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any fiberglass xperts here

Discussion in 'The Hokey Ass Message Board' started by 32v, Jan 23, 2012.

  1. 32v
    Joined: May 20, 2007
    Posts: 952

    32v
    Member
    from v.i.

    looking for some info on what to finnish a metal plug i made to make some glass copys of , basicaly an 18 gauge metal box .after i body work it what do i coat it with so the fiberglass wont stick to it. i am building a heater plenum
    thks for any help
     
  2. Cerberus
    Joined: May 24, 2010
    Posts: 1,392

    Cerberus
    Member

    I have used mold release with excellent results. Johnson paste floor wax works. I've enen used saran wrap when there are no reverse curves.
     
    Last edited: Jan 23, 2012
  3. mashed
    Joined: Oct 15, 2011
    Posts: 1,474

    mashed
    Member
    from 4077th

  4. 32v
    Joined: May 20, 2007
    Posts: 952

    32v
    Member
    from v.i.

    sooo should i paint the metal plug or leave it in primer ???
     

  5. Tin Foil works also
     
  6. ROCKIT
    Joined: Sep 1, 2006
    Posts: 80

    ROCKIT
    Member

    We used to paint plugs in 2K so it could be polished and waxed or coated in release agent.
     
  7. 35 Dodge Hot Rod
    Joined: Nov 29, 2007
    Posts: 182

    35 Dodge Hot Rod
    Member
    from Mecca

    Anytime you're making a mold it will turn out much better if the plug isn't painted. Put your wax release on the plug and let it dry, buff it out to a sheen. Repeat several times.

    Different paints have different results with release agent, it's best not to tempt fate and have a ruined part if your mold doesn't pull.
     
  8. VWJon
    Joined: Dec 13, 2011
    Posts: 9

    VWJon
    Member

    No Paint ! Ever !
    If you 2K it I would Highly recommend using PVA over Part-All paste wax. 2K is very porous and can cause your molds Gelcoat to grab mechanically and thats not fun. Infact the same can be said for Bondo as well.

    I have been build FG molds and sculpting FG for over 23 years now and there isn't much I can't do with it.

    Give yourself a good flange and do not over catalyze to keep your warpage down.

    Laos keep in mind that your parts will be going to be thicker then your metal parts at the mounting points and so therefore you'll need to account for that by offsetting the outside edge for your mounts by as much as 3/16''. If you go to thin it will have little strength.
    Pay attention to how you plan to lay up your parts as well. sometimes you can mold something and not be able to get to it to glass it. Thats why some of your complex parts are done it multiple pieces when they will pull in a one piece mold. Also your flanges help guide a razor knife your gonna wet trim and reinforce your edges to keep from warping and aid in pulling your parts.

    Aluminum foil tape is your best friend. Cover your flanges with it ans it will inure a perfect separation. can be used for a release film as well but will leave lines so if you plan to wet sand your mold out and buff it ( good idea ) it can be done but its better to not use it for that. I use it for toolling or one off quickie molds... those molds usually get thrown away when done anyway.

    Hope this helps you out.
     
  9. 2manytoys
    Joined: Feb 24, 2009
    Posts: 225

    2manytoys
    Member
    from Fresno

    Go to the Fiber Glast web site and find the learning center. Read, follow and understand all the instructions on the site. I built my Divco rear fenders and many other parts with 'glass and have been happy with the results. As long as you don't try any shortcuts you will be fine.
     
  10. Da Tinman
    Joined: Dec 29, 2005
    Posts: 4,227

    Da Tinman
    Member

    your gonna laugh but cover the mold with masking tape. something magical about the tape that glass wont stick.
     
  11. Never2low
    Joined: Jan 14, 2008
    Posts: 1,149

    Never2low
    Member

    I've done alot of FG molds for car audio. I usually mask, then two layers of foil. The only problem with foil, as VWjon stated, is that if you have curvatures, it can leave undesirable wrinkles in the finished product. As odd as it sounds, Pam cooking spray makes a great release agent. Also be aware of "finishing resins" that contain wax. Wax is added to aid in the sanding process. If you plan on multiple layers you have to sand in between layers to prevent delamination of layers.

