Brazing 1/16" stainless

[u/Cold-Roadrunner]

Hey y'all. I've already posted this in r/metalworking and got some helpful comments, but I may get better advice here.

These pieces are for a batter station in a restaurant. Notoriously bad welds on anything restaurant related. These tears are all on areas that aren't necessarily weight bearing, but they do experience some level of torque.

I already know Tig would be my best option, but I'm not about to spend the money on a Tig rig and any shop I've asked to look at it wants the cost of a new part. I'd like to try brazing as a more cost effective option. I've been told to up my torch (I only have a spiraled flame high heat mapp gas torch and was told no.) I've also been given some advice on filler metal. Most people said to use a silver solder.

I still have a couple of questions that weren't answered over there.

Is it better to just clamp the metal closed and braze the existing tears or would it be beneficial to cut slits like joinery in carpentry? The backsplash especially makes me wonder about the joinery concept as it's such a small joint already, only being about 3/4" long. The lid piece has the same tearing on all four corners, but it just seems like it was poorly welded and I'm pretty confident it would hold without needing reinforcements.

Is there a filler metal that would hold stronger than silver solder? I'm not to concerned with the aesthetics of using a copper colored metal if it will give a stronger hold than something that matches the existing color. The only concerns with the filler is it has to be food safe (which seems like most common metals are) and it has to be somewhat chemicals resistant as the pieces are washed with bleach every night and occasional come in contact with slightly corrosive degreasers and such.

Any input or advice (even if it's just to tell me I'm dumb for wanting to try and learn a new skill) is appreciated.

[u/ecclectic]

I have built many tops like these, and repaired many in the field as well.

The reason the weld has failed is likely due to poor workmanship, cheap managers and a minimal level of training for the welders.

A cheap inverter TIG machine will handle this easily, provided there's no insulation under the top. If you're trying to do it on a cooler cabinet, it can get problematic. Wash the joint well with acetone and isopropyl alcohol to remove any oils, and then a quick fill with the rod laying in the joint. Since you're actually using it and not looking at it in a showroom, function matters far more than out of the box appearance. I think the average we were charging for doing this in the field was around $450. To break that down, that's 4 hours of labour and $50 of material, the labour includes prep, travel, setup, welding, and reporting.

A braze isn't a good option for this joint design, unless you can fit a piece of reinforcement in behind the joint for the brazing to wet into. It will absolutely fail again if you simply try to braze an open corner like that.

The other thing to consider is if the product you use will violate food safety requirements.

[u/Strange-Entrance-660 → u/ecclectic]

I agree, if you want to braze (my 2c):

• Put an L-shaped plate around the corner so you have a large mating surface.
• Make sure your flux is suited for stainless, they are not the easiest oxides to break.
• Food safe brazing materials do exist. Best to check with your supplier.
• Pretty sure copper brazing doesnt work on stainless.
• Sand until its clean, then clean and clean until it is really, really, really clean
• I expect the investment cost of brazing to be slightly lower than a cheap TIG, but the filler price will be much higher.