# Anybody used T-Slot aluminum for a frame?



## CDavisRFV (Dec 9, 2020)

I'm new to rafting, but I'm a pretty handy fabricator. Looking into frame options and trying to decide between welding aluminum, steel, OR looking into constructing out of t-slot aluminum. Anybody done this? I've used it to assemble many fixtures in manufacturing settings, and it offers a lot of benefit in terms of adjustment/customization and attachment points. It wouldn't be all that much more expensive than tubing. Figured SOMEBODY has to have tried this, but I can't find any examples online.


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## LLubchenco (Nov 23, 2016)

That. stuff. looks. cool! 
Could see it working, would love to see what you make! Curious if it can actually be made torsionally rigid enough for the raft as the frame adds so much to the support of the boat over waves, etc. cheers


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## B4otter (Apr 20, 2009)

Most frames are fab'ed out of pipe, not tubing. And T-slot looks like it would be nowhere near as strong in addition to presenting edges that could cause problems...


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## villagelightsmith (Feb 17, 2016)

Aluminum pipe is far less expensive than aluminum tubing. So far, it appears to be the most cost-effective way to lose the weight while retaining most of the strength of a steel frame.


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## NoCo (Jul 21, 2009)

I'd make it out of 1 1/4 schedule 40 or 1 5/8 schedule 10. Use speed rail fittings cause they're tried and true, not to mention adjustable. Use your fab skills on your footbar and oar towers. I'm tempted to make a new day frame out of 1 1/4 schedule 10 myself, cause it only supports me and a beer cooler. Anyways keep it simple, cause your going to change your mind on things.


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## CDavisRFV (Dec 9, 2020)

Thanks for the feedback. T-slot is awesome to work with, but I don't know that I want to be the guinea pig on a raft frame. Here's my 10 minute design for a welded frame for my 16' Hyside. Planning to weld the full outer and have the three bay-bars on speed rails or the like. Poke holes in this as you see them - seems like a pretty standard design. L to R: Drop bag and table, cooler bay (65 for now), rower's bay, dry box.


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## B4otter (Apr 20, 2009)

Looks pretty standard, which means tested and validated. You might want to make slots a bit bigger for inner rails - I didn't and had to spend way too much time cutting and grinding later so I could adjust them. You don't need much - an inch or two either side of the shoulder of the speedrail/nurail fitting gives you adjustment you will appreciate if you change any width for cooler or drybox or ? You might also want a couple of "mouse holes" in addition to the slots you show on the outside corners. They don't have to be more than 1" or 1 1/2" but useful for strapping ammos/Pelicans/spare oars.
1/8 inch diamond plate is plenty stout for sideboards - I found .080 remnants and was at first afraid it would flex but turned out fine and slight weight savings. I can't see width from drawing but usually 9 - 11" depending on your tube diameter. The closer you can get to having your diamond plate rest flat on the tube the better your frame will "nest" and contribute strength - if you have some cutoffs of components you can play around and find exact width between inner and outer rails. You don't want to lay the sideboards on top of the rails if you have the skill to recess the sideboard welds to make the sideboard level with the top of the rail. .. You will want 6063 for at least the outside rail if you're going to put that bend in it. I've seen a friend do that bend with 6061 and oxy-acetylene but way beyond my skill set. 
Good luck and the more adjustment you can build in, the better!


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## CDavisRFV (Dec 9, 2020)

B4otter said:


