Rotten Gunnells at Rod Holders

[Sean B]

A few months back I dug into a loose rod holder, mounted on my gunnell. After removing it I found that one of the previous stewards had installed the rod holders into the sandwiched gunnells, without attempting to seal the hole that was drilled through the gunnel. The gunnells are constructed with fiberglass top and bottom, maybe 1/4" thick, with wood sandwiched in between, maybe 3/8" thick). So all the wood in between was rotted out going back inside maybe 1/2" to 1". Same story on all four rod holders in the gunnells. I removed them all, dug out all the wet rotten wood and covered the holes with white duct tape, mainly to keep rain and wash water out so it could have a chance to dry out.

Fishing bug is starting to itch and I figure things have dried out enough by now, and also (mostly) I'm sick of looking at the duct tape. Question is, what do I fill the slotted gaps with, resulting from the rotten wood I dug out? Was debating on either an epoxy-based filler with a thickener, or 3M's 5200. Leaning towards the epoxy because I can fill the areas around the holes that mount the rod holders, then re-drill them out for a watertight installation. Also thought about getting wood dowels to temporarily place in the screws holes, then fill the whole thing with 5200... then removing the dowels to leave the screw holes open ala Capt. Pat methods. Not sure if 5200 will be strong enough, and not sure if epoxy filler will seal it properly - the assembly will see stress and movement from the rods. I also planned on caulking around the holders after the install with 3M 4200UV.

Any advice? If epoxy is the best way, I've already got cans of the two part West System stuff, and so the next question would be what to use with the West stuff as a thickener. Thx

[Rawleigh]

Sean: I would give the inside a good soaking in straight epoxy using a small acid type brush, and, after it has thickened, fill it with epoxy thickened with heavy duty filler. You can use the empty caulking tubes Wests sells with a flexible tube stuck on the end so that you can begin the fill at the back of the cavity and pull the tube out as it fills. tis will limit the cavities left in their. I feel this will give you more structural strength than 5200 and you will be able to drill right thru it to replace the rodholders. I'm sure Capt Pat will have more sage advice to follow.

[thereheis]

a few of mine were the same way, i duct taped a piece of waxed plexyglass on the underside of the gunnell really good ,also put a couple of short screws from under side also for security,coated inside of holder with unthickened epoxy first with small brush and let tack .then filled up the whole rod holder area with epoxy and fillet,let it level it self off at the top.worked out really good.i also used some aluminum backing plates under the rod holders now,,,gonna use the swivel base holders,so i needed some more support underside,,,

phil

[scot]

Sean,

I agree with a combination of both suggestions, use the straight liquid epoxy with the little brush to seal the remaining wood and then go in with a thick epoxy putty to fill the void....as Raweigh suggested. Fabricate some aluminum backing plates....as thereheis suggested. Make the backing plates as big as you can fit under the gunnel.

My $.02

[Sean B]

Thanks guys, epoxy it is. I was also missing the detail of the thin epoxy first to seal the edges of the non-rotted stuff inside. I like the caulk tube idea too.

What would be a good thickener for the epoxy filler I'll make to pack in? I was thinking of using oak sawdust, I happen to have piles of the stuff right now.

Thanks again

[thereheis]

i used cabosil and chopped glass to fill mine with .i had some pieces of fiber glass mat and i shreaded it up and added it to the epoxy , worked great,also added some strenght to the area as well

phil

[Rawleigh]

I just used the West system high strength stuff. Can't remember the number.

[JP Dalik]

Sean,
Colloidal Silica West Filler # 406. Use the 207 hardener if you are in a warm area. The 205 will smoke you out pretty quick above 65 degrees.
If it were me I'd take an oversized hole saw and go up from the bottom stoppin of course before you touched the fiberglass. This is a quick and easy way of removing the bad wood to a point where you have a good clean exposed surface. Then epoxy in a new piece of marine ply (using the hole saw) and coat that with west. Use the 406 to fill any voids on the glass side (you can sock it up tight by taking sheet rock screws and using the existing rod holder mounting holes). Then take another larger square piece of marine ply and sister the whole thing again giving yourself a double thickness where the through bolts come out. West that in and epoxy the plywood. Then drill out the rod holder tube with the appropriate size hole saw. Use West with up to 20% denatured alcohol to seal up the exposed end grain inside the cut out and then when its all dry install the rod holders with 5200. Wipe clean with denatured and call it a day.
If you have grey board or pvc board you can use that as well.
Good Luck

[Rawleigh]

Good idea JP!! You could use the same screw holes to attach a piece of plywood above the gunnell to locate the pilot drill.

[Sean B]

Great advice guys, thanks again. I want the job to outlast me, and now I know exactly how to do it