source for aluminum "hat stringer" stock for boat floor braces ????

I am just digging into my new-to-me 56 model 16foot orlando clipper.
It has a small dent or two and a small bumped in/scrape area to be smoothed out.
It has floor stiffeners which run east-west riveted to the bottom. they appear to be
off the shelf aircraft stringers from back in the day. (it was made in an ex-aircraft plane
by aircraft mechanics I think) These stringers are top-hat shaped roll formed heat
treated .070 inch aluminum ( I bet 2024 ) They have rivets in the center of the flanges
into the floor. The width of the stringers across the outer edges of the flanges is
about 1+7/8 inch. About 1 inch tall. center part of hat is about 3/4 wide. It is
one piece and has a slight curve to match the hull curve.
I have seen something like there in cargo trailers except these are steel.
I am prepaired to make these if I have too .... but If I could find a ready made
duplicate allready heat treated that would be nice. Boeing makes one which
looks similar (bae-1500) but I hate to see the price !!!!!!!!
Do the modern aluminum boat compannies still use riveted stringers ???????
Don't want to use extrusions because it isn't as strong and I want to keep it as
oregional as I can- and this is rite in the center of the passenger compartment in
full view.
Another complication is that the part is 50 inches long. 2 inches wider than standard
aluminum sheets. and the part has to be made perpindicular to the way the sheet was
rolled at the mill. (else it cracks whan you bend it ) Hummmmmm

Any ideas out there ?????

Tim

Re: source for aluminum "hat stringer" stock for boat floor braces ????

orlandoclippertim said:

Any ideas out there

Click to expand...

Pictures.

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Here is a pic of the stringer. It is .070 thick
1+78 across edge to edge
1 inch tall

Tim
I have tried to attach a pic- not sure if it worked ......

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Channel flange:
http://www.premier-metals.com/products/Roll-form.asp

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Tahorover -- Good try ! I faxed a diagram of my part to premier before you posted. Their hat track boeing 1500 is boeing stringer. However it is too narrow and only half the thickness of material. And they didn't have any bigger or thicker. and - just for yucks - they only sold it in lengths of 30 feet a pop. I think I have seen this stuff in cargo trailers except it was steel not aluminum. I have given up finding any allready mad or even having some made on a brake. Nobody has a brake die that can get into the narrow interior width. So I have started building a steel form block to cold form it onto. Its the long route but all I have now. You know the story ! Thanks for your good lead though ...... they were the closest I found !
Tim

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Great news... I found a 14 fot long piece of boeing 1498 hat stringer. I cut off the outboard flanges. It is identicle now except that the center box part is about 3/16 taller. I can live with that. I have to figure out how to bend it now.

Tim

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Sounds like you are pursuing a rebuild worthy of the boat. Needless to say, you have a very cool boat - good luck with it!

Re: source for aluminum "hat stringer" stock for boat floor braces ????

I like that boat design! Very original looking. Would like to see more!

Re: source for aluminum "hat stringer" stock for boat floor braces ????

Thanks, I to think it is one of the best , strongest most practical boats ever built - even today. AND beautifull too.
That stringer stock now has to be induced to follow the gentle curve of the floor -kind of like a rocking chair. This stuff is designed -via its shape -to be rigid. (and it is too) i was told by the guy at Premier that Boeing used some kind of thing with metal rollers which match the profile of the piece when they roll a huge hoop to go inside a fuselage. So I may have to build one of those !
Otherwise the part will probably collapse into a wrenkley kinked -up mess if I try to bend it in a normal way. It has to be differentialy streched on both sides at the same time to make it curve without collapasing. Anyone here ever done sheet metal at boeing or lockheed or douglas ? It would help to see a picture of what the machine looks like ......

Tim