    Materials: http://www.uscomposites.com/

    Tutorials: http://www.fiberglassforums.com/
     
  12. firingorder1
    Joined: Dec 15, 2006
    Posts: 2,147

    firingorder1
    Member

    I'm making a new body for my LSR sidecar. Its a one off so I used a male plug and covered it with foil. Used a roller to get it as flat as possible. Popped right off and the wrinkles are on the inside. True it took a skim of bondo to get a flat surface but foil is great for a release agent.


    [​IMG]
    By weslake at 2012-01-18
     
  13. steve283
    Joined: Jan 17, 2012
    Posts: 13

    steve283
    Member
    from cincinnati

    top notch info,only thing i would add is watch amount of catalyst used,it can kick hot easy.personal choice follow directions and watch the negative places that can lock the part in the mold.
     
  14. 32v
    Joined: May 20, 2007
    Posts: 952

    32v
    Member
    from v.i.

    thks guys lots of good info, i think i will body work it smooth , male plug cover it with hvac aluminun tape and wax the hell out of it
     
  15. My dad learned me the tin foil trick.. also works great for masking off things. Looking good!
     
  16. chaos10meter
    Joined: Feb 21, 2007
    Posts: 2,191

    chaos10meter
    Member
    from PA.



    No Paint ! Ever !

    This is confusing to me, every fiberglas boat mold I have ever seen is painted ?
     
  17. budd
    Joined: Oct 31, 2006
    Posts: 3,478

    budd
    Member

    i have worked in a fiberglass plant in the past, mostly i worked on winding machines, they are used to make pipe anywhere from 1/2" DIA up to 8ft DIA, we also made boats, truck hoods, ventilation systems and you name it, the pipe molds were stainless, everything else was gelcoat, all we ever did was use paste wax, maybe 4 coats all done by hand, no mold release, the part your making has to be made so it will come out and flat sides of a box could be tough, something we also did was drill small holes, 1/8", in the molds to pump air in after, the holes we covered with scotch tape cut with sissors so we didn't end up with those little saw tooth edges sticking up, the tape is so thin it didn't take much work to finish later, your layup should be as many layers of mate as you can within reason with just enough resin to soak it out, useing rollers is a must, heat lamps to help it kick off will speed the process up alot.

    heres the company i worked for only it was owned by someone else back then, the same plant is running in Mahone Bay NS. heres a couple pics of the plant, on the company site they talk about a pole used to launch life rafts off oil rigs, i was there when that was devloped and worked on the first one, i was also there when we pulled it off the mold and it did not want to come off, it was a fun place to work and learn about fiberglass.

    http://www.rpscomposites.com/index.html
     

    Attached Files:

    Last edited: Jan 24, 2012
  18. VWJon
    Joined: Dec 13, 2011
    Posts: 9

    VWJon
    Member

    No paint ever means no Paint. does not mean surfacing agents such as urethane or polyester sanding primers.

    When I say paint I mean latex, enamels, laquers.... so materials that are actually catalyzed and not subjective to being dissolve by solvents. Such as those found in Polyester resins.

    When using Foild I apply Super77 to both the foil and the surface. Then I squeegee it down as smooth as possible.

    A styrafoam EPS sculpture to get covered in foil.
    [​IMG]
    Covered in foil and half way glassed
    [​IMG]
    The finished project.
    [​IMG]
    Picture of me working on it in Gelcoat.
    [​IMG]

    Theres alot of pictures of other people acting like they are working on it on that page but it was done by me and the girl in those pics. the others just posed with it.
     
  19. Never2low
    Joined: Jan 14, 2008
    Posts: 1,149

    Never2low
    Member

    Holy Crap, That's cool!
     
  20. chopolds
    Joined: Oct 22, 2001
    Posts: 6,031

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

    OK, I realize some of you are very good at your fiberglassing jobs, but i don't get the "no paint" part, at all! Paint is much slicker, and less porous than any primer, or surfacer. It should be a smoother mold if the plug is smoother, and that usually means painted.
    Case in point...I've done a few plugs and mold to build some glass parts. Heater/AC plenums, parts to modify existing fiberglass noses, or ground effects, even an entire lower nose piece for an OT foreign car. Did the mods, finished off my filler work, and primered and painted it as if it was finished (of course the mods were done in cardboard, or mesh and filler, not meant to be permanent). Painted and polished the parts as if it were part of a real car. Then did the molds, using wax and water based parting agent. Waxed and parting agent-ed the molds and laid up the final products. No problems at all.
    now I'm not an expert, but if a beginner could do this, why discourage using paint as a final coating, as said, smoother, less porous, and also shiny enough to see imperfections that can be fixed, whether it's pinholes, scratches, or waves?

    BTW, the finished parts came out almost PERFECT, so that I only needed a dust coat of primer for the paint to stick to it. No wrinkles, pinholes, tape edges or anything in the final surface.
     
  21. One of the hardest things to get out of a mold is a square box. If you put a small amount of taper (draw) on your mold , it will make release a lot easier.For a mold that will see continued use, I suggest using tooling gel-coat. It is formulated to withstand the curing cycles of continued use. For a quickie, or one off, regular gel-coat will work . I use a PVA mold release over the waxed mold for the first pull and then many coats of mold release wax between lay-ups. Nothing worse than having time and money tied up in a project that you can`t get out of the mold.
     
  22.  
  23. VWJon
    Joined: Dec 13, 2011
    Posts: 9

    VWJon
    Member

    Yeah, I have run chopper guns alot too.

    I say no Paint so as to help someone who has not done this to not make a mistake by using the wrong paint and having problems. I highly recommend PVA over Part All #2, especially for a one off or low run mold. The really fun stuff is when your running a high run large round parts and using a static release agent. You get one hell of seriosu shock when pulling your parts.

    I agree alot of paints are less pourous and all that. But when it melts or sticks its just a nasty mess. Especially when it messes up your surface and all. I would use Gelcoat on the plugs when ever possible actually.

    As far as Draft goes angle at which to make the mold slide off, I like to use a 2 degree draft whenever possible.

    I like to use cardboard covered in foil tape or 1/4 Luan to make them. Get yourself some Kleen Klay if you are gonna be making flanges.
     
  24. chinarus
    Joined: Nov 9, 2010
    Posts: 504

    chinarus
    Member
    from Georgia

    I am not a newbie to fiberglass but been several years since I did some major repairs to friends race car. Bought some resin at local chain store and was going to do a quick layup on a roof to see how it came out for some headliner panels.. I thought I was using plenty of hardener but may have cut back too much because I was afraid of the temp but the material might be bad as it is still tacky after 8 or 10 hours. I was thinking of mixing up another batch and mixing it "hot" to see if it would kick off the first layer. I can't get the stuff into the sunlight but it is pretty warm in the daytime in the shed. Do I just scrape this stuff off and start over or give it a try?

    Thoughts?
     
  25. Is it soft or just sticky? Do you have laminating resin or finishing resin? Laminating resin will stay sticky so that the next layer will adhere to it. Finishing resin has a wax added to it so that the top surface is not sticky.
     
  26. chinarus
    Joined: Nov 9, 2010
    Posts: 504

    chinarus
    Member
    from Georgia

    Soft and sticky. I used the common stuff you buy at all auto parts and hardware stores
    Bondo 402 3m 1 Quart Fiberglass Resin
    Not any boat repair places close by and I have used this stuff in the past
     
  27. chinarus
    Joined: Nov 9, 2010
    Posts: 504

    chinarus
    Member
    from Georgia

    Found the 3M Specs - for the experts:

    SECTION 2:INGREDIENTS
    Ingredient C.A.S. No. % byW t
    POLYESTERPOLYMER Trade Secret 40 - 70
    SILICA 7631-86-9 0.5 - 1.5
    STYRENE MONOMER 100-42-5 30 - 60

    Intended Use: Automotive
    Specific Use: Fiberglass Repair Resin
     
  28. More than likely the hardener has gone bad. They MEKP hardeners degrade fairly quickly espcially if they have been exposed to any U.V. That being the case you may need to use more hardener than you think because it is not as strong. Look on the crimped end of the tube for a 6 digit number. The first is the year of manufacture the next two are the month if it is more than a year old so if the number is 108XXX or smaller get new hardener before you go any further. If it is critical I would remove what you have done and start again if not you might try putting another coat on.
     

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