Stringer Replacement

[85 Comp ts6m]

Good Day to All you Wizards of the Supra Water World
I have an 85 comp that I'm redoing completely but this is a first with a fiberglass boat so bare with me .
1. when removing the old stringers do you have to sand down the surrounding area and remove all of the old fiberglass and resin or just sand down smooth till your getting a good base ?

2.I've noticed that after I removed the floor and foam that the boat feels a little wobbly, and that both sides by the hull outside strakes seems to have dropped about a quarter of an inch. The boat is on the trailer and the engine is still in it and the deck and hull are still together . After I remove the engine this winter should I block the hull to stabilize it before I replace the stringers and motor mounts or is this not that big of a problem ?

3. And is there an easy way to finesse the pylon out of its mount without resorting to brute strength ?

sorry so long winded

thanks
85 Comp ts6m

[Salty87]

i was tearing mine apart this time last year...won't miss that at all!

1. pretty much all the way. if it looks questionable...sand it down. you want your new work to have a good bond. you'll also want to sand about 6" on either side of each stringer. your new fiberglass should be layed so that each layer extends further out from the stringer. the first layer should be 2-3" on each side of the stringer, getting wider with each layer so you have a stronger attachment. you'll pretty much have sanded the entire hull by the time you're done.

2. i re-did a saltare (23') so slightly different from your hull. i left mine on the trailer too. i don't think it changed shape but the sides were floppy. i used a 2x4 on each side propped into the ground to keep them from bowing out too much. i think most people leave them on the trailer but if yours is sagging you might need to support it better.

3. my pylon was bolted to the main stringers and wedged in pretty good too. i think i yanked it out but might have sawzall'd it.

[85 Comp ts6m]

Salty87 thank you for your input I kind of thought that I needed to take it down to the hull (arrgh) . I kind of figured I'd need to block it also that's not a problem . As far as the pylon goes both it and the steel mount are removed from the boat , now I'd like to separate them from each other they just don't want to let go .
This is where I'm at to date . I hope to have it in the garage by the end of the month we'll see. I'm starting to gather the supplies needed . I'm thinking of using lvl for the stringers and motor mounts because I have left over from another job . one piece full length 1 3/4" thick won't have to double up any plywood what do you guys think ? all new and old wood will be treated with a penetrating epoxy .If anyone has any thoughts I'd be glad to hear them .
Like I said earlier this is my first glass boat job.If i Mess it up my wife and kid may disown me
I'll post a few pics of what I was dealing with later .

Thank You All
85 Comp ts6m

[Salty87]

foam removal is fun, huh? ha it's looking good.

the pylon- you're trying to separate the pole from the base? i never bothered with it, mine is sitting on the side of the house. it's too big for the trash and i didn't re-use it. i have a tower so i just skipped the pylon, it was in the way most of the time.

i'm not familiar with lvl. i used marine grade plywood, soaked good with thinned poly resin, then wrapped in fiberglass. is lvl made of ply's or solid?

what type of resin are you going to use? poly or epoxy?

keep the questions coming.


one last thing...your hull might not sag as much if you take the top cap off. the windshield/dash area is pretty heavy. you need a decent bit of room though.

[85 Comp ts6m]

First off I wish i could use a Tower but the water I run it in doesn't allow towers or ballast bags , so I have to put the pylon back in which stinks but oh well.

The foam was easier than the floor was tho .

LVL is a laminated veneered lumber just like plwood only no cross grain in the laminations and they use waterproof glue to laminate them just like marine plywood .

I'm planning to use epoxy thinned to soak the wood and also to bed in the stringers and glass them over .

I'm planning to use 9oz 8h plain weave hexcel in 3 layers over the stringers and when I do the motor mount stringers I'll use the same but I'll top that with a layer of 20oz kevlar .
I kind of think this might be over kill considering they only used what looks to be a thin mat and then about a 16oz kevlar roving .

What do you think / Am I on track or lost , Sometimes I really can't tell . LOL

I was also thinking that i might try and either cut a slit in the pylon base or maybe drill a hole in the bottom to help get it apart , I can always weld it back together right .

I really don't want to take the deck off at least not right now ,but I might have to at some point I know .

Thanks for your input

85 Comp ts6m

[Salty87]

no tower and no ballast...boooo. i guess i can see how the ballast rules happen but why no towers??

i don't have any experience with lvl but it having no cross grain worries me. if i understand correctly, then all of the grains run the same direction which decreases its strength compared to plywood. that's the same reason that many people prefer plywood to dimensional lumber too.

the epoxy or poly decision is really important. they aren't always compatible...you generally can't put poly over epoxy but you can put epoxy on poly. that means if you seal the wood with epoxy then you need to use epoxy for glassing too. epoxy is significantly more expensive. the boat was made out of poly resin, not much point in making the repairs stronger than the hull but it's your call of course.

i used 8 oz cloth and heavier woven with poly, can't remember the weight. i got most of my supplies at uscomposites.com.

thinking about the top cap and the floor again, you'd def want to block the hull up some at least. with the floor out, there's really nothing holding the hull sides together as close as they would be with a floor in the boat. the top cap can't deform much but the bottom can hull walls can get floppy.

