Full bottom and keel redo
After being in denial about the state of the bottom of BlueJ, I decided this spring to take the plunge and have the whole thing redone. We had done everything else (sails, traveler, rigging, crew) that we could to the boat to make her faster, and we always felt that there was more speed to be had. Be every year, the timing (or the finances!) seemed off, and we just sanded a bit, and splashed some more Micron CSC on her and call it good. This year was going to be different.
So in the first week of April, I trucked BlueJ to Marine Fiberglass in the Twin Cities, probably the best place to have race-boat work done on your bottom. The plan was to:
Soda blast to bare gelcoat and iron
Treat the iron keel with Ospro rust sealant
Seal the keel with Interlux Interprotect 200E
Fair the keel with thickened 200E
Barrier coat the bottom and keel with 200E
Paint everything with VC17m
The first job was the soda blast, which will remove ALL old paint but not touch the gelcoat. Amazing. I was hoping that 1) the bottom would be in good shape, and 2) the keel would be reasonably fair and in good shape after it was brought to bare iron. If these were not true, the cost would have gone up. Happily we were in good shape. Here you can see the original gelcoat.
Next up was the keel. It is important to get it down to bare iron, and treat it with a rust preventive quickly. Then seal with Interprotect. This picture shows the keel after the first coat of 200E, before fairing. The keel was in decent shape. What hurt us in the past was the rough paint, the rust formations that would break through the old paint and disrupt flow and snag weeds.
This is now ready for fairing. The bottom would then be coated with 200E as well, and then whole boat painted with VC17, a very fast bottom paint good in fresh water.
Three weeks after being dropped off, BlueJ was ready to be picked up. Her bottom was smooth and fair. She looked fast sitting on her trailer!
As for speed, we are very happy. Our first series race we won wire to wire, taking the gun and beating faster J/27 and Merit 25s to the line. I wrote this in the team FB page:
After a few races and a few fun sails, my feeling is we have gained a 1/4 of a knot boat speed in the majority of the cases (sailing angles and wind speed). Powered up and upwind we now see 5.24 knots where 5.00 was more typical last year. Not only does that put us pretty much on our polars, it is a 5% increase in raw speed. The new kite helps us maintain that bump downwind, where last night the Merit 25 could not gain at all, and the much faster j27 made only minimal gains. I had estimated before the bottom-job that the bump would be in the 3-4% range, so even if this 5% is optimistic we are going to be more than fine. To note: a 5% gain in speed in the 80 minute race last night saved us FOUR MINUTES of course time. Think about that for a minute! ;^)
Our plan in to be in the water swimming every few weeks in the summer to give her a wipe to keep slime off. But are we happy?? Yes. Only sad I waited this long!
So in the first week of April, I trucked BlueJ to Marine Fiberglass in the Twin Cities, probably the best place to have race-boat work done on your bottom. The plan was to:
Soda blast to bare gelcoat and iron
Treat the iron keel with Ospro rust sealant
Seal the keel with Interlux Interprotect 200E
Fair the keel with thickened 200E
Barrier coat the bottom and keel with 200E
Paint everything with VC17m
The first job was the soda blast, which will remove ALL old paint but not touch the gelcoat. Amazing. I was hoping that 1) the bottom would be in good shape, and 2) the keel would be reasonably fair and in good shape after it was brought to bare iron. If these were not true, the cost would have gone up. Happily we were in good shape. Here you can see the original gelcoat.
Next up was the keel. It is important to get it down to bare iron, and treat it with a rust preventive quickly. Then seal with Interprotect. This picture shows the keel after the first coat of 200E, before fairing. The keel was in decent shape. What hurt us in the past was the rough paint, the rust formations that would break through the old paint and disrupt flow and snag weeds.
This is now ready for fairing. The bottom would then be coated with 200E as well, and then whole boat painted with VC17, a very fast bottom paint good in fresh water.
Three weeks after being dropped off, BlueJ was ready to be picked up. Her bottom was smooth and fair. She looked fast sitting on her trailer!
As for speed, we are very happy. Our first series race we won wire to wire, taking the gun and beating faster J/27 and Merit 25s to the line. I wrote this in the team FB page:
After a few races and a few fun sails, my feeling is we have gained a 1/4 of a knot boat speed in the majority of the cases (sailing angles and wind speed). Powered up and upwind we now see 5.24 knots where 5.00 was more typical last year. Not only does that put us pretty much on our polars, it is a 5% increase in raw speed. The new kite helps us maintain that bump downwind, where last night the Merit 25 could not gain at all, and the much faster j27 made only minimal gains. I had estimated before the bottom-job that the bump would be in the 3-4% range, so even if this 5% is optimistic we are going to be more than fine. To note: a 5% gain in speed in the 80 minute race last night saved us FOUR MINUTES of course time. Think about that for a minute! ;^)
Our plan in to be in the water swimming every few weeks in the summer to give her a wipe to keep slime off. But are we happy?? Yes. Only sad I waited this long!
Hi,
ReplyDeletegreetings from Finland! Just found your blog and what I see? Cool mods for small Firsts!
I would like to know how you've made addition of winches? Haven't found any line of installing them?
Best regards,
-Pertti Koskinen-
Hei Pertti,
DeleteWe added the Lewmar ST14s to the decksides to simplify spin work, in particular during maneuvers. During drops we need the primaries for jib sheets, and as I drive and trim during jibes, its nice to have them back by the driver. We spaced them as to be clear of lifelines, mainsheet trimmer etc. I can measure exact location next time I'm at the boat.
clay