300/440/550 550sx Hull Modernization Build

[Mobile Chernobyl]

Well ordered what should be close to the last few parts for this build.

I got an on/off/bilge combo unit from a 1996-2004 polaris SLTH 780 - I'm a fan of momentary switches so I'm okay with the inconvienence (if any) it might present.

Also ordered:
-Handle bar material for straight bars (7/8" OD, .120" wall)
-Orange polyester webbing, a stainless ratchet buckle, and plastic side release buckles to make - 1 "brap strap" and 2 hood straps, totalled $30 shipped from strapworks.com!!
-2 safety tethers (one is for my 440) to get rid of the zip-tie mod! Can't afford to have this guy's throttle stick WFO and head towards the shore line only to fly into a try and catch on fire!

All I really need yet (Is probably a lot of stuff I don't know about!) is my paint really. I've decided to go with Day Glo brand Saturn yellow (color code 215-17 for anyone interested), which for those that haven't seen it is one of the brightest flourescent yellows one can buy, possibly just short of House of Kolors stuff (Don't have the $$ for HOK tho!). At $30 a quart for enamel oil based, I'm lovin it even more! I'm gonna splurge and use a boat rated UV resistant top coat to try and lock in the color as per Day Glo's reccomedation. Other than that, this guy will have a semi-retro paint job with fluorescent yellow as the hull color, fluorescent orange for ALL accent coloring (powder coated parts like the pole, ride plate, pole mount, etc) and grey (floor hydro turf). I've got a roll of orange cut diamond hydro turf I'll be using on anything that would get turfed, but doesnt put up with alot of abuse (aka - tray walls, chin pad, bond rails?)

Hells yea!

 

[mthomps]

I've following this whole time, Mobile. Can't wait to see the finished product. Detailed pics please!

 

[d_moss]

gnarly take vids when you are done. Seems like everyone that does a project like this never finishes or never posts any riding video.

 

[Mobile Chernobyl]

My buddy and I got a nice go pro and I've already made and used the mount for it on my 440 - so pictures and vid's won't be a problem lol!

 

[tensecrnr]

freaking awesome build u got going...i luv it...

 

[Mobile Chernobyl]

Bubba Tubbies have been mounted!!

Well I started out my day by fastening the tubbies to the hull. I'm impatient and I'm really getting tired of $10 here $10 there purchases, so I simply screwed the foam tubbies to the hull using some SS screws and washers - worked mint, and saved me from losing a day to waiting for adhesive to dry! I plan on just cutting off the extra screw that protrudes into the engine bay and cab-o-sil'ing over the protrusion.

On the foam side - I filled in the indentations the screw made with body filler. I said I wasn't going to do this anymore (body fill then fiberglass over the body filler) but without doing that there would have been big pockets on a vertical plane which would have been almost impossible to keep even a thick cab-o-sil mixture in to "stuff" before the fiberglass was applied. So body filler it was! I've found out why body filler eats away at the foam, if you mix it rich on the catalyst side of things, the catalyst doesnt get fully used - and it contains a solvent or two! So these solvents are what cause the degradation of the polystyrene foam.

So they have been mounted, next thing I did was put sexy radii over the length of the tub's. I put a pretty good radius on the leading edge since it's angle was like 90deg vs appx 100deg to 120deg from middle to back respectively. This angle was pretty well planned out - so if anyones wondering if there was much thought given to the shape of the tubbies, the answer is about 2 months worth of pencil sketches saying yes lol. My main design goals for the tubbies were to not have chines, and have them flush with the bottom. This will not make it as stable as the #zero's or tubbie 2's but that's not really what I was going for - I'll have a superfreak bondrail to help with that.

Here's some shots of the leading and trailing edges

Okay, now comes the all important templating step - this time it was so big that it was actually pretty difficult

Cuttin' out - used 2 layers of 10oz twill cloth - I used the same thing on my nose piece and I'm happy with the strength. These are not integral to the hull's superstructure so they can afford to not be .25" thick of 1708.

And, layin it up

Whewwww!!! Finally got this step done! I've made it out to be MUCH harder in my head than it actually was!

