Frame Sleeve ?

[jasen001]

Hey guys, I'm looking to sleeve my cat frame, and was wondering if any one has any advice. I'm thinking that making my cuts stagger across the length of the boat (ie. 6' on the left top rail and 4' on the lower rail, and opposing them on the other side) as opposed at the same point across the frame.
Will this help any thing (strength and rigidity) , or am I just confusing my self?
What about length of the sleeves them selves ( NRS does 12") ?
And sleeve material, 4" of steel pipe won't add much wieght ( no fly outs till next year, spent my budget on the boat this year).
Any advice?

[Jim Strutz]

I've always wondered how important this is. I know you don't want to break a frame in the middle of some nasty water, but...

I use a relatively short frame on my cat, with a large addition added as a cargo module. In my case these sections aren't actually connected together. The whole boat is allowed to flex a bit, almost like having a joint near the middle of the boat. This actually overcomes one of the complaints of catarafts for white water use, and makes it a better boat in some respects.

But you have a dual level frame, whereas mine is nearly a flat frame, so I think getting yours to flex reliably would be difficult. Still, you might look for a way to do that. Perhaps cutting your frame into two permanently separate sections.

Sorry I don't have the answer you were looking for, but I guess I'm just thinking outside the box.

[Michael Strahan]

breakdown cat frame

Jasen,

If you do this properly the joints will all be very strong. You're not gaining a thing by staggering the joints. There are several ways of doing this; I'd have a look at one of the Alaska Raft and Kayak frames to see how they do it. It works very well.

-Mike

[shapp]

galvanic action

If you have an aluminum frame, do not use steel to sleeve. You will be creating perfect conditions for galvanic action, which basically highly accelerates corrosion.

NRS uses aluminum rod that is 6 inches long, 3 inches into each piece of pipe being joined. You can buy the rod at any good metal supply shop.