Rusty Keel

[C2L]

I have a 34 Hunter with steel keel that is rusting. I would like to 1) remove the rust and 2) refinish the surface and fair the keel. Has anyone done this and how would one proceed to accomplish this? I believe that one should be able to epoxy the keel prior to applying bottom paint to keep the rust from re-appearing.

Thanks in advance for the assist!

 

[David in Sandusky]

Good plan!

Nm

 

[Scott]

Have had good luck using Pettit Rust Lok Steel Primer (#6980). After using it about 5 years, there is very little rust rust when hauled for the winter.

 

[kloudie1]

Did the sanding then fairing with epoxy filled/thickened to peanut butter consistency ..then sanding.. then I coated (two coats) with epoxy barrier coat.. Interprotect 2000.. I think coal tar epoxy is actually better than Interprotect, but I couldn't get my hands on any when I did the keel.

 

[Scott]

Okay

Did the sanding then fairing with epoxy filled/thickened to peanut butter consistency ..then sanding.. then I coated (two coats) with epoxy barrier coat.. Interprotect 2000.. I think coal tar epoxy is actually better than Interprotect, but I couldn't get my hands on any when I did the keel.

What did you use as a filler? I would love to fair the keel properly but would need copius amounts of filler. I'm a cruiser so I"m not too particular. West system 403 is too expensive and doesn't go very far. I've used sawdust for other applications but obviously sawdust is no good for this app.

 

[Tom J]

I have a 34 Hunter with steel keel that is rusting. I would like to 1) remove the rust and 2) refinish the surface and fair the keel. Has anyone done this and how would one proceed to accomplish this? I believe that one should be able to epoxy the keel prior to applying bottom paint to keep the rust from re-appearing.

Thanks in advance for the assist!

Years ago I dropped the iron keel on my O'Day 23 and chipped the heavy scale off and then had it sandblasted. I wanted to use West System epoxy to seal it, so I primed the iron with one of the primers recommended by West System. I then faired the leading edge with epoxy mixed with a light filler, (micro-balloons, I think). The whole keel was covered in four coats of epoxy, the last coat had a mix of abrasion resistant powder. I wanted to fair the whole keel, but it would have been too expensive to do with West System, and I don't race, so... Anyway, the restoration held up very well for the next 12 years, and was still in good shape when I sold the boat. This was in salt water, by the way. I used the same bottom paint I used with the rest of the boat, with good results.

 

[kloudie1]

Scott. I used microbaloons (West 407, I think) mixed into epoxy. Sands well and leaves a good tooth for the barrier coat. some folks use cabosil or colloidal silica. I think that is too hard to sand/shape for general purpose fairing. There are some other suppliers besides West Systems, but West really has a good set of products.

 

[Richard Bryer]

A job WAY too fresh in my mind! I re-did the whole bottom of my '83 this summer. Only got in water Aug 1!

The most difficult part is the stripping of the rust, old fairing, and VC tar ( if you have what I had) . I had visions of getting down to a shiny but pitted surface. Didn't happen. The contractor I had tried soda blasting, but didn't work- took huge amount of soda for very little result. Suspect he didn't have powerful enough equipment. Sand would have probably been better but he didn't want to work among the dry sail boats in the yard with sand, so went to heat gun and scraper for the hull and a needle scaler for the keel. Left the keel surface clean but a dull grey. I was not convinced all traces of rust were gone so I gave it 2 coats of Cornado Sur-Prep V rust converter. Gave it one coat of Interprotect 2000. Then I faired the obvious spots with SystemThree epoxy QuickFair and added 3 more coats of IP 2000. Hint- use different colours of IP 2000 as it is really hard to tell where you have been. Another hint- figure out how many coats very carefully and alternate your colours so you end up with the colour you want ( you can probably guess how I know this!) A gallon (US) of mixed IP 2000 does the hull almost exactly. They say there is a lot more used for the first coat but I didn't find there was that much difference- but I was laying it on pretty thick with a 1/4 nap roller.
The fairing isn't race quality but big improvement on what it was. The bottom looked good at haulout- it should with less that 3 months in the water. A couple of pin point rust spots that I will dremel out and fair in this spring. Here is a pic taken just before launch

 

[Scott]

Thanks

Scott. I used microbaloons (West 407, I think) mixed into epoxy. Sands well and leaves a good tooth for the barrier coat. some folks use cabosil or colloidal silica. I think that is too hard to sand/shape for general purpose fairing. There are some other suppliers besides West Systems, but West really has a good set of products.

Kloudie, I will try it. I have gotten alot of good advice over the years from you. I will try the 407.
Scott

 

[Dan Johnson]

I haven't taken the whole keel down to bare metal on my '83 H34 but have done spot repairs. I use a diagonal wheel grinder to take off all the rust spotting, one spot at a time. Immediately after grinding, I give it a quick wipe with a dry cloth and then spray it with Rustoleum's Zinc Chromate white primer.

Once all the "leopard spotting" is done, I go back over each spot and apply several coats of bottom paint.

One of these days I may get so ambitious as to take the whole keel down to bare metal to redo it completely. A previous owner had it barrier coated but that is now breaking down with creaping rust spots under the bottom paint each season.

 

[Hunter voyager]

I stripped all the rust and old paint off to bare metal and really ground deep into the holes as my keel was very bad. Used a small angle grinder with rough sanding disc and various grinding discs.
I also ground out the gap between the hull and the top of the keel under the heads and around the keel flange taking out all the old mastic and rust. Also along the gap between top of the keel and the bilge.
I then sprayed it with a zinc rich primer.
Sanded it down again to leave the zinc in the crevices but clean steel on the surface.
I the coated with 4 coats of west epoxy. Then filled with auto body filler then sanded smooth. Then 2 more coats of epoxy.
I then filled the gaps to the hull with 5200.

Was done 8 years ago and no signs of corrosion since. Took a long time but was worth it I think.

 

[Mark48]

To fix some small rust spots on my keel, I used the rust inhibitor that one buys at auto stores and then primer and bottom paint. Held up well for this past year. Great lakes.

 

[splax]

This Spring I had mine soda blasted, which doesn't do the job, then chipped at the epoxy-paint buildup flaking off the keel. I plasticized the surface by coating with OsFro to prevent futher rust and provide a good surface for the barrier coat. I used West System that comes in a caulking tube and is mixed at application with the microballoons already in it for fairing. I used the IP 2000 as the epoxy barrier coat, then painted. Not race quality, but a definite improvement in the material condition.