Replacing the stringers, found a problem.

[NEStriper]

Hi guys. Replacing the stringers/deck on a 16' GW National Boat Works. The floor was "fixed" by placing a piece of plywood on top of a soft (falling through it soft) floor and carpet over that. I removed the plywood, carpet, and cut out the deck, leaving about three inches around the whole edge. This was recommended to me to place the new deck on top of this frame.

When removing the stringers, I found that there was a piece of glasses plywood in the bottom that has since started to rot. I dont know what to do about this, as getting it out will be many, many hours of work. Is it necessary? I really don't even know where I would begin to remove that.

I can provide a more detailed picture tomorrow, but the piece is bound by the two outermost stringers and ends where the hull starts to narrow. It looks like it's less than a half an inch deep.

 

[sutor623]

Re: Replacing the stringers, found a problem.

Man if you are going to do it, do it right! Why spend all that time, and then have in the back of your mind that there is still problem. Wear a respirator too man. I got a NASTY URI from black mold that took 3 weeks to go away. Now I just buy aluminum boats.

 

[rickryder]

Re: Replacing the stringers, found a problem.

Could it have been the support to mount the seats? A piece of plywood across the stringers? or is it attached to the hull..... I guess a picture will be able to help us help you Please get all the proper safety gear ....good full face respirator,goggles,tyvek suit ect.....fiberglass dust is nasty stuff along with mold....

We generally leave a small lip along the gunwale as a reference point to get stringer heights and deck placement. If your going to use the lip to attach your new deck ply it must be ground down to good clean glass with 36 grit disc on an angle grinder and washed with acetone before you can lay up your new glass.... that holds true for any old to new glass application.

There is a vast amount of info on doing your rebuild on here! Most people have them in their signatures. Post lots of pictures and ask questions. Good luck and welcome to the dry dock

 

[NEStriper]

Re: Replacing the stringers, found a problem.

Not on top of the stringers, that wouldn't be an issue. It's attached to the hull.



What you're looking at is the transom area, with one horizontal stringer connecting the three vertical stringers. They have been (mostly) removed, but you can see that other piece of fiberglass peeling up (where my finger is pointing). This is a sheet of glassed plywood. Once it started to come up, I stopped, because it made me nervous. I don't know if it's structural.

 

[oops!]

Re: Replacing the stringers, found a problem.

you are in for a full gut here bud.....

we cant see the rotten wood because of the debris.

but in a full gut...remove it all.....

dont worry about structural.....

we can fix it....what ever it is or was for.

dont panic here....its not a problem clean the boat.....take pics....and we can go from there...

but dont worry......really

 

[coreybv]

Re: Replacing the stringers, found a problem.

Here's the thing...

Wood rot is cause by fungus. That's why saltwater boats don't have as much of a rot problem.

If you leave ANY rotten wood in there, then you're also leaving a "starter colony" of fungus to speed up the rotting process on all of your new work.

You've gone this far, might as well do it right.

 

[NEStriper]

Re: Replacing the stringers, found a problem.

I agree with both of you. My structural comment was more about the hull flexing. If that extra piece of plywood and glass is holding the shape of the hull, removing it will cause seriously problems. How does one typically support the hull and reduce flexing? It's sitting on a roller trailer, which can't be the best.

 

[rickryder]

Re: Replacing the stringers, found a problem.

You still have the cap on the boat so that helps.... Most of us build some 2x4 braces and block up the hull along the chines..... oop's thread shows some great info on building a cradle to support the hull

 

[oops!]

Re: Replacing the stringers, found a problem.

if you are doing a full gut re foam and stringer...

get the boat off the roller trailer.....make cradles....or bunks...support the hull properly.

the rollers will cause diviots in the planing surface that will stay there after you foam the boat...or it will distort the hull during re stringer.

im not a big fan of roller trailers to begin with....and during the restoration process, they can cause you a world of hurt !

 

[sutor623]

Re: Replacing the stringers, found a problem.

if you are doing a full gut re foam and stringer...

get the boat off the roller trailer.....make cradles....or bunks...support the hull properly.

the rollers will cause diviots in the planing surface that will stay there after you foam the boat...or it will distort the hull during re stringer.

im not a big fan of roller trailers to begin with....and during the restoration process, they can cause you a world of hurt !

Good to know man. Never really thought about it.

 

[dOb]

Re: Replacing the stringers, found a problem.

It sounds like you?re on the right track. And you?re getting some great advice.