[85 Comp ts6m]

The lake is a flooded strip mine pit very long but only three hundred yards wide at it's widest point , with piers on one side and campers on the shoreline so no ballast tanks because it would create too big of waves and over flood the camping areas and no towers because you could jump your wake and maybe land in someone elses boat .At least that's what the safety committee has told us .

I have blocked the hull now from the trailer to hull and it almost feels like the two are one piece so it's very stable now.

I know that the epoxy is going to cost more but I have more options with using it and I've used it more than polyester resin I quess it's a comfort factor ?

Now you do have me rethinking the LVL though , it is stronger than dimensional lumber and plywood BUT only in a static load NOT in an active load like a boat hull Hmmmm.
I think I'll be using 3/4 marine plywood and just redo it the same as it is now .
Salty87 good call

Well I drilled a hole in the bottom of the pylon base to try and use a drift and hammer to knock it out but it wouldn't budge so I'm going to try some aluminum safe rust remover in the hole I drilled before I just cut a slit in it .

By the way what grit sanding disc did you use for remover the old resin and glass ? I'm using 36 grit and it does ok on the fiberglass but it is real slow on the kevlar roving by the engine stringers , I didn't think it would be that tough .

Thank You For Your input
I am learning

85 Comp ts6m

[Salty87]

safety committee...that sounds worse than having someone jump their wake and land on you. in which case i'd rather have a tower above my head than nothing. lol

i've got little experience with epoxy. poly is stinky and messy, harder to mix together. i know that much. epoxy will work great, no doubt.

i used 3/4" on the stringers and 1/2" for the floor.

i used 36 grit flap discs...http://www1.mscdirect.com/ProductImages/0563737-11.jpg

they ripped through my old stuff real good.

[rickr]

85 Comp
Here is a link to my 87 Comp project
http://www.boatdesign.net/forums/fiberglass-composite-boat-building/ski-boat-stringer-sole-replacement-20668.html

I took the wheels off the trailer, braced the trailer to the floor, then braced the boat to the trailer. I also replaced one stringer at an time to maintain some hull integrity.

I did not have any luck getting the ski pole out of the frame. I sanded the rust off the bracket and painted with some Krylon Rust Tough Enamel

[Salty87]

i found my old pylon and took a pretty good look. it doesn't look like it would come apart, def not easily. if it does come apart after 20+ years, it will take some work.

[csuggs]

I hope you guys don't mind if I join in the fun! I have a 1986 Supra Sunsport Skier that needs floor and stringer replacement. It's nice to know that I'm not the only one! How difficult is it to pull the cap? I know that it seperates where the rub rail is, but what method did you use to lift it?
I've been talking to a guy in Marysville, TN on the phone by the name of Ronny Bennett - he's in the business of doing these types of repairs on inboard ski boats, used to work for Mastercraft and then Supra. I would like to pull information from you guys as well as from him.
Still deciding to take the plunge . . . . . . . . .

[Salty87]

jump on in, csuggs

it's not very hard if you have some room. i rented an auger and dug 6 holes for 4x4 posts. i attached pullies to the posts and had planned to just lift the top....it's really heavy. it all worked but lifting by the ropes didn't work, you need to pry the top off and then use 2x4's or something to lift it.

this is what i ended up with, left the top in the sling for 6 months or so. i used a huge blue tarp to wrap it up for the winter...

http://i8.photobucket.com/albums/a10/salty87/IMG_0269.jpg


note the flat tires, it was fun squeezing the finished hull back under there.
http://i8.photobucket.com/albums/a10/salty87/IMG_0272.jpg

i can't imagine what it would cost to pay someone to do this.

[csuggs]

Thanks for the pics and description. I got a price from a guy in TN that does this for a living - $4400 turnkey. But I hate to spend that money if I can do it myself. Can you give me some of the other gorry details about the job? Materials used, hours spent, detail pics? I have a pretty good idea of what's involved but I figure you can't have too much information about something like this!

