PDA

View Full Version : Can this SS be soldered?



challenger
03-16-2017, 12:43 PM
This is a side piece from a deep fryer I am getting reamed, steamed and dry cleaned by. The tack welds that the factory was "so nice" to supply have popped. I can't weld SS but I have a OA torch and have soldered SS in the past to a very limited degree. Is this a candidate for soldering? The material is almost as wide as a nickel (proper metrology lingo) and the gap that has formed is about as wide as the edge of an organic egg fried and flipped one time but over cooked (more proper metrology lingo). I can maybe squeeze the gap closed end to end but, if not, I'll remove the last of two end tack welds. Is this going to be a suck of the hind tit?
Thanks
BTW I would bring it to be welded by a pro but there aren't any local and the last 18 I used were complete hacks [emoji16]. Not really but there are non local that I'd trust for something that has to pass restaurant health inspector.
https://uploads.tapatalk-cdn.com/20170316/71a70620753c63c5f7dbb726ee1a1275.jpghttps://uploads.tapatalk-cdn.com/20170316/91e01d3a5c4cbd4884d01655518c921e.jpg
Galaxy S4, Slimkat
If I wasn't married I'd quit fishing :)

OKChipmaker
03-16-2017, 01:13 PM
your photos came through as red Xs here.However if the soldered joint is anywhere near food it may not be safe,as solder is lead based.

BCRider
03-16-2017, 01:24 PM
your photos came through as red Xs here.However if the soldered joint is anywhere near food it may not be safe,as solder is lead based.

That was my first thought too. But then of course there's no lack of lead free solder on the shelves these days.

If there's a good 1/4" or more of overlap it would be a primo candidate for low temperature soldering. The trick would be if it is an alloy which can be soldered. You'd need to try it and see.

Since this will see the close eye of a food inspector I would say that if it is down and out of the way of the normal food area that soldering would be acceptable since it would prevent waste food getting in there and getting funky. But if it will be exposed to any area where food to be consumed will contact it then that is a different story. Lead free or not lead free the inspector might have something to say about it.

You don't really need an oxy-acetylene torch to solder that. A basic propane torch would be just fine. On the other hand if you're decent with the O-A then why not gas weld it?

lugnut
03-16-2017, 01:27 PM
As you stated, you have a A/O set up. I think I would try brazing it. I have had very good luck brazing SS.

reggie_obe
03-16-2017, 01:32 PM
Those five tack welds were never keeping anything from collecting in that seam. They were just a fast and easy way for the fryer to be fabricated. I'd be surprised if a mechanical fastener like a SS pop-rivet wouldn't satisfy sanitary codes.

BCRider
03-16-2017, 01:47 PM
Those five tack welds were never keeping anything from collecting in that seam. They were just a fast and easy way for the fryer to be fabricated. I'd be surprised if a mechanical fastener like a SS pop-rivet wouldn't satisfy sanitary codes.

And if the stubs sticking out on the inside would not foul any parts of the fryer that would be a great way to repair this as well. Just need all SS rivets.

softtail
03-16-2017, 02:17 PM
If you got it clean (including inner surfaces), and if you could close the gap, low temp silver brazing would work, but it may distort the rest of it causing the other spot welds to pop. I wouldn't want to braze that as my first project.. good chance you would cook it and the flux. Nothing like cleaning burnt flux off a failed brazing attempt.. especially on something large.. good times.

Assuming it's allowed from health department standpoint, looks ripe for pop rivets imo. Or buy a spot welder.. they are fairly cheap.

wombat2go
03-16-2017, 02:42 PM
I brazed a handle back on to a ss pot here using OA, and Harris Safety-Silv 56 which is free flowing and rated for food.

The joint is strong, but there were 2 appearance problems:
The filler tended to run away from the joint over the curved surface, so the HAZ was bigger than needed.
After some time, there are speckles of rust showing through where the joint was heated.

Doozer
03-16-2017, 02:47 PM
You will warp the shlt out of it trying to silver braze it.
I have a large kitchen sink built in the 1940s or 1950s.
It is stainless steel, bent and seam construction.
All regular lead-tin solder joints. It was in the servant's
kitchen in an old mansion in Buffalo. I am going to use
it as a sink when I remodel my one bathroom.
The secret is to find the proper flux. That way regular
soldering temperatures won't warp it.

-Doozer

softtail
03-16-2017, 03:01 PM
I brazed a handle back on to a ss pot here using OA, and Harris Safety-Silv 56 which is free flowing and rated for food.

The joint is strong, but there were 2 appearance problems:
The filler tended to run away from the joint over the curved surface, so the HAZ was bigger than needed.
After some time, there are speckles of rust showing through where the joint was heated.

You need to passivate the affected area after. If it's a non critical joint like what your dealing with, probably ok to passivate after using silver. Better is to use a nickel based filler. And #2 silver brazing rule after 'keep it clean' is 'keep it contained'. It seems counter intuitive, but a really thorough pre heat will actually help decrease the HAZ by only getting the area you need up to HAZ temp.
If I was going to braze that, I would tip it back about 45 degrees so the crotch of the joint was vertical like a 90 degree V.. would help flux and silver flow down and in.. ledge would provide a nice holder for braze. Knock the hard edge off...that will be the fist spot to char and toast the flux.

Magicniner
03-16-2017, 03:21 PM
Use a low temperature, lead free alloy as used for DIY silver jewellery repair, Killed Spirits (Hydrochloric Acid with Zinc added until no more will dissolve) as a flux and a big old fashioned copper soldering iron heated with a blow-lamp until the flame shows some green.

- Nick

challenger
03-16-2017, 05:33 PM
I have the proper solder for stainless. I forget the name off hand but it's a reddish liquid. I also have silver solder as well as SS brazing material. I don't trust myself to braze this. If it were mine then sure but I'd hate to ruin it by warpage. The parts for restaurant equipment is nuts. I but this thing would cost $300.00. I cleaned the swivel casters and they were just nasty as hell with old grease. After doing one set I said THWI and priced replacement casters. List for ONE was $75.00!!! They are run of the mill swivel plate casters. I went looking for generic and they run maybe $10.00 each. Problem there is the plate dimensions and hole pattern so the casters are on hold.
Anyway thanks for the advice! I'll keep reading and hopefully decide what my comfort level will put up with.
Pop rivets are a good idea BTW. The back side however would look really gnarly AND grease would likely seep through them.

Galaxy S4, Slimkat
If I wasn't married I'd quit fishing :)

Magicniner
03-16-2017, 05:59 PM
If I were asked to repair that I'd weld it using MMA with 316L rods.

softtail
03-16-2017, 07:25 PM
They make both sealing and smooth on both sides rivets.

Mcgyver
03-16-2017, 10:21 PM
If you got it clean (including inner surfaces), and if you could close the gap, low temp silver brazing would work,

what is low temp brazing?

agree with Doozer, silver solder/brazing temps make a mess of thin sheet metal with no crown.

softtail
03-16-2017, 10:43 PM
what is low temp brazing?

agree with Doozer, silver solder/brazing temps make a mess of thin sheet metal with no crown.

Just that, and I agree.

BigMike782
03-17-2017, 07:57 AM
Have it TIG welded.

Mcgyver
03-17-2017, 11:39 AM
Just that, and I agree.

but was is low temp brazing? what filler material and what temps are used.....I've always taken brazing be definition to be at a high temp, ie silver solver or braze.

mattthemuppet
03-17-2017, 06:02 PM
If I were asked to repair that I'd weld it using MMA with 316L rods.

MMA = Mixed Martial Arts? That's pretty extreme :)