Small hole in tansom after kicker bracket installation

G

Gratitude

New member
While having our boat's annual service, we recently had a new heavy duty Garelick EEz-In Aluminum Auxiliary Motor Bracket installed on our 22' C-Dory. Unfortunately, while offshore my fishing buddies indicated that there was water accumulating in the rear cockpit. Upon investigation I did find about 1/2 inch of water sloshing around throughout the cockpit. I turned on both bilge pumps, and the water was evacuated in about 30 seconds. Unfortunately, this became the norm for the balance of the day. At first, I thought it was a loose drain plug, so we reached overboard, and tightened it. No affect. Upon return to port I bought a replacement drain plug, and installed it. Yesterday we took the boat out for a harbor cruise to test. Unfortunately, the issue continued. When I returned to the hoist service to put our boat back on it's trailer we inspected the transom where the auxiliary motor mount was installed. To my dismay we found one unplugged ~ 1/8" hole that went all the way through the transom below the waterline from the prior smaller motor mount that the dealer replaced with the new Garelick. The landing suggested pounding in a dowel, and sealing with 5200. Easy enough. However, my concern is moisture that could be trapped in the transom and potential for dry rot. I realize that I likely have recourse to the dealer that botched the installation. However, before I contact the dealer, I seek the group's advice. Is this a significant issue that requires more than a dowel and 5200?

As always, thank you for your thoughts and guidance.

All the Best,
Jim (Gratitude)
 
Hi Jim,
Sorry to hear about that 1/8" hole. 1/8" is not real big--but obviously has to be repaired--and it is amazing how much water can come in. Although a 1/8" dowel is pretty thin, I probably would drill the hole out with a 9/64 or 5/32 bit, so that the 1/8" dowel will slide in fairly easy. Soak the dowel with epoxy, tap it in, then finish the surface with some of the same epoxy, thickened with Cabosi, after slightly 45° chamfering the outside hole, to expose a 45* on the edge of the glass. On the inside I would try and brush some epoxy over the end of it. hopefully you can reach, and feel to be sure the dowel goes all of the way thru--make it at least 2 1/2" long, (double check the thickness of transom). My recollection is that you can get fingers and a wrench between the fuel tank and transom. Maybe use a small flush cutting saw to cut the dowel flush on the inside--then coat with epoxy.

5200 is not my first choice here.

The question is how much moisture is in the core? I suspect very little moisture got into the core. With it sealed, no more water will get in there. Thus I doubt that there will be any rot occurring.

For those who do not know, Jim (whom I have known thru the internet for many years) is the 3rd owner, after I sold C Pelican.
 
Hi Dr. Bob,

As always, thank you for your insightful answers and suggestions. Both are always appreciated. Your suggestions will be discussed with the dealer that botched the installation, and I will let them make your recommended repairs - at their expense, and I likely never use that dealer again.

All the Best,
Jim (Gratitude)
 
Thank you localboy and Dr. Bob. I will post again after I speak with the Dealer the installed the kicker bracket tomorrow.

Jim (Gratitude)
 
So I contacted the dealer, and arranged for them to pick up the boat from dry storage, and take it back to their facility. I had them completely remove the new bracket. Guess what - there were three (3) holes going all the way through the transom that were unsealed! The dealer repaired all three holes, reinstalled the new bracket, and will return the boat to my dry storage location this afternoon. For the inconvenience, they provided me with a 10% discount on my next service, and cleaned, polished and waxed the boat.

Gratitude (Jim)
 
Good on the dealer for fixing their blunder. That's why I try to do as much boat work myself as possible.

If you did need to repair this yourself, I have some pics that demonstrates a good technique for filling holes in vertical surfaces.

You aren't fastening to these holes, so no need to remove extra core around the hole, but if you did, I also have pics that show a technique for filling the void above the hole with thickened epoxy and avoid having an air bubble up there.

I'm only posting this info here in case people in the future look to this thread for info on how to fill transom holes.
 
They're in my album already, but for your convenience, here you go:

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IMG_3550.sized.jpg

IMG_3549.sized.jpg

IMG_3553.sized.jpg

IMG_3554.sized.jpg

IMG_3555.sized.jpg
 
basically, after you overdrill and excavate a bit of core around your hole you drill a tiny weep hole well above your excavated core, angled down into your hole, so the weep hole makes an air vent on the outside of the transom (I only put the weep holes on the outside (doesn't matter which side you vent), then lay painter's tape on your holes, remove the tape over the holes (masking your gelcoat) and make little reservoirs from aluminum tape that are much taller than the hole you have drilled, and extend ABOVE the weep holes you drilled on the opposite side.

Then you cover the backside with tape to plug the hole, but leave your weep hole open. Keep adding thickened epoxy to the reservoir until it starts draining out the weep hole. then you can tape over the weep hole (but the epoxy usually just sort of stops itself once it starts to kick) once you reach this stage if the reservoirs are draining.

It can help with adhesion to "paint" some unthickened epoxy on the core inside the hole before adding thickened epoxy, but not totally necessary.

Hope that was clear. If you look at the pics in my album, there are some captions that sort of explain things along the way, and are maybe clearer than what I've written.
 
Great pics and explanation Kushtaka.

One question I have is when you over drill, and rout out part of the core with larger holes, (say if you want to properly seal off the core for the main motor mounting bolts), how do you insure when re-drilling the mounting holes after the sealing that you drill through the centre of the filled hole? With the transom being 2 plus inches thick, I worry about not matching the angle of the previous hole and possibly drilling outside of the sealed area.
 
I had the same concern when I over-drilled/filled the holes for my main engine. I mean, many things have to be drilled correctly (trim tabs, etc.), but the engine bolts are looong (so any misalignment would be magnified) and I didn't want to put any stress on that aluminum casting.

I did a number of "cross checks."

1) I never enlarged the hole on the outside of the transom, so I still had that "circle" to go by.

2) I made a cardboard pattern of the engine bracket holes.

3) I swung the engine back into place and triple checked.

So then the big thing was to keep the angle just right. If I remember correctly, I did that by starting with a thin drill bit and holding a metal square on the transom, and then keeping the bit lined up with that (so as to keep the angle correct). As long as it went in and out in the center of the holes, I knew I was good and could do the larger one (it's been a couple of years though, but this is what I remember).

I wasn't so much worried about going outside the epoxy filled areas (as by design they are amply large so there is scads of room that way), but it was more that I wanted the fasteners to line up on the engine bracket with no stress, and then also on a long "backing block" type thing I put on the inside of the splashwell (a T&H Marine thing made for the purpose). Plus the nuts/washers needed to sit flat, so the fasteners couldn't be crooked.

With the three cross checks, it all worked out. Can't say I wasn't nervous though! (But not as nervous as I was with essentially bare balsa holes on my transom.)

With smaller holes in other places, I still tend to make really ample epoxy filled areas. But if for one reason or another I hit balsa when I'm redrilling, I just re-over-drill and re-fill with thickened epoxy such that I've taken care of it and I can drill the desired hole completely through a thick area of epoxy.
 
It's all in your layout.

I made a jig that had my bolt pattern, and I made reference marks on the jig and on my transom (on painter's tape) so I could get it exactly where it was. Then I made a small pilot hole into the thickened epoxy plug halfway in from both the inside AND outside of the transom.

You might want to get someone to eyeball your drill from the side to make sure you are square to the transom, but even if you drift a little bit, if you use a pretty small bit (1/8" maybe even 1/16" for starters) and make your initial penetration into the plug right exactly dead center where you need it, then drifting the angle into the plug won't matter. The small bit helps you get dead center in your plug a lot easier than a bigger bit, it's not really necessary for a good hole though.

Once you have a mini pilot hole drilled use progressively larger bits (increase size conservatively if you aren't confident) going in slightly past half way each time you increase bit size. By the second or third bit the holes should clearly meet, although maybe are not quite straight. Your job is then simpler: make the hole straight. After one or two drill passes nearly through you want to get to the point where you can put the bit in one right in the center of your plug and have it exit the other side right in the center of the plug. If this happens you are good. Ideally you will get to this point before you have drilled your full size hole, and be able to make the last drilling a straight through one side and out the other affair.

If your pilot holes were not perfect and your final hole has some drift in the middle of the transom, it's perfectly okay to let it be, so long as the drift in the center of the plug inside your transom does not penetrate into the core.

As you get practice you can do this in one or two drillings, but if you start with a very small bit, and increase size gradually, you can make a perfect hole through a plug with almost no practice, just go slow and don't bind up the drill. and don't go all the way through from one side to the other until your holes meet and you can go nearly through and have the bit where you want it.

If you do get off center, and your holes just don't meet up, don't worry about it, just refill and try again. If you protect the gelcoat around the holes well, and the area beneath your work, it shouldn't be a big deal to do this a couple times if needed.

Of course, you can also avoid freehand altogether and get yourself a drill guide. The types that are made to help you drill out holes for doorknobs, and deadbolts are good for this type of thing sometimes, as are centering jigs but honestly this is something that can be done freehand with a little patience.
 
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