> Looks pretty standard, which means tested and validated. You might want to make slots a bit bigger for inner rails - I didn't and had to spend way too much time cutting and grinding later so I could adjust them. You don't need much - an inch or two either side of the shoulder of the speedrail/nurail fitting gives you adjustment you will appreciate if you change any width for cooler or drybox or ? You might also want a couple of "mouse holes" in addition to the slots you show on the outside corners. They don't have to be more than 1" or 1 1/2" but useful for strapping ammos/Pelicans/spare oars.
> 1/8 inch diamond plate is plenty stout for sideboards - I found .080 remnants and was at first afraid it would flex but turned out fine and slight weight savings. I can't see width from drawing but usually 9 - 11" depending on your tube diameter. The closer you can get to having your diamond plate rest flat on the tube the better your frame will "nest" and contribute strength - if you have some cutoffs of components you can play around and find exact width between inner and outer rails. You don't want to lay the sideboards on top of the rails if you have the skill to recess the sideboard welds to make the sideboard level with the top of the rail. .. You will want 6063 for at least the outside rail if you're going to put that bend in it. I've seen a friend do that bend with 6061 and oxy-acetylene but way beyond my skill set.
> Good luck and the more adjustment you can build in, the better!


Awesome feedback. I'll definitely make the slots larger; the "drawing" allows for 15/16" on either side of a fitting's specs I found online, but I do anticipate going up in cooler size. Good call on "mouse holing" for accessories. I also wasn't sure if more would be needed for tying into D-rings but forgot to measure for their placement before storing my raft. 

As designed, the diamond plate would be 8 1/2" and I plan on nesting it to sit flat with the top of the piping, which is 11 7/8" from bayside to exterior face. I figured on using .080 and adding contoured bracing strips below if needed. This is all hypothetical, and I'll adjust when mocking up. Not planning on welding it until Spring as I don't have a heated shop at home. I do have access to a bender but don't think I'll attempt that angle on 6061 and be able to trust it! I can't wait to start cutting and really appreciate the help. I intend to add a removable fishing platform up front, but one thing at a time.


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## dsrtrat (May 29, 2011)

Just a thought.
I have a 16' Hyside XT Pro with a 92" straight tube. I don't know if you have the same boat but you might consider adding a couple of inches to the frame length. It's always nice to have flexibility to shift the cooler bar around as most of the newer coolers have tended to get wider. I have an 86" frame on my boat and a smaller rear bay as I use a 16" dry box in the stern. I wish I would have used more of the straight tube but bought a stock size frame. My cooler bay is 17 1/2" inside and a little tight for most of bigger coolers. It fits my 150 qt Yeti but a larger Canyon won't fit.


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## B4otter (Apr 20, 2009)

Yeah, mouseholes for strapping to D-rings was something I had to add later with hole saw and file. If you can put them in the plate before welding it would be a lot easier...
One more thing is to consider if you want to take apart in future for fly-in or storage. Pretty easy to make the four corners swaged (sp?) if you have access to machine - I know DRE has. Then you can lock with pins but if you want to stay away from drawing/swaging simple enough to sleeve or make a connection that works. I've only had my frame apart a couple of times in 7 years but it's nice to have that flexibility...
And yes, dsrtrat (are you in St. George? Why do I think we've met?) is right - if you can squeeze another few inches out I would go for it. I built my frame just over 89" and wish I had gone to 92 or 94... don't know what I was thinking. Coolers have evolved and continue to in direction of lower but wider, I never heard anyone complain their drybox was too wide, etc. If you are going to build fishing platforms I wouldn't worry about making the front/rear access a couple inches narrower.
Winter is good time for notions. I'm old school and use graph paper for drawing ideas and figuring dimensions, the thinking about (aniticpation) part is a lot more fun than the fabrication... I absolutely hate working aluminum (slivers! everything is sharp!) but I do like laying the pieces out and seeing how they all come together. Gave up welding long time ago - one of those skills you have to do regularly or for long enough to do properly - but have 'pards who are happy to and usually don't charge me more than twice what they would anyone else...
Finally, think HDPE for floorboards/beaver boards. Yes, it's heavy - but you can drill it out with 2" hole saw since what you're after is protection, not structural support. I used 3/4" but think 1/2 would be fine. No maintenance, no sharp edges (you can run router around edges and holes with any old round over bit) , and when all said and done, less expensive than building diamond plate floorboards (been there, done that).
Have fun. I definitely wouldn't make anything without the boat inflated to measure... I am headed to boathouse today to put air in many boats (it's unheated and we're going to low teens tonite) and might grab some photos if you're interested. PM me if so.


