Release problem W/Chemlease #15

Discussion in 'Fiberglass and Composite Boat Building' started by Thin water, Sep 26, 2006.

  1. Thin water
    Joined: Aug 2005
    Posts: 100
    Likes: 2, Points: 0, Legacy Rep: 26
    Location: Central Florida

    Thin water Senior Member

    I bought a few molds that were used with Chemlease #15 Mold release. I tried to use PVA on them and it fisheyed badly so I cleaned off the PVA and applied the Chemlease per dirrections. I have made two center consoles with it but the mold does not have a lot of draft and the parts are a real problem to get out. I am thinking about drilling a hole in the mold and putting in an air fitting so I can blow it out and would like to use PVA so I can just soak the part out. Any suggestions on prepping the mold to allow for PVA use? I have a part stuck in the mold now and have wooden wedges all around the flange hoping that it will pop with the sun heating up the mold. Below is a picture of the last console I managed to get out of the mold.

    [​IMG]
     
  2. Buckle
    Joined: May 2004
    Posts: 83
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Plymouth, UK

    Buckle Composite Engineer

    mould release system

    Hi, We have used chemlease for many years, and the system is a very reliable system provided moulds are maintained, treated with respect etc.

    C15 from my understanding is a sealer. Depending upon the type of tooling gel, typically 1 or 2 sealers are required. (Applied with an hour delay between coats). If you were to gel, apply pva onto C15 sealer, it will fish eye like mad.

    TO over come this problem, we usually apply 6 monocoats an hour later (3 mono's, 1 cure, 3 monos). Monocoat is of lower slip than C15 sealer. The monocoat will reduce this fish eyeing.

    Using just the C15 system is the cause for your problem.

    To prevent pre-release, we also apply one wax to adhesion.
     
  3. tja
    Joined: Sep 2004
    Posts: 126
    Likes: 1, Points: 18, Legacy Rep: 11
    Location: canton oh

    tja Senior Member

    Tja

    Hello. Seal the mold with two coats of sealer 15 let it sit over night and then four to five coats of Chemlease PMR. Make sure mold temp is at least 70 degrees. The warmer the mold is the better the release cures. They make two versions of PMR one has more slip then the other. Since you have little draft use the one with more slip. If you contact Chemlease they can further advise you. Get rid of the PVA it will not work with any chemlease products. Good luck. Sincerely, Tom.
     
  4. fiberglass jack
    Joined: Dec 2005
    Posts: 463
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    Location: toronto

    fiberglass jack Senior Member

    get out the drill, and drill a hole say 1/8 at the bottom of the mould ,before u gel place a small piece of scotch tape over it, to release make sure there is no resin sticking the part to the mould around the flange, with a dull punch tap the part thru the mould to start the release them place a airblower gently release the air into the hole u should hear the air releasing the part to much air and the part may explode like a bomb be careful, when u drill and the part is still on the mould try not to drill through the part if u do place some tape over to stop the air
     
  5. Thin water
    Joined: Aug 2005
    Posts: 100
    Likes: 2, Points: 0, Legacy Rep: 26
    Location: Central Florida

    Thin water Senior Member

    Chemlease

    I see from the above posts that the #15 is a sealer, not a release in itself. That explaines a lot. The guy I got the molds from mentioned that he used Chemlease mold release and gave me the can of #15. I ASSuMEd it was what he had been using and since I have only used PVA I did not know the difference. I go the part out with hot water without hurting it or the mold.
    Thanks for the replys, I am going to add the blow hole. Thanks fiberglass jack for the info on blowing up a part. I hadn't considered that but it looks like a very dangerous situation. If you blow 100 lbs/sq in air pressure into the mold and have a 10" x 10" area lifting it makes for 1000 lbs of lifting pressure (10" x 10" x 100 lbs/sq in). Water under pressure is much safer since it looses all pressure if the mold gives/breaks at all and since it does not compress it won't expand after a failure shredding the part and you with debris. My father is an engeneer and they pressure test with a small tube of water going into the part at high pressure, if it fails only a few drops drip out.
     

  6. fiberglass jack
    Joined: Dec 2005
    Posts: 463
    Likes: 16, Points: 0, Legacy Rep: 95
    Location: toronto

    fiberglass jack Senior Member

    i use air all the time use a airgun the type to blow dust off ur self with
     
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