T-Slotted Aluminum Extrusions

[Piggiron]

I have a boat project in mind that entails connecting 2 aluminum canoes together and placing a top deck over them. Basically making a kind of catamaran/pontoon type boat.
To this end, I started looking into T-slotted aluminum extrusions figuring they would make an easy method of connecting the 2 canoes together and attaching the top deck while minimizing weight.
I started off looking on Online Metals, but they only have it in 6063 alloy, hardly suitable. Looking elsewhere, I found it in 6005A – T61 alloy (https://www.amazon.com/80-20-1515-ULS-T-Slotted-Extrusion/dp/B0B9NYY38D/ref=asc_df_B00BLO4CI0/?tag=hyprod-20&linkCode=df0&hvadid=693071814238&hvpos=&hvnetw=g&hvrand=10540798706383381409&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9057544&hvtargid=pla-2493507239712&mcid=8010a1164b7331e399cc2cdee51fb84d&gad_source=1&th=1) which after Googling compares it as close to 6061 aluminum.

This got me wondering what all alloys T-slotted aluminum is produced from and which one(s) would be best suited for my purpose. This will only be used in fresh water so no salt water corrosion concern.

Before anyone asks, I already have a 16' aluminum Jon boat, but I have issues navigating the river when the water level is low. Last summer the water level got so low, I couldn't use the Jon boat. One trip had 3 people in a single canoe using a trolling motor that bottomed out in a couple places requiring 2 of us to get out and pull it past the low spot, something near impossible with the Jon boat due to its weight.

Using T-slotted aluminum, I'm figuring it will be easy to attach and separate the canoes, if desired.
Any info on alloy types available along with sources would be appreciated.

[TerryWerm]

That 8020 stuff is great to work with, I don't think you will be disappointed with it. I have used it a number of times in the past and love working with it. Compared to building and welding various machine structures from steel or aluminum tubing or bar stock, 8020 is also less expensive once materials and labor are figured in.

Since you will not be in a marine environment, and this stuff is clear anodized, the T61 should be as good as anything else. 

Some alloys work better for making extrusions than others, and that is probably a bigger factor in their choice of alloy.

Just my 

[Piggiron]

T-slot looks to be perfect for what I want to do, but they sure are proud of it. Cheapest I could find the 15 series (1.5"x1.5") smooth runs almost $0.70/inch plus shipping. The 10 series is $0.35/inch, but I'd need a lot of inches for my project.
The connectors, brackets, and caps aren't exactly cheap either especially for the milled connectors which they advertise as the strongest and stiffest type.
I was originally thinking about using the 15 series, but now I wonder if I could get by with the 10 series.
More research....GROAN !

[34_40]

Price per INCH!  = OUCH! LOL 

[Piggiron]

Price per INCH!  = OUCH! LOL 

Yep, only place I found that lists it by the foot is Online Metals and it's almost $1/inch and they only have it in 6063 alloy.
According to their product guide, I don't think it would be an option even if the price was better.

"6063 - Often called architectural aluminum due to its exceptionally smooth surface finish and weaker strength, this material is suited for applications where appearance is more crucial than strength. It is rated as having good forming, fair machining, and excellent anodizing characteristics. Typically used in pipe, railing, furniture, and decorative materials."

[Piggiron]

Aside from a huge price difference, are there any differences between extruded square tubing with or without radius corners ?

[TerryWerm]

Not really. I doubt there is any real difference in strength. If one is stronger than the other, I will bet it is the one with the square corners.

ON EDIT:  Whoops, I got that backwards. The radiused corners would be stronger.