Welding Tips and Tricks

I need to build a two wheel dolly cart like in the photo for portaging my boat this year. It would need to support 1,000 lbs max. The cart uses wheelbarrow tires rated at 500lbs each, with a rectangular frame approximately 3ft x 2 ft. I need to make it strong yet light enough to carry it on board the boat. These are used to put under a boat, strapping over the top with ratchet straps and it supports the boat, motor, fuel and some camping gear over uneven terrain including rocks and mud. My boat weighs 120 lbs, 65 lb motor, 50 lbs fuel, 200-300 lbs of gear, 100 lbs misc gear. I'd like to build this out of square tubing.

What size tubing would be appropriate for this? Would 1 inch sq tubing work for this?? I don't know what size metals can support what type of weight...any charts for this? Thanks

HHS 1.5" x 1.5" x 0.095"
or
HHS 2" x 2" x 0.095"

What's my 2 cents, take it for what it's worth.

Rudy Ray wrote:HHS 1.5" x 1.5" x 0.095"
or
HHS 2" x 2" x 0.095"

What's my 2 cents, take it for what it's worth.

X2. You could always go with thicker walled tubing as well but you can engineer strength into your build and use even less metal. If you have any close up pics of the cart you want to build...you will get tons of ideas from the great fabbers around here.

I don't have any other pics, these are all that I could find online. I've been trying to locate someone who has one of these so I could see what they were using but no such luck. I would think 1.5" square tubing would work.

I would want nothing doing with trying to drag 1000# of tippy v hull up on to a wheel thing that will be rolling and tipping over the whole time, probably while you are being attacked by black flies! I made something like this for my canoe once. would be way easier to to attach and a lot less wobbly. looks like they only used 3/4" sq tube in this pic. It you get real creative, you could probably have 2 tubes that are wider than your gunnels that the wheel assembly slides over on each side so you can break the rig down into easier to stow parts.

Ha, you'd be surprised how easy the portage can be with the right equipment and the fishing is world class...it's worth the effort.

The other style of portage wheel you posted are the folding/flip style.

The wheels actually flip up onto the side rails while in transit across the lake. When you get to the other side, all you have to do is flip them down and lock them in using screw/pins. Here are some pics of this style so you get the idea of how it works. I can't wait to get starting building these. I'll definitely need help selecting the right strength/size tubing for this project as well.

The flip style wheels have a common tube that spans across the width of the boat and bolts to the side of the boat using a bent "L" bracket.

The "A" frame or "Triangle" wheel section slides into that cross rail which allows it to fold up and down. Some type of "D" shaped bracket is welded then bolted to the side of the boat and also uses one of the seats as the bottom support. This is the point to which the folding section sits on then is secured using a large "T-bolt" to screw it down. This allows you to hit the portage running so to speak. You hop out of the boat and away you go.

On the two-wheel cart style, you have to unload all your gear first. You then flip the boat up from the front, slide the cart underneath, attach ratchet straps over the top, re-load all your gear, then haul it all across the portage. It's more hassle and takes longer doing it this way but at least you only need one cart and it can be shared amongst several boats.

Here is a shot of the "D" type mount where the wheels screw into.
Here is a shot of the handle to pull the boat. Some people use a long bar, center mounted chain and carabiner. This style clips to the front of the boat instead of bolting on a true handle.

These folding style portage wheels were made after hours by a welder from a mining company on the Iron Range in northern MN. He no longer makes them so I need to make my own. If you guys get me onto the right size metal I'll be in good shape. I'd hate to have the metal fail on me on the portage.

ole496 wrote:These folding style portage wheels were made after hours by a welder from a mining company on the Iron Range in northern MN. He no longer makes them so I need to make my own. If you guys get me onto the right size metal I'll be in good shape. I'd hate to have the metal fail on me on the portage.

If I were to build it, I would use no less than 14ga. and probably 11ga, and 1" tube.

What is outside width of your gunnels where you want the wheels?

My boat is a Grumman Sport Boat. It's 112 lbs., 15' 4" long, 43" wide at the widest point, 32" across the back transom, the wheels would be towards the back half of the boat, which is approximately 40" across. This would push the wheels out around 4-6" away from each side...so total width of 52" inches wide with the wheels on.

I just scientifically tested 1" square 1/8" (.120" wall)supported at two points about 60" apart and when I stepped my 240# on it I measured 3/4" deflection. Definitely would not fail, but would be a little on the springy side for my taste, which may cause undesired camber. 1" sq .120 wall is 34# for 24' while 1 1/2 sq 14ga (.083 wall) weighs 38# over 24' and would be more rigid. Even 1 1/2 16 ga (.065)wall would be fairly rigid and is 30# for 24'. In the pictures I think they have 3/4-1" sq tube. While more springy, that would not fail (as in break into multiple pieces). I think the trick will be the connection to the "d" bracket you described. If that is securely mounted to the seat and the wheel secured to it, a lot of strength will be gained. I would think making sure the toe in/out alignment of the wheels is fairly neutral would be crucial to an easy to move rig. Tack weld it all up then affix your boat to it and load the sucker down and try to roll it around your yard. Adjust as required. Post pics as you go.

Thanks for all the advice, I appreciate it. I'll be getting to work on this project in about 3 weeks when the Minnesota weather turns a little warmer.

ole496 wrote:Thanks for all the advice, I appreciate it. I'll be getting to work on this project in about 3 weeks when the Minnesota weather turns a little warmer.

The Pennsylvania dirt rat said six weeks...

Otto Nobedder wrote:

ole496 wrote:Thanks for all the advice, I appreciate it. I'll be getting to work on this project in about 3 weeks when the Minnesota weather turns a little warmer.

The Pennsylvania dirt rat said six weeks...

I checked the extended forecast, PA shows snow maybe 5 days of the next 30 with this week being in the 40s 50s and 60s at some point. We've had snow on the ground for probably 5-7 days so far. It's not going to start snowing until April at this rate

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