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5200 versus 4200

Discussion in 'Technical Discussion' started by Nordhavn68, Dec 1, 2011.

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  1. Nordhavn68, Dec 1, 2011
    #1
    Nordhavn68

    Nordhavn68 New Member

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    Dec 31, 2009
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    Seabreeze, Delaware
    I have just had to remove 2 of my Cantilupi underwater LED lights from the transom of our boat. This was due to the fact that the inner light cartridge which failed was made of aluminum and its clearance within the bronze housing was so tight that galvanic corrosion had sealed the iner core to the outside making it totally impossible to remove. Not a good design. The original fixture to hull installation used 3m 5200. It took me 6 hours per fixture to remove them without damaging the hull or lights. I have limited experience using 4200 but would certainly like to avoid the process I have just been thru if I ever have to remove these in the future.

    Does anyone have an opinion on 4200 specifically in below water line thru hull applications? Fixture housing temperature is not a problem as the LED units do not run hot. Any wisdom is appreciated.

    David
  2. RT46, Dec 1, 2011
    #2
    RT46

    RT46 Senior Member

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    i have had some luck using a heat gun to help remove the stuf.
  3. Capt J, Dec 1, 2011
    #3
    Capt J

    Capt J Senior Member

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    I used a spray product I think it's called DeBond, that is made for removing 5200 and softens it up quite a bit, that and a good razor knife. It helps quite a bit. 4200 says "for above the waterline" on the cartridge and is not designed for under the waterline.
  4. Nordhavn68, Dec 1, 2011
    #4
    Nordhavn68

    Nordhavn68 New Member

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    Location:
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    The 3M website says above or below WL but I have not looked on a tube as I wanted to make sure 4200 would be ok. The other issue that concerns me somewhat I drooping since the sealant will be applied to a fitting that is horizontal rather than vertical. Maybe 5200 Fast Cure would be the best thing to use, especially since the outdoor temps are fairly low and I need to be able to relaunch in a week to 10 days?
  5. Capt J, Dec 1, 2011
    #5
    Capt J

    Capt J Senior Member

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    You can use the fast cure, if temps are low. 5200 will also cure under water as well. The tube of 4200 I have right here says above the waterline. I'd want 5200 under the waterline personally.