The lay up step presented some fun challenges - I ended up having to cut fold slits in the vertical direction so that the hull's gentle curve could be compensated for. I always thought cloth was like super flexible but it turned out to need some assistance after all! I staggered the bending slit's by about 6" on each layer so that they didn't bulk up and throw off the shape.

Tomarrow I would like to have a majority of the bond rail mold made and attached to the ski - who knows, if I'm cruisin along with it there may be a new bond rail being laid up tomarrow!! Bitchin!

I'm also thinkin of something kinda cool for the momentary switch on the handle bars. I've played around with PIC microcontrollers a few times before on projects and I was thinking of somehow tying in some logic to that switch and possibly the engine "ON" state. We'll see if that pans out, not likely during this initial build stage but possibly over winter. My intention is that I could sell a waterproof potted unit that would work as follows:

During engine "ON"state you can cycle through run modes, starting with momentary action if you press and hold it for longer than oh say - 2 seconds. If you simply press it and release under .5 seconds or so, it would run continuously until another quick impulse is received. During engine "OFF" state it will only function as a momentary switch. As a safeguard - if you have it running continuously and the motor switches from "ON" to "OFF" it will bring it out of continuous mode automatically (I've killed a battery already by having it run without me noticing).

Let me know if anyone has interest in something like this - like I said it would be a small completely waterproof module that would be dead nuts simple to hook up, and handle the current load of 2 500gph pumps. In reality the only potential client for a product like this would be someone that has a bar mounted momentary switch - so that leaves a lot of people out.

 

[Mobile Chernobyl]

Startin the rails... Bond rails!

So the Bubba Tubbies are in place and are pretty solid. Given they should have a very little chance of hard contact with something I'm pretty satisfied with them. Sure I could have gone with a Biaxial Cloth layup, but I don't have a vacuum bag setup to make that possible on an object with rather harsh and constantly changing curves!

Tonight I started working on the bondrails using a modified ScottS Method. Like ScottS, I fastened the host piece of foam to the existing bondrail - Only I did it with 1" drywall screws instead of bolts. These screws protrude about 1/8" at max on the other side - so what I will do is shave them off with my dremel. This helps me because when it comes time for removal of the bondrail mold there will be no evidence of screws or anything - and when the bottom is laid in it will patch the 1/8" holes the screws made in the existing bond rail!

Here I am putting the backer strip onto the foam - this distributes the screws load and holds the foam down hella'in.

Since I only did a 1/2" sheet to start with - the idea was to layer up as many more 1/2" sheets as I needed to obtain the bondrail height. This helped me because 1/2" foam is A LOT more flexible than it's nearest sibling, 1" foam. This was awesome when it came to the rocker nose because the laminated layers molded to any curve and hugged the existing bond rail spot on.

Switched back to the 3M foam adhesive, rocks, all I can say.

I decided also to throw in a modified rear bondrail, however it will not have any "meat" where people normally make the cut-outs for water flow. I needed to do this since I cut off appx 1.5" of the rear in this section, that and I value my knees (money makers I always say!) and they undeniably make for a nice lifting point.

So after all is said and done - I layered up 1/2" blocks progressively until I hit a thickness of appx 2.5" to replicate the bondrail on the superfreak. I'll have the nose more rickter/matrix ish however and I'll also tie in a little of the BOB gen 3 phallic shaped bond rail profile possibly.

I threw in a ghetto-fabbed 1/4" thick piece of foam on the top (bottom in pic) that will be sanded down to create a smooth transition from the existing bond rail. This will take all of a minute with a sanding block and 40grit.

Shot of the rear build up in preparation for the superfreak style integrated sponsons

 

[the WaTeRhAwK]

Man, how resilient is all of this going to be? With as much time in between sections, and no chemical bonding between layups?


It's looking killer btw.

 

[Mobile Chernobyl]

It'll probably fall apart before it hits the water right!! lol

#ShouldaBoughtASuperjet :deadhorse:

 

[the WaTeRhAwK]

I'm not saying that, It's just that since there is not chemical bonding in between steps, I'm wondering how much environment it can actually take, as opposed to a regular vacuumed hull layup. Also, do you think the amount of layers is sufficient for an adequate wall thickness?

