Results 1 to 8 of 8
  1. #1
    Join Date
    Apr 2009
    Location
    Perth
    Posts
    3
    Post Thanks / Like

    Default West Systems 2-part Epoxy Resin - Removing Bubbles

    Hi All,

    With the help of a friend, I recently completed making a computer desk from a Marri slab, and as anyone who has worked with Marri will know that there was a fair bit of filling to do for the massive voids and sap lines.

    We used West Systems 2-part epoxy resin which gave excellent results, but found that small air bubbles were a problem a lot of the time.We did our best with a pin, but I've since read on this forum that people have some other tips for removing bubbles, such as:

    - Stir resin and the hardener together slowly with a wide stirrer;
    - Use a heat gun to heat the voids in the wood before pouring the epoxy in. This apparently makes the bubbles rise to the surface because the wood is warm;
    - Use a heat gun (low pressure) on the resin once it's poured in.
    - Then pop remaining bubbles with a pin.

    I heard from the guy that I got to do the initial levelling and sanding of the slabs that you can hook up a hose to your car exhaust and blow the exhaust onto the affected area of resin shortly after pouring and this dissipates any bubbles...something to do with the Carbon Monoxide in the exhaust?

    I never actaully tried it, but interested to know, does anyone have experience with this, and does it work?

    Cheers,

    Chris

    (this is my first post - I really enjoy the forum and the feedback everyone gives)

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many
     
  3. #2
    Join Date
    Oct 2008
    Location
    Perth
    Posts
    1,001
    Post Thanks / Like

    Default

    A big breath from your mouth will usually work. Sometimes I use 25mm retic pipe and breath down it.

  4. #3
    Join Date
    Apr 2009
    Location
    Perth
    Posts
    3
    Post Thanks / Like

    Default

    Hi Wongdai,

    I forgot to mention in the thread above, we did try this with small straws, but found it wasn't that effective. It was also a tough slog seeing as we used so much resin over such a large slab. Another problem with this was that condensation formed in the straw after a while and occasionally dripped into the wet resin, resulting in a cloudy spot.

  5. #4
    Join Date
    Jul 2008
    Location
    Mandurah WA
    Age
    52
    Posts
    1,628
    Post Thanks / Like

    Default

    Hey Chris,

    My experience with filling voids with epoxy, you shouldn't use layers of more than about 6-7mm, sometimes you may need to do 3 or 4 layers to get them level. Also pouring from a height of 250 - 300 mm leaves a stream of about 1 - 1.5 diameter, this breaks up the bubbles before they get to the void, you cannot rush epoxy, if you build up too quick, you get clouds because the resin hasn't had time to disipate the heat and the vapours from curing, you won't see any layers from above the fill, only if you can see from the sides.
    The idea of blowing on the job is to use the carbon dioxide to disipate the bubbles, a propane torch is best, but don't get too carried away,(or blown away) waving the flame about 200mm above the job will work wonders. The rule of thumb that I was taught was if it was warm enough to work in a Singlet and shorts, about 25 degrees C (Minimum) don't bother mixing the brew. I usually leave the gear out in the sun before mixing the brew so that everything is warm, and haven't had a problem since.

    Just my 2 bobs worth.

    Just noticed you are in Perth, Have a chat with Charlie or Lainee at Fibreglass and Resin Sales, they will set you straight. (No affiliation just a satisfied customer)

    HazzaB
    Last edited by HazzaB; 26th Feb 2010 at 11:07 PM. Reason: added info
    It's Hard to Kick Goals, When the Ba^$%##ds Keep moving the Goal Posts.


    Check out my Website www.harrybutlerdesigns.com.au

  6. #5
    Join Date
    Apr 2009
    Location
    Perth
    Posts
    3
    Post Thanks / Like

    Default

    Hazza,
    Thanks for the tips, I'll keep them in mind for the next time, and thanks also for the contact.
    Cheers, Chris

  7. #6
    Join Date
    Mar 2009
    Location
    Geelong
    Posts
    52
    Post Thanks / Like

    Default

    The best way to remove bubbles from epoxy once you've mixed it is to put the mixture under vacuum. This may be difficult without a pressure pot of some sort and a pump but certainly works. I guess try other peoples methods first as they would be much cheaper.

    Ash

  8. #7
    Join Date
    Mar 2011
    Location
    AVOCA BEACH
    Posts
    27
    Post Thanks / Like

    Default

    hi do you think that vibration will work to dissipate the bubbles. so using like a concrete vibrator to vibrate the resin??

  9. #8
    Join Date
    Oct 2006
    Location
    Tallahassee FL USA
    Age
    72
    Posts
    4,395
    Post Thanks / Like

    Default

    I don't think carbon monoxide (from car exhaust), or carbon dioxide (from breath) is the active ingredient.

    Low-pressure wind, e.g. from breath (if you can maintain long enough), or a hair dryer at its lowest heat setting, creates a slight vacuum above the epoxy or varnish, so that the bubbles pop from internal pressure. The same principle (called Bernoulli effect) lifts airplane wings. Also used in venturi to create vacuum in carburetors and other applications. Leaf blowers can create a similar phenomenon.

    Cheers,
    Joe
    Of course truth is stranger than fiction.
    Fiction has to make sense. - Mark Twain

Similar Threads

  1. How to remove air bubbles from clear resin
    By gmcginty in forum FINISHING
    Replies: 21
    Last Post: 17th Dec 2012, 11:08 AM
  2. Epoxy: Techniglue Versus West Systems
    By thumbsucker in forum WOODWORK - GENERAL
    Replies: 16
    Last Post: 23rd Jun 2007, 12:44 PM
  3. Epoxy resin
    By kiwioutdoors in forum BOAT DESIGNS / PLANS
    Replies: 9
    Last Post: 29th May 2007, 10:54 PM
  4. West Systems HELP Please
    By Quokka in forum WOODWORK - GENERAL
    Replies: 11
    Last Post: 27th Jan 2006, 12:31 PM
  5. Need help-Removing bubbles from Envirotex
    By Chart in forum FINISHING
    Replies: 6
    Last Post: 13th Aug 2005, 07:53 AM

Tags for this Thread

Posting Permissions

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