How to fix Jobo plastic?

Discussion in 'Darkroom Equipment' started by 36cm2, Nov 18, 2009.

  1. 36cm2

    36cm2 Member

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    Making big strides in setting up my darkroom, but took my CPE2 processor out of storage today and it's got 2 small cracks and a puncture in the plastic of the water trough. Any ideas on the best way to seal them? I'm not sure what to use that will be 100% watertight, permanent and not eat the plastic. As always, your collective depth of knowledge is greatly appreciated.
     
  2. MikeSeb

    MikeSeb Member

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    Don't know where you're located, but if JB Weld is available there, us it. It'll do the job. It won't look pretty, however.
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    A Walther's product named GOO will make watertight seals on small holes. On larger holes you can use it to glue a patch over the hole or crack. It is thick like Syrup and very sticky but if given time to dry will be quite water tight and water repellant.

    PE
     
  4. Kino

    Kino Member

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    Marine Epoxy, if give time to properly cure, is a good way to fix a Jobo.
     
  5. John R.

    John R. Member

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    Absolutely, a marine epoxy such as West System or System Three is definitely the way to go. Do not use the 5 minute epoxy, the cure is not as robust. You would want to use the West 105 resin and 205 fast or 206 slow hardener (depending on the open working time you need). Temperature has an effect on working time before it kicks so take that into consideration.
     
  6. 36cm2

    36cm2 Member

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    Wirelessly posted (BlackBerry8330/4.3.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

    Thanks guys. I was thinking marine epoxy as well, but will look into the Goo and JB weld as well. I didn't think Jb weld stuck to plastic, but it's been years since I've used it.
     
  7. Anscojohn

    Anscojohn Subscriber

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    Marine-Tex is also good. It even cures under water.
     
  8. Photo Engineer

    Photo Engineer Subscriber

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    GOO sticks to everything in the universe. :D

    PE
     
  9. Perry Way

    Perry Way Member

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    sounds like a booger :surprised:
     
  10. Kevin Caulfield

    Kevin Caulfield Subscriber

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    They make it from boogers.
     
  11. Kirk Keyes

    Kirk Keyes Member

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    I thought boogers were made from GOO?
     
  12. Firestarter

    Firestarter Member

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    I recently repaired a crack and a chip from one corner of my CPA2 top cover using fiber glass sheet and resin. I repaired it on the underside and then sanded the repair flush on the front side, resprayed it with a red paint and sealed it all with clear lacquer and it looks like new. I think a resin or epoxy glue on its own won't add much strength to the repair and may crack again. I am almost tempted to cover all the underside of the tray as it makes it so much stronger as they are very flimsy as standard.

    I have also used these materials to fabricate an unusual shaped shore for my gutter drains and it works perfectly with no leaks so water is not an issue.
     
  13. 36cm2

    36cm2 Member

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    Thanks again to all for your tips. Went to the hardware store and asked them for some Goop. Cashier said he didn't have any. He kept blowing his nose a lot. Empirically that could support either of the Goop/booger chicken or the egg theories. Not wanting to probe further, I asked him if he had JB Weld. He did and my CPE-2 is now nicely slathered and curing. Hopefully tomorrow it won't look like a sieve in action. Firestarter, I think your method is the most comprehensive but, as I am generally lazy and unmotivated, the Goop/Weld options prevailed.
     
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  15. Kirk Keyes

    Kirk Keyes Member

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    Ha! That's a good one.
     
  16. Andrew4x5

    Andrew4x5 Member

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    I would recommend a urethane based product because it sticks to anything and it remains flexible when it dries (like your Jobo processor). McNett Corporation makes a number of variants, such as "SeamGrip" (used to repair wetsuits and tents) and "Freesole" (used to repair running shoes). They are generally sold in sports stores.

    Andrew
     
  17. ic-racer

    ic-racer Member

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    I would try a 'welding' type of glue that melts the plastic back together. Like Tenax.
     
    Last edited by a moderator: Nov 20, 2009
  18. Photo Engineer

    Photo Engineer Subscriber

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    Some plastics will not melt. IDK if Jobo plastic is that type, but I suspect it probably is.

    PE
     
  19. paul ewins

    paul ewins Member

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    For hairline cracks in the Jobo processors and the drums my first choice is a liquid plastic cement of the type used for model aircraft. This is the sort that comes in a bottle and is brushed on, rather than in a tube. The advantage is that it will get drawn into the crack by capillary action and "weld" it shut. They aren't any good for larger gaps since they don't add any new material. The "Testors" plastic cement I use is actually Methyl Ethyl Ketone, while when I was in high school we used Methyl Methacrylate for the same purpose.
     
  20. 36cm2

    36cm2 Member

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    Filled it up with water today. Looks watertight. Very very happy.
     
  21. John R.

    John R. Member

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    The advantage of using epoxy like West System, Systems Three, MAS or other brand is that epoxy will flex even though it will hard cure. The 5 minute types have even greater flex but the bond is not quite as structural. Other resins, such as poly based are very brittle when cured. They are a wide range of DIY type epoxies hanging on hooks in stores. These simple epoxies can vary greatly in bond strength on various substrates. Surface preparation is very important no matter what you use. Products like Goop and other standard household adhesives should not be used if you desire a long duration quality repair. Another factor is that epoxies are gap filling adhesives, whereas many standard adhesives are not.
     
  22. Doc W

    Doc W Subscriber

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    Slightly off topic, but I have to share. I have a large darkroom "spillyway," i.e., not a sink that can hold water but a long trough made of wood where I put my trays for printing. It is covered with water resistant paint and last summer, I wanted to make it a little more water resistant so I bought some very serious marine paint. When it came time to do the job, I read the instructions which pointed out that this paint was pretty nasty stuff and should be used only in an extremely well-ventilated environment. Hmmmmm, I thought. My darkroom is ventilated but ... Anyway, I called the manufacturer and told this young guy on the line my situation. He replied, and I am not kidding:

    "You really need to use this like it says, in a well-ventilated place like ... the OCEAN."
     
  23. 36cm2

    36cm2 Member

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    That's ok Doc. I'm installing an ocean in my darkroom. I'm also going to put in an island and have Gilligan and the Skipper take turns agitating my negatives.
     
  24. Doc W

    Doc W Subscriber

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    Maybe haul out the longboards and catch a few waves while the prints are drying.

    Now let's see, Ginger or Mary Ann.. Hmmmm

    Sounds excellent to me!
     
  25. johnnywalker

    johnnywalker Subscriber

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    This is my experience also, but the stuff I used was in a tube. I broke the sheet film feeder along the glue line and tried lots of glues, including epoxy. Nothing worked. Finally emailed Freestyle, who contacted Jobo. The answer was model airplane glue. Worked perfectly. Some of the glues I tried worked on other plastics, but not the Jobo. Turns out each type of plastic can have very specific glues.
     
  26. Ronald Moravec

    Ronald Moravec Member

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    MEK or Acetone both available from the hardward store. USE outside.

    If the plastic will not melt, then the marine epoxy with a styrene sheet over the crack.

    For a temporary repair, MMM waterproof tape. It will stick to a dry surface and no amount of water will wash it off. I use it over paint chips on a car during winter. Some have been on for years sealing the metal. Get the wide clear. It will not stick to anything already wet.