Somebody's got a hook

[396_WAYS_TO_SPIT]

I just put a straight edge on my hull and found some light!! :2purples: :2purples: :2purples: So along with setting a new intake now I have to do some blueprinting. He is what I saw on one side. From the transom its straight for about 3" then it dishes up(into the hull) for about 16" long then it gets flat. This was approx 2" from the intake. What should I do? What would be the best way to go about this? Should I glass it or use pixy putty? What will I gain if I fix it? Pics would help if anyone has some......
396

[396_WAYS_TO_SPIT]

I did a little search and found this. Would this be a good way to do it?????
I think Jeff's get a lot more detailed but to get a basic here you go!
Mark a X 5 foot forward from the transom center of the keel line.
Take a chalk snap line and hold at the X point. Now pull the snap line from the X point to each outsidecorner of the transom and snap it.
when you have done this you will have a delta design laid out on your bottom. This is your primary running surface on your boat.
Take a straight edge and slide it (running same as the keel line) over the entire surface within the delta. any low spots or concave are suction points in your bottom. 99.99% of all boats have them, caused from the boat molds getting hot, or just trailer setting over time.
Grease or pencil mark the low spots.
Sand scuff or scar in and around these spots for your filler.
I would recommend a filler like Mar Glass (a bondo like agent with fiberglass fibers added) or any other similar product. Some even lay fiberglass over it as the filler. I don't think its necessary yet it is correct also, many will use bondo only. I like to use the Mar Glass and detail finish with bondo on the small holes after.
As you are filling you want to keep working your bottom with a long board sander between each dry coat for maintaining your straight line and running your straight edge for verification.
If you use Mar Glass as the bulk fill you will have small holes from heat - Use bondo to fill these holes and increase your sanding grit # as you go to finish.
Rough scar in 30-60 grit
Rough Flat Block in 60-80 while shaping
flat block 120
flat block 220 for finish.
primer or seal
finish sand
Gel Coat/Paint or speed coat.
WaLa you is a pro! Good Luck its easy!

[396_WAYS_TO_SPIT]

i will post info as I get it. This might help others that are planning on doing thier own bottoms......
Here is randy'(hbjets) pics..
http://www.hotboatpics.com/pics/data/500/3hook001.jpg
http://www.hotboatpics.com/pics/data/500/3hook002.jpg
http://www.hotboatpics.com/pics/data/500/3fix002.jpg
http://www.hotboatpics.com/pics/data/500/3fix003.jpg
http://www.hotboatpics.com/pics/data/500/3fix004.jpg
http://www.hotboatpics.com/pics/data/500/3fix005.jpg
http://www.hotboatpics.com/pics/data/500/3fix006.jpg

[396_WAYS_TO_SPIT]

more of jeff doing his magic...
http://www.hotboatpics.com/pics/data/500/3fix009.jpg
http://www.hotboatpics.com/pics/data/500/3fix011.jpg
http://www.hotboatpics.com/pics/data/500/3fix013.jpg
http://www.hotboatpics.com/pics/data/500/3fix015.jpg
http://www.hotboatpics.com/pics/data/500/3fix016.jpg
http://www.hotboatpics.com/pics/data/500/3fix017.jpg
http://www.hotboatpics.com/pics/data/500/3fix019.jpg

[396_WAYS_TO_SPIT]

.....
http://www.hotboatpics.com/pics/data/500/3fix020.jpg
http://www.hotboatpics.com/pics/data/500/3fix021.jpg
http://www.hotboatpics.com/pics/data/500/3fix022.jpg
http://www.hotboatpics.com/pics/data/500/3fix023.jpg
http://www.hotboatpics.com/pics/data/500/3fix024.jpg
http://www.hotboatpics.com/pics/data/500/3fix025.jpg
http://www.hotboatpics.com/pics/data/500/3fix026.jpg

[Cas]