 

[Mobile Chernobyl]

Well... most areas have 6 layers or more of 1708 where it can be considered to be the structural hull - giving me nearly .30" of material.

Reading through this thread you'll find that this is my first build as well as first time fiberglassing anything. So admittedly I'm not the best person to poll on experience when it comes to lay-ups. I've given it as much effort as possible to use known methods for proper bonding to existing parts. Although there is a lot of new material going on SMC or previous layups - I've made it a point to have as much surface area for lap joints as possible - always aiming for a depth of 1" to 1.5" of overlap. Surface prep has been something I've stuck true to and anywhere I am bonding to old hull I will sand through the gel coat with a 40grit wheel and then air clean it, then finish it up with a liberal application of acetone about 10 minutes before each bond so as to insure that the solvent fully evaporates, but also not too soon to allow time for my hands to accidentally touch it before the next layup.

- the same goes for new layup on previous layups, which acetone happens to help in this situation because it is a known thinner of the type of epoxy's we use for fiberglassing. Whether or not I am getting close to the chemical bond is unknown - I am at least giving it every chance possible to make a clean mechanical bond.

At this point - you can probably tell the build has taken much longer than planned and it is not the only hull I ever plan to ride. If it lasts me 1 to 2 years I would be very happy and consider it a successful first build. If something DOES break - it will only teach me what I've done wrong, where as if something doesn't break and I've done something wrong in the lay-up - that will teach me nothing and I could drag those incorrect lay-up methods along with me!

If you want I could possibly get technical on this and prepare a fiberglass test strip with a lap joint which would be known chemically bonded (going by continuous bonding methods), and then a test strip of 1 week delay with my prep method, and I also proably have some SMC left from the hull which I could also prepare a test sample of that. All would feature 1" lap joints on a consistant surface area (1in^2) - and I could test the tensile strength of each bond and possibly even get the stress/strain curves printed for you? I'm still a student so we have access to some convienent testing equipment and I've used a tensile tester for crazier things in the past! I'd use 1708, double layer for each and bring a control strip which features no lap joint.

Future builds will consist of custom plugs of an entire hull and vacuum bag or possibly vacuum infusion like we use on our carbon fiber FSAE cars at university. That or I'll just buy a damn superjet :wink:

(Sorry if there seems to be a condescending tone - I'm going on >4 hours of sleep after laying out the bond rails last night!)

 

[the WaTeRhAwK]

Not condescending at all bro, just focus on the build...lol you're doing a great job. If this works out well, your delayed methods will prove suitable for what we do. I've studied FRP in the past, and usually builders try to avoid non-chemical bonding structures between layups, because after cure, epoxy shrinks and will turn loose of surfaces, especially those put under various stress points, and I thought it might be an integral structure concern in consideration to the type of stress we put on these things.

 

[caseville9036]

I'm also thinkin of something kinda cool for the momentary switch on the handle bars. I've played around with PIC microcontrollers a few times before on projects and I was thinking of somehow tying in some logic to that switch and possibly the engine "ON" state. We'll see if that pans out, not likely during this initial build stage but possibly over winter. My intention is that I could sell a waterproof potted unit that would work as follows:

During engine "ON"state you can cycle through run modes, starting with momentary action if you press and hold it for longer than oh say - 2 seconds. If you simply press it and release under .5 seconds or so, it would run continuously until another quick impulse is received. During engine "OFF" state it will only function as a momentary switch. As a safeguard - if you have it running continuously and the motor switches from "ON" to "OFF" it will bring it out of continuous mode automatically (I've killed a battery already by having it run without me noticing).

Let me know if anyone has interest in something like this - like I said it would be a small completely waterproof module that would be dead nuts simple to hook up, and handle the current load of 2 500gph pumps. In reality the only potential client for a product like this would be someone that has a bar mounted momentary switch - so that leaves a lot of people out.

