caulk: polyurethane or silicone?

Discussion in 'Roof/Floor Repair & Maintenance' started by nomoretent, Jun 10, 2011.

What is your preference for exterior seam seals?

Poll closed Jun 13, 2011.
  1. polyurethane caulk (eg 3M™ Marine Fast Cure 5200 Adhesive Sealant)

    8 vote(s)
    61.5%
  2. 100% silicone

    4 vote(s)
    30.8%
  3. acrylic latex with silicone added

    0 vote(s)
    0.0%
  4. sythetic rubber solvent based thermoplastic (eg dyco 20 20 or Quad OSI)

    2 vote(s)
    15.4%
  5. other (please post a brief why)

    1 vote(s)
    7.7%
  1. nomoretent

    nomoretent Member

    Messages:
    387
    Likes Received:
    2
    Joined:
    Jun 5, 2011
    I've read hundreds of responses on which type of sealant to use to caulk roof seams. I thought I'd make it easy and just do a poll. I know a lot of people feel pretty strongly based on their experiences using caulk, I was just hoping to get a feel for a % preference.

    WARNING: I am a newbie so if I phrased something wrong or missed an option, please feel free to nicely correct me. :)
     
  2. jenryan

    jenryan New Member

    Messages:
    137
    Likes Received:
    0
    Joined:
    Mar 27, 2010
    I'm in the begining stages of a sideboard replacment and i have been spending hours reading posts.....one thing that sticks out is the 3M Marine caulk - 5200 & 4200. 4200 is half the strength of the 5200 and designed to be removed if needed. 5200 is considered permanent. I purchased the 4200 at Ace Hardware for 15.99 per tube. Best price I could find and no shipping!
     
  3. Xolthrax

    Xolthrax Franconia, Pa.

    Messages:
    4,649
    Likes Received:
    12
    Joined:
    Mar 17, 2007
    Location:
    Franconia, Pa. Butter capital of the East
    I used 3M 5200 based on an article in RV magazine and advice from a friend who used to repair RV's for a living.
     
  4. EastBeast

    EastBeast NO soup for you!

    Messages:
    183
    Likes Received:
    0
    Joined:
    Jul 20, 2010
    Thumbs up on the 3M products.
     
  5. rabird

    rabird Howdy!

    Messages:
    7,415
    Likes Received:
    599
    Joined:
    Mar 3, 2006
    Location:
    N. TX
    I didn't care to do this more than once and knew what it might look like if I tried to caulk.

    I went with ETERNABOND ROOFSEAL WHITE 2" X 50' ROLL

    Easy and functional. Looks: dirt seems to stick to the tape, especially where I push on the roof to get it in and out of the garage.
     
  6. Bullfrog Bheer

    Bullfrog Bheer Well-Known Member

    Messages:
    2,880
    Likes Received:
    26
    Joined:
    Feb 19, 2010
    Location:
    Central Wisconsin
    I used the 3M 5200. It took a while to fully cure but I'm really happy with the end results and it seems like some top quality caulk.
     
  7. Popsrock

    Popsrock New Member

    Messages:
    29
    Likes Received:
    0
    Joined:
    May 24, 2011
    Bullfrog Bheer - please define "a while to cure". Thanks.
     
  8. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    15
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    I've used what came OEM with the camper and that was the 100% silicone.
    The main reason is that it is adequate for the job it is supposed to do (has lasted five years for each application, although Starcraft recommends sooner) - but more importantly, it can be removed (and quite reasonably), should a repair/replacement become necessary. Maybe also add that I have removed the silicone (and all silicone residual) from the roof using alcohol and not damage the original paint.

    There are tougher caulking agents that can be used, for sure, but getting them off should it become necessary can be a problem.
     
  9. nomoretent

    nomoretent Member

    Messages:
    387
    Likes Received:
    2
    Joined:
    Jun 5, 2011
    Flyfisherman: very reasonable response.

    I'm worried we're shooting ourselves in the foot by trying to get the best of bost worlds: were using 3M polyurethan 4200 which is supposed to be semi-removable (now what the heck does SEMI-removable mean???) [:!]
     
  10. Flyfisherman

    Flyfisherman New Member

    Messages:
    3,682
    Likes Received:
    15
    Joined:
    Mar 4, 2003
    Location:
    Shallotte, North Carolina
    I don't know. Most 3-M products are high quality (they ought to be for the price they charge!). Have no idea what it would involve removing the 4200.
    But let me say what I do know about the urethane sealant used for automotive windshields. No better sealant could be used, just look at all the windshields it holds in place all around the world! You bust a windshield and when they go to replace the glass they CUT the old urethane sealant where it's connecting the glass to the metal. Then they lay another fresh bead of urethane sealant over the old and slap the new windshield over that. And when the sealant sets it's a done deal. It ain't EVER coming off!

