Re-hanging 400#/180kg Cast Iron Keel

[Jammer]

Originally Posted by Spot

I have also read enough stories that make 5200 seem like something you never want to have to take apart yourself.

Removing 5200 is not difficult when at least one surface is metal. Simply heat the metal enough for the bond to release. It doesn't take much. Once the pieces are apart, the residue can be removed with a sharp scraper or abrasive wheel.

[Spot]

Thanks Jedi, thanks Jammer.

I chased the first couple eyelashes, just opening the crack to receive resin, only to realize that a quick flip of the wrist would pop a small piece off.

Repeat 32x and take an oversized drill bit to add a chamfer to the bolt holes.

Why does one area seem damp? Is the nighttime dew falling under the boat? Grab a worklight and another tool to keep sanding. Check inside boat for water, all seems dry.

Hit the hole again with the poly-carbide disk and it is definitely wet...water in the lam. Does not smell or feel different than fresh water. Other pukas seemed dry except for the one mounting hole.

Suggestions? I had the thought to strip rest of gelcoat in this area and vacuum bag it and see what collects in the trap. I am also thinking this could be a season killer if it's going to take a month or more to dry out.

[s/v Jedi]

Originally Posted by Spot

Thanks Jedi, thanks Jammer.

I chased the first couple eyelashes, just opening the crack to receive resin, only to realize that a quick flip of the wrist would pop a small piece off.

Repeat 32x and take an oversized drill bit to add a chamfer to the bolt holes.

Why does one area seem damp? Is the nighttime dew falling under the boat? Grab a worklight and another tool to keep sanding. Check inside boat for water, all seems dry.

Hit the hole again with the poly-carbide disk and it is definitely wet...water in the lam. Does not smell or feel different than fresh water. Other pukas seemed dry except for the one mounting hole.

Suggestions? I had the thought to strip rest of gelcoat in this area and vacuum bag it and see what collects in the trap. I am also thinking this could be a season killer if it's going to take a month or more to dry out.

If you can vacuum bag it then yes, do that. Also, heat it up a bit with a heat gun while doing so. It won’t take long because it is a small area. Wash/rinse with denatured alcohol, see if it shows wet again after it evaporated.

[Spot]

Originally Posted by s/v Jedi

If you can vacuum bag it then yes, do that. Also, heat it up a bit with a heat gun while doing so. It won’t take long because it is a small area. Wash/rinse with denatured alcohol, see if it shows wet again after it evaporated.

Thanks Jedi. It doesn't sound so bad when you look at it that way the next day... It seems pretty localized, I think I made it into a bigger problem than what it is.

[Jammer]

The only advice I have is to stay in touch with your actual goals for the boat. Don't make a permanent repair for a temporary problem. Is this your "forever" boat? How long is "forever" etc. Previous owners left some problems for you, don't be afraid to leave some problems for the next owner.

[Spot]

Originally Posted by Jammer

The only advice I have is to stay in touch with your actual goals for the boat. Don't make a permanent repair for a temporary problem. Is this your "forever" boat? How long is "forever" etc. Previous owners left some problems for you, don't be afraid to leave some problems for the next owner.

Food for thought for sure, thanks Jammer. The repairs have been more than planned and have kept me from sailing.

I was able to pull a vacuum on a small section yesterday, 22 inches Hg below atmospheric pressure. The result was an immediate but small amount of water, 1/4 cup or 10 ml or so. Letting the pump run a couple more hours did not gather more. This morning I decided to grind off all of the gelcoat as I had made it unsmooth digging out the eyelashes/pops. I did not notice any big wet spots as before, but maybe felt one small damp one...? I went and got my finest breather fabric and finest vac bag film and set up to vacuum the whole area. I could not get the bag to draw down past 2 inches Hg, even after adding tape and kneading the mastic and plugging holes inside the boat. I also tried doing smaller areas and removing the quick-release with no improvement. Last picture is after a denatured alcohol wipe after using spec thinner to remove the leftover mastic from the hull. Perhaps I was just dealing with a small local inclusion between gelcoat and fiberglass.

[s/v Jedi]

You are good to go. You do need to seal the glass, so a barrier coat would be next, followed by sanding and then it’s time for a big mess with 5200. I recommend long sleeved shirt because it ain’t fun removing 5200 from skin

[Spot]

Originally Posted by s/v Jedi

You are good to go. You do need to seal the glass, so a barrier coat would be next, followed by sanding and then it’s time for a big mess with 5200. I recommend long sleeved shirt because it ain’t fun removing 5200 from skin

Thanks Jedi.

My 3M rep at work sent me 2 tubes of black 5200, a little unexpected but very much appreciated! I will have to find an old black long-sleeved shirt

Is 3/16" (4.8mm) enough for this application? Does it expand any when curing? Checking in hindsight makes my estimate of 2 tubes seem a bit short.

I am planning on using masking tape on the neighboring surfaces and peeling it before it skins over.

[s/v Jedi]

Originally Posted by Spot

Thanks Jedi.

My 3M rep at work sent me 2 tubes of black 5200, a little unexpected but very much appreciated! I will have to find an old black long-sleeved shirt

Is 3/16" (4.8mm) enough for this application? Does it expand any when curing? Checking in hindsight makes my estimate of 2 tubes seem a bit short.

I am planning on using masking tape on the neighboring surfaces and peeling it before it skins over.

You need to use a notched spreader; West System has one I like with 3 or 4 different size notches. You can see how flat the surfaces are and estimate which notch is good. Squeeze-out will show if you did it right, I would not overdo it. When there is no squeeze out, you can separate again using wedges that you hammer in between, check and add sealant etc.

