welding an appliance
 

I have a small leak in my dishwasher, a little “seep” where a fitting is welded to a stainless steel hot water tank. I thought I could fix it with JB Weld, but that hasn’t worked - water is still seeping out (like a teaspoon an hour). I am thinking of disconnecting all the hoses and wiring plugs from the tank, Dremeling off the epoxy, and using a TIG welder to add material to the fitting/tank junction in hopes of sealing the tiny crack that must be there. It is impractical to pull the tank out from the machine, so I’d be attaching the clamp to one of the two fittings while welding the other fitting. The heat will, I’m sure, be localized enough to not damage nearby or connected components. However, I wonder if I will “fry” the circuit board that is at the other end of the machine, simply via electrical current? What do you all think?

If you make contact with the clamp next to spot you weld, no current will flow to other parts of the machine.

I do have to wonder, can't you buy this component as a replacement? I have had good luck getting parts for just about anything on the www at the various parts places.

I didn't know you had graduated to tig welding!? That's something on my bucket list.

https://www.repairclinic.com/Shop-For-Parts/Appliances

you can see if the part is available

I've welded stainless steel with ordinary MIG wire and it worked well. Not pretty like stainless steel on stainless steel, but it was strong and worked.

As you know, get it very clean, stainless steel wire brush then clean with solvents. And do a practice run elsewhere so you can figure out your voltage and wire feed flow - avoiding the bubble gum look and also not burning a hole in it. Good luck :)

A replacement tank is $1600 …

Double check me, because it has bee a few years. But may beat the $1600 reqiured for a new tank Others here can chime in.

Find the crack. - Clean area real good. Get a can of penetrant dye and spray area. After about 30 min, wipe clean and dye should remain in crack or pore. File or grind crack with die grinder.

Clean again with new stainless wire brush.

Get a AC/DC buzz boxxwelder, a tig rig that can clamp to the stinger. a red tungsten elettrode, bottle of argon (unimix works good for most metals), and small stainless tig rods (316L ?).

Practice on scrap metal, then have at it.

If you have high freq start on your tig welder, turn it off and make sure your ground is solid and you will likely be ok with the control board. Couple questions, how thick is the tank less then 1/16"? How good are you at tig? Pulse control on your Tig? Any access to the inside of the tank? Another possibility is tig braze, lower temp. Can you run another argon purge line from your regulator into the tank?

This must be a very nice dishwasher if you're even considering doing this. Can I ask what type?

I'm not good at all. But I can practice on scrap and I don't need to actually make a solid weld, just to melt spot enough to close up the crack. I do wish I hadn't put all that epoxy on it . . . The material is thicker than 1/16". This machine is a "tank".

Hobart LX30H

The equivalent new Hobart costs about $8K.

Post a pic if you can. Whenever I fixed cracks with epoxy, I do what you did, dremel out the crack and especially the ends into good metal to relieve stress. I love JB Weld for somethings but it's got a pretty high durometer and probably fractured from vibration. I like to use Loctite EA E-40HT because it's high temp and oil resistant/impervious (like JB) but most importantly it has a low durometer so is excellent at withstanding vibration. Surgically clean surface interior and exterior too, scuffed with scotchbrite for maximum surface area and therefore adhesion.

Deja-vu? I seem to remember another thread about a commercial DW repair.

Can you get the tank out?

Sand off the top surface well and clean with alcohol you should be fine, as low a heat as you can get away with and a shade 9 lens so you can see, I would really recommend running an argon purge to the inside of the tank.

You can also try using a sharp prick punch right beside where the leak is to form material over and close the crack.

EDIT, If you can't purge the inside try about 55-60A but move the torch along pretty quick so you only penetrate 1/2 way through the material, that should keep the inside of the tank from getting badly oxidized, should not need any filler wire.

What is a new quality dishwasher worth? What is your floor worth? If you have a basement, what is that worth?

Just a flip side of the coin....

But yes, very repairable.

Cheers

The fact that you already put JB Weld on the tank pretty much makes me not comment on the possibility of welding. I would look for either a used machine to cannibalize for parts, or buy a new machine.

I think that's not how "welding" works.....

3M marine sealant # 5200 . Stuff is amazing .

What about a kitchen stainless saucepan that has 4 small spot welds (well - now 2!) holding the handle on? Would JB weld be up to the task?

Hmmm, not sure what you are saying here but this is exactly how welding works.

Did you get that welded yet, if you were closer I would do it for you, did a couple years in that industry long ago, usually small stress cracks on much larger tanks.

My welding skills are primitive but my boat repair skills are far better. I would probably assess the leak, clean the area really well exposing about 1" past the leak, and then use marine epoxy and glass cloth to thoroughly seal it from the inside. No worries about fried electronics, heat damage, or making the hole bigger which is my standard fare when welding thin and rusted exhaust systems.