I?m only jumping in because I saw you mention ?Horizontal Stringers.? I found them on my boat as well and I never could find much about them. Someone referred to them as ?hull supports.? I replaced mine close to the original design, with a few modifications. I think they serve a similar purpose, just not as rigid as a vertical stringer.

At this point my best advice would be to measure everything you can. I mean everything. Draw a diagram of how it is set up. Take lots of pictures. Once you start grinding away, the ?landmarks? start to disappear. Pictures and measurements will help a lot when you?re staring at an empty hull and trying to put it all back together.

It?s hard work, but you?ll be glad you took the time to do it right. And this is the place to learn how.

Good luck. I?ll leave you to the experts.

 

[NEStriper]

Re: Replacing the stringers, found a problem.

You still have the cap on the boat so that helps.... Most of us build some 2x4 braces and block up the hull along the chines..... oop's thread shows some great info on building a cradle to support the hull

What thread is that? I've heard it mentioned a few times, do you have a title or a link?

Thanks everyone. Tomorrow the first order of business is getting it off the trailer... somehow. I just really, really want this done by June 1st. This is my spring break week (still in college) so I only have until Sunday and then the occasional weekend to get work done.

 

[BansheeVision]

Re: Replacing the stringers, found a problem.

The thread is entitled "hull extension in progress with pics" by oops! You should not have much trouble getting your boat racked-up. Remember this is a 'temporary' structure, so I would not go out an purchase a bunch a expensive materials to construct it. On the other hand it is critical that you properly support the hull, and your boat will probably be lounging on it for the next few months.

Nice boat and cool Airstream in the pic.

 

[rickryder]

Re: Replacing the stringers, found a problem.

http://forums.iboats.com/showthread.php?t=234392

 

[NEStriper]

Re: Replacing the stringers, found a problem.

Thanks for that link, quite an impressive read. His structure seems like overkill, although clearly he has quite a bit more experience than I do. I feel like in the two or three days it took me to build that, I could put the stringers back in and provide more structural support. I am not far from the fiberglass prep stage. Is there a more temporary solution without so much cost and time involved? Or am I being naive?

 

[oops!]

Re: Replacing the stringers, found a problem.

the reason for the over build was that there was concern over the fact that the extension section was exactly at the plaining point of the hull.....and that the most stress, and weight transfer is right at the extension joints.

actually when i started that project, i had little experience on glassing and naval architecture....
but now that i own a boat repair business....and do full gut repairs all the time....there is actually very little that i would change on the boat. it is one sleek....fast...strong hull

any how.......as for your question....im kinda confused as to what you are asking.
can you explain further?

the rule of thumb is to replace what was there....but do a better job of waterproofing or encapsulating the wood from intrusion

 

[NEStriper]

Re: Replacing the stringers, found a problem.

That makes much more sense.

My question is how would you go about easily and cheaply supporting the hull? I took a look today and it doesn't seem to be warping at all where the rollers are pressing against the hull, although I'm sure they are or will over time. Whats the support solution so I can get back to work?

Thanks!

 

[Woodonglass]

Re: Replacing the stringers, found a problem.

Here's a drawing I made up really quickly of how I would suggest you make a cradle. You could put casters on it so you can roll it around easily. Made from 2x6's and pad the long slanted support rails with some scrap carpet or cheap towels from the dollar store. Rails should extend from the transom up to where the bow starts to curve. Hope you can make sense of the drawing.

 

[rickryder]

Re: Replacing the stringers, found a problem.

How about wrapping some 2x6 in cloth/carpet to make bunks,block up the hull,Lay the bunks on the rollers and secure with zip ties,lower the boat on bunks....Seems simple.... Would that work for a boat that size and the cap on? It looks to be in the 14/16 ft range?

 

[Pontoon24]

Re: Replacing the stringers, found a problem.

I think you would do yourself a favor by getting the shop vac and cleaning out all that debris and then get more pictures (maybe with circles and arrows) that show exactly what your talking about.

If the wood is rotten you need to get it out but if the entire piece is not rotten it may be better to clean it up and epoxy a new piece onto it. That was the case in a boat I just replaced stringers in. The center one went deep down into the keel and because the bottom of the wood was not rotten it would have done more harm to remove so it used a chisel to get the top smooth and epoxied a new piece to it.

When you get the hull blocked up measure from the floor of your shop up to the rub-rail on both sides to make sure the hull is straight and not twisted.