Transom Hardware

[CTsalt12]

So I re-bedded all my transom hardware last spring, which is just bilge drain and transducer. The lower portion of my transom was found to be  waterlogged due to bad bedding of hardware by PO.  When I checked the hardware this year, it appears the 4200 kept water out of the bilge drain, but not the transducer holes, despite having done it a year ago.  Could it be possible that the dampness of wood core is preventing a solid bond of 4200, and let the water in this season?  Regardless, I doused it in acetone, vacummed as much moisture out as possible, and used a blow dryer to try and evaporate water.  

Also, I've noticed when poking around in the transducer screw holes that it appears the holes go all the way through the transom, and I swear I can feel foam in the far end.  The stringers are on the other side of the transom where the ducer gets mounted.  Is this at all a possibility?  My stringers are coated in hard fiberglass material.  

Anyway, what do y'all recommend?  Re-bed with new holes (or use existing holes?) and risk water intrusion again? or use no screws and just 4200 the ducer to the transom?  I am actually leaning towards the latter.  Keep as few holes in the boat as possible.  Help me out I don't know what to do here.

[Blue Agave]

"Could it be possible that the dampness of wood core is preventing a solid bond of 4200"

Negative, the 4200 chemically reacts to moisture and forms a bond.

[Curious]

It could be coming from just really wet plywood.  But if the holes go all the way through the transom and into the stringer foam then the moisture is probably wicking into your ducer holes from wet stringer foam, assuming your stringer foam is wet.  When I redid my transom last year, the inside transom skin was intact but very thin down near the bottom.  So where the stringer tied into the transom was glass, but I remember seeing a little area of what appeared to be foam showing through the fiberglass skin right at the base of the inner transom skin.  I assumed it was foam from the stringer that crept past the inner fiberglass skin when it was poured.

For what it's worth, when I drilled and dug out my transom core (plywood), there was soft black, wet, rotten wood adjacent to scupper hole, drain hole or screw hole confirming what we all know about the negative effects of improper bedding of holes. Everywhere else the wood was clean and stiff, but still wet.  When I dug a screwdriver into it a little moisture would seep up and out of the wood.  This tells me that the plywood had been wicking water and was saturated, even nowhere near a compromised area.

[gran398]

Spot-on assessment there

[CTsalt12]

Hmm good stuff here.  If it were your boat would you re-drill or use no screws and just 4200 or use formula 27 something along those lines to attach to transom no holes.

[dirtwheelsfl]

Drill small holes (especially screw holes) 2X the diameter, and fill completely with thickened epoxy. I use little syringes and cut the tip to whatever size. Then come back and drill to proper diameter, and only as deep as your screw needs to go....

[slvrlng]

Drill small holes (especially screw holes) 2X the diameter, and fill completely with thickened epoxy. I use little syringes and cut the tip to whatever size. Then come back and drill to proper diameter, and only as deep as your screw needs to go....

This!!

[gran398]

Agree...but get it inside or under cover, throw a fan on it or a heat lamp... and sit for her a week or two and let her dry out.

Otherwise, its an epoxy plug imbedded in wet/damp...just a bigger hole.

[Curious]

If you can cover up the old holes by applying the ducer without screws, I might consider that method.  A buddy of mine used some kind of two part epoxy to mount his transducer setup and it is stuck on there rock solid, no screws.  I'll try to get the name of the stuff.

[Curious]

Here it is:

http://www.sternmate.com/index.html

The whole system is called stern mate and it comes with the adhesive I mentioned in the last post.  Has anyone else tried this method of transducer install?  It looks like an interesting concept.  At any rate, for your application it would cover your holes and affix the thing onto the transom with no fasteners or more drilling needed.  Once you have it in the right spot you can then fine tune the placement of the transducer on that mounting surface.  Something to think about.

[seabob4]

Nando alluded to a great point about 4200 and/or 5200...the bond it creates whether exposed to water or not.  The key to holes in the boat is to seal them so you keep outside water from getting in the boat.  What water is in the stringers and foam is already inside the boat, you live with that everyday.  Short of ripping all the wood and foam out of your boat, it will stay with you, day in, day out.  So, as long as no more water is getting in...don't worry about it.  Yes, it's going to continue to do it's insidious bit of dirty work behind the scenes, as long as big cracks don't start forming in your splashwell (can you say really big motorized anchor?), and your floors still will support you, you'll be OK...

BTW, if you put a nice bead of 5200 or 4200 on the backside of your ducer mount, wait a week, remove the screws, and that ducer won't go anywhere until you want it too...