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## raferguson1 (Feb 13, 2007)

A few comments:

1. Tubing is the strongest shape, pound for pound and for the size.

2. Tubes do not have corners, so probably safer when people are getting tossed around. Easier to hold onto also, and less likely to create wear points. 

I am sure that T-slots are super-flexible, but not sure that the flexibility is worth it in this case. I am sure that there are existing tubing fittings that would let you move rails back and forth.

T-slots would be almost impossible to get a full strength weld on.

Richard





CDavisRFV said:


> I'm new to rafting, but I'm a pretty handy fabricator. Looking into frame options and trying to decide between welding aluminum, steel, OR looking into constructing out of t-slot aluminum. Anybody done this? I've used it to assemble many fixtures in manufacturing settings, and it offers a lot of benefit in terms of adjustment/customization and attachment points. It wouldn't be all that much more expensive than tubing. Figured SOMEBODY has to have tried this, but I can't find any examples online.


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## CDavisRFV (Dec 9, 2020)

raferguson1 said:


> A few comments:
> 
> 1. Tubing is the strongest shape, pound for pound and for the size.
> 
> ...


All good points - I thought I'd ask since I've used it for other projects in the past and enjoyed the flexibility. If I ever were to try and weld T-slot, I'd box it with 1/8" plate. A guy built a t-slot track "car" powered by a 1,000 cc Hayabusa motor without boxing the welds, so I think bolted angle and plate fittings would suffice for a raft frame.


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## CDavisRFV (Dec 9, 2020)

B4otter said:


> Yeah, mouseholes for strapping to D-rings was something I had to add later with hole saw and file. If you can put them in the plate before welding it would be a lot easier...
> One more thing is to consider if you want to take apart in future for fly-in or storage. Pretty easy to make the four corners swaged (sp?) if you have access to machine - I know DRE has. Then you can lock with pins but if you want to stay away from drawing/swaging simple enough to sleeve or make a connection that works. I've only had my frame apart a couple of times in 7 years but it's nice to have that flexibility...
> And yes, dsrtrat (are you in St. George? Why do I think we've met?) is right - if you can squeeze another few inches out I would go for it. I built my frame just over 89" and wish I had gone to 92 or 94... don't know what I was thinking. Coolers have evolved and continue to in direction of lower but wider, I never heard anyone complain their drybox was too wide, etc. If you are going to build fishing platforms I wouldn't worry about making the front/rear access a couple inches narrower.
> Winter is good time for notions. I'm old school and use graph paper for drawing ideas and figuring dimensions, the thinking about (aniticpation) part is a lot more fun than the fabrication... I absolutely hate working aluminum (slivers! everything is sharp!) but I do like laying the pieces out and seeing how they all come together. Gave up welding long time ago - one of those skills you have to do regularly or for long enough to do properly - but have 'pards who are happy to and usually don't charge me more than twice what they would anyone else...
> ...



I think my 90" plans max out the flats, but I'll definitely double-check before cutting anything. I want it to be as long as possible. My Hyside is early-2000's vintage and measures 15' 10" OAL. 

Good call on HDPE flooring. I was an operations manager at an injection molding plant in TN before moving to CO. The plant still manufactures slats for pig farmers that are designed to be elevated and are perforated for.. you know. They are conveniently 24"X48", so I'm going to get a few shipped out to see if that will work for a rower's floor. If they're machinable enough, I may use them for fishing platforms as well. I've seen a 400 lb german man stand on them without flexing, so they should be plenty strong! 

dsrtrat - I like your setup a lot! Looks very clean. I just bought trailer axles and steel, so I have lots of projects waiting on me once the snow melts. My son and I floated Loma to WW in a tiny, borrowed raft, so I picked up this 16-footer without really knowing what all went into a _real _whitewater rafting setup. I just knew I didn't want to do a multi-day trip again in an Intex Mariner when the rest of the group had tables and bimini tops!


