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Keel damage

Started by mikehennessy, October 21, 2019, 10:17:39 AM

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mikehennessy

While preparing the boat for it's long winter sleep, I noticed a damage spot on the keel which looks like delamination.  I do not believe I ever hit anything in the water and the spot is mid boat just where it sits on the trailer. 

Looks like water can penetrate in there.

Any idea on the best way to repair?  Anyone else have something like this happen?
2018 Sunday Cat "Good Chemistry"

Bramble

In your picture, is the bow to right?

bruce

It looks like a void that opened up under impact. Is it hollow around the edges? This video shows something smaller but similar.
https://www.youtube.com/watch?v=rz5WCfipaNw

I found a void on my CB trunk. I ground it back to solid material, built up layers with chopped strand mat and laminating polyester, leveled it with 150G paper, feathering the surrounding gel coat about an 1" to provide a good bond for the new gel coat. Com-Pac provided the gel coat free, since it was their defect.

The gel coat Com-Pac provided was thickened, and was a great consistency for the small gouges and chips that I also filled, but required thinning beyond the recommended amount with styrene to make it sprayable. I used 20%, and it was still too thick but manageable. If you thin beyond the recommended amount, do a test to make sure you you don't get cracks or other defects on curing. I briefly tried brushing with a foam brush, but the brush marks didn't flow out well so I went with the spray. After curing, I leveled with 400G to remove the dry orange peel, followed up with 600G, grey ScotchBrite pad, and Novus #3 and #2 rubbing compounds. Gloss and color look great, a little light at first, but a little boat grime and they blend right in.

I promptly and carefully cleaned my airbrush with styrene and acetone, and it suffered no ill effects. Once the gel coat flashes it can't be sprayed anymore, but it's still soft enough to be cleaned with solvents. I cleaned the airbrush before it flashed.

There is a YouTube channel, Boatworks Today, that does lots of fiberglassing. In your case, it is structural so I'd plan on feathering the glass back beyond the exposed void. How much varies, BW Today would say as much as 12:1. I'd use epoxy in this case, with a suitable glass, not CSM, and gel coat on top.

Scary if you haven't done something like this before, but is doable with basic skills. At least it's in a spot that isn't highly visible.
Bruce
Aroo, PC 308
Narragansett Bay, RI

MacGyver

Looks like a strike and void area all in one.
Typical for voids to be on corners like that, Every boat manufacturer has done that at one point or another on the various boat repair jobs I have done over the years.

Mac
Former Harbor Master/Boat Tech, Certified in West System, Interlux, and Harken products.
Worked on ALL aspects of the sailboat, 17 years experience.
"I wanted freedom, open air and adventure. I found it on the sea."
-Alaine Gerbault.

Zephyros

#4
Before you figure out the best way to repair the damage first you need to figure out what caused it. The Suncat trailers are notorious for causing keel rash, look closely at your keel, your photo shows multiple scraps and gouges. Most likely this was caused by the keel guide board vertical steel brackets used to hold the keel guide boards in place, there are three on each side. When you launch or retrieve you boat, when it is floating above the guide boards, without the benefit of trailer mounted side guide posts, the boat no longer stays parallel to the keel guide boards. The immediate affect is keel fiberglass brushing against the keel guide board vertical steel brackets.

The fix to the issue is as follows:
The first photo below shows the Magic Tilt trailer and three starboard side keel guide board vertical steel brackets. The second photo is my Performance brand trailer, similar to the Magic Tilt brand, with new bunk boards and new custom made and carpeted blocks of wood I made to protect the keel from the sharp edges of the keel guide board vertical steel brackets. Also, you will see the black rubber mat I wrapped around the trailer cross member for additional protection. The third photo shows the trailer mounted side guide posts I added to my trailer.

mikehennessy

Thanks Tom and Bruce for your advice!

I will add the PVC trailer guides and evaluate modifying the retrieval area.  Since the boat is only 10 months old, I'll push seller for repairs.  Prevention is the best solution.

-Mike
2018 Sunday Cat "Good Chemistry"

bruce

I forgot your boat was new. Warranty claim for sure, mine didn't show up until year two.

Tom's done a great job padding the offending brackets and frame components. Not sure how difficult it is to align the boat on the trailer, but I recall that Capt Nemo was happy with his PVC piping that funneled the keel between the guides. I can't find good photos, here or on the TSBB, but this fuzzy Photobucket image might give you the idea. Looks like he bypassed the carpeted bunks entirely. Not sure I'd go that way, but the funnel idea seems reasonable.
http://cpyoa.geekworkshosting.com/forum/index.php?topic=8030.msg59171#msg59171
Bruce
Aroo, PC 308
Narragansett Bay, RI

Zephyros

#7
Here are photos of Captain Nemo's PVC Keel Guide mod, from my photo library. I reviewed and considered his design as it does eliminate the keel contact with the keel guide board vertical steel brackets. In the end, I went with my design as I did not care for the large plumbing apparatus and by using the trailer mounted guide posts, you achieve a similar funnel solution.

Also, depending on the angle of the boat ramp, your keel may be above the rearward section of the keel boards, thereby entirely missing the the PVC Keel Guides, but this is entirely dependent on the ramp angle.

bruce

Thanks, Tom, that's a lot of pipe. I would think just joining a flared section on the end of the boards, all carpeted, would do the same thing. I take your point about floating high above the boards.

I'll put my 2 cents in about goalposts. As I visual guide they work well, but they land high on the boat, and can give way easily from the leverage. Personally, I prefer the lower bunk-style guide-ons like CE Smith puts out. I use the single-post model, and can pivot the boat on them. The two-post model would do even better.
https://www.etrailer.com/dept-pg-Boat_Trailer_Parts-pc-Bunk%7EStyle.aspx
Bruce
Aroo, PC 308
Narragansett Bay, RI

Zephyros

#9
Hi Bruce,

Great point about "give way easily from the leverage". That is why I choose the CE Smith 60" model as they actually have a 40" steel post under the the 60" PVC outer cover. Here is the link and photos from etrailer.
https://www.etrailer.com/Boat-Trailer-Parts/CE-Smith/CE27640.html

I've forgot to pull my fenders in before and the posts brought the boat to a dead stop, no movement, no flex, until I moved the offending fenders.


bruce

I will say this about the CE Smith brackets, at least on the 27660, in salt water I get about 5 years out of them before they rust through. Rinsed with fresh water every time, drainage holes drilled where water might collect.

Trailer components can be a real crap shoot.
Bruce
Aroo, PC 308
Narragansett Bay, RI