SUBJECT: # 27706: Caulk for wet surface???
Polecat (18.104.22.168) from MARYLAND on 12/10/2006 5:04:00 PM
My friend's brand new welded aluminum boat leaks where the two lower motor mount bolts go thru the transom. The nearest dealer for this brand boat, the same dealer that installed the motor, is more than 500 miles from the boat.
Needless to say, the boat will not be going back to that dealer.
Plywood is sandwiched between inner and outer sheets of aluminum where the bolts pass thru the transom. For certain the plywod is wet, but not soaked or waterlogged.
The mounting bolts and motor will be removed to properly caulk the holes. What is the best sealant to use in this circumstance since it will be next to impossible to get the wood completely dry before applying the proper sealant?
Thanks for your help.
- 12/11/2006 6:01:00 PM
FreeOnBoard from TX says Take the time to do it right
If the wood is wet to the touch, I'd stuff the bolt holes with paper towel for a few hours to wick up the surface moisture. With the bolt holes open, I'd hang a trouble light by each hole, for warmth, and let it air dry for a week or two, at least until the wood is completely dry to the touch. Then swab the inside of each hole with the slowest epoxy you can get. Let the first application soak in and set, then repeat. Finally, coat the bolts and the holes with 5200 when you remount the motor. Don't know if there's anything you can do about water that may be soaked far into the wood. Good luck.
- 12/11/2006 8:49:00 PM
Polecat (22.214.171.124) from MD says Thanks!!!
Planning to do something similar to your suggestion as soon as we see the extent of water saturation in the wood.
Factory says to just fill it up with silicone. We can do better than that.
- 12/12/2006 6:15:00 PM
Dunk79 (126.96.36.199) from NJ says Plywood..
FOB is exactly right... Except if the wood is wet with saltwater I wouldn't worry about it for 3 seconds. Takes saltwater 15+ years to rot wood. Fresh water will rot it in 2-3 years.. 5200 is what you want to seal it with. Yes try some heat first to get as much moisture as you can out. The more moisture you get out the more epoxy it will soak up.
You might consider using Git-Rot. It's a thinned out liquid epoxy made to soak into wood and it sets up just like epoxy. Problem is nothing will soak into wet wood so you need to cook it out as dry as you can. I'd pick up one of those 500 watt work lights at Home Depot for 15 bucks and really put some heat to it maybe a foot away from it. I would not leave it unattended while you do this..
Another one is the "The Rot Doctor" Plug that into Google, but he's wild on his prices..His claim to fame is his epoxy is some kind of natural epoxy that loves wood or something like that, but he has a Git-Rot version also.. I used it once, but didn't see any differnce between in and the Git-Rot you can buy at any marine store.
- 12/12/2006 6:30:00 PM
FreeOnBoard from TX says If you use that stuff from the Rot Doctor...
Thin as water and it does soak in like they claim. I used it as the first treatment on some transom holes, then filled them with epoxy and glass a day later. The epoxy never did set up solid, I had to drill it out and let the holes air dry for a week to get rid of all the solvent residue. Then the epoxy worked fine.
- 12/12/2006 6:39:00 PM
Polecat (188.8.131.52) from MD says Great advice!
Thanks guys!!! We'll get it as dry as we can before applying sealant.