Bottom Work: Propspeed and WestMarine PCA Gold

We have traditionally used Trilux 33 non-copper based anti-fouling paint on the saildrive and props. The performance on both has been ok, but not great. The saildrive typically starts growing stuff after a few months of warm water. The props have typically been similar, needing the growth scraped off once or twice during the Chesapeake boating season. The bottom paint has been West Marine CPP, which is an annual ablative paint. It works reasonably well, with only a few barnacles to scrape off on each haul-out.

Overall Bottom - Some Barnacles

Two years ago we installed Flexofold props. While doing the installation, we looked at other boats in the boat yard. Quite a number of big boats used Propspeed and they typically had little or no growth on the props. Propspeed works by making the surface too slick for the growth to get much adhesion. Based on the condition of other props, we decided to give it a try. The first thing we had to do was to get past the sticker shock of the product. But we decided that we were going to try for two years in the water, making it easier to purchase.

The results speak for themselves. Here are some pictures from our haulout in October, 2018, following two years in the water. We cleaned the bottom once during the period. More frequent cleanings may reduced the amount of growth that collected.

We used the same anti-fouling that we had always used before on the saildrives. Sure enough, they had a thick coating of marine growth. The comparison between the props and the saildrives is pretty remarkable.

Starboard Prop with Helical Rope Mark

The props looked the best. There is a helical strip of growth on the stbd prop, which looked like abrasion from a rope wrap. Sure enough, there was a piece of line stuck between the saildrive and the prop. LUX has sat most of the past year due to family events. Propspeed likes to have good water flow to help dislodge the growth and we were not able to provide the appropriate level of activity. Even still, the props and hubs look remarkably clean, relative to what we’ve seen with anti-fouling paint. We had noticed a slight reduction in boat speed, which may be due to a few barnacles and those that attached to the hull.

The growth on the props was easy to remove, except where the abrasion from the rope had removed the Propspeed coating. We only needed to push the barnacles off the Propspeed. 

Port Prop - Note Barnacles on Saildrive

This year we are using Propspeed again and are extending the use to the saildrives too. The saildrives had been coated with epoxy, so we applied a coat of West epoxy over the existing epoxy. There were some places where the aluminum saildrive was exposed, so we used a neat procedure of wet sanding through the epoxy before it cures. The next day we sanded the cured epoxy.

The final step was applying Propspeed to the props. Oceanmax instructions say to apply just the finish coat on epoxy, which is what we have on the saildrives.

We increased the amount of Propspeed that we purchased, but found that the 500ml kit was almost twice what we needed.

We switched bottom paint this year, going with West Marine PCA Gold, which is supposed to be a basic multi-year paint. It took nearly 3 gallons to cover the bottom. It will be interesting to see how well it holds over the next two to three years.

Applying Propspeed

In the last picture, take note of the number of jack stands supporting LUX. We have hauled out at Jabins Yacht Yard for the last several haul-outs. This time they described a catamaran that they had hauled and blocked using stacks of blocks under the hulls and jack stands at the ends. The hulls split along the center line, making them very afraid of using the Leopard-recommended blocking. (I suspect that they paid for the repair and I doubt that it was a Leopard catamaran.) The result is that they used seven pairs of jackstands on each hull. And even though it wasn't our problem, there was an additional charge for the extra blocking.

Update: July 2021

We've been using PropSpeed on our FlexoFold props for the last two haulouts. The first was in 2016 when we initially installed the new props. We reported the results in 2018 above.

During the 2018 haulout we coated the saildrives with the topcoat only as we were unsure about the undercoat on aluminum. The results were great in July 2021. Yes, three years - last year was the lost year and we didn't haul Lux as we normally do.

Barnacles on the saildrives came right off. The topcoat on the saildrives looks good and is shiny. We plan to roughen the surface with sandpaper and reapply the top coat to the saildrives.

The props showed some erosion of the PropSpeed after the 3 year interval, but still had much fewer barnacles than any time in the past when we've used bottom paint of any sort. The barnacles that existed were easily removed with a cloth - they just don't stick to the stuff. We were tempted by the lower price and larger quantity to try the PropGlide product, but think that we'll stick with what we know works.

We were also happy with the performance of the West Marine PCA Gold bottom paint. It didn't work well on the rudders, which we think was due to erosion of all the paint, perhaps from the water flow from the props. The rest of the hull had some soft growth and small barnacles in some places. We've definitely seen much worse. A more regular program of diving and cleaning may be the answer. We had the bottom cleaned about once a year. Lux was in Delegal Creek, Georgia for the winter of 2019-2020 and was in the Chesapeake the remainder of the time. We will use PCA Gold again this year.

We also note that Jabins Yacht Yard now uses foam padding between the support blocks and the hull. We positioned blocks per the owner's manual with additional bow and stern jack stands.