Hull Blueprinting 101 by Jeff Bennett
Hull blueprinting means different things for different hull designs. I will limit this discussion to vee bottom jet boats. It's assumed that the reader has a working knowledge of body work and fiberglass repair. It is best to talk with or get the help of someone who understands this skill. Also, there are many ways to blueprint a hull, this is the way I go about it.
Basically, vee bottom hull blueprinting means to return the bottom of the hull to the shape that the manufacturer made it. Over time, hull can change shape or warp due to improper trailer fit, or hulls being removed from the mold too early. This results in a "hook", which is when the bottom of the boat at the transom is lower than the adjacent hull forward. This acts like trim tab or cavitation plate in the downward position. The results of this hook is to generate more lift at the rear of the boat and it pushes the nose of the boat downward. The faster the hull speed, the more this occurs. Because of this tendency to push the bow down, it prevents the hull from getting loose (free from the water) and top speed is reduced. Usually the prime motivation of hull blueprinting is to increase top end speed, there are many steps required to accomplish the task.
First, the amount of hook must be measured to determine whether or not the effort is worth while. The easiest way is to use a 5-foot straight edge and place it lengthwise from the transom forward. Examine the bottom at several locations, along each lifting strake and at least one location between each lifting strake. You should concentrate on the lower part of the hull and at least 2 or 3 lifting strakes outboard from the centerline. At every location measure gap(s) between the straight edge and hull, the gap(s) is the amount of hook. If the hook is any more than 1/16" than a hull blueprint may be worth while. If you decide to blueprint the hull, there are a series of steps required to accomplish the task.
1) The boat needs to be stripped (remove the motor, battery, fuel, steering wheel, possibly the upholstery and anything that might be in the way when the boat is turned upside down.
2) Now it is time to turn the boat upside down, Used car tires with blankets over then work will for this. First lay the tires on the ground behind the boat and with the help of 6 or 8 of your friends (more if the boat is over 20 feet) and slide the boat off the trailer onto the tires. Next, line up 3 or 4 tires in a location that when the boat is lifted up on one side, they will be between (not sure) on the opposite side. Have everyone except 1 person gradually lift up on one side of the boat and the other person (not sure) boat does not slide off the tires. When the boat is at 90 degrees and resting on its side have each person one by one go to the opposite side and the gradually let the boat down. One person needs to move the now vacant tires to the other side and put in place for the boat when it is upside down. As you are letting the boat down, make sure nothing drags on the ground and the tires are completely supporting the boat. Should you have a hoist there are many way to aid in this process (like Don Capone's rig) .
3) Using the straight edge, make a detailed contour map the bottom by measuring and marking how deep the gap(s) are and the locations. A grease pencil is a good choice for this map. The blueprint area should be 5' long and out to the 3rd strake from the centerline (2nd if you have a 2 strake per side boat).
4) The amount of the step will determine how the "hook" should be filled in. Never, by the way grind out a hook, (not sure) made this mistake and ruined otherwise good hulls. Anything less than a 1/16" gap should be filled with body filler. This will work as long as it is sealed by primer and or paint. The best filler is 3m Premium grade filler, which is waterproof. 1/16" to 1/8" gap can be filled with either Duraglass or fiberglass mat and resin. Anything over 1/8" should be filled with fiberglass (not sure exact words, "mat, cloth?)
5) Next, you need to grind the areas that will be filled. Use a 40-grit disk on a body grinder. The gel coat does not need to removed, but all shinny spots need to be eliminated and the surface must be rough.
6) If you need to fill any areas with fiberglass, use 3oz mat and resin and do them first. A single lay up of 3 oz (not sure) when soaked with resin. If you are not going to add fiberglass, go to step 7. Use a roller and remove any air bubbles (not sure) in the sun. You can use fiberglass cloth over the mat, but you do not need to ass any strength and in this case mat is fine.
7) Once the fiberglass is dried, grind it with a body grinder and prep the surface for the body filler by washing the area with acetone on a rag.
8) Fill next with Duraglass filler. Mix up a small batch of Duraglass and spread it on the areas you wish to fill. (not sure) and standing on the side of the boat, quickly place the straightedge length0wise (relative to the hull) and slowly pull (not sure) towards you as you scrape the excess material off the bottom. Start the filling from the centerline and work outboard (not sure)Duraglass dries, use the body grinder again and smooth out the high spots. Repeat this process over the blueprinted (not sure) another application(s) until the hull is within 1/16" of being true.
9) Now do the final filling using the regular body filler. This is basically the sane as Step 8, but instead of using a grinder use a long board with 40-grit sandpaper, sanding lengthwise. It will take three of four applications before (not sure)
9b) The hull to intake interface needs to be blended. Just make sure that there is no part of the intake hanging (not sure) facing steps and that you fill and smooth any gaps between the intake and hull. The finished blend should be a (not sure) intake should look as though it is part of the hull.
10) Once the boat is straight, again use the long board with a 100-grit sandpaper and detail out the bottom. (not sure) around the intake will require hand sanding without the long board.
11) Use glazing putty to fill the pinholes. Again sand with the 100-grit sandpaper.
12) Mask the blueprinted area off and prepare the surface for primer by cleaning the surface with a thinner or acetone, be careful to not remove the glazing putty, which will be attached by the acetone.
13) Primer the blueprinted area using a polyester primer. Put on a thick coat because it will help fill any remaining pinholes in the body filler. Dust coat the primer with a black lacquer to be used for the wet sanding step.
14) Wet sand the primer with 220-grit wet/dry sandpaper. Follow that with 400-grit wet/dry.
15) Now you are ready for the finish coat. Since polyester primer has been used, you have a few options on type (not sure) usually use catalyzed acrylic enamel or a lacquer based graphite finish (AKA speed coat), which is available from (not sure) Marine. Gel coat is the strongest finish, but it requires the most work. As I mentioned at the beginning, it is assumed you have a working knowledge of body work. If you do not feel comfortable with the final paint step, either find someone who (not sure) the graphite paint because it is almost impossible to screw up.
16) Let the final finish dry thoroughly (24hrs) and be careful not to scratch it when you put the boat back on the trailer (not sure) ready for the lake. Good luck.

