Best keel fairing material

[dargiem]

I have a 1988 Catalina 30'' TRBS and need to dig out and re-fair between the keel and boat(this boat has a lead keel.) Also noticed water seeping from, what turned out to be a small crack in the paint/fairing on the keel side of the joint.
Any suggestions on the filler material to use for the job and a primer to use before I paint the bottom with anti-foul?

Thanks

Mike in Noank

[paulk]

Some people use Bondo, but we''ve had pretty good results with West Epoxy & microballoons. (They call it microlight fairing spherules, or something like that.) If you use the wrong stuff (like fiberglass shards, for example) it sets up too hard and can be really difficult to sand back to where you want it. It should be sealed off with epoxy paint after sanding to avoid water getting absorbed into it.
Have fun!

[cysltd]

There are several approaches that we used in my boatyard.
The easiest is to clean out the keep seam of cracking or loose filler, sand and fair the bottom paint along the seam and apply a bead of caulking in the seam (3M 4200 or 101 is fine) and paint over.When you clean out the old filler, leave it open to drain as long as possible - several weeks if you can. We would sometimes brush or syringe some acetone into the seam to aid in drawing the moisture out.
Bear in mind that there will always be some movement in that area.

For more severe opening along the seam, we would grind out along the seam(go 3- 6 inches up along each side), remove loose caulking, and fill with Vinyester mixed with compatible filler, sand to fair the seam out and paint. In some cases, we used several layers of fiberglass cloth along the seam to avoid cracking.

I would advise that you have the keel bolts checked to make sure they are tight. Check with the manufacturer on the correct torque. This should be done while the boat is hanging in the straps of the travel lift. Over time, some bolts loosen very slightly.

By your description, it sounds like your situation is very routine and the simpler solution may very well be fine.

[Denr]

VC Watertite, its actually made for this very reason, do not use Bondo, its not meant for under water use.

[Lecy]

If you use West System remember that while the epoxy itself is waterproof, the fillers (I think 407 is the best West System filler for fairing) are porous. Therefore they need a layer of epoxy over them to seal out water. A barrier coat will accomplish this or a thin layer of epoxy with hardner in it brushed over the fairing will seal it.

[resdog]

I second the DO NOT USE AUTOMOTIVE FILLER. It will swell up with water and fall out almost immediately. VC Watertite works great as would epoxy resin and a filler powder.

[sailingdog]

The microballon and microfiber fillers are easier to sand but will absorb water... and should be coated with a barrier coat of epoxy after being sanded fair. The sillica high-density filler doesn't absorb water but is basically ground glass or sand, and almost impossible to sand fair.