Lets talk about "BLUEPRINTING"

[TTriton]

A hull.. I know a little about doing this.. But before I start going on one persons word on how to do this I would like to hear from others who have done this or know more about this than I do.

Lets get this forum going so POST!

[us1]

What boat are you blueprinting

[TTriton]

18' Critchfield

During my compleate rebuild of the boat I plan to spend some time on the bottom straigting out the chines and makeing sure the bottom is as perfect as I can get it. I wanted to learn all that I can about blueprinting to see if there is any other ways to work on the bottom or other things that I need to do

[Laker]

What I have done is make everything about 5 feet up the center pad and back on an angle to the corners, Flat sharp and clean. All angles of the strakes must be perfect. Its not hard but its allot of work.
I use a long board sander (3 feet long) I got at a body shop about 12 years ago and it works great.
Its good to know what your plan is before hand however because some boats come with hooks, perhaps some have rockers from the factory but I have not seen one. And some, Like my Vector had a con cave tunnel running down the center of the pad about the same shape as one on a water ski.
Some may disagree but I found on my Vector, filling in the Concave and sanding all but 1/8th inch out of the hook and then making very thing else flat, sharp and clean really helped that boats handling and top speed. It popped up on the pad faster with a I6 merc and ran 4 miles per hour quicker. I was able to get it to run 97mph with a mod 235 Rude (Scary tho) The down side is that it would porpus badly but that boat seems to do that in general. On my ventura I did the same thing and saw a good 3 MPH out of it. I always use West systems Epoxy, Adjust your cure time for the Temp and humidity you are working in. And remember
HAVE FUN!!!

[Raceman]

Lee, I think you've first got to decide what you're looking for with the boat and go from there.

I do disagree at least partially with Laker's comments on the Vector with a possible exception. I've got tons of time in the old Vectors and saw a number of them ruined by filling and straightening the bottom over the years, but contradicting opinions on that keep popping up and here's what I've come to think, at least in the case of the Vector or all the hooked Streams: I believe the bottom as designed by the factory is superior from a standpoint of top end speed. This is further supported by the difference in top end between the Vector and Viking, and I've seen both in Comp models that were basically the same weight and the Vector was always faster. There may very well be some great variations from this design as molds shifted and from the boats themselves aging over the years and suffering from deterioration/weakening in the structure and/or improper storage or support on a trailer. I believe that in all cases, a properly blueprinted Vector bottom in the factory configuration is faster than a bottom that has been filled or straightened or both.

That having been said, the bottom on your boat is totally different. As I told you before, the last roundy round race I ever ran included your boat with Rusty Cambell in the driver's seat. Unfortuately I blew over in the start and that was the end of my best boat. I thought at the time that your boat was a cut down 20' Allison and I think it's probably very similar. To this end, I might see if Darrus would give you some ideas on the bottom, or maybe some of the successful current crop of Allison racers. I never put a straight edge on the pad of my '98 2001, but understand they had a slight hook which was really a small lip at the rear most part of the pad. Paul Allison, (Darrus' father) drew me one on a table napkin once and I went home and built it on my 16. The boat would turn about 800 RPM's more, but was borderline undriveable, because it was off the water. A call to Mr Allison, and he told me that the boat was running too fast for the lip and I should straighten the pad. As far as your boat goes, I think it'll be easier to drive with the pad perfectly straight, faster with the lip. Whatever you do, strive for uniformity, strength (a flexing bottom never helped anything, even if it's a hook) and sharp edges.

One thing I've always wanted to try, and this'll probably provoke some negative comments, is to put a double step or lip in the pad, to aerate it the way some offshore boats are. My old Seebold has such a configuration in the bottom of both sponsons and I can't see why a V bottom wouldn't respond in the same way. There was some conversation about it on the old board, but the person who cast the most doubt seemed confused with the difference between aerating and the effects of a hook or lip and I just got sick of the debate, so let it drop.

So it boils down to this: conservative or radical? conventional or experimental. If you decide to go with the latter, I'll draw you a sketch of what I think might work.

[Laker]

Im with you Raceman, I was told by Ron Baker to leave at least 1/8th in the hook and thats what I did. Seem the hook creates an Edge to hang the boat on but the makes it much more sensitive if that Hook/edge is too big. I asked Roark once while I was visiting the STV plant in TN, about putting steps in the pad of a V bottom. At that time he had A Prototype VBottom sitting out back that he was thinking about building to go against the Allisons (1996) I was Trying to get him to build one I could try but he was loosing interest by then and sold the business about a year or so later. Anyway he said that If I did that to my boat (A 380 ray) I would loose critical Adhesion if the pad. It would creat too much airflow and limit the top speed Via handling problems. I also heard once about putting aluminum strips on the outsides of the pad about 3 feet long to create a tunnel effect on the pad and It was a similar result. I would still love to try it tho! :D ;)

[TTriton]

for this boat i plan to go conventional and try to keep it as original as possible while cleaning up any damage that time has done. I do plan to go experimental with a mold that I have but don't plan to build that for quite a while.

[nelsoncat]

Reading about the differences in hull config between the original Vectors and the mid 70's on.
It was said that the mod was a good one to make to the newer ones performance wise. It would be nice to hear some differing opinions from some who have done it, successfully or not.

Sincerely,

Nelsoncat

[Firestarter]

Raceman, I need to get a digital camera, you are about 20 years to late. This is about , an airated vee bottom. Back in the 70's and very earily 80's in Toronto, a group of guys had a private marina for their own toys. One of these toys was they built a few (probably less than 10) Challenger 21's. These boats had an airared bottom.
Now this is hard to explain, but, if you can use your imagination. About 4 feet forward of the transom, is a step, it is about 2 1/2 inches hight and about 3 feet wide, it looks like a large notched transom. Inside the boat on the backside of the step (forward of it) their is a chamber that was glassed in. In the top of the chamber were two ABS plastic fittings (90degree)that had pipes that head toward the back seat, once they reached the backseat they aimed up to the top of the motor well where they ended and were left open. Now at the step, they drilled a bunch (actually the number is 21) 1/2 inch holes into the chamber. So as the boat moved forward it created a vacuum which pulled air down the ABS pipes into the chamber and out the holes causing the water to be airated.
I know that with a 235 Johnrude the boat would run 69-70mph, and when the Airation tubes were added the boats were running 77-78mph. Back in around 1981 they had 1 that ran a hair over 100mph with a pair of CCC motors on it.
Their is a little Canadian history for you guys, To bad I was in diapers to remember much of it.

RT

[us1]

Its like the guys said earlier, some times hooks and rockers are put in the design of the boat for handling reasons. I would recommend talking to the manufacture before changing the shape of the bottom. Other wise all the info about is pretty good.

[TTriton]

there is some good info in this forum so far but what I was getting at is how is it done? Its just a matter of using a board sander and maiking all the angles straight? Or is there more sience in this?

[us1]

It’s using a long flat sander to bring the bottom to perfect original specs. or to newer better specs. Some times you may need to add gel coat or even fairing compound to fill in voids and achieve flatness.

[espen]

Hi !
My friend and I did make a aerated step 2 foot from the back and maybe 3/4 of an inch high on a boat in the 80s . It was a 18 foot Smuggler with a very deap v. We cut away the v and glassed a new pad/buttom with a step that was 1foot wide flat and more and more narrow to the bow.
It had a 90 hp yamaha with a round eare prop and with the engine high it was difficult to get on plane. With the step not aerated the boat was not able to get on plane....we got a hose down there and we suddenly had a great vakuum cleaner !
could suck water out of the boat like nothing else.
The boat ran 56 knots.
I think ariation can be a bennefit , but maybe the prop dont like it.
Maybe the real bennefit of a steped boat is that it can be more stable lenght wise with the same top speed as a boat hanging out. Did read a article in Powerboat about formula had put in a ton of reserch to perfect the stepped buttom. 2-3 mph on heavy inboard boat is what they got if I remember right.
Espen

[TTriton]

I am famialr with seeing the large offshore power boats with a steped hull but didn't know about the areation tubes. Do the big powerboats have this? Or do they pull in air from the sides where you can see the steps?? I kinda feel stupid now since I didn't know about this technology.

[DRAGIN FLY]

It works on heavy or wet running boats newer step bottoms don't have vent tubes I did alot of work and testing on 43' sport fishing boats (Ocean Tech Marine) running Airated bottoms with vented tunnel drives with surface 6 blade props it works on heavy wet boats not critchfield's if you can't get on top and running mostly dri this works if you want more speed when you have 6 people in your boat this might be the ticket Good Luck

[TTriton]

I wan't interested in this for the Critch but just want to understand ALL aspect of boats and boating. You can never know or understand to much of anything. I'm still working on understanding Stephen Hawking theories. Got a while to go with that.. But that is a whole other forum of discussion.

[ShipBear]

How's the bottom on your Hull now..??
Seems like it should have already been B/P..
You may only need to clean things up..Sharpen..Does it have any Hook, etc..?

Later Larry :D

[BarryStrawn]

To sharpen up the corners on strakes or a pad I run masking tape along the vertical surface with some sticking up above the horizontal. Just lightly press the tape down on the side where you don't need any buildup - not all the way up to the edge. Then you can brush a bead of gelcoat into the gap formed by the original radius and the tape "dam". It will puddle up next to the tape and pull down in the crevice to where you pressed the tape. Then just block sand to a crisp edge after it cures out. Hull upside down of course and needs to be cleaned, sanded, and prepped first.

[TTriton]

it is in fair shape I guess.. I havn't gone over every thing on the bottom yet.. Still working on the inside. I don't see a hook just needs some repairs done. It has had a ruff life and several of the patches are shabby and other are just breaking out. I plan to remove all the bondo that is there and patch everything up nice. Just wanted to get all my idea's togeater before I get there. And right now I have some time to do thinking since I got injured while cleaning up after the hurricane. Got 6 weeks to think about my plans.

[dan agnew]

lee the critchfield will best respond to flat flat flat pad. the chimes need to be flat on bottom and sides!!! square the pad and chimes knife edge the edges and along the ass end of the pad and all chimes up to the side. the boat will run a little faster and be easier to drive if you add speed rails just like the 13 foot critchfields have you can buy or make your own. we tried the bottom mod on my 18 critchfield but it would not turn in a 100 acre pond.

raceman, you are right it is a 20 foot ally the old gt20 cut down and narrowed up you could sit in my cockpit and drape your hands over each gunnel. rustys old boat [now lees] you sat a little forward than mine. rusty weighed about 1/2 what i did so we installed merc breakaway steering to get the cables under my feet and the glassed in dash gone.
I must say that last year we took a 17 foot vector and filled in the concave, squared the pad took all the hook out and made a undrivable vector into a one hand 80 mph cruiser.
in 1978 we were a hydrostream dealer and after wayne weeks ran his 117 noa speeds i had to have one, rigged a v-6 149 on a gp tower and went bouy racing only to find out that you did not run that around bouys. I called wayne and asked him how he turned his boat and he said" I DONT" he would haul ass in a straight line but splash his way around the corners. anyone that can run like that comp vector/omc could didnt need to turn hard much

[Raceman]

Hell, I didn't know Wayne ever went around a corner in his. Every time I ever encountered him it was in a straight line.

[dan agnew]

raceman
my point exactly. he was a rocket in a line get off the line and the boat went fool. i had the same boat with almost the same power, 6x2 149 cross flow but it was on the gp tower with the .7 gear and harold nauss built us a trick 13 " x 22 left hand cleaver that set it on fire but same thing no turning. wayne told me that found his would not turn and he moved to the straight aways and drags. we found danny critchfield and got the boat after rustys. david dumas owned the plug, and i dont know the deal he and danny made on the boats. i loaned david my power head for use in the race in beaufort sc and david outran rusty. rustys dad told me after the race to get my powerhead back from david and take it back to prosperity and never loan it out again. a few weeks later we had our critchfield ready and on clark hill rusty and i ran about three laps side by side until my brakes hung down and it was all over. rusty sold the boat after that race and winfield scott drove it until the noa folded. anyway i say blueprint,sand until your fingers bleed then borrow some from a friend and sand his down to a puppy

Danny

[Jeff_G]

Danny, does Mike still have the Formula V boat? Any chance of you guys going racing again?

[dan agnew]

jeff neg if you remember mike stuffed the boat at hazelhurst and trashed the boat. he really needs a 100 cuin rig or a 120 boat not enough time and really not enough $$$$. he just bought a new house [had a fire in the old one] two yr old future racer six year old go cart wanabe.raceman when you get to be my age you too can have g-kids to sit on your lap and ask about the good old days of football and racing. great tales, as i remember them anyway. see rocking is good.
back to jeff, i heard that formula v was a dead issue, not true?
hell we could not get any liter,or more power out of that omc every time mike got out ya heard it cuss us a little and sigh.man what a load!!!

Danny

[Jeff_G]

Actually there are about 8 or more if everyone would show up. The cage capsule issue hurt so but you can put in a bolt in cage for about $200. Also some of the guys went to the new Super Sport class. We are revamping the Formula V and will be agressively promoting it. We have boats and motors for sale if anyone is interested. They had a good field at the Nationals too.
We are also working on some new race sites as we speak, so that will help. Last year we paid out over $8,000 in appearence money. ALL drivers got paid. At the Beaufort race the payout was $250 per boat, just for showing!
You know me I'm not ready to hang things up. SST 120 looks OK but Creel and ARD are "retiring". SuperSport is averaging 10 boats at our races.
We are also probably bringing back the Formula V Div. II boats without capsules and limited to 60 ci. They can only run in Div II without the capsules if they run in FV itself they would need the capsule, cage. Call me for any additional info. I would love to hear from you.
843 844-8739