Thursday, June 28, 2012

Using Git-Rot Penetrating Epoxy on a Bulkhead

As we were rebuilding the Navigation Station we noticed that there was a section of the bulkhead that had some dry rot in it.  I could push my finger against the veneered bulkhead and while the veneer in this section appeared solid, you could tell it was soft behind it.  After removing a little bit of the veneer we could actually push a finger into some sections of the plywood and it was soft.  (not so bad that it was just falling apart, but bad enough that I was really concerned).

I started to read about scarfing two pieces of wood together and then fiberglassing over them.  This seemed like a lot of work and would still be a "patch".  I considered removing the bulkhead and replacing it all together, however on this boat, the bulkhead is tabbed in under the subfloor, tabbed in along the hull as well as tabbed in on the roof.  This particular bulkhead goes up the port side, across the ceiling in a decorative rounded shape and down the starboard side.    I quickly deduced that this was beyond my expertise and would likely be upwards of $5K at a yard.    So I started to really do some reading on penetrating epoxy and it's use specifically on stringers on boats.  If this stuff was strong enough to form a new "foundation" in the form of stringers, it may really do wonders on this small section of the bulkhead.

So with instructions read, and the web researched, I picked up a bottle of Boat Life's Git-Rot at my local West Marine.  I did notice that there are other brands of penetrating epoxy and some are geared toward home repairs.  I am assuming that these are likely similar in concept but I stuck to the one made for marine applications in this case.  (I don't think it mattered, but don't know for sure).

The job started by refrigerating the whole package of Git-Rot because if you are not applying it in 50-70 degree weather the manufacture recommends cooling it overnight in the refrigerator.  I can assure you at the end of June in South Texas, even with the AC on in the boat, it was warmer than that.

We drilled a series of holes into the bulkhead at about a 20degree downward slope being careful not to drill all the way through the bulkhead.  This allowed the injection spots for the epoxy to go through all layers of the plywood where needed.  Once drilled the product was mixed and shaken for the very exact amount of time (60 seconds) and then slowly squirted into each hole.
I started at the bottom of the vertical area to be epoxied and would slowly fill until the epoxy started to come out of the hole.  I would then move to the next.  I did this through each hole (about 18 of them or so) and as soon as I was done with the 18, I would start over again.  The goal is to keep doing this until the wood won't absorb any more of the solution.
I did this with 3 squirt bottles (about 4 ounces each) on the first day.  I started to really see it penetrating the wood because as I would inject the epoxy in one hole, I would at times see it start to seep into the wood below or adjacent to it.  This was a great sign for me as it showed that it was really being absorbed into the wood like a sponge.

The next day, I came back and repeated the process and it took about another bottle and a half (about 4 ounces each).  At this time, no more was being absorbed into the wood.  After letting it dry overnight, I sanded the surface of the wood smooth where some of the epoxy had gotten on the surface of the wood.

The test was in the "knock"  Before I started I knocked on the bulkhead and when I got to the rotted section it went form a crisp knock sound to a thud.  After using Git-Rot, I could no longer stick my finger in the wood anywhere, there was no "give" on the veneer and the knock test sounded crisp all the way across the bulkhead even over the spots that previously responded with a thud.

I would call this process a success and was glad to have been done in a few days (between applying the product and then veneering over the surface where I drilled the holes) rather than attempting to tear out and replace that bulkhead.

As is the case, if we do a project and don't find information or some good step by step "how to" instructions, we have been recording the progress and then putting them together as a video in hopes that it helps others.  It should be known that I am not doing this because of any product sponsorship and I happened to Choose Boat Life's brand but there are others out there that would likely work the same way.  This is being posted in hopes that if you are attempting a project like this, you find it useful.  It also has the secondary benefit of helping my chronicle the work we are doing on our own boat.  Like most boats, it seems that with every repair, we find something else that we determine we should correct as well.