[Cas]

Squirtcha also has an excellent step by step on the way he redid his bottom....on the boat.
Here's the link
http://jetboat.homestead.com/Kidsriding.html

[Tom Brown]

Should I glass it or use pixy putty? What will I gain if I fix it?
Fillers aren't relaible when used to fill heavy thickness. To fill anything more than 1/8", I'd grind and build with glass matt and resin. Once you have an approximation of the height you are looking for, use a catalized fill/glaze.
Keep in mind that you will have to glaze the entire area you've been working on, as per HBJet's pictures. Don't just glaze where it looks rough because everywhere you touch will have pinholes.
To get it straight, use a 3x17" long board. ... like this:
http://www.hotboatpics.com/pics/data/500/3fix006.jpg
I don't know about jets but I've done a couple of outboards. A little hook doesn't seem to make any difference at all. At least, not that I could measure. I have no doubt heavy hook would slow a boat considerably, though. How much hook are we talking about? What is the gap between the hull and your straight edge?

[Squirtcha?]

Fillers aren't relaible when used to fill
heavy thickness. To fill anything more than 1/8", I'd grind
and build with glass matt and resin. Once you have an
approximation of the height you are looking for, use a catalized
fill/glaze.
Keep in mind that you will have to glaze the entire area you've
been working on, as per HBJet's pictures. Don't just glaze where
it looks rough because everywhere you touch will have pinholes.
To get it straight, use a 3x17" long board.
I don't know about jets but I've done a couple of outboards. A
little hook doesn't seem to make any difference at all. At least,
not that I could measure. I have no doubt heavy hook would slow
a boat considerably, though. How much hook are we talking about?
What is the gap between the hull and your straight edge?
This much made a difference. I reckon a flattie driver could liken it
to riding around with his cav plates latched all the way down?
It didn't translate to a lot of speed, (couple miles per hour) but
the handling improved tremendously. There was a little more than
a 1/4" of hook when I started.
http://www.homestead.com/jetboat/H._hook_1.jpg
I agree with Tom regarding the material to use. I built mine up with
fiberglass anywhere that it was more than 1/8", then used Durglas
and finished with Rage Gold. I believe Jeff even states this in his
documentation somewhere.
Here's the same area after polyester priming.
http://www.homestead.com/jetboat/what_hook.jpg

[canuck1]

Sell the hull and replace with aluminum

[396_WAYS_TO_SPIT]

Sell the hull and replace with aluminum
Wow, thats the best answer I have heard yet :yuk: :yuk: :rolleyes: :)

[Riverat84]

Sell the hull and replace with aluminum
haha...

[396_WAYS_TO_SPIT]

This much made a difference. I reckon a flattie driver could liken it
to riding around with his cav plates latched all the way down?
It didn't translate to a lot of speed, (couple miles per hour) but
the handling improved tremendously. There was a little more than
a 1/4" of hook when I started.
http://www.homestead.com/jetboat/H._hook_1.jpg
I agree with Tom regarding the material to use. I built mine up with
fiberglass anywhere that it was more than 1/8", then used Durglas
and finished with Rage Gold. I believe Jeff even states this in his
documentation somewhere.
Here's the same area after polyester priming.
http://www.homestead.com/jetboat/what_hook.jpg
I do remember that your hull did handle very nice. I just noticed the hook today while I was ripping the intake out. Its not that bad but I will know when she gets flipped next week. Ill call you this weekend and maybe you could shed a lil light on this for me;)
396(michael)

[canuck1]

Wow, thats the best answer I have heard yet :yuk: :yuk: :rolleyes: :)
Thank You

[tahitijet]

here is mine at the start. had from 1/8 to 3/8 hook all over and the about 5/8-3/4 down the keel and beside the intake.
http://www.hotboatpics.com/pics/data/500/709P3020133-med.JPG
and this is after the setback, and reseting the intake at 4*, and alot of work.
http://www.hotboatpics.com/pics/data/500/709P4110245-med.JPG
I'd recomend anywhere you have more then 1/8" to grind and use matt and resin. Then when your close spread rage gold over almost all of it and sand it. When you have applied and sanded enough rage to have it as perfect as you want and nice and feathered out. skim coat the hole thing in with a glaze like evercoat.
there is a newer versin of rage i think it's called xtreme, that is supposed to not have any pinholes. this would eliminate the need for a glaze
then use a good high build filler primer and block and paint or speed coat
whatever you do make sure your fillers are water proof.

[JAY4SPEED]

Is it possible to apply gelcoat after filling a hook with glass then smoothing with filler and glaze as opposed to painting? Would there be a reaction with the poly gel?
Jay

[BrendellaJet]

Is it possible to apply gelcoat after filling a hook with glass then smoothing with filler and glaze as opposed to painting? Would there be a reaction with the poly gel?
Jay
When working with boats of this vintage most are made with polyester products, so the fillers should be polyester based as well(Rage is..pretty sure the fibral is too) You could gel coat over all of that stuff, or you can speed coat it like in the pics.