(Topic ID: 177052)

Repairing cracked and broken plastics

By cottonm4

7 years ago


Topic Heartbeat

Topic Stats

  • 13 posts
  • 8 Pinsiders participating
  • Latest reply 4 years ago by PinballAir
  • Topic is favorited by 16 Pinsiders

You

Linked Games

No games have been linked to this topic.

    Topic Gallery

    View topic image gallery

    IMG_2830 (resized).JPG
    IMG_2829 (resized).JPG
    IMG_2817 (resized).JPG
    IMG_2822 (resized).JPG
    IMG_2821 (resized).JPG
    Screen Shot 2016-12-29 at 10.14.52 AM (resized).png
    IMG_2815 (resized).JPG

    #1 7 years ago

    I have read some posts on Pinside on how to repair cracked and broken plastics. I never thought an of the posts offered a final resolution. But I think I have the solution many are looking for. HINT: It is not superglue.

    After trying a superglue repair that did not work, I went to my local plastics supplier and asked what would be needed to repair cracked and broken PETG plastics. What she sold me was a product called Scigrip 3; She also sold me a syringe and needle to use for application.

    This stuff works !! You probably can't tell it in the picture but that is not an industrial needle. That is a sharp needle like a doctor or junkie would use. This is all you need. Just push the plunger ever so slightly and watch the fluid flow.
    IMG_2815 (resized).JPGIMG_2815 (resized).JPG

    http://scigrip.com/products

    Here is a screen shot of the website. What you are looking for is Scigrip 3.
    Screen Shot 2016-12-29 at 10.14.52 AM (resized).pngScreen Shot 2016-12-29 at 10.14.52 AM (resized).png

    What is neat about is product is that (in my limited experience---I have repaired two plastics, so far) that it flows like water and it does not eat the inks on the plastic parts. This is the backside of a plastic I just put back together. There are several cracks and one chuck was completely broken out. I did not do anything special; I was lazy and did not bother cleaning the cracked and broken areas before I started slopping on the adhesive.

    IMG_2821 (resized).JPGIMG_2821 (resized).JPG

    IMG_2822 (resized).JPGIMG_2822 (resized).JPG

    This is the front side after the bonding repair. Trust me, the repair is solid.

    IMG_2817 (resized).JPGIMG_2817 (resized).JPG

    After I made the bond, I sanded off the excess adhesive and smoothed the repair area. I did some experimentation and found that PETG plastics can be buffed and polished on a buffing wheel without melting. I still need to sand this area and polish a little bit more, but I now have a solid and serviceable part. It won't look perfect, but under glass it won't look bad.

    For plastics repair, my opinion is that this is the way to go.

    IMG_2829 (resized).JPGIMG_2829 (resized).JPG

    IMG_2830 (resized).JPGIMG_2830 (resized).JPG

    #2 7 years ago

    Will be curious to see how this holds up under game play conditions, how much did the can of Scigrip run you?

    #4 7 years ago

    Thanks for adding that thread. I sure missed it. Lots of good info in that one.

    3 years later
    #5 4 years ago

    I bought scigrip 3 and industrial syringes. If you come across this thread, do not waste your money if your game is an old chicago coin.
    I tried it on a plastic for a 1975 Olympics. It did nothing.
    It did not soften old plastic at all. It dried too quickly to fasten plastics. And is too thin (viscocity) To work without submerging plastic in it. At that point you risk loosing the screen printing.
    I do not know if it will work on modern plastics but i will not be trying that. It is headed for the trash.

    #6 4 years ago
    Quoted from PinballAir:

    I bought scigrip 3 and industrial syringes. If you come across this thread, do not waste your money if your game is an old chicago coin.
    I tried it on a plastic for a 1975 Olympics. It did nothing.
    It did not soften old plastic at all. It dried too quickly to fasten plastics. And is too thin (viscocity) To work without submerging plastic in it. At that point you risk loosing the screen printing.
    I do not know if it will work on modern plastics but i will not be trying that. It is headed for the trash.

    Sorry it did not work for you. I have no explanation.

    The piece of plastic in post #1 is still going strong after 3 years.

    I like the thin viscosity. The liquid flows into all of the cracks easily. No need to submerge.

    #7 4 years ago

    That is why i was specific about the game and the age.
    It looks like it worked great on your plastic.

    #8 4 years ago

    Uhhhh.... Mylar.

    #9 4 years ago

    I've used Scigrip #4 with similar outstanding results.

    It's a solvent welding process which utilizes Dichloromethane to fuse the parts together. This weld is stronger then glue and has held up for years in my pinball plastic repairs.

    #10 4 years ago
    Quoted from rplante:

    I've used Scigrip #4 with similar outstanding results.

    I have been thinking about trying it myself.

    Do you know what the difference is between #3 and #4?

    #11 4 years ago

    Chicago coin plastic may be polycarbonate instead of acrylic or part.

    #12 4 years ago
    Quoted from Phantasize:

    Do you know what the difference is between #3 and #4?

    https://www.google.com/search?q=scigrip+%233+vs+scigrip+%234&oq=scigrip+%233+vs+scigrip+%234&aqs=chrome..69i57j0.10763j0j7&sourceid=chrome&ie=UTF-8

    One is flammable. One is not.

    "Q: What is the difference between Weld-On 3 and 4 clear, water-thin acrylic solvent cements? A: Weld-On 3 is non-flammable and very fast setting. Weld-On 4 is flammable and moderately fast setting. Both are water thin clear solvent cement for bonding acrylics."

    #13 4 years ago

    #Zitt
    I had that same feeling. Perhaps CC used a different plastic than other manufacturers.
    I also thought it just may be too old and whatever the scigrip reacts with has long left that old plastic.

    Reply

    Wanna join the discussion? Please sign in to reply to this topic.

    Hey there! Welcome to Pinside!

    Donate to Pinside

    Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!


    This page was printed from https://pinside.com/pinball/forum/topic/repairing-cracked-and-broken-plastics and we tried optimising it for printing. Some page elements may have been deliberately hidden.

    Scan the QR code on the left to jump to the URL this document was printed from.