welding

[dmfa200]

here is a weld i did practicing with some new welding fixtures. i havent cleaned the weld with anything yet in this picture. there is absolutely zero weld showing on the inside. you cannot even feel the seam with your finger, silky smooth.

i was proud of it till i showed it to my welder friend. What looks perfect to the eye looks horrid under microsope. He said it would never pass inspection but it was a good start.

In my line of work, microscopes are not used to look for defects.
Xray, dye pen, ultrasonic, and eddy current testing are done.

A microscope would only show defects on the surface of a weld.
Xray, ultrasonic, and eddy current can detect or show defects under the surface not seen by the eyes.

There are several code standards that welds are made to.
Some are more stringent than others, so you might still have made a code weld.
Keep up the good work.

 

[ScubaSteve]

Well, don't you micropolish the inside anyway? Seems like that would remove a majority of the rough spots.......

Let's face it, if you're using a microscope, then every little scratch is going to show up!

 

[h22lude]

So I found a place that specializes in food and pharmacy grade sanitary welding. I told him what I was doing and he said he didn't know if he could weld inside the keg. I don't think he realized it would be open. But anyway, he said to bring in a keg and he will check it out. Fingers crossed. It sounds promisig since this is what they specialize in. The guy I talked to was extremely nice

 

[Komodo]

Bingo.
+1 what ScubaSteve said . . .if you had a less than perfect weld, can't you grind/polish whatever on the inside to make it cleaner? I'm not saying it's optimal . .but with all the scrounging brewers do, I've often wondered this.

 

[grubb]

Talked to my welder again today and he is positive that the kegs are aluminum. He tried to stick several different magnets to the kegs and also took it to a couple of his welding buddies and they all confirmed they are indeed aluminum. Has anyone herd of this and what can i do expect for weldless fittings. I have already bought all the weld fittings.

 

[ScubaSteve]

Magnets don't always stick to stainless. Depends on the composition of the metal. Kegs *can* be made from aluminum, but you don't see it too often. They are usually made of 304 SS, which is non-magnetic, unless machined or work hardened in a particular way. Aluminum just can't take the beating that SS can....especially in a full 165 lb keg...so it's kind of a bad choice for a pressure vessel!

Something that I've noticed about *some, NOT ALL* welders ...they can often be stubborn and even hotheaded. Just go read a bit on forums like weldingweb or millerwelds. Maybe you should get a second opinion (and not from his friends!).

I'd hate to see you sell those kegs only to find out that they WERE stainless....and have to spend the time hunting down replacements.

 

[dutchoven]

Take a file to the keg. Find an edge near the handle holes. If its aluminum, you'll be able to take off quite a bit of metal easily. I'd be surprised if your kegs are aluminum.

 

[Hypnolobster]

Talked to my welder again today and he is positive that the kegs are aluminum. He tried to stick several different magnets to the kegs and also took it to a couple of his welding buddies and they all confirmed they are indeed aluminum. Has anyone herd of this and what can i do expect for weldless fittings. I have already bought all the weld fittings.

Yeah right, tell him to get a big deadblow mallet and try and actually dent the handle collar. Or, pick them up and notice that they're not light.
It's stainless, unless you got some super wacky kegs.


e: to clarify, stainless kegs are unbelievably strong. They manage to get rolled around and banged up and dropped off trucks and handle it perfectly. They're so strong that if you get one to turn into a kettle, it's almost impossible to get dents out, especially if you want to reform the top or bottom.

 

[JayWeezie]

well there's learning to weld...and learning to weld sanitary fittings for brewing. Welding on an exhaust pipe for your car is something completely different from welding something that needs to be sanitary so you don't create a home for bugs

How is something welded for sanitary purposes? My cousin is a wlelder and I was gonna get him to do mine. Is it something any skilled welder would know how to do?

 

[dmfa200]

Material must be prepared correctly, purged from the back side. Welds should have no sugaring, no discoloration of the weld area. Complete fusion of welds with no porosity, cracks, crevices etc. No excessive weld build up. Welds should blend in smoothly with the base material.
Welds can be ground smooth, and polished if the profile is unacceptable.
For homebrewing purposes it's not absolutely critical.

No, not many welders are "good" at tigging stainless and fewer know how to weld to sanitary specifications.

 

[lehr]

Where are you in Michigan. I could look at it for you if your not to far away.

 

[Ohio-Ed]

If you feel like doing some reading, here is a thread I started to document my search for a welder to get some work done on my kegs:
https://www.homebrewtalk.com/f51/welding-questions-148798/

BTW... for most of the brew process, the welds don't have to be sanitary. You really only NEED sanitary welds for those in contact with the wort after cooling.

I have since bought a TIG welder and started practicing. I welded my first to couplings into my HLT to add a copper coil this week. Here is a couple pictures of a practice coupling I did:

Ed

 

[grubb]

I live in bay city, mi. Let me talk to the welder and i will let you know. Thank you for the offer.

 

[ScubaSteve]

Okay, here's another way to tell if it's stainless. Weigh a keg. It should be approximately 35 lbs empty. If it's aluminum, I suspect it'd be a lot lighter.