Best method to remove old keel to hull sealant.

[SailingSeafarer]

Hello Everyone, I kindly ask for a recommendation to best remove the old sealant between my keel to hull joint. A recent survey suggested it to be resealed (although I have no rust and bolts are in good condition). Yesterday I tried to remove the old sealant (does look like its breaking down/old) however it was not easy to remove from the joint or surrounding rim. Can anyone recommend a tool or method to best remove the old sealant? Thank you for your time.

[UNCIVILIZED]

Are you looking to re-bed it using a flexible compound, or bond & tape it to the stub/sump? And any idea what's on there now in terms of compound that's being removed?

[rognvald]

SS,
I just did mine again this year. I used a scraper blade with a sharpened hooked end to remove the old sealant. If you used 5200, it can be fairly labor intensive. However, if you used a polysulfide, it's not that bad. After scraping the keel joint cleanly, I sanded with 80 grit, wiped with acetone and then lightly coated the joint with a slurry mix of West System epoxy with High Density filler to seal the bare spots. After the epoxy cured, I sealed the groove with Boat Life Life Seal which cures in 24 hours. Should last another ten years. Hope this helps.

[SailingSeafarer]

Thank you for your replies. Previous owner most likely used 5200 or comparable product. Although it is breaking down, the adhesive is still very strong to joint, hull, keel. Difficult to get it back to a smooth surface to reapply. I will try a scraper blade with sharpened hook next, sand, acetone, seal bare spots, and apply "Sikaflex" which was recommended to me to seal the joint. Thanks again. If anyone else has a method of removing old keel to hull sealant, I welcome suggestions.

[rognvald]

Seafarer,
I took a picture of my keel before I sealed it with caulking. It clearly shows the vee-groove I enlarged. The orange is Petit Tie Coat Primer for some repairs on the keel. Also, the leading edge of the keel was not removed since I did a spot repair on it last year and it was in perfect shape. Hope this helps.

[Terra Nova]

One of the least labor intensive methods to renew the exposed edge of the keel to hull caulk is to use an oscillating multi-tool with the deck caulk reefing blade.

[estarzinger]

^^ this . . . A Fein with any of several cutting blades (depending on the shape of the surface you are trying to clean) is the ticket.

[rognvald]

Originally Posted by estarzinger

^^ this . . . A Fein with any of several cutting blades (depending on the shape of the surface you are trying to clean) is the ticket.

Evans,
I have used a Fein Multimaster for many years and tried it initially on the keel/hull joint. However, it was much slower than the scraper blade(manual) and would periodically catch on the uneven surfaces(mating surfaces where exposed lead and fiberglass interact) in the vee-groove dramatically slowing the process. I did, however, use the Fein when I initially shaped the "V" after opening the connection. Also, the removal of the polysulfide was not a "picture perfect" process and in some areas held tenaciously to the substrate. In my opinion this, again, was a much more labor-intensive repair than one would initially assume. I thought this perspective would be helpful to some who are contemplating this repair/recon project. This is the 3rd time I've effected this task on my boat. However, there's always more than one way to skin a cat. Hope this helps. Good luck and safe sailing.

[UNCIVILIZED]

The heavy duty, 100% cleaning method is to drop the keel. Media blast the old sealant off of it & the mounting stub. Then re-fit using a mix of epoxy & milled fibers, to get a perfect fit, & to seal everything. And then lower the keel again, & apply your flexible agent.

[Terra Nova]

Originally Posted by SailingSeafarer

...my keel to hull joint. A recent survey suggested it to be resealed (although I have no rust and bolts are in good condition)...

Originally Posted by UNCIVILIZED

The heavy duty, 100% cleaning method is to drop the keel...

An inappropriate and entirely unnecessary amount of work to meet the simple survey recommendation.

[Suijin]

Since you're not dropping the keel, you want to remove as little of the existing sealant as possible. In other words, just what has deteriorated. If you cut too deeply you'll never get caulk back in there and you're just ruining perfectly good seal. I've used a Fein multitool for this purpose with the default cutting blade. I've tried the caulk cutting blade, but that's more for slicing through caulk or separating it from a surface, not for actually cutting it out.

I would not consider skimming the join with thickened epoxy. It just ends up cracking and trapping water. Better to caulk, smooth/sand and paint the caulk.

[rognvald]

"I would not consider skimming the join with thickened epoxy. It just ends up cracking and trapping water. Better to caulk, smooth/sand and paint the caulk." Suijin


Suijin,
The reason that I seal the juncture with the slurry mix is that I use my Multimaster with a 40/60 grit sanding pad to clean the remaining caulk from the fiberglass vee which exposes the raw glass/fairing compound of the keel. I feel better being certain that the glass/compound is sealed properly so that there is no ingress from water degradation/moisture. Then after the epoxy has kicked, I seal with the compound du jour(this year I used Life Seal for its quick set/curing time and tensile strength). I have always said that the process of working on boats is controlled insanity. Unfortunately, I believe I crossed the bridge many years ago. Good luck and safe sailing.

[rognvald]

Keel/hull joint sealed with Boatlife LifeSeal prior to painting.