Encapsulating an iron keel do's and dont's.

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Various discussions have taken place on the topic of encapsulating iron keels with fibreglass. None of them seem to arrive at the best way of carrying this out. Many warn of the coating coming free of the iron keel. What is the correct procedure to guarantee success ?
 
It is something I've considered. My understanding is that iron will absorb atmospheric moisture and it is impossible to stop it. That moisture will allow some rusting to occur after you've sealed it, which will separate the fibre glass from the iron. It does mean that when you grind back the keel something waterproof needs to go on immediately.

You also want to do it when there is the minimum of moisture in the atmosphere, so a cold dry day. Trouble is that cold days are not good for fibre glass, so I suspect a enclosed space with controlled humidity is necessary to do a reasonable job.

My plan B is just to buy a boat with a lead keel the next time.
 
dt4134 said:
It is something I've considered. My understanding is that iron will absorb atmospheric moisture and it is impossible to stop it. That moisture will allow some rusting to occur after you've sealed it, which will separate the fibre glass from the iron. It does mean that when you grind back the keel something waterproof needs to go on immediately.

You also want to do it when there is the minimum of moisture in the atmosphere, so a cold dry day. Trouble is that cold days are not good for fibre glass, so I suspect a enclosed space with controlled humidity is necessary to do a reasonable job.

My plan B is just to buy a boat with a lead keel the next time.
Click to expand...

Thanks for your reply.
That is my understanding too.
The question therefore becomes "How to seal the keel in preparation for encapsulatuion with glassfibre?".
 
I had this issue about 3 years ago.
I was going to use Primocon but my local boat builder suggested i use Temacoat, a two part epoxy paint. I decided to try it. On application this product seemed quite strong, thick and good adhesively strong. Apparently it is used on hulls of metal ships. It did not prevent minor specks of corrosion appearing after a season but it certainly contained it significantly. I would use it again if the need arose.

http://www.tikkurila.com/industrial...aces/metal_products/temacoat_rm_40.3318.shtml
 
VO5 said:
Various discussions have taken place on the topic of encapsulating iron keels with fibreglass. None of them seem to arrive at the best way of carrying this out. Many warn of the coating coming free of the iron keel. What is the correct procedure to guarantee success ?
Click to expand...
Simple. There isn't one, which is why you can't find one.
 
I had my keel grit-blasted and primed with five coats of epoxy. The job was done professionally in Greece in my absence, presumably in close to ideal conditions. I then applied four or five coats of Coppercoat. After one season there were two areas in which rust was showing through and one where a scrape from a fishing float had removed everything down to bare metal. I repaired the damaged areas using several coats of West epoxy and a Coppercoat repair kit. After two more seasons spots of rust are again showing through, in non-repaired areas. Having carried out what most authorities suggest is just about the ideal treatment, but without achieving total success, I suggest that what the OP wants may not be possible.
 
Iron keels

I don't have any personal experience on my boat. However a few months back when helping 2 friends (2 different boats up together) they hada visit from Jotun tech rep. He supplied a 2 pack which he reckoned was just the stuff for iron keels. He indicated rust did not have to be converted just grind smooth then put the 2 pack on. Follow with a primer of the same system then a/f.
I can't tell if the system worked but this Jotun man was convincing considering his main business is steel ships.
I had tried 12months before on one of the boats grinding then rust converter (acid) then epoxy. It was better than nothing but rust still emerged bubling off the epoxy and a/f.
good luck olewill
 
Every boat I have owned over the last 40 years had an iron keel and none of those boats were new when bought. If the keels were prepared and painted properly, rust was never a real issue apart from a localised touch up prior to applying new antifoul.

Iron keels vary in quality and some need more preparation than others. Westerly had times when their keel iron seemed pretty poor, but even then not really a problem once dealt with. The first problem is to remove all the existing coating, but once done it needs to be immediately protected and that is two separate actions that are difficult to combine and to combine yet again with a third variable of the weather. Grit blasting will remove all the existing coating, but unless the atmosphere is dry and the keel recoated immediately problems can arise, not least because the large chunk of heavy metal will often stay relatively cold for a long time whilst the ambient temperature has risen, encouraging any moisture to drop out on the keel surface and largely unseen. Having a keel professionally grit blasted during the week and then arriving at the weekend to paint it is not good but very common. Having it grit blasted and then painted immediately with coat #1 is much better if you trust the person doing it, do it yourself or at least monitor the job and the humidity on the day. All of this is essential for any kind of two pack coating or glassing and the reason why so many fail later, IMO.

