Hull to keel transition rust repairs

[Reddragon]

Hi everyone, my first post here!

My fiance and I bought a Winga 78 last year and now is the first time we do body work on it (or any boat for that matter).

The paint on the keel has lifted from the surface and was cracked in some places with traces of rust bubbling through the paint. We decided to completely remove all layers of paint down to the iron, file away the rust and put fresh layers on top. Today I used a spatula and a hammer to remove the layers of paint. (Picture 1 below)

Work was slow and at some places the paint sticks to the keel really well so I couldn't quite get under the paint with the spatula. We bought a wire cup brush for a hand-drill to try getting the paint off with that thing tomorrow (and to remove the rust from the keel surface) (Picture 2).

So right now we have a few issues/questions and we hope for some good advice from you fine sailors

1) How do we best get all of the paint off the keel if the wire cup brush isn't strong enough?

2) Should I use the wire cup brush until I literally can't see any rust particles/color on the iron surface anymore or would that be overkill?

3) What exactly and how much of it should we put on the keel?
Our current plan after removing the rust is:
3.1) Clean surface (acetone alcohol?)
3.2) Epoxy primer VC Tar2 (how many coats? Do you think two will suffice?)
3.3) Anti-fouling copper-based paint (how many coats?)
Clarification: We have that copper-based black paint left over from the previous owner, which is the same paint that is currently on the hull, so at least for this time we plan to use it on the keel - unless you make a really convincing argument why we shouldn't

4) The paint on the hull itself above the keel still looks good so we don't want to touch it this year. However, there is a rubber-like layer on top of the paint around the whole keel where the keel transitions into the hull (around 5 cm broad). What is it for and what should we do with that? Should we remove it and then reapply a new rubber ring after we finished painting the keel? What exactly is that rubber called and what is it good for?

Or to put it in one sentence: how would you deal with the keel-to-hull transition area?

Thank you for taking the time to read this! We are looking forward to your good advice

[Fore and Aft]

Reddragon the keel really needs to be sand blasted back to bare steel then epoxy coated. But it sounds like you are going to have a go yourself so I would remove as much rust as possible first with that wire wheel. Maybe use a plug in drill because you can really give them a flogging when you push hard on the keel at high revs. Once the keel is as rust free as possible I would then coat the keel with a product like this.
Pettit | Rustlok Steel Primer WHatever rust lock you use make sure it is suitable for below the waterline.
Then two coats of your epoxy paint and two coats of antifoul. All done in one day so you get a good chemical bond.
As a surveyor I have seen mixed results using this system, often when the yacht is slipped in a years time there are a few patches of paint that have not adhered. Nothing serious but sand blasting back to NACE number 2 standard and epoxy coated produces the best results.
Cheers

[Jim Cate]

^^^^^

The above is good advice. In many areas it is difficult to get things sandblasted, so knowing an adequate alternate method (as described) is a good stopgap.

Good luck with it... iron keels are a PITA!

Jim

[RaymondR]

I'd use a 5" or 7" grinder with a wire brush, you can really get mean with those whereas a drill is under powered and hard to hold.

After you have removed all the rust flakes you can use an acid to really get it clean and remove the rust from the pits.

I'd put on an epoxy primer first, you want something which is really thin and will get into the little pits and cracks to give good adhesion for the following coats.

[gmakhs]

If you are looking for a non expensive alternative :
Use the brush to get the rust off.
Use rust stabilizer to get rid of the rest of the rust.
Use Iron epoxy puty , (berry cheap in construction stores , smooth it out , primer and then antifouling.

My keel came.covered with iron putty from.the factory and has no visible rust .

[GordMay]

Greetings and welcome aboard the CF, Reddragon.

[MartinR]

Sandblasting is the ONLY method that will give you a long life expectancy. You can brush as much as you like, it will leave small inclusions of rust, and they are the seeds for new rust. After sandblasting use an epoxy primer.

If you absolutely can not sandblast, wire brush it as good as you can, use phosphoric acid to get rid of the residual rust, then coat it with primer directly. The ideal primer in this situation is lead based, but in many places not easy to find. Epoxy or tar-epoxy will both work. My preferred primer: Intershield 300. Is very abrasive resistant in addition to giving good protection. But expensive.

Best guess, the rubbery coating on your keel hull connection is a chlorinated rubber paint. Is more flexible than epoxy, so less likely to crack.

[rmlarson1098]

[QUOTE=Reddragon;2859564]Hi everyone, my first post here!

My fiance and I bought a Winga 78 last year and now is the first time we do body work on it (or any boat for that matter).

The paint on the keel has lifted from the surface and was cracked in some places with traces of rust bubbling through the paint. We decided to completely remove all layers of paint down to the iron, file away the rust and put fresh layers on top. Today I used a spatula and a hammer to remove the layers of paint. (Picture 1 below)

Work was slow and at some places the paint sticks to the keel really well so I couldn't quite get under the paint with the spatula. We bought a wire cup brush for a hand-drill to try getting the paint off with that thing tomorrow (and to remove the rust from the keel surface) (Picture 2).

So right now we have a few issues/questions and we hope for some good advice from you fine sailors

1) How do we best get all of the paint off the keel if the wire cup brush isn't strong enough?

2) Should I use the wire cup brush until I literally can't see any rust particles/color on the iron surface anymore or would that be overkill?

3) What exactly and how much of it should we put on the keel?
Our current plan after removing the rust is:
3.1) Clean surface (acetone alcohol?)
3.2) Epoxy primer VC Tar2 (how many coats? Do you think two will suffice?)
3.3) Anti-fouling copper-based paint (how many coats?)
Clarification: We have that copper-based black paint left over from the previous owner, which is the same paint that is currently on the hull, so at least for this time we plan to use it on the keel - unless you make a really convincing argument why we shouldn't

4) The paint on the hull itself above the keel still looks good so we don't want to touch it this year. However, there is a rubber-like layer on top of the paint around the whole keel where the keel transitions into the hull (around 5 cm broad). What is it for and what should we do with that? Should we remove it and then reapply a new rubber ring after we finished painting the keel? What exactly is that rubber called and what is it good for?

Or to put it in one sentence: how would you deal with the keel-to-hull transition area?

Thank you for taking the time to read this! We are looking forward to your good advice [/QUOTIf you have a/c power, forget the battery powered cup brush and get a 4 inch (sometimes called a 4-1/2 inch) grinder. Use flat wheel brushes that fit the grinder; cup brushes are a pita. They tend to kick-back commonly (and quickly!) if you touch any obstruction, like working in a corner.
Safety glasses, at least, are mandatory.
Use the wire wheels ON EDGE, rather than in the flat position. Just hold the grinder 90 degrees either way from flat.

[oleman]

You need to move up to a 7" or 9" angle grinder and other tools of that class. Air driven tools are best because they actually cool off in use. You will find that attachments designed for the commercial tools can be very aggressive to the operator and the material so be careful with these tools.

A 60 degree in 7" or a straight twisted wire, wire brush is great for serious rust removal.

Other tools worthy of trying are needle guns and rotary chippers know at a shipyard as a growler.
Abrasive blasting either wet or dry is very effective but normally a contractor job.


Good luck with your vessel.

[MartinR]

Lead primer can be bought in the UK, by the way. Not allowed in Sweden anymore.