    So there you are. (Decisions, decisions, decisions). But I think I might check into that semi-removal option before I used the stuff for a better understanding of what I might be in for down the road ... just in case.
    Oh, and post back what you find out so I'll know!
     
  11. Xolthrax

    Xolthrax Franconia, Pa.

    Messages:
    4,649
    Likes Received:
    12
    Joined:
    Mar 17, 2007
    Location:
    Franconia, Pa. Butter capital of the East
    For standard 3M 5200, that means 7 days, and not one day less (just ask my jeans!)

    It's a bugger to remove, but not impossible. I rest easier knowing how strong it adheres.
     
  12. Bullfrog Bheer

    Bullfrog Bheer Well-Known Member

    Messages:
    2,880
    Likes Received:
    26
    Joined:
    Feb 19, 2010
    Location:
    Central Wisconsin
    I think the directions said: at 70 degrees, 48 hours tack free and 7 days to fully cure.
    Well it was no wheres near 70 degrees when I did it and I used paint thinner on my finger to smooth it out...that didn't help it to cure any faster, but it sure looked good and professional when it was done.
    In my case, I'd say it was closer to 2 weeks before it was good and cured.
     
  13. gunrock

    gunrock New Member

    Messages:
    49
    Likes Received:
    0
    Joined:
    Aug 12, 2010
    River Forest told me they use geocel 2300. I used it, awesome stuff. You can pick it up at abc supply locally for $6 a tube or probably any other local roofing company as its used by roofers too.

    That is cheaper than a lot of caulks offered by the RV dealers too. You can get info on it on geocel's website. They respond quickly to e-mails.
     
  14. rj laney

    rj laney New Member

    Messages:
    55
    Likes Received:
    0
    Joined:
    Jul 23, 2011
    i restored my roof 2yrs ago,coleman corners were replaced with 3x3 stainless angle then fiberglassed the ends to cover up where the oringinals curve, then coated whole top with elastomer roof coating (8 coats) used butle tape down where center seam was(couldnt see it with coating on) added trim piece then put thin bead of 100% silicone on edges of trim. also used tape on roof rack and did edges with silicone, pup was left uncovered for the 2 yrs in very hot weather and cleaned up very nicely with no signs of problems so far.if i ever have to reseal again i think i would just run masking tape down middle of trim(so i could get screw cover trim back in)and coat edges with same roof coating.this stuff cures great and reduces heat plus useing roller leaves nice uniform texture. no caulking on roof at all.. :)
     
  15. turborich

    turborich Active Member

    Messages:
    1,908
    Likes Received:
    6
    Joined:
    Jun 22, 2010
    Location:
    Las Vegas, NV.
    GE Groov silicone caulking. It withstands UV, heat and cold, doesn't shrink, paintable, doesn't attract dust, remains flexible.

    I haven't used the 3M caulking but their other products are very good.

    Any caulking is probally better than no caulking though. Roofs leak & rot out due to lack of maintenance.
     
  16. freenaz

    freenaz Member

    Messages:
    823
    Likes Received:
    1
    Joined:
    Jun 7, 2011
    Great question I was about to do a search on this.
     
  17. nomoretent

    nomoretent Member

    Messages:
    387
    Likes Received:
    2
    Joined:
    Jun 5, 2011
    Follow up:

    A year later and the 100% GE Silicone I used on the vertical trim is holding up great. I put a bead of clear on and though it sometimes shows surface dirt, it scrubs off easily, has shown no shrinkage or aging. I know I may have to remove and replace it another couple of years, but that stuff has been so easy to work with I don't mind it. You can hardly see it next to the white trim because it's clear; it looks very nice on the PUP.
    [​IMG]

    Meanwhile, the 3M 5200 has yellowed, dried out, and cracked so bad it looks like a turtle shell. It is dry and not spongy or plyant at all. I will HAVE to remove and replace it all this season, which is bad because it is supposed to be impossible to remove.
    [​IMG]
    [​IMG]

    I just wanted to post my own experience and ask if anyone else has been displeased with the 3M products. Thanks!
     
  18. kckndrgn

    kckndrgn New Member

    Messages:
    67
    Likes Received:
    0
    Joined:
    May 21, 2012
    I need to do a roof repair to my camper this winter, just curious if you have any pictures of the corners that you created?

    Thanks
     

Share This Page