Clint

[Salty87]

i put some pics together here:
http://supraboats.com/bbs/showthread.php?p=10444#post10444

i have tons more if there's anything in particular you're curious to see

talking just stringers/floor/carpet? $4400 isn't too unreasonable. i started to save receipts and decided that wasn't a good idea. i probably spent in the vicinity of $1500 just for materials for the floor (don't forget shipping on all of this if you can't buy locally). that probably doesn't include carpet/glue.

time is hard to tell. i went pretty slow taking it apart. no garage so that slowed me down too.

do you have any experience with fiberglass? there's a steep learning curve, it's nasty work (both tearing out the rot and then you get fumes from the resins when you're done with that), but seeing what i've seen i wouldn't let anyone else do the work. if you're patient and can read directions, you can do it.

[wotan2525]

I have a feeling that Salty87 and some of the other DIYers did a better job than I did. I didn't pull the cap and used (mostly) the same methods of replacing the stringers that the factory did when they were new. I figured, it lasted almost 20 years the first time.... if I get another 10 out of it, I should be happy. No reason to over engineer it.

I didn't pull the cap, and didn't replace the stringers in front of the windshield (they were still pretty solid.)

I paid a guy $1800 to do the stringers. I had the entire interior already removed (including floor) and it was returned to me in the same condition -- but now with good stringers. The guy said he waaaay underestimated the job and would never undertake anything like that ever again. I still had to do the floor, new interior, and carpet -- as well as reinstall the engine and all running gear. $4400 doesn't sound that bad compared to some of the quotes that I had. My boat was out of the water for 2.5 years.

Good luck!

[Salty87]

i let mine just basically sit for a year with a crappy cover. it was tub full of wet foam. my original plans were like yours, wotan. leave as much alone as possible. it just didn't work out that way.

csuggs- everything depends on what you find under there.

[csuggs]

Well . . . I haven't pulled the floor up yet, but I have discovered a couple of soft spots both on the port-side stringer. One where the exhaust goes below deck and one about two inches from the rear motor mount on the same side. For now, I have removed all of the motor mount bolts and some other smaller screws that were used to hold the fuel line in place along the side of the stringer. Some water is coming out of the holes, but not all of them. The motor mount bolts seemed tight when I took them out. I am planning to let the boat sit in my garage over the winter (cold in WV) and dry as much as possible. In the spring I will probably pull the floor up to inspect below deck and then determine what I must do. I'm hoping for the best!

I just bought this boat in August, and got to use it about 6 times before winterizing. The good news is that it runs strong (351W) and performs really nice. Does not let any water in except when taking a wake at slow speed! - over the bow of course. Also, I didn't notice it sitting too low in the water when we had it out so my situation may not be as bad as some. I didn't even notice the soft spots on the stringer until I winterized the motor.

Here's a thought. I wonder how many boats are on the rivers and lakes that have wet and/or rotten stringers, and guys don't know it? How long do you suppose you can run like that without risking a ruined hull because the stringers start to "sag" under the motor? Hmmmmm. . .

[Salty87]

you can get a long time out of a rotten floor. the whole boat locks together sort of like a stone archway. things will still happen though...shaft and/or strut can get bent as things settle around. stringers only get worse. the engine components will start to corrode from the extra moisture they're sitting in. that's another reason why i painted my engine, it was nasty. my 3 yr old carb looks like it was original.

what you're seeing with water draining from around the engine area is that there's no way for the water to get out. it's pooling in low spots and the foam is soaked. the stringers are absorbing the water. i don't know if you can actually buy more time by draining the water. i'm sure it helps but it also opens holes in the stringers.

wet foam will never dry, especially if it's tucked away in a nice damp space. freeze cycles won't help things. it's probably too late (cold) and def. not what you want to do with a boat you just got but pulling the floor and foam now would let the stringers dry out a bit and you might get lucky like wotan and not have to replace them all like i did.

but, like i said, you can get a long time out of a rotten floor. mine had mold growing on the carpet it was so bad by the time i started my rebuild.

[wotan2525]

In my opinion -- and definitely not gospel -- if the wood at the engine mounts is solid enough to hold the bolts, you're not in the danger-zone. I don't think there is much of a chance of the hull collapsing or deforming as even the fiberglass around the stringers is fairly rigid and the construction is sound. My problem was that the engine bolts rotted out so badly that the engine physically twisted in the boat, caused the drive-shaft to wear a hole through the side of the shaft-log, and the boat sank. Sure.... we made it to where it was only in a foot of water .... but it was sitting on the bottom and it was a project to get it out. I knew the bolts weren't into anything strong enough, but I thought the weight of the engine alone would be enough (this is a 454, afterall.)

I bought my boat much like you did, used it 6 times before the engine blew up.... pulled the engine, rebuilt it, put it back in.... used it another 6 times before it shifted and wore a hole through the shaft log. It also bent the driveshaft, tweaked the coupler, and bent the strut. Not a good day.

It doesn't sound like yours is that bad. I'd start doing some exploratory surgery and see just how rotten that wood is.