Floor/stringer repair: how far?

I need help. I have pulled everything out of my 77 Ski Nautique. I have drilled into the stringers in several areas and have yet to find good wood. I do not have the time or expertize to redo the floor. I am in North Dakota but willing to travel. Please let me know.
ducky@gondtc.com. Thanks.

Friday, it has only been a few months since I completed my floor, so I cant tell you you how well it will hold up. It appears to be at least as strong as the original floor, though- it is very hard and about the same thickness. The foam I poured is also more dense than it was from the factory- I dont doubt it was originally 2 lb density.

If I were to go it again, I dont know if I would use the 5200 on the bulkhead. Otherwise, I think my approach was very well thought out.

If you plan on replacing the entire floor, I would do it with plywood over light density foam (2 lb). If you only have a spot repair or a single stringer to replace, its worth considering my method. Its no small task to put down 7 layers of fibergla$$- its time intensive and a rather unpleasant project. I certainly dont doubt its strength though.

I'm planning on using this same process on my 83', looks like you did a great job. I'm putting together a web page to post all the pics of the project. I have a couple of questions. Its been awhile since it looks like you've completed the project, how are the floors holding up? Would you recommend the same process for others, if not what would you do differently? Thanks for the help!!

Mark, I also expected all of my work to be done in a week- 5 weeks later, here I am. Laying down the glass on the floor took the most time due to all the layers and having to measure and cut so many pieces. I busted most of it out in 14 hrs though.

Joel, I like the spare there too. My real motivation to move it was to gain access to the ring welded on the trailer to attach the turnbuckle. I wanted something holding the front of the boat down, rather than just forward- its solid as a rock now.

Hollywood, its all about product placement. Im expecting my sponsorship from A/B to come through any day now.

Tim,

I am still not done yet. This whole process sure has taken more time than I originally thought. Of course, at first I though I was fixing about 2 square feet of area.

I have all of the foam in and plan to start laying fiberglass on Friday. I have plenty of mat and cloth, but I am worried that I am going to run short of resin. I only have 3 gallons, but based on your pics, I think I am replacing a little more floor area. I think I will order another gallon just to be safe.

That's a bummer about the carpet. I have read a number of posts where someone has ordered yards of carpet, but received only a few feet. I bet you will be glad to get your boat back in the water. You have done a great job. I have been following the thread on your motor upgrade and I am looking forward to hearing how it performs.

I took a few pics but they all came out crappy. Ill snap some more tomorrow in natural light. Proof that its actually together:



I hope it still feels as fast as it did without a windshield!

Did you get the windshield back together?

Looks good. How much resin and how many yards of fiberglass did you end up using?

Looks like you did a good job. Isn't it fun to fiberglass? I can see that you have good overlap onto the existing fiberglass, so your repairs should be plenty strong.

It looks like you still need to grind on the edges a bit (otherwise you will cut yourself eventually). Also, it looks my assessment of 6-8 layers and 2.66 gallons of resin was pretty close. Again, great job.

I'm in Champaign Illinois, about 100 miles south of Chicago. There are not a lot of lakes around here, so we actually ski in the cooling lake for a nuke.

I was worried about the high temps and humidity we have here during the summer, so when I bought my supplies from US composites, I opted for the slow hardener for the layup work and bought a small amount of the 1:1 stuff for gluing and patching. I haven't used any of the slow stuff yet, but on Sunday in the 95 degree temps the 1:1 epoxy had only 1/2 the pot life indicated at 80 degrees.

Tim,

I've been taking pictures, but I'm old school and still use a film camera. When I get them developed, I will post a few of them. I need to figure out how to do the photobucket thing.

As far as skiing verses fiberglass work, I guess my priorities were a little messed up. The 95+ degree weather would have been perfect for curing epoxy resin.

sounds like from both of your sources the mat is giving you more thickness than I would have guessed and that will help out. I am not guessing on the cloth though I have used all kinds extensively, and the 6oz 1/100th inch is about right. Don't know how 1.5 oz mat gives more thickness than that but I have never used mat in a project except as a thin finishing layer before painting and it seems to be the case based on the info presented.
-Joe.   

Joe, youre right- the cloth Im using is fairly light and didnt add a lot of thickness. The mat seems to have more weight to it, though its only supposed to be 1.5oz. The glass seemed to be fairly thick when I did the stringer, and I only used 3 layers. It also seemed quite strong and very hard. Just by eyeballing it, I thought 7 layers would be thicker than 1/8". When I spoke to the US Composites rep, he talked me out of going with the 6oz S-glass (saying it was overkill) and that the 4oz E-glass was plenty thick and strong for my application.

David, I have just over 2 gallons of resin left (plus the associated hardener). As you can see in the pics, I am not going the full width of the floor- there is only 3" of foam on either side of the stringer for the most part. The section that is close to full width is about 30" long. Only the one perpendicular support spans all the way to the main stringer, so I should only have to wrap into the bilge over a 3-6" section.

I think I will proceed with the repair as planned and hope I get the thickness I need from the materials I have. Thanks to everyone for their input!

You can, but the floor with be much thicker than you need in order to get the flexural strenght that you need.

If I were you, I would glass on side of the floor at a time. Do one side full thickness and let it cure. Once it cures, grind the edge where the other side of the floor will join it to a 12:1 taper. This way, you can work inside the boat and not worry about stepping in your work.

The easiest way to spread resin on a large area is with a foam paint roller. Roll out air each third layer at a minimum. After overall thickness achieved, fill in low spots with scrap mat. Turn down each layer onto the side of the main stringer going further down each layer (make sure to grind off the bilge paint first. The mat will not want to make the 90 degree bend, so you may consider easing (1/2" radius or so) the corner. If you want the corner nice a sharp when you are done, cut narrow strips of mat (or cloth) and and build up the corner. Then when cured, you can grind the corner square again. You will have to modify this aproach in the area of the aluminum engine frame, but hopefully, yoiu get the idea.

Remember, CC did not use woven roving (18oz.) in the construction of the floor (at least not in my boat).

Depending on the material you purchased, you may need only 6-8 layers. Do a quick test to find out. How many gallons of resin did you purchase. I would guess you need to start with 2.66 gallons, especially since you are doing the entire floor.

joe did you vaccum bag the sandwich layup or just brush/spray on the resin to wet out the cloth layers?