Steel Stringers?

[Bondo]

Re: Steel Stringers?

That's Better...........<br /><br />Look at a Building Bar Joist,....... Only Smaller.......<br /><br />I also Play with Steel,....... More than Boats even............<br />I do it with a Welder,+ a Grinder,.......Stress Tests occur as the building continues,...... No cad...... <br /><br />As "I am very confident that it will not leak."........ I Assure you that they Will Leak.......Someday........

 

[OldBoatGuy12]

Re: Steel Stringers?

Someday I will be dead and gone, and the glass will have rotted I am betting on them not leaking for a looooong time. I just don't see how they could be any worse at developing leaks over time than regular glass and wood.

 

[OldBoatGuy12]

Re: Steel Stringers?

Oh, and the bar joists were exactly what I was thinking of, except flat strap instead of round stock inbetween the angle iron. I've got to find some time this week to model that up.<br /><br />Grinders are my friends. I swear I use them in the shop more than anything, especially the 4.5" one. Sooo useful, especially for tearing boats apart

 

[Tail_Gunner]

Re: Steel Stringers?

In trying to develop a long term stringer with high rigidity & sheer strength qualities, i am @ a loss why one would use a component that is degraded by good old water.<br /><br /> If you are going to go to these lenghts why not use a composite material that will never degrade in a water enviroment and stronger than steel?

 

[Tail_Gunner]

Re: Steel Stringers?

Originally posted by Tail_Gunner:<br />

 

[OldBoatGuy12]

Re: Steel Stringers?

Fabrication will be much easier and faster, will likely cost much less, and good old water degrades everything in a boat anyway. Just a matter of how long it takes. There isn't supposed to be any water in a hull anyway Not foaming will help alot with getting rid of the stuff that does get in. I have some ideas to further help with that, but don't want to disclose those yet.<br /><br />I don't want to put much money into my boat and this is, so far, a very solid alternative that would help achieve that.<br /><br />I really am not going into much length. It takes less than an hour to build a model, then another hour to test. Not much time at all. I can get done with fabrication of the stringers, after taking all measurements and figuring out cuts, in a day. I am blessed with access to a very nice shop(my grandfather's) that enables me to do this.<br /><br />Edit: Forgot to mention that there is a huge shortage of materials right now anyway. You can't find carbon fiber anywhere and if you do, its even more ungodly expensive than it has been.

 

[Bondo]

Re: Steel Stringers?

Oh, and the bar joists were exactly what I was thinking of, except flat strap instead of round stock inbetween the angle iron.

That's all Fine,+ Dandy,...........<br />Except,.......<br />Flat Stock has NO Compressive Strength.........<br /><br />Round Stock is Stronger in the directions you Need.........<br /><br />I'm just trying to help you,...... You're trying to Reinvent the Wheel.........

 

[OldBoatGuy12]

Re: Steel Stringers?

It won't have as much as round stock...no...but I'm thinking it will have enough. We will just have to see when I get it modeled.

 

[paulie0735]

Re: Steel Stringers?

Ok, I’m curious now…….<br />How do you plan on fixing this steel work to the hull?<br />What material are you using for the floor?<br />How do you plan on fixing the floor to the steel?

 

[OldBoatGuy12]

Re: Steel Stringers?

1) Not completely sure. Most resins are supposed to bond pretty good with metal, so I had planned on just glassing them in like a regular wood stringer. That was one thing I was looking for suggestions on. <br /><br />2)Floor will just be regular 'ol plywood, standard procedure.<br /><br />3)Standard procedure again, hopefully the resin will bond nicely to the steel. If not, I will just make some tabs so I can bolt it on then glass over like normal. <br /><br />I just found out the prices and I am a little bit excited. A stick(20ft) is $11.28, and my stringers are each 10 ft. long, so I'm actually doing pretty well as far as price goes

 

[samsam]

Re: Steel Stringers?

Originally posted by coleasterling:<br /> 1) Not completely sure. Most resins are supposed to bond pretty good with metal, so I had planned on just glassing them in like a regular wood stringer.