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## jgrebe (Jan 16, 2010)

raferguson1 said:


> 1. Tubing is the strongest shape, pound for pound and for the size.
> 
> 
> If by tubing, you mean round tubing, then that is not correct. Square tubing is stronger than round tubing in bending strength for the same OD and wall thickness. About equal in shear and compression/tension strenght which is less important in a raft frame. The strongest shape if the bending is in one plane (which can be assumed) and given the same cross sectional area / weight per foot is an I-beam but not a practical shape for a raft frame. Rectangular tubing with the long axis in the vertical plane is probably the best all around shape for strength to weight and ability to fabricate


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## climbdenali (Apr 2, 2006)

Take my few comments for what they're worth:
1. Never seen the aluminum t-slot- it looks cool. I did build my first frame with steel unistrut as crossbars. It was a great frame, but there were sharp points that weren't the best. The siderails on that frame were 2"x10" wide mahogany. I never really used the uni-strut holes for bolting boxes in, as I had intended. In the end, that frame was optimized for walking about the boat, and cost.

Speaking of steel, I'm far from an engineer, metallurgist or welder, so I may be off base on this, and will stand corrected. I recall looking up strengths/weights of steel vs 1.5" Sch. 40 Aluminum, and finding that for an equivalent strength, the steel's not really that much lighter. I think it was something like 7% lighter to use 1.25 emt vs 1.5" sch 40 aluminum. That said, I don't own any steel frames anymore because Al2O3 cleans off of boats much easier than rust stains.

2. If you're going to use fittings for your middle three crossbars, I would strongly consider making the whole frame break-down-able. Either use fittings on the #1 and #5 bars, or swage the joints, or whatever. Point is, even if you very rarely actually take it apart, you can if the necessity ever arises.

3. HDPE. ::sigh:: It's heavy, expensive, flexible (unless fully supported or very thick), and doesn't do well with UV. I would strongly consider either aluminum diamond plate for floors and decks, or 1/2"-5/8" plywood. You can get away with CDX for $25, or for a nicer looking and longer lasting product, marine ply for $50. Spar varnish the decks every year or two. Done.

4. Beaver boards: I like them for protecting the floor in the rear from hard objects, but it's also important for handling to get at least some of that weight off the floor. Therefore, I think it's important that the beaver boards not be lightened up too much, becoming flexible. We always hang the boards from straps that run up over the tubes to the exterior d-rings. This keeps the weight off the floor, helping with handling and with keeping the floor from getting pinch flats. Also build with 5/8" ply.

5. 4 bay frames are BIG. And Heavy. I would consider building a 3-bay frame plus a single bay trailer frame. You retain the ability to have 4 bays to fill, but give yourself the flexibility of running a lighter frame for low water, or shorter trips. It also keeps things more manageable for lifting.

Anyway, those are my preferences/comments based on years of experiences. Lots of ways to wrap a boat, er, skin a cat. Have fun!!


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## climbdenali (Apr 2, 2006)

One more thought for you, after looking at the sketch a little more:

I would bring the inside rails inward so that they're more or less even with the inside tube of the boat- maybe an inch wider than the inside of the boat on each side. You're never going to put anything wider than between-the-tubes width of the boat in the frame, so bring those rails on in and give yourself all the walking space you can. That's what decks are for, after all. If your inside width is 48", I'd shoot for 50" bay openings, for example.

Along those same lines, I would push the outside rails out as far as you can without getting ugly overhang. The plan view looks like you're pretty close to the right spot, but you'll be able to see it better with an elevation view or if you just put a board across the boat with a little bit of weight on it. Don't forget that tubes flatten out and aren't really perfectly round in the cross section, especially once they're loaded, so that gives some room to play with in terms of not having overhang even if the edge is past the vertical tube centerline.



CDavisRFV said:


> View attachment 61622


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