Reducing drag!
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=6202
Printed Date: June-13-2024 at 7:17pm
Topic: Reducing drag!
Posted By: stang72
Subject: Reducing drag!
Date Posted: April-03-2007 at 10:26pm
|
The cheepest performance trick....reduce that drag!
I was just wondering how much time does anyone spend under the boat???? A good buffing and wax job as well as smoothing out and polishing the rudder and fins can reduce enough drag to gain a couple mph top end!!! Try it and see! ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Replies:
Posted By: Gary S
Date Posted: April-03-2007 at 10:50pm
|
When I did that it cost me an engine rebuild! When I got my boat it was in bad shape,but I got it running and used it for one summer.On that summers Labor day I decided to clean the bottom.I had waterpump trouble,if you drove off it was fine once it warmed up,but if you idled off it would over heat.Well after I cleaned it,I idled off not thinking,went about 1 mile,looked back and saw steam coming from the exhausts.Shut it off and luckily it was so hot it would not turn over,if I had gotten it started I'd have cracked something for sure.So now it's on a lift to keep it clean,I don't want to jinx myself by going under it again. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: stang72
Date Posted: April-03-2007 at 11:42pm
 Your safe as long as ya don't get a rag stuffed in the water intake!
------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: Randy_in_Ohio
Date Posted: April-04-2007 at 12:09am
|
I buffed out the bottom of mine. took it out today for the first time this year. I think you may be right, I did see an improvement.
Gary, What do you use to polish the fins and rudder? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1602&yrstart=1991&yrend=1995" rel="nofollow - 1993 Sport Nautique |
Posted By: stang72
Date Posted: April-04-2007 at 12:46am
|
Randy,
My fins and rudder were pretty rough (machine marks,nicks etc)...you can wet sand them a bit and buff them with a high speed buffer using compound or metal polish. Also...On many older boats...the bottom can have chips and scratches...worth the time to fill and smooth! It all adds up...all those surfaces! ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: 8122pbrainard
Date Posted: April-04-2007 at 5:19am
|
A low drag bottom will make a difference. Think about sail boats and the work the pros put into their bottoms to gain speed. Of coarse on a sail boat, a small % makes a big difference. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 81nautique
Date Posted: April-04-2007 at 7:11am
|
Gary,
Thats in my future before it gets in the water this season. Not really for speed but I can't have anyone crawling under my boat and seeing how filthy it is under there now can I. Gonna get it off the trailer once I get the motor work finished and compound and wax the bottom. I have one gash to repair from the PO, he said he used to float the boat on the trailer, after looking at the gash I think he tried power loading once and said never again.  ------------- You can’t change the wind but you can adjust your sails |
Posted By: boat dr
Date Posted: April-04-2007 at 8:49am
|
81,If you are speaking of the America's Cup,yea they spend mega bucks looking for that .25 knot increase in speed. Only downwind can these boats outrun their own wake,the catamarans ,Hobie & Nacra, are a different animal. Planing hulls means less boat is in the water.Waxing a Hobie is a sure way to slow it down,shaping the rudders,and boards and cleaning up nicks and scratches,Do..........boat dr .
, ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: Riley
Date Posted: April-04-2007 at 8:54am
| I've heard a waxed hull creates more surface tension and actually slows the boat down. That said, I wax mine because I moor it, and the mung cleans off much easier when it's been waxed at the beginning of the season. |
Posted By: 8122pbrainard
Date Posted: April-04-2007 at 8:56am
|
Doc, You have a very good point regarding the planing hulls. I read someplace that someone was experimenting with a golf ball like surface on a boat. My understanding it worked because it trapped air under it reducing the surface tension to the water. Now all we need is to train the barnicles to grow on the bottom in a pattern like a golf ball!! ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 81nautique
Date Posted: April-04-2007 at 9:33am
|
Like I said, I'm cleaning it because it needs to be cleaned and the wax does help with cleanup during the season. I boat in some pretty brown river water and it has to be wiped down as soon as it comes out of the water or else it's hell to get off. I think the buff and wax helps seal up a porous gelcoat and aids in cleaning. Guess I'll have to give up that .25 knot increase I was not looking for. ------------- You can’t change the wind but you can adjust your sails |
Posted By: JoeinNY
Date Posted: April-04-2007 at 11:28am
|
In sailboat racing the hot surface is usually a non waxed but wetsanded about 600 grit boat. There are a couple wax type substances from sailing that claim to be as good or better than a freshly wetsanded boat. A lot easier to wax than to keep it perfectly smooth if your not racing boats where a 1/4 knot makes a difference. I don't race sailboats as much as I used to, but if any of y'all ever want to feel what its like doing 25 knots through 3 foot waves on a 17 foot catamaran just look me up on a windy day. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: boat dr
Date Posted: April-04-2007 at 12:11pm
|
Joe,from your post about a 17 I assume your a Nacra guy,Have raced a H-18 for 20 yrs.Have yet to master it so no need to move up.
We had our first regatta last week end, weather proved who was in control,and it was not the race committee.Plenty of rain and 20 to 25 knts.I am not as mad at the wind as i used to be,maybe age ,or is it wisdom...... JOE SAID: I don't race sailboats as much as I used to, but if any of y'all ever want to feel what its like doing 25 knots through 3 foot waves on a 17 foot catamaran just look me up on a windy day..... Words do not tell that story: gotta be there to feel that RUSH.boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: eric lavine
Date Posted: April-04-2007 at 12:24pm
|
I new you had a sensitive side doc, being a blow boater and all. lol eric ------------- "the things you own will start to own you" |
Posted By: JoeinNY
Date Posted: April-04-2007 at 12:41pm
|
yep doc, nacra 5.2, two of them they got real cheap when they stopped being a current production class. They were fast enough to beat all the hobies on the lake until my arch sailing nemesis got himself a brand new hobie fx one summer before last, he used to be me 1 out of three times without handicap, 2 out of 3 with handicap with his old hobie 18. Now he is back on shore and one corona ahead of me by the time I finish. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: Gary S
Date Posted: April-04-2007 at 6:51pm
|
Randy- since I have an old boat it does not have fins.The rudder I had out because I had to get a replacement so I used a DA sander then buffed it.But now I have the original rudder on,the PO had found it and I didn't bother to do anything with it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: SkiBum
Date Posted: April-05-2007 at 6:23pm
I always thought the perfect ski boat would be the width of the boat guide bouys with a flat bottom and golf ball dimple surface with large dimples to trap air. I can picture soft foam in the place of evil wakes exiting the back of the boat. I guess if I just don't sand the orange peel off my boat I could test that theory. ------------- Bill http://www.freewebs.com/billsboatworks - http://www.freewebs.com/billsboatworks www.freewebs.com/billsboatworks 1987 SN Rebuild Project |
8122pbrainard wrote:Posted By: boat dr
Date Posted: April-05-2007 at 6:38pm
|
Ski Bum, the product is called;Miracle Micro Balloons,and has been banned in most one design sail boat classes.
It works by trapping water in those "dimples" water sliding over water,same as a golf ball.The surface looks simular to "orange peel" but much more uniform.....boat dr ------------- boat dr /diaries/details.asp?ID=4631 - 1949 Dart /diaries/details.asp?ID=1533 - 1964 American Skier |
Posted By: 8122pbrainard
Date Posted: April-05-2007 at 6:48pm
|
Bill, I think you should try it!! You can always sand off the orange peel later. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 87BFN owner
Date Posted: April-05-2007 at 7:57pm
Posted By: stang72
Date Posted: April-06-2007 at 2:33pm
|
Very true about the bunks...especially if you have BUNK carpet(I nearly lost one at the ramp once)
I stand by the clean waxed bottom...I have done it and each time I pick up about 2 mph top end! Maybe if I just buffed and left the wax off , it would even be better!!! I suppose the more important part is to hone the hardware, fix scratchs , chips and remove oxidization....= less drap! ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |