Epoxy resin products - which? why?

Discussion in 'Techniques' started by Dog Star, 3 May 2018.

  1. Dog Star

    Dog Star Western Thunderer

    To scope the topic - to get a better understanding of which epoxy products work well and which epoxy products do not deliver...

    So we have epoxy products advertised as being 1 minute, five minute, 24 hour and other various times in-between. Apart from the time for which the product is usable after mixing hardener and adhesive, how do the physical properties of the products differ with setting time? Which of the properties of epoxy resin glues ought to be considered when choosing a product?

    What materials can be glued satisfactorily with epoxy resin?

    How do specific brands vary in performance?

    As a starter, I prefer products with the Araldite brand over those with the Evo-stik brand because I get a more reliable / predictable result with the Araldite product... both for 5 minute and 24 hour versions... which seems kind of weird given that the Araldite and Evo-stik products share the same parent company. When I have used Evo-stik brand the mixed product appears to be not as firm / rigid as Araldite and in some instances gives me joints that peel apart. In most cases, failed joints are brass to resin when detailing JLTRT kits.

    thanks, Graham
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  2. Steph Dale

    Steph Dale Western Thunderer


    This is a very complex subject. First of all, I'd suggest getting away from 'consumer' grade glues and buying products where the performance is known and guaranteed. So not Araldite or Evo-Stick, but industrial versions from Henkel, Loctite, 3M and Devcon. With these adhesives there are detailed product data sheets available from the company's websites and things like handling 'pot' times will be stated. 'Best before' dates and batch codes will also be clearly marked on the packaging.

    In general; longer curing time versions are stronger, but significant impacts on that overall strength are down to cleanliness/moisture/keying of surfaces (including those used for mixing), exceeding use by dates, exceeding pot times.

    You'll get industrial adhesives through CPC, RS or other online sources very easily by mail order these days. I tend to use Devcon as it's available in my local model shop and I get consistent good results with it (e.g. split axles).

  3. Mr Grumpy

    Mr Grumpy Western Thunderer

    I took Steph's advice and used Devcon for my class 22's split axles a couple of years ago, and each axle are still in one piece.
    I couldn't get it from any local source so used Amazon.

  4. unklian

    unklian Western Thunderer

    What Steph says 100%. Broadly you get what you pay for and the faster it sticks the faster it is likely to fall apart . Devcon 5 minute is a bit of an exception to that rule I have found though .
    Last edited: 3 May 2018
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  5. eastsidepilot

    eastsidepilot Western Thunderer

    I've used Devcon for years, never had any problems. Use the 5 min. type for split axles.

  6. D816Foxhound

    D816Foxhound Western Thunderer

    As above, I use Devcon 5minute epoxy on, mainly, brass to resin, but also brass to brass, whitemetal and plastics. It works and I have not had the need to try anything else.

  7. oldravendale

    oldravendale Western Thunderer

    I use both short and long time curing versions of Devcon, and as Steph does the 24 hour version on split axles. I've only ever had one fail and I'll put that down to the surfaces being less clean than they should have been. Otherwise total success, although the 5 minute version is, in my experience, less strong than the full fat version.

  8. daifly

    daifly Western Thunderer

    I'm puzzled by the '24-hour' reference for a Devcon product. Is this the '2-ton' Devcon? There is nothing in their range that I can find that mentions 24 hours.
  9. Steph Dale

    Steph Dale Western Thunderer

    Yes, I think that's what's being referred to here. I certainly know and use the '2-ton'.

  10. oldravendale

    oldravendale Western Thunderer

    Steph is correct, of course.....I didn't check the description. I just know that it takes 24 hours to cure.

    Sorry to create confusion.

  11. daifly

    daifly Western Thunderer

    Thanks Chaps!
  12. simond

    simond Western Thunderer

    I make it about 1 hour 40 per cwt...
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  13. Bob 81C

    Bob 81C Active Member

    Devcon 5 minute every time, I used it to repair thing for customers and it's never failed on a whole host
    of materials.
    Last edited: 6 September 2018
  14. isambardme

    isambardme Western Thunderer

    Should any other Thunderers require Devcon 24 hr, I've just bought some from a Durham supplier on fleabay selling it around £5.75 inc free GPO p&p. Cheers,

    Bob 81C likes this.
  15. Steph Dale

    Steph Dale Western Thunderer

    It's worth just checking the date on the packet. The last lot I bought from a no-name supplier on eBay was out of date, so back it went...

    daifly likes this.
  16. Dog Star

    Dog Star Western Thunderer

    Steph (@Steph Dale), I hope to buy some epoxy resin adhesive at the Bristol Show this coming weekend, please post photos of your preferred adhesive products so that I and other WTers know what to look for on the trader's stands.

    thanks, Graham
    Last edited: 22 January 2019
  17. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    upload_2019-1-22_18-30-39.jpeg upload_2019-1-22_18-31-17.jpeg
  18. Ian@StEnochs

    Ian@StEnochs Western Thunderer

  19. John Bradshaw

    John Bradshaw Member

    I have used Devcon products to make repairs to highly stressed machine parts, including machining down to tolerance (not ideal I know, but at sea if you don't have a replacement spare you have to make do) and it works.

    I'd agree on the advice to go for the more industrial brands, they tend to be more expensive but they are designed around defined performance specifications. Adhesives have a bit of a bad reputation in model railways (well, maybe apart from liquid poly...) but if you make sure the jointing surfaces are clean and allow the adhesive to cure correctly you will get an extremely strong and reliable joint.
  20. Giles

    Giles Western Thunderer

    Yet another vote for Devcon ! Appears to be the best of the bunch for general use. I do occasionally use Araldite 24hr for some jobs, but the only time I ever use any other brands are when i actually want the poorer qualities of flexibility, or the ability to remove in the future (mounting gearmotors for instance...)