I am running the same switch on both of my ski's and would love to have a solution like you just described. I'll get onboard for two if you get to making them.

 

[Mobile Chernobyl]

All valid concerns Waterhawk -

With Epoxy that shrinkage issue is a lot less of an issue than with polyester/vinyl ester resins though because it mainly occurs within the gel state vs with poly/vinyl they experience slight expansion before curing then shrinkage and have another issue to worry about - they typically form more crystalline-like structures which can become brittle. With epoxy, after the gell state any shrinkage occurs at a fairly linear rate which the resiliancy of the epoxy resin has a favorable chance to cope with.

This is all well and known for new/fresh build structures but that is not the case as you make it with my franken-yacht.

The fact remains unclear though - I did not find any easy to find research papers in my .edu's general library on the strength characteristics of post cure bonding to existing fiber composite structures. Also an epoxy to SMC bond would be interesting. If I have some spare time this semester I'd definately like to prepare some dog bone samples and run a batch on the tensile tester to have some data for people here building and restoring/modifying hulls! Hell we have one in our car club's lab so it should be easy so long as I remember to do so!

Caseville - I will probably work on it over my fall semester. I'm beginning my focus on embedded microcontroller design and logic in school so it will become alot more clear how to transcend computer code onto a small microprocesser then lol. I wanna make this thing like the size of a golf ball so I'm not gonna use an Arduino.

 

[Mobile Chernobyl]

Bond rail profile laid out and masked up!

Well I started by flipping the hull back over to get a more accurate view of the bond rails. From there I started carving away at the foam...

Nose

Front right side

Rear right side

Rear Left Overall

I then used my trusty foil tape to mask off the foam so I could remove the bond rail mold easily after the 1708 has cured

I combined a few aspects into these rails. They are a constant 3" wide, with a constant 1.5" flat, but what changes is the depth - so the only variable left then is the angle at which they fold.
-From front to rear it starts out as 45 deg angle and ends up around 60-65 deg towards the rear, with a 1" depth to 2.25" depth from front to rear respectively. This kind of gives it the illusion that it gets wider around the tubbies but it really never gets wider or narrower until the very front - where it acts mainly as a bumper/splash guard and not a water scooping bond rail.

We'll see how the layup goes!

Now that my Tubbies are fully cured I've decided that I will throw 1 layer of 1708 biax on the bottom face overlapping to the hull, with a 10oz glass on top of that to smooth things out/hold things down. The surface of the tubbie was just not firm enough for my liking, and I don't want to have to do any repairs if necessary.

 

[the WaTeRhAwK]

just curious, but why aren't you countersinking the handlepole and bracket?

 

[Mobile Chernobyl]

Unless by "Countersink" you mean something other than the obvious - you may want to have a closer look

The pole bracket will be about right at the bond line, about 6 inches back from the nose. There is a big void in the nose area - in picture 2 of my last post you can see the sanding block and a sharpie marker there. That is the flat where I will eventually mount my pole bracket. It actually starts flat and level with the engine bay opening to tie into it, but then goes up hill to follow the rocker parallel. It is appx 7-8 layers of 1708 biax material directly under the mount zone.

In terms of countersinking, it's pretty extreme actually. Most builds I've seen have the bracket slightly above the bond line - but since I made a new nose I opted for a mount point appx right on the bond line. It's sort of Rickter-ish but it has a slight different angle at which the bracket mounts.

Take a look a few pages back when the nose was still foam and maybe you'll be able to visualize it better

 

[the WaTeRhAwK]

I mean like how superjets and sxi, sxr's etc... have everything flush with the top of the ski, instead of protruding up past the top surface level of hood and nose. I haven't seen the handlepole or bracket on the ski yet, so yeah I may be misunderstanding it to be a different way, I just figure it not to be flush mounted with the top of the ski, because of the small area between the top surface of the hood and the current depth of the pole channel running through it.

 

[Mobile Chernobyl]

Yep you'll just hafta wait and see! I didn't come this far to make it look like ! lol

 

[Sanoman]

Awesome build man! For someone that has never done glass work,you are doing great.

You ain't playin possum ,are you!? lol