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Thread: 5 Minute 'Waterproof' Epoxy

  1. #1
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    Default 5 Minute 'Waterproof' Epoxy

    I've noticed on a couple of forums that people are under the impression that 5 minute epoxies are not waterproof, so aren't used for submarine model making or repairs.

    I've been selling epoxies for over 25 years and I've only every encountered this on submarine forums, so I'm puzzled how this snippet of information came about. It seems to be 'cast in stone' these days.

    The hardener in these epoxies is a mercaptan, and has a strong, garlic-like odor to it and is easily recognizable. It does not have the same adhesive strength as the slower curing materials, and it is usually a paste-like material, so I can imagine it letting loose on a plastic or very smooth surface, so maybe this is the reason some have had failures?

    I've used 5 min epoxies in many underwater situations and never had any problems, so I'd like to hear from anyone who has, just to see what they did.

    The base part of the resin system is usually the same material used in the slower curing resins, only the hardener being different, so the material is actually waterproof. Bond strengths are lower, but still strong enough for anything on a submarine model.
    Stop messing about - just get a Sub-driver!

  2. #2
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    ME-
    we have a product here called 5 min araldite - its meant to be H20 proof expoxy - but the moment the dry product is saturated it tends to de-laminate / de bond. It feels all flexible to touch rather than a hard solid.

    Have watched a U boat sub surface all by itself.
    Operator was perplexed as why the boat had surfaced - lots of TX input and nothing.
    Waded into lake to bring her in relieved that what ever the problem the sub was on the surface - WRONG!
    Poor chap discovered what he was seeing was just the deck. It had delaminated /de bonded from the boat proper. All that TX input was actually driving the boat at a fair clip into harms way - the boat took 3 weeks to find at my local dam using professional divers.

    Oils ain't oils and not all products I guess are the same.
    It would be nice to know which ones are ok and which have these quirks to be avoided.

    J
    Last edited by Slats; 06-10-2010 at 11:18 AM.
    John Slater

    Sydney Australia

    You would not steal a wallet so don't steal people's livelihood.
    Think of that before your buy "cheap" pirated goods or download others work protected by copyright. Theft is theft.




  3. #3
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    Default

    I don't use epoxies at all for subs since discovering modified acrylic adhesives. They really are the dog's doo-daas.

    Deluxe Fusion, Devcon Plastic Welder, Stabilit Express etc.

    They do pong a bit, not as bad as polyester resin, but still enough to rattle the missus if you're working in the house. They also sand really well and accept fillers.

    Andy
    Last edited by Subculture; 06-10-2010 at 12:38 PM.
    DIVE IN! Go on, go on, go on, go on, GO ON! http://www.diveintomodelsubmarines.co.uk

  4. #4
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    Default

    I bored out the sail window on the Kilo and filled them in with extra strength slow set epoxy from ACE Hardware to represent the glazing. The epoxy dried to a translucent amber. Curious thing is that the epoxy didn't harden as I expected it would. It has a somewhat rubbery feel. Well the notes at the back of the pack claims it's resistant to solvents, moisture and impact. I remember seeing a marine version which I assume can be used on boats. Unfortunately the store no longer stocks it.
    Make it simple, make strong, make it work!

  5. #5
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    Default

    As the Germans say- the devil is in the detail.

    When they say something is water resistant, that means it will withstand the odd shower from a watering can. You need something that is waterproof, and that's what it should say on the tin.

    I too have found epoxy adhesives tend to remain 'chewy', I think that is part of the idea to help retain flexibility.
    DIVE IN! Go on, go on, go on, go on, GO ON! http://www.diveintomodelsubmarines.co.uk

  6. #6
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    Default

    I think the reason why my epoxy has a rubbery consistency. I may have made an error in the mix ratio of the resin/hardener. Since the components come from individual tubes I may have squeezed out more hardener. I remember reading that adding more hardener to the resin doesn't mean it'll be hard.

    I initially attached my Kilo's resin stern planes using the slow set epoxy. I clamped the resin and styrene together using rubber bands to get a close fit and squeeze out extra epoxy. Here I noticed that the epoxy set hard and the resin stern piece was firmly attached to the styrene.

    Later I found out how good or bad the bond was when I was fitting the movable planes and the square brass tubing. It was a tight fit and I was pushing the brass piece in when I heard a loud crack. The front half of resin port stabilizer snapped off it's attachment point on the styrene hull.


