will TR-104 mold release (carnuba wax) migrate into PE/VE resin? How to prep for adheasion after?

Discussion in 'Boatbuilding' started by leaky, Jan 21, 2018.

  1. leaky
    Joined: Sep 2008
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    leaky Senior Member

    I'm building corecell sandwich parts on a table, mostly just flat panels, still got a bunch to do, up until now was using PVA sprayed onto my surfaces.

    The PVA has become less practical in the temperatures we have now, last time I used it I believe it was frosting up a bit on the surfaces and it caused very long drying times (even when warmed back up) and seemed to undermine the mold release qualities leading to some sticking. Also the use of water is harder now, where before I could rinse my parts and/or clean the mold surface thoroughly with a hose that option is gone. I've got ways to keep things room temp to cure the resin but with the wax mold release I can avoid some of that process since it's not water based like the PVA.

    So for the above reasons, I'm moving onto wax for the next so many parts this winter. Haven't use it a ton especially lately and when I have I always think about the same things - how do you know it's cleaned off? And since it seems to dissolve in solvent, what keeps it from migrating into the resin?..

    A couple things I'm wondering is should I do anything to help prevent migration of the wax into my actual part? For instance I have considered rolling a coat of resin on and letting it cure some just to make sure any migration would stop there - is that helpful or not needed? These parts are not gelcoated during molding rather they are cleaned, sanded with a 40 grit geared sander to a rough/dry surface, cleaned again, then tabbed into the boat to be finished later. Then secondly - as far as cleaning the mold release off my parts - what is the right process to use?

    Thanks in advance!

    Jon
     
  2. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    As long as you have applied the wax correctly there is no concern about wax migrating into the laminate.

    But if the ambient temperatures are low you may run into release problems if the resin sits uncured on the wax for extended periods of time.
     
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  3. leaky
    Joined: Sep 2008
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    leaky Senior Member

    Thanks!

    Just wondering so to make sure I do not do that, how would you not apply it incorrectly so it could migrate? Want to make sure not to do that!

    I put 6 coats on yesterday, letting it cure for an extended period overnight. Directions said "for best results" put another coat on, let harden, then proceed but I'm not sure if those results are related to finish or release.

    That's interesting on the temperatures too - what makes the temperature cause things to stick?

    Maybe that's what went south with my PVA last time. I keep the panel heated in place for 2 to 3 days (which includes a cover on the top of the panel I weight down) then I will leave the panel there for a good week or so - trying to minimize potential warping.

    Jon
     
  4. ondarvr
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    ondarvr Senior Member

    The resin can slowly dissolve the wax, so if it's cold and the resin sits uncured on the mold surface for extended periods of time it may stick.

    Follow the directions on the can for best results.
     
  5. leaky
    Joined: Sep 2008
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    leaky Senior Member

    Ahhh Ok that makes sense thanks again! I actually wonder if the reason why I had some problems w/ the PVA may have been similarly related to such a situation - my first couple parts went perfectly but it almost seems as the temperature dropped the release got worse and worse.

    I built that panel today, when I was done I changed from the small heater that keeps the tent room temperature ballpark after some time, to my big heater that slams the temp right up to 100 degrees - figured I'd make sure it cures quickly to avoid what you are describing. On some drips that landed on waxed surfaces away from the panel I noted they had absolutely no adhesion to the surface and peeled right off - so appears to be working very well, actually better than PVA it seems.

    What is lacking on the can is any description of how to remove the wax, which is funny because on the can they state it's easy to remove :). My best idea is to use the interlux stuff advertised for mold wax removal and probably follow up with a wash w/ soap designed for dewaxing and degreasing.

    Jon
     
  6. jorgepease
    Joined: Feb 2012
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    jorgepease Senior Member

    I remember trying to glue some fiberglass angles using plexus and the adhesive failed. I was told it was because of leftover wax on the part. I would double check that since you aren't using gelcoat.
     
  7. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    Any surface that was to be bonded should be cleaned anyhow, and mold release products don't last that long on a surface after de-molding.
     

  8. leaky
    Joined: Sep 2008
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    leaky Senior Member

    Whatever the case I'll certainly clean it, sand/grind with a 40 grit, and clean it again before I try to bond to it.

    Jon
     
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