I don't know how well resins bond to metal, but in the beginning you were talking about powder coating or painting the metal to keep it from rusting. I wouldn't think resins would bond to powder coats or paint very well and you can't powder coat it after it's installed. If you have a 10' piece of metal resined and glassed into a boat I don't think metal and fiberglass will expand and contract the same way. The metal would seem to expand and contract faster and more. It would seem either the boat would have to warp or the metal would bust itself loose. Fiberglass boats have been around for a long time, somebody must have thought of this and tried it. If it was a good idea, it would be done. I'm trying to think of something made with fiberglass that has big pieces of imbedded metal but I draw a blank.?? You might be putting too much emphasis on light weight, lighter is not neccessarily better. The boat was safe enough the way it was built, you won't be making it safer but you might be making it unsafe if your idea doesn't work. Sam

 

[Bondo]

Re: Steel Stringers?

I just found out the prices and I am a little bit excited. A stick(20ft) is $11.28, and my stringers are each 10 ft. long, so I'm actually doing pretty well as far as price goes

If it's a Price Issue,.................<br /><br />You Wouldn't Believe the amount of Building,+ Rebuilding that I do out of Job-Site Dumpsters................... <br /><br />Talk to the Right Man,+ He'll Gladly allow you to Root thru it,+ haul away All the Weight you Want,......<br />You're Saving him Money...........<br /><br />4' Plywood can become 10' Stringers,.... With a little Glue.......................

 

[OldBoatGuy12]

Re: Steel Stringers?

Price is an issue, but I won't compromise safety for it. As far as people not doing it, maybe its just never been done right? That's what I am trying to do.<br /><br />I've thought of a way to attach the stringers that will allow a little flex.<br />(Although I'm still not sure if the expansion and contraction rates will be a problem. Wood and glass certainly don't have the same properties. If I end up really feeling that it matters, I will just engineer flex into it. Not really a big deal)<br /><br />Structural adhesive will work I think. Half of my car, dad's truck, and our minivan is held together with the stuff. Its got a little bit of give in it and it bonds perfectly with metal. I'm going to pick some up and do some tests.<br /><br />Haven't gotten around to modelling the bar joists yet. My grandmother has been working me to death these past weeks

 

[Bondo]

Re: Steel Stringers?

Price is an issue, but I won't compromise safety for it.

And How do you have a Safety Concern with laminating Plywood together,... Vs using Steel,..????...<br /><br />After All,........ Laminating Wood together is a Known,+ Steel Stringers are an Unknown......

 

[tommays]

Re: Steel Stringers?

In My youth i found resin and glass did not bond well to metal with out some hardware to help hold the whole thing toghter<br /><br />I did have great luck when i used a fiberglass cast with 1/4-20 screws to put are sailboat boom back toghter on Block Island after it failed at Sea<br /><br />IT was so strong we won our divison at block island race week and did not replace the Boom till the fall <br /><br />tommays

 

[OldBoatGuy12]

Re: Steel Stringers?

Originally posted by Bondo:<br />

Price is an issue, but I won't compromise safety for it.

And How do you have a Safety Concern with laminating Plywood together,... Vs using Steel,..????...<br /><br />After All,........ Laminating Wood together is a Known,+ Steel Stringers are an Unknown......

Nonono, I was referring to that in the steel designs. I know the plywood would work just fine.

 

[Lou C]

Re: Steel Stringers?

I can see why you'd want to try something other than wood, but think about it, when the boat was designed, one would think that all aspects of the design were more or less taken into account, for example, the degree to which fiberglass flexes, when bonded to wood. That is a known quantity, it the steel flexes more or less than the wood originally did, there could be delamination problems. I would focus on making the wood totally sealed, using CPES and epoxy as needed, and if you are not foaming, most of the typical moisture problems will not be as much as an issue. Is it legal to not foam a boat in a rebuild, that was originally foamed (as per Coast Guard requirements??)<br />The fact that no one seems to be using this in mass produced 'glass boats may tell you something.

 

[flashback]

Re: Steel Stringers?

I think you will have a rusted mass of nothing in a couple of years if you encapsulate steel in glass and resin...IMHO.........

 

[OldBoatGuy12]

Re: Steel Stringers?

Getting ready to start this...Wish me luck!

 

[samsam]

Re: Steel Stringers?

Originally posted by coleasterling:<br /> Getting ready to start this...Wish me luck!

Good luck! Please post pictures. BTW, make sure the hull has the correct shape ( no twists, dents, bulges etc) before you start putting it back together, it won't take too long before whatever shape you have is locked in. Sam