resin weeping

Discussion in 'General Modeling' started by raucutt, May 10, 2003.

  1. raucutt

    raucutt New Member

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    I've already progressed quite a way on my resin model project before I noted the resin had some weeping. I noted the paint was disforming. Any cures for this? I've put in a lot of work, and I really don't want to do massive restoration.
    Many Thanks in advance.
    Bob
     
  2. Sluis Van Shipyards

    Sluis Van Shipyards Master Member

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    I'd wait for someone else to chime in on this because I'm not an expert, but I've heard heating resin parts in the oven will cure some problems like that.
     
  3. Harlock

    Harlock Well-Known Member

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    Did you wash the parts with soap and water before you started painting? That's a must. In the areas where the paint is getting funky, try sanding back down to the bare resin, and wash the bad areas with DENATURED ALCOHOL. Then, re-prime and paint.

    John
     
  4. raucutt

    raucutt New Member

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    I washed the parts. I tried cleaning with alcohol. In one area, I sanded down and put down a layer of bondo, that seem to help there, but it appeared the weeping migrated further to a new area. Very frustrating, especially since over all the piece looks so good.

    Will these things just dry themselves out over time??
    Thanks,
    Bob
     
  5. Jedi Dade

    Jedi Dade Sr Member

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    The only time I had problems with resin weeping was if I didn't use enough hardener int he casting process. If that is the case you' repretty much screwed. You can try heat, but heat can sometimes to as much damage as good since ALL of the resin will get soft in the heat. It should help the checmical process to finish and harden the weeping spots, but I've had pretty poor luck trying to fix weeping resin. If it was a kit you purchased I'd talk to the seller, if it was something you cast yourself I'd recast it being more careful with the mixing ratio for your resin.

    And as always wash your parts with warm soapy water before doing anything with them [​IMG]

    Sorry to hear about the problem and I hope you get it straightened out.
    Jedi Dade
     
  6. Vinyl Guy

    Vinyl Guy Well-Known Member

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    I've been told by several people either in the urathane industry or kit manufactures that certain urathanes have a greater propensity to "weep." This is either due to their nature or they may be more sensitive to proper weighing. Their advice has been to stay clear of the white resins and use those that are more off-white. By off-white, I mean the color like those used by Backlot Studios on their TIE Bomber, Backlot's X-Wing & TIE stand, or on CC's X-Wing.

    Dan

    "Vinyl Guy
     
  7. rayra

    rayra Well-Known Member

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    funny, I've seen the opposite, the white-curing resins routinely seem better and easier to work.
    It's the cheaper or past-shelf-life or improperly-mixed urethanes that screw you.

    low-temp cooking (~200F) is the only way I've heard of, and even that is no solution if the resin is really fubar.
     
  8. minieffects

    minieffects Well-Known Member

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    To be honest it really comes down to the quality of the resin and the proper use. I have used dozens of resins in my 19 years in the film industry. the major contributors to resin weep is low cost resin that has alot of oils in it and poor quality control in the mixing process. This is really a tough problem to solve because you dont know the extent of the damage. You could clean affected areas and the oil will secrete elswhere. In addition typically heat accelerates the problem. Even though urethane resin is an exothermic cure it needs to be properly weighed and mixed. Over the years I have found 5 companies that seem to deliver quailty material:

    BJB enterprises http://www.bjbenterprises.com/
    Smooth on http://www.smooth-on.com/
    Silpak http://www.silpak.com/
    Ptm&w http://www.ptm-w.com/
    and recently Motion Picture Effects in burbank ( http://www.makeupkits.com/) I use there procast now and love it. and the cost is resonable.
    And by the way typically the reason for the difference in color of resin because each type has different properties, shore hardness, cure time, demold time. etc..


    One of the reasons I dont go near resin kits, unless I know its creator, is because the person typically producing them is doing it on the side and is trying to keep costs down. They then charge a fortune for bad product. There are reputible people out there its just a matter of finding the right ones. I personally would send it back and demand a better copy or my money back.

    Sorry about your problem, hope it works out for you.

    Minieffects


    Side note. you can also contact the manufacturers and ask there tech support what the best fix for urethane leaching is. I will call a couple of my distributors and ask.
     
  9. cobywan

    cobywan Sr Member

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    It's almost impossible to deal with. We had a casting in the shop that weeped right through a CA patch. The best bet is to grind out a large pocket around the weep point and patch it with Bondo. But it probably won't work.
     
  10. REL

    REL Sr Member

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    Like other's said, it was either bad resin or it wasn't mixed right. There's really nothing you can do but ask for a replacement, sorry man.
     
  11. Blad

    Blad Sr Member

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    <div class='quotetop'></div>
    Nice generalisation :(



    Weeping resin usually comes down to improper mix as stated, heating can help to cure, but it'* and miss. Sanding right back may help, cutting out the area if possible would be best. Ideally try and get a replacement.

    Good luck. :)
     
  12. Jestefarean

    Jestefarean Sr Member

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    The only weaping I have encountered is with the Smooth-On 320 series resin. (and Smooth On owns up to this issue) It's a tan resin that is prone to seperation (in it's individual parts) The end result is you have to be obsessive about premixing the A+B components individually before mixing the resin, and then be aggressive with mixing the 2 components together. IF you do this it seems to work well, if you don't throw the piece out and start over. Ive actually sworn off the resin, which I love, because Ive lost to much to seperation.

    There are other causes, but I thought I would share for anyone who uses the 320 series and who has run into this. The good news is, if you are consistent with the premixing, and mixing it is a very nice resin.
     
  13. minieffects

    minieffects Well-Known Member

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    <div class='quotetop'></div>



    <div class='quotetop'></div>

    My intention was not to gereralize, I was just pointing out that in my expeirence I have seen more bad kits than good. Not to say that there are not alot of great kits and people out there producing them. In all industry you have high quality products and you have cheap knock offs, the same applys to the resin kit industry. Dont you agree. If I offended anyone I do apologize. :)

    My strongest advice is buyer beware. Try to research the company or person making the kit. Check with the forum or on the web and see if anyone has had bad results with a particular person or persons.

    all the best
    minieffects
     
  14. Don Jarr

    Don Jarr Active Member

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    Hi all

    Up until recently I have bought and used loads of different resins, from very cheap to more expensive ones, (surprisingly the cheapest one I buy is a fast cast two minute cure one, and that sets perfect each time. Stir it gently, and little or no bubbles.)

    However I recently I bought some 30 min cure white smooth-on for something I was making and it was the first time using smooth-on. Mixed as per instruction, I took the cast out the mould and it was fine, left it on the bench which is in the sun, and when I returned 30 mins later it had been weeping at just random little spots. I stuck it in my oven for 15 mins on 200 degrees and left it in there till the oven is cold, and up to now it has cured the problem permanently in the few times it has done it. DoesnÂ’t do it everytime, just now and then.

    Try curing it off in a oven m8, and if you donÂ’t have a separate oven for this, place the cast in one of those sealable roasting bags, as it gives off fumes which is not nice if you cook dinner in the same oven.

    :) Don
     
  15. cobywan

    cobywan Sr Member

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    Make sure you GENTLY shake your two resin parts half an hour before you need to use them. The "B" components are prone to seperation an that causes weeping too. Just give the resin enough time to de-bubble before casting.
     

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