composite stringers

[VinceJ]

Ok, I know there was a thread relating to this issue, but it didnt bode well with what I need to know, so sorry for starting a new one...what are the advantages or disadvantages of composite stringers and who manufactures these?....I am at a loss in finding viable info on these and trust me I have worn google out looking for a manufacturer...any one with experience with these giving me some info is greatley appreciated...any safe corner cutting is for me just because of time constraints with my work schedule...thanks in advance!!

Vince

 

[Bondo]

Re: composite stringers

any safe corner cutting is for me

Ayuh,.........
In that case,.......... Use Plywood..........

 

[VinceJ]

Re: composite stringers

Thanks Bondo....what is your rationale for going with plywood?....just from what I have heard, cutting out the rotten stringers and wetting in preforms seems quicker than vacuum pressing ply...you have a ton of experience more than me so gimme the readers digest version of this rationale.

Thank you
Vince

 

[oops!]

Re: composite stringers

vince
i saw a thread here on composite. ill search for it.
they said they were stronger but huge dollars.
im looking.
tashasdaddy will prob know all about them too

oops

 

[oops!]

Re: composite stringers

vince
search composite stringers here on the forum.

the name coosa comes up its light, strong, rot free and really expencive.
worth looking into if you want to cut so
me weight.

oops

 

[salty87]

Re: composite stringers

i had started a thread but it didn't get much action. the company i was looking at is out of FL, Compsys is the corporate name and Prisma is a line of products they make. they have insructional vid's on their website...preforms dot com. you can also search youtube by 'mas epoxy' and you should find a stringer replacement clip from ship shape tv.

i posted the question on a few different boards and couldn't find anyone with personal experience. i'm assuming its because of price. these guys sell to manufacturers and although they'll take our dollars too you need to speak engineer to talk to their distributor. i have that number at work or you can call the number on preforms dot com and they'll give it to ya.

darn, ya got me thinking about them again. the youtube video makes stringer installation look absolutely simple. wet things down, lay em out, wet em again and wait for them to set up.

 

[Bondo]

Re: composite stringers

Ayuh,........ I just checked out the Video,................

Are you going to Rebuild an old Boat,......... Or go into Production,..??.........

I bet the initial Fitting would be a serious Task in an Old Boat rebuild,....
Most aren't square, or symmetrical...... Try pulling a few String Lines,+ See.....

And you Still end up with a Foam Filled boat............

I'll stick with My Well Drained Plywood,+ Glass...............

 

[drewpster]

Re: composite stringers

I sent emails to both of the companies mentioned> I did not get answer. We live in a computer driven world, if they don't answer emails, they don't want my business.
I assume after John Graviskis? hocked them on his "boat repair" show they got rich enough not to sell to individuals. In the early days of that show he did cater to the resto/ repair type boat owner. Since he bought his 57' Monterey and got wealthy in the process, he hocks toys to high end yacht CEO and CFO types. Money must change a man. However he does throw in the occasional 6 second bit about tabbing in a $7000.00 pilot house. Or how to use your $10.000 fighting chair. valuable info, my $#@!

 

[BillP]

Re: composite stringers

You have to be careful when talking "composite stringers". Some mfgs actually call wood on glass a "composite stringer". I mentioned this in another post but Pursuit boats used to call their glass on wood stringers "composite stringers".

Anyway, most composite (foam) stringers eliminate the chance of future rotten wood. They are used mainly to shape the glass for it's best structural properties. The glass shape is known in the industry as a "hat stringer". Standing alone the foam typically has low strength compared to the glass that attaches it to the hull. The other reason to use foam is purely labor savings...it's easier than cutting and fitting wood, pipe, cardboard or other form materials. Stringer fitting of wood is major labor intensive compared to glassing labor and cost.

The advantages of compsys stingers is they eliminate big labor for the boat mfg and labor is the main cost in boat mfg. The foam fits the hull exactly without trimming, cutting or any other delay. It only takes one person to carry and set their stringers for a typical 20' boat...in a matter of minutes they go from the shipping box to being ready to glass. Several layers of glass are molded onto the stringer so all the glassers have to do is set the stringer down in the correct position and start glassing. Additional glass is added where more stringer strength is needed.

If you want to achieve the same thing on a home builders budget use cardboard tubes cut in half to make the stringer shape. Tack them down with resin and then glass them like any others. This will give composite hat stringers that won't rot. Otherwise use pressure treated wood and get another type of composite stringer that won't rot.

 

[salty87]

Re: composite stringers

Ayuh,........ I just checked out the Video,................

Are you going to Rebuild an old Boat,......... Or go into Production,..??.........

I bet the initial Fitting would be a serious Task in an Old Boat rebuild,....
Most aren't square, or symmetrical...... Try pulling a few String Lines,+ See.....

And you Still end up with a Foam Filled boat............

I'll stick with My Well Drained Plywood,+ Glass...............

try the youtube video. now i'm not selling these but, they show that you just trim the excess foam/cut the cloth to trim the forms to precise shape/size. no way you could shape wood faster, could buy alot more beer with wood though.

 

[micks110]

Re: composite stringers

I don't know if this is off topic or not? But can you use the pink home depot insulating foam 1" sheets cut down to size and glass over that instead of pt wood?

 

[HVAC Cruiser]

Re: composite stringers

I used Coosa board for my transom and some of my bulkheads. Very expensive, 3/4x4x8 was around $250 a sheet. Coosa is easy to cut, form impervious to water light weight etc.. BUT if you look at the specifications its actually not as strong as plywood, but its only a few pounds off. I called them and spoke to a rep they were very careful with their words in saying its comparable in strength. A lot if not most of the strength with your stringers is going to come from your fiberglass layers you put over it. That is why some manufacturers have used either hollow fiberglass or foam core stringers.
The main advantage is that it won't rot if water does infiltrate

Hope this info helps a little

Regards

 

[HVAC Cruiser]

Re: composite stringers

UH guys just noticed, up until the post from "CompositeExpertHelp" This post is 2 YEARS OLD, Sorry Mod Squad, didn't realize it at first

 

[Bob_VT]

Re: composite stringers

I sentence this thread to LIFE in the archives closed.