED STATES
    State/Province
    Maryland
    Posts
    12
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    3

    Default

    The tape and superglue method work well but another method that I think works better is to create a slotted fixture, 1/8 slots that go through the fixture so that it looks like a grate with slots running all the way down. Next face off an aluminum plate and place the sheet on the plate then place the slotted fixture on your sheet and use a hot glue gun to inject glue through the slots to the back side of your sheet. You can also just cut up the glue sticks and put the pieces in the slots and put the entire thing in an oven. The hot glue will seep though the slots to the backside of your sheet. This method also allows you to place a weight on the fixture so that there are no air gaps between the fixture and sheet.

    So it should look like this
    _________________
    | Oven |
    |_________________|
    | |
    | Weight |
    | Slotted fixture |
    | Sheet |
    | Faced off plate |
    |_________________|


    Best parts are no tolerance stack up issues like with the tape and super glue and glue can be reused since gravity will cause remainder to stick to back of next sheet.
    Do not use the hot glue you get at Walmart it is very weak compared to normal hot glue. Weak hot glue has its place but this is probably not it.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •