Cracked Fiberglass Shaft Log

[lively]

I would only drill a hole I'n the rear transom area about 2 foot or so off the transom wall and about 3" above the floor into the
Side of the stringer , if you have supertrapps exhaust tips I would remove center nut and investigate the seal ring and look for
Possible entry , more hole u drill the more u weaken the stringer and more filling you have to do ..
When I did mine I also took a pick and dug into the hole and removed the the wood to feel for wetness ...

Little did I know I opened the main valve for the nasty ass water ! Lol

When you fill the holes back up if the wood is dry then mix up some strands of CSM (chopped strand mat)
And silica to thicken like a peanut butter consistency ,, I use more silica , and then take a sandwich bag and fill it with your filler
Cut corner off and squeeze into hole and fair it out smooth .. Don't be frightened of stringers going bad ...

I'm 26 and have never played with wood to this extent ..
.. It is a great thing to concur and alot of beer !!

[djm284]

Progress was slow this weekend as I came down with strep throat. But, I was able to tough it out for about 5 hours on Saturday (thought it was just a bad cold) before realizing I should just stop and go to bed.

Checked the two engine mount bolts closest to where the water is seeping from the stringer and they are tight. Checked the same bolts on the other side and they were also tight. Rest of the engine mounts are covered with taped plastic, so I'll check them when done with the grinding. Also drilled a few 5/16" holes in the stringers looking for moisture or rot - one hole on each side 2' from the transom and 3" up and one hole a couple inches above the area where the water is seeping near the aft starboard engine mount. The wood that I drilled out all looked good with no moisture or rot at any of those points.

No supertrapps, just flaps at the end of the exhaust.

Here are some pics of the weekend's progress/findings with some questions at the end...

Overall progress:

IMG_7210.jpg


This is the problem area where water is seeping. The drill hole a couple inches up had no moisture and wood looked good. Along the bottom corner I've drilled/scraped about 1/4" deep. What comes out is a blue/green colored almost plastic-like substance. Assuming this is the resin used to attach stringer to the hull. Water seems to be coming from the forward end. The screw to the top right of the picture holds the pvc tube for the blower, no water came our when I removed the screw.

IMG_7200.jpg


Closeup:

IMG_7206.jpg


A couple more potential problem areas. First is on port side on corner of the stringer where the exhaust goes under the floor. Second is the glass around the exhaust in the same area. See some signs of rot in the first pic, but not very deep:

IMG_7207.jpg

IMG_7209.jpg


Questions:

1. For the original job (reseting and glassing the shaft log) what is the best way to fill the areas where I had to grind down the the hull (red areas)? lively mentioned cutting a piece of glass that fits into each void. For the second layers, do I level the area with epoxy, or push the second layers down into the voids as well?

2. Based on what I've found so far, any thoughts on how to move forward with the area that is seeping water? Where/how should I continue to drill without causing a new problem?

3. Do I need to consider taking up the floor now? If I wait until late fall, how much more damage am I risking? Is there a quick fix way to do further investigation, dry out under floor, and/or remove wet foam without doing a full floor removal, at least enough to get me through this season without allowing significant further damage from the water.

4. For the cracks around the exhaust, what's the best way forward? I'm thinking pull the loose stuff, then add CPES and glass over it.

Thanks!

[lively]

if you have water just dry it out the best you can and (tab ) the side of the stringer to the floor to cover the void you ground into ...


as far as the glass work goes i learned from playing with it on a scrap board ... you want to put at least 25 oz of glass over the shaft log and use woven or 1708 .. just
something that has good structure ..

and when you patch fiberglass that is damaged the best way to get an accurate cut is clear film , plastic bag, anything seethru that you can trace the design (void) and
depending on how much actual glass you ground out will determine how much you need to put back ..
what i do is just cut my template X 4 and then layer out larger pieces 1" to 1" 1/2 OD to spread the load of glass evenly to the hull ...

research how to fiberglass on google .. it helped me alot ! and i am by no means a pro .. but id like to think i am lol

good luck man .. anything you alter or upgrade is 100% better than they did in 1986 .. so be happy with what you got

dont get into the floor just yet .. enjoy it for the summer and make it a winter project !

[Okie Boarder]

Mine didn't cover the hole either...it looks as though they put some sort of silicon filler in there. But, mine had been repaired once so not sure that was factory.

I finished almost all of the grinding today. 4.5" angle grinder with 40 grit flap disc made the job pretty easy. Used dremel for the hard to reach spots. Dremel battery died so just have a little touch up to do except for two hangups that I'll explain in another post. Pic of mostly done grinding is below. By the end of the day I did a little more than what is shown in the pic.

