Stringer Question

[Zetman]

I can't tell if the stringers in my boat are original or have been re-done. In the pictures you can see a crack that runs down the bottom of one of the stringers. This stringer does not move at all. Its is bedded down firmly. My question is should I do something to this..fill it, epoxy and glass over it or nothing. Help Please I don't know what to do. Zetman

 

[180shabah]

Re: Stringer Question

It looks as though there has never been much bonding the stringer to the hull. If the wood is still in good shape I would probably grind out the joint and go at it with some resin and glass.

If there is a better approach I'm sure someone will chime in soon.

What kind of boat is this?

 

[Robj]

Re: Stringer Question

Hello there,

I am not an expert, but it looks like the tabs holding the stringer to the hull have failed. If so, in my opinion it definitely needs to be repaired. If the stringer is solid and not rotten, maybe you can just grind it and then reglass, epoxy is probably the best choice for the repair. If there are any signs of rot in the stringer, then I would replace it, especially since you already have the floor off. It is not that much more work to replace the stringers when you have the floor already removed.

Good luck

Rob.

 

[croSSed]

Re: Stringer Question

Is the top of the stringer just bare wood? It looks like it in the pictures. If that is the case, poke all around on the stringer with an ice pick to make sure that there is no rot. If there is no rot, AND the stringer is dry, grind away the old tabbing, remove the stringer (if you can get it out in one piece) and re-tab the stringer in, using this process:
1. Before installing the stringer, apply cloth/resin to both sides of the stringer, as well as applying bare resin (mix in some fibers, too) to the top and bottom of the stringer.
2. Completely clean the "stringer bed" of any foreign material; sand the bed down with an angle grinder/sanding disc, get all dust vacuumed up, and prep the area by wiping down with acetone, and wiping dry with a clean cloth.
3. Prepare a bed for the new stringer by laying down 2 layers of cloth/resin.
4. While it is still wet, place the stringer in place and weight it down to have it "glued" in place when the resin drys.
5. After the resin has set up (at least 6 hours) create fillets of resin mixed with microfibers and cab-o-sil on both sides of the stringer to further strengthen the bond between the boat bottom and the stringer.
6. After this has dried, tab the stringer in on both sides, twice. The first layer of cloth can extend on the bottom of the boat out about 2"; have the first tab reach the top of the stringer, but not encapsulate it. The second tab have extend on the bottom of the boat about 4" and have this tab be a continous piece that goes over the top of the stringer to completely encapsulate it so that no water intrusion can harm the wood. If the stringers have rot in them or are completely saturated with water, make new stringers; use the old ones as patterns if you can get them out in one piece. If you have access to a table saw, this is really easy, and wood is pretty cheap, AND you know that you are installing stringers that have absolutely no rot in them. See my project that I'm working on and look at the stringer section in particular. I hope it is helpful to you:

http://s110.photobucket.com/albums/n103/tadpoleig/

Good luck!
TG

 

[Zetman]

Re: Stringer Question

Thanks for the fast input. No rot is on any of the stringers. I'm a big guy and can't even budge these stringers. Would it still be necessary to go to such work to grind down everthing. I don't mind the work, I just don't want to invest the time. Thanks again for the input. Zet

 

[Robj]

Re: Stringer Question

If the only problem is this crack, stringers are dry and not rotten, personally I think I would just grind and reglass. Let some of the experts answer this. Also if you are doing as croSSed suggest in removing the old stringer, which is still the best way to do the repair but involves much more work, I would then make a new stringer from ply rather than re-install an old stringer. To do all that work, you might as well put in a new stringer and then you know you are good for at least 15 years probably longer depending on how good you do the repair.

Good luck

 

[croSSed]

Re: Stringer Question

If the stringer not rotten, is not wet, and you can't budge it, then by all means, leave it in the boat; just grind away the old tabbing and re-tab it in with new cloth/resin. And, do a better job than the factory did - make sure to completetly encapsulate the stringer. Surface prep is of the utmost importance! Best wishes!

TG

 

[jdooner]

Re: Stringer Question

Will not this method of mounting create a hard spot? I've been searching for the proper way to do this for days trying to find the correct way for replacing the stringers and have seen hard spot warnings and am just a little confused, actually a lot.
Jdooner

 

[Robj]

Re: Stringer Question

While I am not an expert on hard spots, this is how I see it. Take a balloon, if you poke it with a needle it will pop, however it is much more difficult to pop it by poking your finger. This is the same with your boat hull, if you have a small contact area between the hull and stringer, and a large force is transmitted, it creates high point loads. This can cause the fibreglass to fail if the contact pressures are large enough, like the needle popping the balloon. The idea is to transfer load to a large area and distribute the load evenly throughout that area.

I was faced with the same dilemma with regards to bedding my stringers in putty or not. Yes hardspots were a concern, but I figured the loads between the hull and stringer will be distributed evenly, for the length of the stringer so hardspots should not be a problem. My stringer does not contact the hull, and putty distributes the loads evenly between the stringer and hull. Eliminate high point loadings to the hull, and you have eliminated hard spots. Hope my reasoning is correct. I did a lot of research before I decided to do it that way, plus that is how my boat was originally built.

With re-tabbing your stringers, you are just grinding existing glass and then reglassing. I don't see how you could set up a hardspot.

I am sure others will be commenting also. Some may say I am out to lunch, but that is how I see it. Good luck and have a great day.

Rob.

 

[jdooner]

Re: Stringer Question

Thanks for the clarification. Never heard of the hard spot until I read the bateau2 article and it had me worried.
Thanks again,
jd

 

[tashasdaddy]

Re: Stringer Question

is this crack at the joint between the hull and the stringer, or has the stringer slip? it also, in the bottom picture, looks like someone in the past has sistered a splice beside the stringer.

 

[Zetman]

Re: Stringer Question

No, in the last picture the stringer is not sistered, Its just a 2x2 piece for the the floor support, The crack is along the stringer on the top not on the bottom of the boat

 

[Boomyal]

Re: Stringer Question

Some clearer (focused) pictures would help Zetman. What I see is what appears to be a crack in the fairing/bonding compound between the hull and the bottom of the stringer.

Also, again hard to be sure due to picture quality, the wood looks like mahogany and that would be original. No one would have repaired using mahogany. That stuff must have been a lot cheaper when Gulfstream was building boats.

It would be good to take a wider angle picture of all that you have exposed.

 

[Zetman]

Re: Stringer Question

I had to re-size my pictures, When I did that the quality went fuzzy..I will ge better pictures to show..

 

[rickytickycamaro]

Re: Stringer Question

Nice boat, and project good luck!

 

[180shabah]

Re: Stringer Question

Ricky - welcome aboard.

However, you need to start your own thread so that all responses will be to you, instead of mixing two people's issues together.

 

[rickytickycamaro]

Re: Stringer Question

Rookie mistake.
Thanks!