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View Full Version : Stern light not sealed. core exposed and wet... advice?



banfield
08-20-2003, 02:43 PM
Hi, My stern light recently failed on my 22' classic. I pulled it off, and found that it wasn't sealed to the transom, letting water behind it, which has wetted the wood core of my transom showing in the cutout for the light.

Obviously I need to silicone the (fixed) light back to the transom, but since there is wet wood exposed behind the light, what would you all recommend doing here?

By the way, my boat has had some transom repair sometime in the past, and it appears that this detail might have received a bit less attention that it deserved. Should there be any wood exposed, even behind the stern light fixture? Should I dry it out, then glass it over, including the holes for the wires to come through the transom? Or just seal the light on the outside and not worry about it?

Thanks,
Don Banfield

MOP
08-20-2003, 06:01 PM
Hopefully if you do a good job sealing the top side the bottom should eventually dry. Wood needs to breathe to be able to dry. If you have a few days you can use the old boy scout solar still trick used by many shops to dry wet panels that have not gone to rot yet. Tape off the under side then use clear plastic sheeting tented over the hole, you can tape it or as we do use light chain around the outside edge to hold it fairly tight to the surface every hour or so in hot sunlight you will see water droplets have formed on the plastic. Pull it off and flip it over keep doing that till the plastic stays dry, it will have pulled the water out then seal it good from the top side. A good and proven point is to never seal any deck fitting or its attaching hardware on the under side! Reason if there is any water intrusion it will leak through and hopefully will be spotted before much harm is done. If sealed in and out and a leak develops it will have no place to go but into the coring un noticed. When ever you mount anything in a cored panel, cut your holes then taking an Allen wrench in a drill whiz out all the coring between the two layers of glass in the screw holes use control cable wire. stuff the area with chopped fiber glass and resin to seal and reinforce, essential on all through hull installs important on decks.

Cuda
08-20-2003, 11:02 PM
Great advice MOP! The only part I didn't understand it what is the control cable wire used for?

MOP
08-20-2003, 11:45 PM
I don't drill through both layers of glass when mounting any kind of hardware in a cored panel. I mark all my holes drill just the top layer then clean out the coring between the two layers back in 1/4" to maybe an 1" depending on what I am mounting and the stress it may be under. The larger holes I will pack chopped fiber and mat between the layers. The smaller I usually inject epoxy and Cavisil then re drill the holes later. On holes cut with a hole saw I let the tip of the guide drill in the hole saw just pierce the bottom layer, I tape the hole over before applying the epoxy this when things cure you can use the saw to clean the hole and go through the bottom layer. You use the drill hole to keep the saw lined up. Note you may have to change the bit to a longer one on thick panels. Make sure the drill tip is firmly in the bottom hole before you crank up the drill, run the drill fast but go in very slow. Also on stressed pieces use good backer plates.