Author
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Topic: Bottom paint speed penalty.
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DaveS |
posted 07-10-2008 11:10 PM ET (US)
I took my 17' Outrage out on the water for the first time this summer today. It was a beautiful day. Made several passes up and down the Delaware River and the engine (1991 120hp Johnson) ran like a champ, but I was only able to hit 39mph (GPS). The engine is mounted up one hole and it has a new 13" x 17' aluminum prop and was able to hit 5500 rpms. At that point, it started to porpoise, so I backed off a bit. I just couldn't get it passed 39 mph. The bottom paint is in bad shape but I thought I'd hit the low 40's with this setup. I was running with my younger son and myself in the boat with a full tank of gas. The engine itself is in great shape with good compression. Am I loosing that much because of the old bottom paint? Thanks for the help. Dave
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Casco Bay Outrage
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posted 07-10-2008 11:41 PM ET (US)
Glad to read you finally are back among the fish and seaweed! |
DaveS
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posted 07-10-2008 11:58 PM ET (US)
I was going to tell everyone of my "conquest!" Two really nice catfish, the biggest, about 10", but I didn't want to brag! :) |
swist
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posted 07-11-2008 08:46 AM ET (US)
Not knowing what that hull would do without paint makes it hard to say what you are losing, but yes, most commonly-used bottom paints take some speed off the top end - waxed gelcoat is pretty slippery and you are taking that out of the picture. There are some specialty paints which are supposed to give a slicker finish that may have less impact, but I have no eperience with them. |
Tohsgib
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posted 07-11-2008 10:17 AM ET (US)
Bottom paint if smooth will not detract much if any speed. Bottom paint in poor condition can do horrendous things to your performance. Waxing a bare bottom is slower than not waxing...JUST FYI. The wax makes an airpocket and the little bubbles actually slow you down. I know what you are gonna say..sailboats do it...well it probably helps under 8 knots or so but at 40 it is impeding speed. |
DaveS
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posted 07-11-2008 04:00 PM ET (US)
Thanks for the info. To follow up, the bottom paint is really kind of ratty, I can only imagine how many coats there are on this thing. I started using a pressure washer to remove some of the paint and it did an OK job. Nothing fancy but enough to see I've got my work cut out for me. So, I guess I can conclude that my bottom paint is the culprit. I'm not upset I can't hit 45mph, I just wanted to see how much the bottom paint was costing me, speed wise. Thanks again. Dave |