Okie, a few questions for you...

1. How did you make those cuts the length of the pvc, hacksaw?

2. When you did the thickened epoxy, did you end up going with the "peanut butter" consistency? (by the way, I'm using West Systems epoxy [105] with slow hardener [206]colloidal silica [406] as the thickener. Local boat store is West Marine and West Systems is what they stock, but suspect different brands should all work pretty much the same)

3. Did you end up fashioning some sort of molding for the bottom under the hole, or just smooth it our from underneath?

Attachment 9369

Yes, I used a hacksaw IIRC.

Yes, I thickened it until it was the peanut butter consistency.

Yes, I made up some sort of "plate" for the bottom so the thickened epoxy wouldn't ooze out.

[Okie Boarder]

...and here are my questions for everyone, including a few issues I ran into.

1) Should I leave the 1" x 3" piece in place? I'm thinking no, but welcome other opinions. It would make for less unsupported epoxy, but my new exoxy would have to be a thinner coat onthat end.

2) When grinding down I hit a few areas that had voids. Are these from air pockets? Below are some pictures of the biggest void, which is about 2" accross. How should I handle this? I'm thinking I should grind it out until I hit solid glass all around the edges and then fill it with thickened epoxy. You can see in the second pic that there is still some hollow area under the fiberglass.

Attachment 9371

Attachment 9372

3) This is the biggest problem. I was grinding towards the forward end of the work area, and all off a sudden hit a wet spot in the fiberglass. I kept grinding around the area so find where it was coming from and water continued to seep out of the upper part (starboad side) of the ground out hole. Kept seeping out for at least an hour, and may still be leaking (had to stop and cover boat for the night). When I covered it up it was seeping maybe up to a teaspoon every minute or two.

I can't figure out where its coming from. Before starting the project, I sprayed a small amount of water (maybe 1-2 quarts over 2-3 minutes) over the shaft log to confirm the original leak. That water was minimal. Some may have hit around the bottom of and below the hole, not the top though. This was the only water the boat has been exposed to since July, except for some rain (not a lot) getting through the cover occasionally. Non of the glass or resin around the log, even where I made it leak yesterday was wet like this.

Any thoughts as to how this could happen and what I should do? Hoping I dont need to grinding up my whole bilge? You can see from the pics that I'm almost up against the sidewall of the bildge.


Started around the middle. Whole area wet...

Attachment 9373

Attachment 9374

Attachment 9375


Thanks!

I would try to get to solid material as much as possible. If that spot is more like a patch, you might grind it, but look at how good of a bond it seems to have to the main hull. There's no reason to grind away material that is solid and well attached.

You definitely have water somewhere and since that spot if near the stringer, that would be suspect. Probably water has gotten in somewhere from the back side and has penetrated under that layer of glass and is causing some delamination (or there was already a void there). The best thing to do is figure out a way to get it dry then seal it back up, for now. Some of the suggestions so far seem like they could get you headed in the right direction. One thing to note is this is telling you that you have water up inside (surprise surprise), so be prepared for a rebuild at some point.

[Okie Boarder]

Questions:

1. For the original job (reseting and glassing the shaft log) what is the best way to fill the areas where I had to grind down the the hull (red areas)? lively mentioned cutting a piece of glass that fits into each void. For the second layers, do I level the area with epoxy, or push the second layers down into the voids as well?

2. Based on what I've found so far, any thoughts on how to move forward with the area that is seeping water? Where/how should I continue to drill without causing a new problem?

3. Do I need to consider taking up the floor now? If I wait until late fall, how much more damage am I risking? Is there a quick fix way to do further investigation, dry out under floor, and/or remove wet foam without doing a full floor removal, at least enough to get me through this season without allowing significant further damage from the water.

4. For the cracks around the exhaust, what's the best way forward? I'm thinking pull the loose stuff, then add CPES and glass over it.

Thanks!

1. You can lay a layer of glass to fill it then smooth as much as possible. You could also do some thickened epoxy with CSM, but you would get more strength out of a layer of glass, I think.
2. I would just try to dry the area and glass it for now.
3. Based on the fact you're finding some good wood when you drill and not much water, I'm not sure you are totally in the danger zone yet. I'd be more inclined to make sure all the motor mount lag screws are tight and go from there.
4. That could be a reasonable approach. There isn't anything extremely structural there if I'm thinking correctly based on the pictures. CPES probably won't help the wood a whole lot, but it can't hurt.