5200 gives you plenty of time. Also, don’t torque the keel bolts down too much. It is key that the keel is at right angles and you have squeeze-out all around, but still some room for further tightening. You can Google to find recommendations, like after how many hours and how much etc. I have heard about tightening over a couple of days even.

[Spot]

Originally Posted by s/v Jedi

You need to use a notched spreader; West System has one I like with 3 or 4 different size notches. You can see how flat the surfaces are and estimate which notch is good. Squeeze-out will show if you did it right, I would not overdo it. When there is no squeeze out, you can separate again using wedges that you hammer in between, check and add sealant etc.

5200 gives you plenty of time. Also, don’t torque the keel bolts down too much. It is key that the keel is at right angles and you have squeeze-out all around, but still some room for further tightening. You can Google to find recommendations, like after how many hours and how much etc. I have heard about tightening over a couple of days even.

Thanks for the tips!
I have used a notched spreader installing tiles at home.
I am planning to get one more tube of 5200 so there is a bigger margin for my inexperience.

Will the 5200 hold the bolts enough to keep them from falling out during assembly? I could add an O-ring for this purpose.

[Spot]

In the meantime, I had a talk with 3M tech support and seems like the application plan is sound. I also discovered that there is still some moisture in the area.

I was going to lay in one more last coat of epoxy tinted to match the hull. Upon sanding to prep for this I saw discoloration. I ground back the epoxy and 2 of the holes (middle two but opposite sides) are still 'weepy'. Since I still need to sand and coat 2nd half of the blade 2 times there is no hurry at this point.

Wondering if a series of 1/4" (6.4mm) holes in a 1 or 1.5" (25-38mm) grid pattern in the suspect areas and maybe 1/2" (12 mm) deep into the 5/8" (16mm) fiberglass portion of the hull to aid drying would be worthwhile? I would epoxy fill and barrier coat before keel re-attach. I am also cleared by work to bring home a bigger Gast pump than the one I have so I could try that (another round of vacuum) too.

[s/v Jedi]

Originally Posted by Spot

In the meantime, I had a talk with 3M tech support and seems like the application plan is sound. I also discovered that there is still some moisture in the area.

I was going to lay in one more last coat of epoxy tinted to match the hull. Upon sanding to prep for this I saw discoloration. I ground back the epoxy and 2 of the holes (middle two but opposite sides) are still 'weepy'. Since I still need to sand and coat 2nd half of the blade 2 times there is no hurry at this point.

Wondering if a series of 1/4" (6.4mm) holes in a 1 or 1.5" (25-38mm) grid pattern in the suspect areas and maybe 1/2" (12 mm) deep into the 5/8" (16mm) fiberglass portion of the hull to aid drying would be worthwhile? I would epoxy fill and barrier coat before keel re-attach. I am also cleared by work to bring home a bigger Gast pump than the one I have so I could try that (another round of vacuum) too.

Did you get any hints as to where the moisture comes from? From which direction and which source? Does it have a taste or smell?

If it moves through the laminate then hmmm

I think it is a good idea to drill a hole a couple inches from the spot in the direction that you think it comes from and a hole at the opposite side where you think it doesn’t come from, then see if they start showing moisture or not or only one etc. This way you can expand drilling more holes only where needed.

Is there a visibly different layer of fiberglass? Like a final layer they did in the end? Maybe this is where moisture travels through if it’s weave wasn’t filled all the way with resin and then some flow coat over it etc.

[Spot]

Thanks Jedi.

I drilled about 2 dozen holes in the bottom in the suspect area. Only 2 of them weeped after drilling by tapping one's finger on the hole and wiping across the hull. No drips, floods, squirts...just a couple small spots that are not dry. I was checking the shavings as I drilled and those seemed dry too. Nothing odd about the liquid touch or smell. I do not see any layers of glassing that are split at the big holes. Current thought is to redrill the weepy areas in a week. If dry I will fill with epoxy,maybe a bit of fiberglass rod, and carry on.

[s/v Jedi]

Originally Posted by Spot

Thanks Jedi.

I drilled about 2 dozen holes in the bottom in the suspect area. Only 2 of them weeped after drilling by tapping one's finger on the hole and wiping across the hull. No drips, floods, squirts...just a couple small spots that are not dry. I was checking the shavings as I drilled and those seemed dry too. Nothing odd about the liquid touch or smell. I do not see any layers of glassing that are split at the big holes. Current thought is to redrill the weepy areas in a week. If dry I will fill with epoxy,maybe a bit of fiberglass rod, and carry on.

Agreed.

For closing these holes: countersink them first, then buy some cheap 4-6 ounce fiberglass tape on Amazon, wet it out with epoxy, cut pieces off, roll them up and stick them in there, letting it flare out a bit at the countersink. After cure, cut off excess and fill the rest of the countersink (epoxy thickened with colloidal silica). On the inside cutting off excess is probably good enough.

[Spot]

The keel and blade refinish and keel hanging are complete. Thanks for all of the ideas and tips!

I ended up using fiberglass rod and epoxy to fill the 24 holes.

I was able to complete the install with the 2 tubes of 5200 that our 3M rep at work sent my way (thanks!) and also got to talk to their tech support about ideal thickness, etc. (thanks again!). There was plenty of squeeze-out and some in the tube to spare. I used 3/16" of aluminum as a spacer material to set the thickness. Before all of that I washed and sanded the epoxy surfaces and levelled the boat.

After the bolts were in, we had a sudden downpour, so I taped a drip edge with wide masking tape around the keel to keep the rain off the joint.