We have stripped many keels back, but always only by hand with scrapers and maybe some stripper to get the first few of many antifoul coats off. After that comes the grinder and powered wire brush but be careful because these can 'polish' the surface and anyway will not remove any paint in the pores of the casting. Once done we would wait for the right weather, then dry sand to remove any new surface rust and then clean off the dust. We would then use a liquid rust killer ( not a primer one, just a liquid, bought from Halfords or the like) painted on then wiped off after say 30 minutes ( it doesn't stick to non-rusty metal) because rightly or wrongly I thought it would get into the surface pore rust. After that is the easy bit to apply multiple coats of Primocon at the stated intervals, five coats as a minimum. Primocon now is the advised primer for antifoul so no problems in overcoating. Thereafter all that is required each lift out is a quick rub down of any local bits of rust and a dab or two of Primocon before antifouling again.

Seemples, not too expensive and after the initial job not hard work.
 
prv said:
Why would one want to wrap an iron keel in fibreglass in the first place?

Pete
Click to expand...

Because it has been proposed to me by a yard.
Because ultimately I intend to coppercoat.

I have searched the net and not found a solution that satisfies permanency.
Therefore I am understandably reluctant to give the yard a go ahead despite their assurances they have encapsulated several iron keels successfully.

So now the question is how to treat an iron keel to properly prepare for coppercoating.
 
vyv_cox said:
I had my keel grit-blasted and primed with five coats of epoxy. The job was done professionally in Greece in my absence, presumably in close to ideal conditions. I then applied four or five coats of Coppercoat. After one season there were two areas in which rust was showing through and one where a scrape from a fishing float had removed everything down to bare metal. I repaired the damaged areas using several coats of West epoxy and a Coppercoat repair kit. After two more seasons spots of rust are again showing through, in non-repaired areas. Having carried out what most authorities suggest is just about the ideal treatment, but without achieving total success, I suggest that what the OP wants may not be possible.
Click to expand...

Point taken, thank you vyv.
When you mention epoxy, I take it you mean two part epoxy ?
 
VO5 said:
Because it has been proposed to me by a yard.
Because ultimately I intend to coppercoat.

I have searched the net and not found a solution that satisfies permanency.
Therefore I am understandably reluctant to give the yard a go ahead despite their assurances they have encapsulated several iron keels successfully.

So now the question is how to treat an iron keel to properly prepare for coppercoating.
Click to expand...
It is not clear whether they are really proposing to encapsulate the keel in a GRP laminate - which is unlikely to work. I suspect they are intending to use an epoxy coating in the same way as Vyv describes before applying the Coppercoat.

If that is the case, it is common practice and Coppercoat sell the materials to do it. success depends on preparation and correct application and may not be 100% effective as it is difficult to clean the iron casting completely.

The subject of Coppercoating comes up regularly here, and people seem broadly satisfied that it does what is claimed of it, but it is important to follow the manufacturer's instructions and use their recommended materials.

Think you really need to get a full explanation from them as to what they are proposing, as I think you are possibly confusing things if you think they are actually going to encapsulate the keel in GRP.
 
Robin said:
Every boat I have owned over the last 40 years had an iron keel and none of those boats were new when bought. If the keels were prepared and painted properly, rust was never a real issue apart from a localised touch up prior to applying new antifoul.

Iron keels vary in quality and some need more preparation than others. Westerly had times when their keel iron seemed pretty poor, but even then not really a problem once dealt with. The first problem is to remove all the existing coating, but once done it needs to be immediately protected and that is two separate actions that are difficult to combine and to combine yet again with a third variable of the weather. Grit blasting will remove all the existing coating, but unless the atmosphere is dry and the keel recoated immediately problems can arise, not least because the large chunk of heavy metal will often stay relatively cold for a long time whilst the ambient temperature has risen, encouraging any moisture to drop out on the keel surface and largely unseen. Having a keel professionally grit blasted during the week and then arriving at the weekend to paint it is not good but very common. Having it grit blasted and then painted immediately with coat #1 is much better if you trust the person doing it, do it yourself or at least monitor the job and the humidity on the day. All of this is essential for any kind of two pack coating or glassing and the reason why so many fail later, IMO.

