Foss Foam Rudders

Ahoy All , Iam wondering if anyone has taken their Foss Foam rudder apart ?

I would like to find out what if any, steel reinforcements are inside the F/G rudder .

Is the lowest bronze pentle connected to anything inside the rudder ?

Douglas: Hi!

If Calliste’s rudder is completely dry, as I guess it would be if she’s still on the hard, I reckon careful use of a stud-detector or hand-held metal detector would reveal all.

Industrial X-ray services, using machines of the size that TSA uses at airports, would provide a better picture.

The Foss Foam company website shows a fin rudder being constructed. See So that’s no big help.

Foss Foam no longer lists BCC as a standard rudder. E-mail to Bob Walker (his e-mail is on the newrudders website) may be prepared to look through the company archives.


Mea culpa! Pointing to the Walker family’s was my error.

The company that holds the moulds for making BCC rudders with a GRP-shell over a foam polyurethane core is now The Foss Company ( in Newport Beach, California.

The Walker family’s operation in Florida was started by a colleague of Chuck Foss, who started the original Foss Foam (Chuck Foss of course earned his fame making inexpensive pop-up foam polyurethane blanks for surfboards).

Local government laws prevent The Foss Company blowing their own closed-cell polyurethane foam in Newport Beach. TFC subcontracts that work to Finco Fabrications, in Santa Ana CA (see Rudder Making - FinCo Fabrication).

Visiting the Florida-based Walker family-run website is not a bad thing, however. Their website has a concise page on taking care of a foam core rudder (see

The important point is, especially when on the hard, to do everything to shield the rudder from sunlight and heat.

If left in direct sun, especially if painted with black antifouling, the temperature of the rudder can rise to the point that the closed-cell foam core and the GRP shell separate. Local expansion of the foam core will distort the shape of the rudder.


Thanks Bil!
I just hauled here in the Caribbean with black bottom paint. Fortunately I was sitting E-W and the sun passed directly overhead. so it wasn’t a problem this time.

Something I do every time I haul. I drill a 1/4 hole on the bottom edge of the rudder.this shows me if I am taking on any water. Then I just put a 1/4 teak plug back in and top it off with a little epoxy.