    I cleaned the cured epoxy off the attachment point and used regular CA and baking soda to rebond the stab to the stern.
    So 1 stab is attached with epoxy, the other with CA. We'll see which one holds when I finally get the kilo wet..
    Make it simple, make strong, make it work!

  7. #7
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    I just won't use it, especially when there are so many good alternatives.

    To add to my recent post on this - I have also seen a 4 piece Revell hull of the Flower Class part company with 5 minute araldite letting go. Ok the guy should have welded the plastic with a proper stryene hobby glue.

    As far as mixing goes the 50:50 ratio of 5 minute araldite is not going to alter the bond much if you make a SLIGHT differential error. Yes you should aim to take all care to nail the ratio precisely but the manufacturers fully anticipate the end user is likely not to nail it every time.

    I now use Bostik Titan Bond Plus for all wet exposes and submerged applications - hell this even sets underwater! Working time is 15-30 minutes, initially cures in 3-4 hours, sets hard in 24 hours, but keeps on curing for up to 7 days.

    http://bostik.co.nz/directoryproduct...erwater%20Glue

    here is the Tech data sheet:
    http://bostik.blackweb.co.nz/doc/TITAN%20BOND.pdf

    If I need a quick 5 minute fix for a minor part- I use Green ZAP CA.

    If I need to position a part quickly that needs a tough expoxy bond, I will cut a drain channel into the part to take the Titan Bond glue, tack adhere the outside of the part in position with a few drops of Green ZAP CA, mix the Titan bond, and then pour it into the drain channel, utilising gravity.
    Alternatively
    For say installing the a dive plane horizontal assembly (like in your photo), I will drill and insert brass pieces into the assembly and dove tail these into corresponding holes drilled in the hull. I will then apply Titan bond to the hull and assembly and push fit these together. I then clean up any overrun with a rag, support the hull and assembly at right angles and leave to set for 24 hours before doing the other side. Slow - but good processes occasionally take time.


    J
    John Slater

    Sydney Australia

    You would not steal a wallet so don't steal people's livelihood.
    Think of that before your buy "cheap" pirated goods or download others work protected by copyright. Theft is theft.




  8. #8
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    Default

    Quote Originally Posted by Slats View Post
    ME-
    we have a product here called 5 min araldite - its meant to be H20 proof epoxy - but the moment the dry product is saturated it tends to de-laminate / de bond. It feels all flexible to touch rather than a hard solid.

    Poor chap discovered what he was seeing was just the deck. It had delaminated /de bonded from the boat proper.

    J
    Araldite is a Ciba Geigy product, nothing shabby about it at all. What this looks like to me is a wrong choice of product, as I can't imagine trying to glue a deck to a boat with a fast setting epoxy. How would you get that all along the hull before it started setting up? I suspect the resin had partially cured before he'd finished.
    It would also be interesting to know what the boat was made of, and what surface prep was carried out. Epoxies don't just give up, they fail because of - bad surface prep, bad mix ratio, bad mixing, inadequate temperature.
    Stop messing about - just get a Sub-driver!

  9. #9
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    Hi Mike,
    I still use Araldite but not the 5 minute variety. With what you identified here
    "surface prep, mix, temp, and the speed it which it cures", makes a lot of sense.

    I think with those potential errors possible -as you state it comes down to choice of application or perhaps poor choice for some jobs. That is I think the 5 minute stuff would be best used for minor small jobs - rather than lasting large ones such as the Flower hull and the U boat missing its deck.

    All good info.

    Thanks
    John
    John Slater

    Sydney Australia

    You would not steal a wallet so don't steal people's livelihood.
    Think of that before your buy "cheap" pirated goods or download others work protected by copyright. Theft is theft.




  10. #10
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    Default

    That Titan Bond plus looks a superb adhesive, unfortunately it doesn't seem to be available outside of Australia.

    There are a far more limited range of adhesives to modellers here in the UK for some reason, generally if you want the really GOOD stuff you have to look at industrial grade products. Unfortunately they tend to come in industrial quantities with corresponding price tags- frustrating.
    DIVE IN! Go on, go on, go on, go on, GO ON! http://www.diveintomodelsubmarines.co.uk

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