Mold polishing procedure?

Discussion in 'Fiberglass and Composite Boat Building' started by Willie, Jun 11, 2007.

  1. Willie
    Joined: Oct 2005
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: South Africa

    Willie Boat builder

    Hi

    I need some advice on mold polishing procedures. We have made a new mold for our 21ft production boat, but are constantly having problems with hulls being stuck in this new mold and a lot of time is being lost doing gel repairs on the mold and product.

    I would really appreciate any advice that you guys can give me.

    Thanks
     
  2. waikikin
    Joined: Jan 2006
    Posts: 2,440
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    Location: Australia

    waikikin Senior Member

    pva

    Willie, you wanna wax your mold like 5-6 times & use PVA at least for the first few pulls or forever if your happy doing the extra prep & cleanup with it, even though it can downgrade the finish(often improves a crappy molding surface) its way better than wasting time on gel repairs, & also how about draw angles & a split mold to ease part removal. All the best with it from Jeff:)
     
  3. JRL
    Joined: May 2007
    Posts: 83
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    Location: Palm Beach Gardens, FL

    JRL Im with stupid

    Ive found semi permanant mold release to be stupid proof if you follow the insturctions to the "T". As in 20 minutes means 20 minutes...no exceptions.

    If you try it make sure you put your most detail oriented guy on the job. People who take short cuts, and/or, are bad with time need not apply (they dont even need to be in composites for that matter).

    Once your mold is prepped with this stuff its a real time saver.
     
  4. tja
    Joined: Sep 2004
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    Location: canton oh

    tja Senior Member

    Tja

    Find and use Chem Trend PMR as per directions. This is a semi permanate mold release that works very well. If the mold is new use sealer15 first and then PMR This is the only product I use. I've gone as high as 30 pulls before retreating the mold with one coat and then put back into production. Make sure your shop and the mold temperature is at least 70 degrees F. The warmer the mold is the better. When you wipe it off use two cotton towles. One to take most of it off and the other to wipe it completely dry to avoid streaks. Do not use Free Coat. The smell will kill you. Good luck.
     
  5. gunny
    Joined: Dec 2005
    Posts: 19
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    Location: stl,mo.

    gunny Junior Member

    where do you find chem trend pmr at? i did a web search and came up with nothing ...sounds like a good product vs partall paste and pva (which does work pretty good)..
     
  6. tja
    Joined: Sep 2004
    Posts: 126
    Likes: 1, Points: 18, Legacy Rep: 11
    Location: canton oh

    tja Senior Member

    Tja

    Go to www.chemtrend.com and click on locations. Call the number listed and they will be able to give you the dealer closest to your location. Tom.
     
  7. gunny
    Joined: Dec 2005
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    Location: stl,mo.

    gunny Junior Member

    thanks tja , will do..
     
  8. the1much
    Joined: Jul 2007
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    Location: maine

    the1much hippie dreams

  9. pacific808
    Joined: Nov 2007
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    Location: Hawaii

    pacific808 New Member

    What works for us when we are using new or used molds puchase from other is. A good watersandind with 1200. Then a thourough rubbing out with compound. then a polish with wax. Lastly a thourough waxing with mold realese 3x minimum. We also spray PVA every time, at times it seems redundent but why change something that works.
     

  10. Jeff Therrell
    Joined: Jul 2005
    Posts: 37
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    Location: Granite Falls NC

    Jeff Therrell Junior Member

    Axel mold release has a new product.This is a sealer and release combination XRT sealer and 818 release you put 2 coats of sealer and 3 coats of release. We released small parts in an hour and a half with no sticking problem.This was the fastest and slickest release I've ever used.
     
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