Reinforcing a Square Nose

[smoofers]

So, after talking about reinforcing my buddy's (Travis) SN (red) for the last year or so we finally came to the conclusion that we would do it this winter. In my quest for a superjet I finally found one two weeks ago on craigslist. I bought a (white) '90 SJ - bone stock, running, and minus a hood for $450, and decided I would just start building now and wait until march to ride it. As it stands now, we are both shooting to have our skis done by the Lone Star Freeride. Travis knew we needed to reinforce, as I personally busted his cracked hull open last summer and nearly sank it (don't worry I helped him repair it the next day).

About the time we were going to order glass I stumbled upon my SJ and we decided to gut both boats and reinforce them, as well as add some other goodies which I will detail in a separate build thread. My purpose for this thread is to show what is exactly involved in reinforcing - from start to finish. Travis nor I have ever reinforced a Superjet, but I have a long background in fiberglass and have built many a custom car interior and made a few hull repairs. Some may disagree with our methods used, but in my humble opinion we did our reinforcing properly. My garage is nicely equipped, but I don't consider any of the tools I own to be out of reach for the regular garage builder. I do have an air compressor, but it is not required for this job, just very helpful. As I consider myself the "average" garage builder, I want to show that this project is not a huge undertaking.

 

[smoofers]

The first step in reinforcing is to remove (or mask off) anything that will hinder your glass application, as well as avoid any messy cleanup of dripped resin on under hood parts. Can a person reinforce their hulls without pulling the motor, ebox, gas tank, waterbox, and other extras? My answer, maybe... but I wouldn't attempt it myself. In my experience, anything that can get in your way when you are trying to lay glass... will get in your way, as well as get dripped on.

While waiting for my glass supplies to arrive, I disassembled my entire boat. Total time from running ski to gutted hull was maybe 5 hours tops, I took many a smoke break and drank quite a few beers.

Once I had a bare hull, I dumped in a good bit of comet (abrasive bleach cleaner) and went to town on my nasty hull with a scrubber sponge, a car washing brush, a few gallons of water and a shop vac.

Below is the dirty, dissasembled hull, followed by the finished clean hull - wich wasn't very clean.... I found out the top 2mm's or so was waterlogged, oil soaked, and rotten.

 

[smoofers]

I know there is much debate over whether or not to grind the hull ribs. My choice was to grind them down and get them out of my way so I could lay a nice large single piece of glass that would go down easy and be free of any air bubbles.

My tool of choice is my Harbor Freight brand 90 degree air angle grinder. I don't know what it is about HF air tools, but in my experience they usually break fairly quickly, but if you can fix them they last forever (as is the case with my HF 90 grinder, airsaw, 1/4" and 3/8" air ratchets). I use a 40-grit roloc disc on my ninety grinder and find that it pretty much works for anything.

As my air compressor is fairly small in capacity and horsepower, I could get about two large ribs ground flat before I would have to let the air tank fully recharge. My method of dust cleanup was my shop vac with its hose positioned right next to what I was grinding, and it worked like a charm. In the first pic you can see a random piece of wire - i just made loop through two of my holes in my firewall with it and used the wire to hold my shop-vac hose in place.

For my hull bottom with the rotten section (or ALL of it), 45 seconds with the ninety grinder had it down to fresh glass again. I also ground down the first three ribs inside the nose, as well as the small ribs on the upper hull sides. I debated on weather or not to grind down the large rib with the threaded insert in it, but decided to lop it off as I am not really going to use the stock cable/hose routing anyway.

One thing I MUST stress is that when you do any grinding, you do it SAFELY. I wear saftey glasses and a NIOSH approved respirator with at least HEPA filters. A respirator is CRITICAL for this step, as well as the next step. You DO NOT WANT TO INHALE SUPERJET HULL DUST!!!! I also keep a bottle of baby powder (talc) in my garage for use when sanding or grinding fiberglass. Rubbing any exposed skin down with talc before sanding fiberglass minimizes the amount of tiny, irritating glass fibers in your skin. PLEASE BE SAFE!

 

[smoofers]

With the ribs ground down, the next step is to sand every single surface that you will want resin to bond with. I used an electric D/A sander with 60 grit paper for the big areas, and then went behind that with a few different home made sanding pads and 60 grit paper. SAND EVERYTHING thoroughly, as you want the resin to have a good chemical and mechanical bond with your hull. I even hit the insides of my bond rail as they will be filled before glass is applied.

