Adjoining aluminum – NO welding

I’m wanting to build an aluminum framed table (18”H x 48”L x 30”W) that can hold a weight of about 300 lbs. This will be a fire pit table, so my joints can’t be those composite T fasteners. I was curious what the best method would be for adjoining the tubing pieces that meet.

I have access to plenty of 1” and 1.5” square aluminum tubing as well as the 90 angle.

Some of the common methods I’ve seen are adhesives, rivets and nut/bolt.

What is wrong with rivets or nuts/bolts?

-Ron

Why no welding?

Outdoors dissimilar metals will cause the aluminum to corrode.

Bill D said:

Outdoors dissimilar metals will cause the aluminum to corrode.

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Um, weld it with aluminum wire?

unless there is a need for that table to be light, using aluminum because it is "free" seems like the wrong choice, need AC tig (or proper mig setup) to weld it, screws and rivets may make that frame look not exactly aesthetically pleasing, and you can forget about glues, even painting it may not be straight forward

steel or stainless steel is a lot better choice, even if you need to pay for it

and avoid stainless hardware in contact with aluminum, it will make aluminum corrode, use galvanized nuts/bolts/rivets if you have to

Simple gusset plates & rivets like airplane construction. or rivet nuts and screws. or through bolted.

Luis & Fab's RV-7A Construction Log >> Blog Archive >> Riveting the Firewall

Miter the horizontal pieces at the corners and mount them inset behind the legs so the joints don't show. You can make L brackets out of heavy aluminum angle to fasten the horizontals together with long through bolts fastening the frames to the legs (through one frame piece only). You will have access inside the legs for nuts before the top is installed. Don't forget spring washers to keep things tight with temperature change.

Stainless screws are OK for use with outdoor aluminum.

Bill D said:

Outdoors dissimilar metals will cause the aluminum to corrode.

Click to expand...

Fire pit table out of aluminum...

Will this be in close contact with the fire? If so, aluminum is a terrible material choice. The flames will oxidize it and in short order, you will have a scorched hole in your table. What's worse is if you burn wood or charcoal in it and then it rains, or you have a heavy dew. The water combines with the ash and makes lye. Lye eats aluminum like my kids east M&Ms.

Or, if you're building a table and putting the flames on top, like a hibachi, you need to be careful because aluminum conducts heat extremely well, and 70F aluminum and 300F aluminum look exactly the same. Guests with burnt arms won't be happy...

But, if you're trying to build a light table to have near-ish to your fire pit... fine, and everyone here has given good advice. Just keep the aluminum away from the actual fire.