We have stripped many keels back, but always only by hand with scrapers and maybe some stripper to get the first few of many antifoul coats off. After that comes the grinder and powered wire brush but be careful because these can 'polish' the surface and anyway will not remove any paint in the pores of the casting. Once done we would wait for the right weather, then dry sand to remove any new surface rust and then clean off the dust. We would then use a liquid rust killer ( not a primer one, just a liquid, bought from Halfords or the like) painted on then wiped off after say 30 minutes ( it doesn't stick to non-rusty metal) because rightly or wrongly I thought it would get into the surface pore rust. After that is the easy bit to apply multiple coats of Primocon at the stated intervals, five coats as a minimum. Primocon now is the advised primer for antifoul so no problems in overcoating. Thereafter all that is required each lift out is a quick rub down of any local bits of rust and a dab or two of Primocon before antifouling again.

Seemples, not too expensive and after the initial job not hard work.
Click to expand...

Thanks for the detailed explanation Robin, I appreciate the effort.
You reckon then Primocon is the route to follow ?

My Sealord has a glassfibre hull and an iron keel.

I think perhaps the project to coppercoat should be done in two stages, viz, first coppercoating the hull and rudder and antifouling the keel as usual.
Then on the next lift, dealing with the keel as you suggest and then coppercoating the keel.

Is that a better idea ?
 
Tranona said:
It is not clear whether they are really proposing to encapsulate the keel in a GRP laminate - which is unlikely to work. I suspect they are intending to use an epoxy coating in the same way as Vyv describes before applying the Coppercoat.

If that is the case, it is common practice and Coppercoat sell the materials to do it. success depends on preparation and correct application and may not be 100% effective as it is difficult to clean the iron casting completely.

The subject of Coppercoating comes up regularly here, and people seem broadly satisfied that it does what is claimed of it, but it is important to follow the manufacturer's instructions and use their recommended materials.

Think you really need to get a full explanation from them as to what they are proposing, as I think you are possibly confusing things if you think they are actually going to encapsulate the keel in GRP.
Click to expand...


They say "fibreglass"....
Frankly, I am now reluctant to take the risk despite all the emphatic assurances which I have no doubt are well meaning because they have done a flawless repair on a nasty dent in the bow as a result of the previous owner not securing the plough anchor properly to stop it from pecking.
They also assure me they have had success in treating other iron keels in this way.
But the idea of the covering sliding off is a real worry. It makes sense as the "propsed encapsulation" would not have any significant anchor point to hold on to, except the surface of the keel itself, which I am now convinced, according to the advice given on this thread is a very real risk.
 
Well, if they are really talking about fibreglass in the sense of a GRP laminate, then you are right to have concerns. However, there is nothing unusual or particularly risky about applying coppercoat to old iron keels provided they are slurry blasted and coated with an epoxy primer using the recommended epoxies. This is covered in the video on the Coppercoat website and in their promotional materials.

The decision really comes down to your assessment about whether you want to spend that amount of money to have the job done properly or whether you want to stick to using conventional antifouling.
 
Tranona said:
Well, if they are really talking about fibreglass in the sense of a GRP laminate, then you are right to have concerns. However, there is nothing unusual or particularly risky about applying coppercoat to old iron keels provided they are slurry blasted and coated with an epoxy primer using the recommended epoxies. This is covered in the video on the Coppercoat website and in their promotional materials.

The decision really comes down to your assessment about whether you want to spend that amount of money to have the job done properly or whether you want to stick to using conventional antifouling.
Click to expand...

My ultimate intent is to coppercoat, and to have the job done properly.
The hull is not a problem. What worries me is the keel.
The advantage I have is that across the Straits there is a Morrocan yard whose fees for lifting and dry berthing are cheap. They also allow owners to do their own work while ashore.
If I have the boat coppercoated then it is a simple matter of lifting, power washing and rub down, refloating, which is a more convenient option than all the antifouling rigmarole, you see ?
The initial investment pays off in time and effort over the next few years.
 
Additionally, and I forgot to mention, I have a chum who is a diver.
He offers to change the anodes and scrub underwater if I lead the boat to a quiet anchorage with little current, so that's another plus.
 
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