With the hull sanded, vacuum the entire hull twice, then blow it out with compressed air (if available). After that, put some gloves on and and take an acetone soaked rag (dripping wet) and wipe down the whole area - twice - with a clean rag each time. I then blow my ski out with compressed air to make sure it is completely dust free. Now, I know you want to run your palm across your freshly prepped hull and admire your handy work, but DON'T TOUCH IT. You don't want to contaminate your freshly cleaned hull with your oily fingers (who knows where they've been!).

 

[smoofers]

Now the fun begins....


My fiberglass order came in right about the time both skis were ready to be glassed (great timing huh). For this project we chose to go with Jeffco Epoxy resin, some glass micro-balloons, and two yards of 50" width, 18oz knitted biaxial (+/- 45) E-glass.

For the bond rail, Travis and I began mixing up ~4oz of epoxy and added the glass micro-balloons at a 1:1 ~1:1.5 ratio of glass to micro. Some people prefer to foam their bond rails for the sake of weight, but in my opinion, the thickened epoxy is only going to weigh a few more ounces than the foam AND with the epoxy you are adding strength.

When using micro (balloons) you want to mix your epoxy and hardener first, then begin folding in the micro. Again, WEAR A RESPIRATOR for this step. Micro is amazing stuff, so amazing it acts like a fluid when you pour it into a cup. It also is light enough that it goes air born with the slightest whiff of air. Again, you do not want to breathe this stuff! Back on topic, slowly fold the micro into the epoxy a few ounces at a time until your mix is how you want it. Ours was the consistency of light cake batter.

With the hull on its side, adjust the angle so that the thickened epoxy will make a smooth transition between the two hull halves. This part of the process is the longest part, as it takes two seperate pours to fill in one complete bondrail. The first with the ski flat on it's side, the second with the rear of the ski elevated, as to keep the epoxy up in the nose section.

Once the epoxy is poured, smooth your transition from the epoxy to the hull with a paintbrush (disposable). We also found it usefull to use a bondo spreader to keep the resin from flowing over in spots, as well as smooth the epoxy out. Thickened epoxy self levels rather well, and we found that as it cured to a cake frosting consistency, the bondo spreader was even more effective at making the epoxy do what we wanted, while still self leveling after we messed with it.

My garage is around 65-70 degrees (F) and we found that the thickened epoxy still took a good 3 hours to tack up. I put a small space heater between the skis to give the hulls some gentle heat while they cured. It also didn't help that my resin was probably about 55 degrees when we started pouring (damn FedEx and their cold trucks). If you are in a colder climate, I recommend heating your garage a day or two in advance of any glass work.

 

[smoofers]

After both hull sides are done and cured, it's time to fit some glass. We decided to measure for our panels and then transfer those to paper to make a pattern for cutting the glass (excellent work Travis). After test fitting our patterns we taped them down to our fiberglass and cut out our shapes. We wanted a slight bit of overlap from the sides to the bottom, as well as having our panels reach all the way up behind the hood seal ridge. A bit of trimming was required to clear the exhaust hose, etc., we pulled out our panels and did one last round of prep.

The prep included once again, sanding the hull sides with 60 grit paper. The cured epoxy comes out buttery smooth and somewhat waxy to the touch - not good for epoxy to bond to. It must be sanded again to roughen the texture back up. This was followed by another bit of dust removal (shop vac and air) and then another acetone wipe down.

 

[Fro Diesel]

ah p-funks :439: keep up the good work!

 

[smoofers]

Yes - P-funks rock:439: thanks!

With the final prep all done, we gently put our side panels back in place. The easiest way to lay a good panel is to have your surface relatively level, hence we laid the SJs on their sides to make glassing easier.

We started out mixing 8oz (part a) and found that that wasn't quite enough for one hull side, so for the next ski (bear in mind we are glassing two hulls at once) we mixed 10oz and it was the perfect amount to finish both. So, it took ~9 oz per side.

We started glassing by folding back half of the panel and brushing epoxy to wet out the surface. We then folded the panel back, pressed it in place and folded back the other half and repeated. For this step it was much easier with two people but is doable with one. While one person was fitting the last half of a panel the other person was wetting out the edges and overlaps with a brush. It really helps to pay attention to detail here and attempt to wet out all the potential air bubble spots first, then worry about the large flat sections of panel.

On a side note, when ordering my glass I figured what the hell, and splurged on a 3" aluminum fiberglass roller. With all my fiberglass experience i have actually never used a roller until this project. I then realized it is worth it's weight in gold.

