keel help

Dil

.
Jul 13, 2020
57
Hunter 30T Neptune
In preparation for this season, I notice rust along the keel and hull connection, Hunter 30 1991 bolt on keel. I also notice small rust spots all over the keel. I have begun cleaning out the keel Hull connection, first question is do I try to get rid of all the oxidation on the iron? In some spots it's 1/4 to 3/8" thick. The small little spots not associated with the connection, is this from failed sealer coat? Do I need to blast the whole keel down to raw metal? and if I do what do I put back on before bottom paint? the keel bolts in the bilge look ok no rust. The rust spots are slightly blistered.
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
21,991
CAL 35 Cruiser #21 moored EVERETT WA
You need to get down to solid metal if you hope to seal up the area and stop further rust. What ever you put on rust will just flake off. You will need to treat the metal promptly to stop further rust. It starts when you produce fresh metal. You have a window of opportunity to coat the metal with a rust inhibitor, but do not leave it for overnight.
Once coated with a rust inhibitor you can then fair the area with an epoxy fairing compound. Sand it smooth and then bottom paint.
 
Jul 19, 2013
387
Pearson 31-2 Boston
You need to get down to solid metal if you hope to seal up the area and stop further rust. What ever you put on rust will just flake off. You will need to treat the metal promptly to stop further rust. It starts when you produce fresh metal. You have a window of opportunity to coat the metal with a rust inhibitor, but do not leave it for overnight.
Once coated with a rust inhibitor you can then fair the area with an epoxy fairing compound. Sand it smooth and then bottom paint.
What I'd add to your advice, is after grinding the keel to bright white, treat with five layers of straight epoxy, the really hard stuff. Then fair as needed or desired.
 
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dLj

.
Mar 23, 2017
3,729
Belliure 41 Back in the Chesapeake
What I'd add to your advice, is after grinding the keel to bright white, treat with five layers of straight epoxy, the really hard stuff. Then fair as needed or desired.
I agree with you on this, but on this specific keel there is a difficulty with that seam. It will be really difficult to get the metal clean all the way to the base of that seam without serious material removal. It looks like that seam is metal on both sides. I think using Ospho here would be very beneficial prior to epoxy coating. I just posted on another thread about that.


dj
 
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JBP-PA

.
Apr 29, 2022
472
Jeanneau Tonic 23 Erie, PA
Dlj's advice about Ospho or another rust converter is important. Remaining rust will continue and will cause paint to flake off. Clean off the loose rust with a wire wheel and coat it with two coats of Ospho. It doesn't have to be polished, just no loose bits.
Then go after that keel/ hull joint with chisel, maybe grinding disc to make sure all the loose stuff is out. Ospho again. Then you can start to fill and fair.
 
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Dil

.
Jul 13, 2020
57
Hunter 30T Neptune
thanks I have a soda blaster scheduled to at least get started with this issue. I do not know much about bottom maintenance but I am guessing this one has been let go awhile. as I was chiseling away with a screw driver I realized that this has been addressed in the past in a few different ways at the keel Hull joint I found some type of epoxy that water had gotten under and became un bound along the same joint I found caulking that was Im guessing a touch up of the failed epoxy. Well launch might not be early may after all.
 
Jan 4, 2006
6,926
Hunter 310 West Vancouver, B.C.
thanks I have a soda blaster scheduled to at least get started with this issue.
Unfortunately, the soda blaster is only good for FG cleaning. You'll need a sand blaster to cut into the steel. Maybe if the gods are smiling on you, your soda blaster can be converted to a sand blaster ? Maybe keep the compressor and a new head which will handle sand ?
 
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