Hey Brian,
Welcome to the forum.

Sounds like a good project. My first thought is 16 gauge might be light for picnic table at the ranch. I agree that 1/8" would start to get heavy. Your welding will improve by the time you weld enough of 16 gauge tube!

It would help if you had a drawing or picture of what you have in mind. Most of the time the design is more important to the strength than the material. A good design might be ok, it takes a lot of material to overcome a poor design.

 

Not being a wise a&&, but you have to consider the amount of weight on the bench seats.

6-8 foot long table could conceivably seat 3 people on either side. People tend to be large these days Get 6 250lb people at a picnic table, and you've got a load And if they're that big, you have to consider the load of food to feed em' (just kidding)

Also consider whether you're going to have umbrellas sticking in the center of the table. Little bit of wind will topple a light table, I know this for a fact. We have steady winds here at around 20+mph steady all day long. Gusts to 40.

I've seen a lot of crappy lawn furniture fall apart under "heavy" use.

 

So I drew out my "design" as best I could. What I am considering is:
2" x 2" 16ga square tube for the vertical and horizontal framework
1 1/2" x 1 1/2" square tube for the gussets
2" x 2" x 1/8" angle (dashed lines) to bolt 2x6s to for table top and benches

Not Pictured:
1 1/2" x 1 1/2" 16ga from the 7 5/8" horizontal piece to a piece of 2" channel in the center of the table on both sides. (to support table top)
1 1/2" x 1 1/2" x 1/8" angle from one bench support to the other running underneath each bench board. (2 - 2x6s per bench=2 pieces of angle per bench)

I don't foresee ever having umbrellas in the center of the tables since there are 200 year old oak trees that the tables will be under. There are pretty good winds tough, and some of the hunters are a little "large".

 

What ever you use to top out the bench seats and table top are good for a lot of the strength. I won't say don't use gussets at the bench seats, but if your welding is solid I don't think you need them.

Here's a smaller version I built several years ago for mid-sized kids to adults. I built it so that it would be just a wee bit big for the littlest of folks and a bit small for adults. But the concept is the same. An inch or two in height isn't gonna make much difference if the basics are there.

I think I've posted pics here before but no way I'd be able to find them.

 

What ever you use to top out the bench seats and table top are good for a lot of the strength. I won't say don't use gussets at the bench seats, but if your welding is solid I don't think you need them.

Coming from wood-working, the temptation to over-gusset everything has been one of the hardest things for me to overcome. You really have to recalibrate when going from wood to metal. But that's kind of the point, right? Metal is way, way stronger.

 

What's underneath the picnic benches? You have a lot of "surface area" in your design so you need the ground to be flat.

I've only built picnic tables out of wood but you could consider building it the same way.
For instance like this:

I prefer a wider bench to sit on compared to the picture (I use three 2x4 with a little space between them) but I think you already thought of that.

I'd also consider having it hot dip galvanized when done, but I guess that would depend on the climate where you live


I also think 16 gauge (1/16") sound a little on the thin side. Perhaps consider 14 gauge?

BTW, the ones I made out of wood are pretty heavy as well so you need to be two adults to move them. 2x2"x14 gauge is 2.2 lbs per foot.

 

the post by Pete S is what i was thinking EXCEPT do the table frame as an a frame and a frame benches.

 

Sandy: Thanks for the pics. That is pretty close to what I was thinking. Originally I was gonna use diamond plate for gussets, but that stuff is around $100 for a 4' x 8' sheet 1/8" thick. I'm thinking I may just cut out the gussets all together.

Pete S.: Thanks for the pictures. Originally I had planned on building A frame tables, but I don't want any "accidents" :drinkup: at the ranch after a long night of telling hunting stories. Those guys may bust their head open trying to get out.

I never thought I'd do this much thinking and planning on a simple picnic table.:dizzy:

Thanks again guys. Keep 'em comin!

Brian

 

Have you seen the commercial tables that blackbart builds?
weldingweb.com/showthread.php?t=247371

 

You beat me to it. I remember reading about him using the HF bender for making them. Good job.

 

The ones I build are for an abusive, commercial crowd. For your own use, Your design is fine,although I would bump up to 14Ga-1/8". I don't think you need the gussets, but it will need a brace from the bottom cross member to the middle of the table. You can go 5' to 6' between supports using 2X lumber. A design like Pete.S. showed looks simple.

 

Do you have dimensions for this?

 

The last few that I have built feature VERY high seating, as my wife has a leg issue, and can not stand up easily from normal height.
Everyone that uses the table remarks how comfortable the higher seating is.

This one included an iron pulley as a wheel, so that one person can mmove the table for mowing ,, etc,,

I used synthetic decking for the last three that I built, one of them is over seven years old, and still looks new.

Right before I put the table area on the red one above, my daughter said that an extended area would be nice, so food could set there, rather than in front of the seated people.
So, the top was extended mostly to one side, over the wheel/pulley. (slightly to the opposite end)

I also built a high seated bench, again with wheels, so one person can move it.

The seating is 24 inches high, the top is at 37 inches. (the bench is 24 inches high)

 

I also made a simple "Z" bench,,
All of my steel is 2X2X1/4 angle, and 1" solid bar (I had the material.)

More synthetic decking,, oh, yea, and stainless bolts from eBay.