After wetting out your edges and compound curves, hit all of your glass with the roller. Step back, look for dry spots, dab some resin, and roll again. Using a roller makes glassing almost too easy, as I found that it made the resin to glass ratio very consistent, and eliminated any large puddles, and air bubbles with ease. The roller really helps keep the amount of resin it takes to wet out the glass minimal, and gives you a lighter, stronger, bubble free panel.

After the glass is wet, flat, and air bubble free, clean up your roller with acetone, wipe down any drips, and then take a break, smoke a bowl, and relax... Ah, one panel done, two to go...

Enjoy your break, as you have a good 3-5 hours until the glass tacks up and you can move to the next panel.

 

[The Penguin]

If I'd have know you were going to all that trouble - I would have dropped off the other SN hull I have for you to glass at the same time.

if yer doing 2...what's 1 more? :biggrin:

oh - you are going to be reinforcing the handlepole mounting are...aren't you?

 

[smoofers]

After glassing bot hull sides the only thing left is the bottom.

Again, for the bottom we transferred our measurements to paper and made a pattern. We opted for one big panel, with the engine mounts and hold down bracket stubs cut out. When you cut out for your engine mounts and stubs, don't worry about your cuts being pretty, they'll lay down once you get em wet with epoxy.

The bottom was done the same way as the sides, with half the panel pulled back to wet out the surface with resin, then pressed down, and repeating on the other half. The bottom actually was not hard to glass at all - I was surprised how well this thick glass laid down near the engine mounts and other compound curved areas. Again - roll the crap out of your panel and make sure and wet out any dry spots.

That's it - hull is reinforced. You can reassemble within a day or two, assuming your glass is fully cured. As for these skis, I have some grey bilge paint in the garage I plan to paint the inside of the hulls with in a few days. As soon as the paint is done, pics will be posted.


All said and done it took a total of about two and a half days work and about $150 dollars in materials. Not to bad considering split between two skis that's only $75 per ski. Best part is, the inside of our hulls look sick, and we can bash the crap out of them for a few more years.

- Look for my complete SN build thread in the next few weeks.

 

[smoofers]

Pengin, I have been debating reinforcing the handlepole mount. Honestly, I can't find a reason not to. We were just exhausted and out of time to work after finishing the 3 sides. I bet you that pipe you have for sale I'll have the handlepole mounts glassed within the week. If you want to borrow our patterns for the hull sides and bottom you are welcome to - they came out perfect.

 

[SQUARE JOEL!!!]

If I'd have know you were going to all that trouble - I would have dropped off the other SN hull I have for you to glass at the same time.

if yer doing 2...what's 1 more? :biggrin:

oh - you are going to be reinforcing the handlepole mounting are...aren't you?

Same with ASS SKI! I mean, what's another one???

 

[SQUARE JOEL!!!]

Looks good smoof!

 

[The Penguin]

Pengin, I have been debating reinforcing the handlepole mount. Honestly, I can't find a reason not to. We were just exhausted and out of time to work after finishing the 3 sides. I bet you that pipe you have for sale I'll have the handlepole mounts glassed within the week. If you want to borrow our patterns for the hull sides and bottom you are welcome to - they came out perfect.

definitely needs to be done - it's a weak spot. fill voids with foam, level off and put at least 2 layers down - best to take 1 layer all the way down to the bond line.

hang on to those patterns - Square Joel and I both have some reinforcing to do.

 

[Boris]

You did all that work so you might as well tackle the pole mount.
That area flexes like crazy especially if you run a stiff pole so throw a couple layers on there.

Looking good so far.

 

[SQUARE JOEL!!!]

You did all that work so you might as well tackle the pole mount.
That area flexes like crazy especially if you run a stiff pole so throw a couple layers on there.

Looking good so far.

He said stiffie!!! :biggrin: Sorry, couldn't help it!

 

[TJLSuperJet]

what a weekend!

nice post brotha! cant wait to throw the handlepoles on there!! the pics are classic...ha ha... and yeah that was a long productive weekend.... :bananalama:

 

[SQUARE JOEL!!!]

nice post brotha! cant wait to throw the handlepoles on there!! the pics are classic...ha ha... and yeah that was a long productive weekend.... :bananalama:

Welcome Travis!!!!

 

[BruceSki]

you guys are troopers doing fiberglass work in shorts and t shirts.


no wussy long sleeves and lotion around here. bring on the itch

and no cold showers either.



reinforcing looks good. id heed the penguins advice and do that pole mount... its the weakest point on the square(well my .02 at least).

 

[QuickMick]

good work guys.

OK Im in line as #3.. let me know when I can bring it to you. After all you have the patterns and roller!!..

Ill throw down for the materials and beer. :Banane57: