Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: Adhesive

  1. #1
    Join Date
    Feb 2016
    Location
    East Anglian
    Posts
    638

    Default Adhesive

    A very basic piece of advice please. The best adhesive to glue an amber cabochon of 8mm into an 8mm bezel set ear stud and any general words of wisdom.

  2. #2
    Join Date
    Dec 2009
    Location
    Central London
    Posts
    8,845

    Default

    There is no need to glue cabochons. They are he easiest of all shapes to set if you make your own cup.
    Bought cups of course do not fit most stones of the same nominal size unless the stones are man made.
    Just watch some videos on the subject, or buy a simple book for beginners, such as Anastasia Young.

    Amber being rubbery will not glue well, because glues tend to be rigid. If you are desperate to finish, try gel superglue. Dennis.

  3. #3
    Join Date
    Aug 2010
    Location
    England
    Posts
    1,902

    Default

    I would suggest that you try Araldite Instant which sets quickly and is a clear glue, see; https://www.amazon.co.uk/Araldite-In.../dp/B006JYQ1I6 I have used this glue many times when required without any trouble, when set it is colourless and does not effect the colours of semi transparent stones.

    James

  4. #4
    Join Date
    Feb 2016
    Location
    East Anglian
    Posts
    638

    Default

    Thanks again for your advices.

  5. #5
    Join Date
    Jan 2018
    Location
    Derbyshire
    Posts
    130

    Default

    Ah, just the info I was looking for.
    My design doesnt involve completely flat surfaces so if it’s going to work it needs a good adhesive. Do you think it would be secure enough for something like this?
    Click image for larger version. 

Name:	CC33CB72-03E4-41B9-99EA-81F031A8B4E3.jpg 
Views:	20 
Size:	11.6 KB 
ID:	11482
    The sea glass doesn’t have a highly polished surface but the silver will obviously be smoother. Would I perhaps need to slightly roughen the surface on the metal at the point of attachment?
    Hazel

  6. #6
    Join Date
    Dec 2009
    Location
    Central London
    Posts
    8,845

    Default

    It's not completely clear why you want to glue your sea glass Hazel, perhaps a picture of it would help.

    In principal glues work better on roughened surfaces, because that increases the surface area. Both gel superglue and clear epoxi, such as Araldite help to fill small gaps where the fit is uneven.
    That said, mechanical retention is more certain to work in the long term and less likely to yellow the colour as it ages. Dennis.

  7. #7
    Join Date
    Sep 2011
    Posts
    1,086

    Default

    It's a common misapprehension that glue should be applied to roughened surfaces because it increases surface area. In fact the opposite is true. Glues work by making permanent a vacuum between the two surfaces. The thinner the adhesive layer the better the adhesion. You don't rough up a solder joint, do you? Solder will only flow across a close, smooth and tight joint.
    Author: Pearls A Practical Guide
    www.pearlsapractical.guide
    www.Pearlescence.co.uk

  8. #8
    Join Date
    Mar 2016
    Posts
    116

    Default

    Quote Originally Posted by pearlescence View Post
    It's a common misapprehension that glue should be applied to roughened surfaces because it increases surface area. In fact the opposite is true. Glues work by making permanent a vacuum between the two surfaces.
    Pearlescence, are you sure about that? It worried me but I'm no glue scientist myself; I found this in the Guardian's Notes and Queries:

    'How does glue work, why is it sticky and how can it bond seemingly impervious substances like glass and metal?

    MOST adhesives work by first flowing and spreading over the surfaces of the materials (e.g. the glass or metal) to be joined. This obviously requires the adhesive to be of a relatively low viscosity so it is often sticky to the touch. The flowing and spreading action needs to be extremely effective so that the atoms of the adhesive and the materials to be joined come into contact with each other. This allows the molecules of the adhesive to be attracted to those of the materials being joined and then 'intermolecular forces of attraction' (present in all materials) can now hold the adhesive to the surfaces of the materials being joined. Note that the adhesive does not have to react chemically with the glass or metal. Finally, to be able to resist separation of the joint, the adhesive must usually now harden. Some adhesives do this via loss (by evaporation) of the solvent or water into which the adhesive had been dissolved by the manufacturer of the glue. Others do this by chemical reactions occurring within the adhesive to form a (strong) polymeric adhesive.

    A J Kinloch, Professor of Adhesion, Imperial College, London SW7'

    Note: According to The Royal Society 'Anthony Kinloch is the acknowledged world leader in the science and technology of adhesion'
    Last edited by Paul Kay; 31-07-2018 at 10:27 AM.

  9. #9
    Join Date
    Jan 2018
    Location
    Derbyshire
    Posts
    130

    Default

    Thanks for replies.
    Dennis, I've glued because I couldn't think of a better way to fix it into the domed shell with my current skills. Neither the glass nor the metal are a flat regular shape so it would be really tricky to make and fit a soldered bezel and I'm just not that keen on wrapped wire designs. Plus if I wrap it in wire it loses the impact of the colour pattern in the glass.
    How would you approach a design like this?
    Hazel

  10. #10
    Join Date
    Nov 2017
    Posts
    946

    Default

    Perhaps solder 4 prongs to the inside of the dome?

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
  •