Spring Preparations

Our list of preparations below the waterline for launch include antifouling on the bottom, saildrive and propeller and new zincs.  As usual, I've learned quite a bit researching paint and zincs.

Regarding bottom paint, we need to put on paint that is compatible with the existing paint, or remove the existing paint.  Pat Sturgeon, the dealer we bought the boat from told me he had put Interlux Fiberglass Bottomkote on which, according to the Interlux compatibility chart was compatible with all their paints with a light sanding.  

At the Toronto boat show we decided to go with Micron CSC which is supposed to have "excellent" antifouling properties.  So this past weekend, armed with drywall sanding handles and mesh and a pressure washer we went at the bottom to give it a light sanding.  Problem was, the paint was not a hard paint, but rather very soft.  Not Fiberglass Bottomkote?  I dug around the Interlux website and learned that in addition to Fiberglass Bottomkote they make Bottomkote XXX and Fiberglass Bottomkote ACT both of which are soft paints.  Fiberglass Bottomkote ACT is also compatible with other Interlux products with a light sanding, but Bottomkote XXX isn't compatible with anything other than itself, and oddly enough is also their least expensive paint for "the cost conscious boat owner". I emailed Pat Sunday morning with my dilemma and to his credit he got right back saying that he uses either Bottomkote XXX or Trilux II.  Trilux II is also a hard paint, so that pretty well settled it.  We either had to remove all the paint or just go ahead and recoat with Bottomkote XXX.  Stripping wasn't something we looked forward to, so I rationalized that Bottomkote XXX has "good" antifouling properties, and we don't plan to be sitting still too long, so hopefully it will do the job.  Thankfully Hindson marina had a couple of gallons so we got them and put the first coat on Sunday.  Then I realized that Bottomkote XXX has an "immersion" time of 48 hours to 5 days depending on which Interlux document one reads.  So if we were to put the second coat on Monday, it would be nine days until we immersed it on our launch day of May 3 ... so decided instead to wait until this coming weekend to get us within 5 days. Monday was then dedicated to washing and waxing the hull.

On the saildrive and prop, copper based antifouling paints cannot be used because they cause corrosion of the underlying metal. Trilux II is suitable but needs to be applied over a good primer.  Interlux recommended Interprotect 2000 epoxy primer and 2 or more coats of Trilux II.  We also got the Interprotect on this past weekend.

So the plan was to go up Saturday and Sunday to put another coat of Bottomkote XXX on and a couple of coats of Trilux II on the saildrive.  I have the prop at home and have been preparing it this week.  Unfortunately spring does not appear to have fully sprung because the forecast for the coming weekend is a high of 6 Celsius.  Not only cool to work in but the data sheets for Bottomkote XXX and Trilux II say the ambient temperature and substrate temperature need to be at least 10 Celsius!  Touching base with Interlux technical support, Dale told me that the paints might not adhere to the first coat and might not cure at all. So I've decided to take advantage of the warm weather forecast tomorrow to get the second coat of Bottomkote XXX on and the first coat of Trilux II on the saildrive.  Monday is supposed to be in the teens too, so that will have to be when we put the second coat on the saildrive.

With regard to zincs, I've learned that in fresh water the sacrificial anodes should be magnesium rather than zinc.  We have a bolt on hull anode to which all the through hulls are connected, a ring on the saildrive and a couple of "buttons" on the Flexofold two blade prop.  So next question was what material were the existing zincs?  After all, it's a German boat ... would they put different sacrificial anodes on for Great Lakes bound boats?  Zinc weighs twice what magnesium does for the same volume so based on product data on line I was able to determine that in fact all the sacrificial anodes were Zinc not magnesium.  Hanse owners take note!  They all have a calcium coating on them which means that they are not doing their job ... glad I figured this out fairly early on.  Handy hint ... CLR does a great job dissolving the calcium!  So I have spares now, except for the Flexofold but I think I will just clean up the existing ones and leave them on.

So that is it below the waterline.  More on this year's projects in other posts.