Weld or screw/ bolt an aluminum crossbar to trailer?

[Veloo]

I have a couple of pet bike trailers.
Both are the Solvit Houndabout model rated to hold 50 and 100 pounds.

Good product overall but I'm thinking to improve on it by adding a crossbar on the underbelly front end.

The arm that attaches swings back for compact storage but as a result, the manufacturer may have opted not to put a bar in that area because of less clearance. They went with a nylon strap instead which doesn't give proper support for the larger dogs.

The bar on the rear where the wheels go are 1 inch.
Looks like the arm will not even clear a 3/4" tube so thinking to go with 5/8" if that even exists in square aluminum.

The material for the cover is screwed into the side of the frame tubes as you may be able to see below.

Question is - should I add a crossbar by finding someone to weld one on or should I screw one into the frame?

I realize an improper weld can be a weak one.
Wasn't sure how compromised a frame would be with a couple of screw holes added to the bottom.

[Hindmost]

Find a piece of tube the same as the frame is made of, cut and fish-mouth a piece to fit between the two frame rails, prep for welding and take it to a welder. (Wait, trailer is steel or aluminum?)

[Black Dog]

Solve the problem from the inside by putting a floor liner made of a plywood.

[Veloo]

Did that already BD. A better platform but still lacks stability on the front end.
I'm guessing the omission of the bar was also a cost savings.

Originally Posted by Black Dog

Solve the problem from the inside by putting a floor liner made of a plywood.

[Hindmost]

If welding is off the table, find the square tubing you described, cut it, drill it, and attach it using U bolts.

[fords4life]

I will always say welding is better, but figure it's going to cost you at least an hour or 2 for a minimum. I think for that purpose you could get away with bolting another piece on just to add some stability. If you used a piece of rectangular tubing, you could do 2 bolts on either side and help lock it in better to prevent any pivoting/twisting around the bolts, just some lock-washers or nylock nuts to keep from rattling the nuts loose.

[FriarQuade]

You could insert a star flanged nut into a round tube and then bolt it in. Sheer strength of the bolt becomes a factor at that point.

[Ozz]

What about an aluminum mesh panel that sits on top of the side bars? You could probably attached with zip ties to see how it works before bolting directly to frame.

Here: Home Depot, but probably pretty common

[Black Dog]

Get 1” aluminium tubing from Home Depot. Cut it to be a few cm longer than the length of the outsides if the support bars. Flatten the ends in a vice or with a hammer and drill a hole in each flattened end that will line up with the centre of each support bar. You can drill holes in the support bars and run a small carriage bolt through the holes to attach the new tube. File the ends of the flattened tube to remove any sharp edges and place the new tube above or below the support bars depending on what will work best. The length of the flattened section should be about equal to the diameter of the support bars. I hope this makes sense. It’s a cheap and sturdy solution that requires simple tools that you will have at hand.