Keel joint maintenance

[andylipsberg]

I’m new to these repairs, would like to ask what materials shall I use. I don’t see any reason for repair, but some maintenance is required here.

please advise the best approach. Thanks.

 

[FairweatherDave]

Looks to me like me someone has picked off the sealant a bit. Any evidence of a grounding on the keel edges / an impact with anything? And presumably no water ingress around keel bolts.
The antifoul doesn't adhere to the sealant as well as it does to the keel or hull so this could be pretty normal and just antifoul over. I did have a dig round my keel join and used a specialist product a couple of years back but I have a similar looking issue. I'll just be painting over.

 

[FairweatherDave]

Arbomeric MP20 is what I used

 

[lustyd]

+1 for painting over if you don't have non-cosmetic issues. Don't forget that if you dig it out, the weight of the boat is on that joint right now so with the keel hanging once in the water whatever goop you put in might be under tension and could pull away leaving a hole.

 

[alahol2]

Maybe smooth it with a bit of CT1 and a wet finger and/or paint over it.

 

[andylipsberg]

Looks to me like me someone has picked off the sealant a bit. Any evidence of a grounding on the keel edges / an impact with anything? And presumably no water ingress around keel bolts.
The antifoul doesn't adhere to the sealant as well as it does to the keel or hull so this could be pretty normal and just antifoul over. I did have a dig round my keel join and used a specialist product a couple of years back but I have a similar looking issue. I'll just be painting over.

nope,there was no grounding and no water coming through. Maybe little bit of cleaning, epoxy putty, primer and then antifouling? Wouldn’t that make smooth joint then?

 

[andylipsberg]

Arbomeric MP20 is what I used

isn’t is simmilar to sikaflex?

 

[andylipsberg]

Maybe smooth it with a bit of CT1 and a wet finger and/or paint over it.

It says You will need to remove the old silicone first and clean the area before applying CT1.

 

[James_Calvert]

I also use sikaflex or ct1 applied with a finger, having sanded it a little to clean it up. Then antifoul at least a day later.

 

[alahol2]

It says You will need to remove the old silicone first and clean the area before applying CT1.

It depends if it's silicone already in there, it may not be. Not sure how you tell.

 

[V1701]

I'd have thought it less likely to be silicon than not & would also clean it up, scrape what's in there already out as much as possible and use CT1/OB1...

 

[andylipsberg]

I also use sikaflex or ct1 applied with a finger, having sanded it a little to clean it up. Then antifoul at least a day later.

which sika did you use?

 

[James_Calvert]

Sika 291i. The toothpaste tube size is more than enough for me.

 

[andylipsberg]

Sika 291i. The toothpaste tube size is more than enough for me.

thanks. I'll go with that.

 

[James_Calvert]

I find those wet wipes for decorators good for cleaning up fingers etc afterwards. You'll need something to hand, otherwise it gets everywhere.

 

[PeterWright]

If you want to use Sika, the whole joint should be made with 292i and there is a 3M alternative which does the same job, basically a material which adheres really well to both grp and cast iron and cures to a hard rubber like consistency. The joint is designed to absorb a small amount of relative movement between hull and keel, hence the importance of not using anything which cures hard. Sika 291i is less adhesive than 292i so more likely to fall off the joint.

The main problem I see is that the black painr has cracked off the joint. If it has not exposed any of the cast ironor grp, I would be inclined to just put more black paint back on. Yes, it will almost certainly fall off again, because the joint will move a bit under sailing loads.