I slipped my boat recently as it has been out of action for some time after I had an accient and found that the keel only dropped about 30cms but then jammed. As it was on a hardstand I removed the keel case top and tried to scrape any loose flaky rust using a metre long piece of flat steel.This removed a lot of build-up and I could see daylight throught the base in most areas but, no luck, it jammed again.This was repeated by three people taking turns above and below.The hydraulics seem fine. Is there a stop mechanism on the keel in the hydraulics? Has anyone ever used diluted phosphoric acid to remove rust from the keel whilst it is inside the keel box to save trying to remove it? I think this would be relatively benign for the fibreglass surrounds and it could then be careened, cleaned with a rotating wire brush and treated with rust neutraliser and epoxy tar.She is back in the water on her swing mooring in Sydney Harbour now and the thought of slipping her and putting back on a hardstand is frightening-cost wise.Any comments would be very welcome.
If you have the origonal "Fleetfoil" ram fitted the distance travelled will be the length of the ram less about 50mm, there is no stop untill it has reached the end of the cylinder. If you have recently topped up with hydraulic fluid, and the pump resevior is over filled, then there may not be enough space left to take all of the fluid from the ram and the keel will not fully lower.
Thanks Rob for your timely response, I will definitely check out the hydraulic ram, even though it hasn't been topped up. I was thinking that I might drain off some hydraulic fluid and see if that makes a difference.