Rust on stainless welds

[Kent]

Ha! I have done exactly the same thing on a project recently. I am a hobby welder not a fabricator so have an excuse for stupidity!!

I made a rod holder by welding a piece of pipe onto some flat plate in almost exactly the way that flange is made. I thought I would polish the welds up a little to give it a nice finish. I used what I thought was a brass wire wheel which is actually just a brass coating on steel wire. It looked lovely for about a week and then I ran the propane heater in the garage which the ran out of gas which leaves a very light condensation on everything. Came back the next day and the welds looked identical to that!!!!

While we are at it, whats the best way to clean them up?

Try a proper stainless brush and a good going over, followed by a clean new abrasive pad, not something I have ever done in the first place though

 

[Welderpaul]

They are BZP bolts too.

Looks like it wouldn't matter if the valve moved slightly inwards. Saw the flange off plus an inch or so of pipe and weld a new flange on.

 

[TechnicAl]

2nd pic right at the top there's a small portion of weld that isn't rusty. Maybe it's the pic (or me) but it doesn't look like mild steel... the colour's wrong, there's rust at the toes of the weld (and what looks like cold lap) but the bead itself is brighter with less of a blue-grayish hue than typical for carbon steel
Either way the numpties that made it have managed to FUBAR it and contaminate the pipe and flange with iron well away from the welds too

I wondered if that was caused by dilution bringing some of the Cr through

Whatever it is it will be interesting to find out

 

[hotrodder]

I wondered if that was caused by dilution bringing some of the Cr through

Whatever it is it will be interesting to find out

Didn't think about dilution. If the OP ever comes back maybe he could wave a magnet at it after brushing off some of the rust to see what sort of response it gives?

 

[TechnicAl]

and I didnt think of that......

hope he comes back with the answer

must admit Im used to jobs that have documented QA procedures and control......

 

[dan.taylor.1]

We do seem to pay a lot for agri jobs when often, the welding, quality and finish isn't really that good!

 

[Rob55]

Thanks for the input everyone. I have just had the following response from supplier:

Our stainless steel supplier has said that the reason the flanges are rusting is because the weld has been wire brushed with a mild steel wire brush after welding. This has left deposits of mild steel on the surface of the stainless steel. To remove this Mild steel deposit, the surface must be wire brushed using a Rotary Stainless Steel wire brush .

They are sending me the correct brush so I'll try that and see how it goes. I've been told to keep repeating it until the rust stops reappearing.

 

[Paul.]

Re brushing alone wont cure it, the brush will be contaminated as soon as it touches the rust, it will need an acid treatment as well, I've had to deal with this exact problem before, pickling paste as well as brushing is the answer, either one of the traditional ones such as antox or pelinox, or the more friendly but slower working citric based ones will do it, but it should be down to the manufacturer to sort it really, not palm it off on the customer.

 

[zx9]

.................... but it should be down to the manufacturer to sort it really, not palm it off on the customer.

Agree with Paul, I don’t see why the OP should have to sort out problems caused by the contractor, that’s what retainers are for.

 

[Kent]

We do seem to pay a lot for agri jobs when often, the welding, quality and finish isn't really that good!

yep, most are totally self taught. was looking at something like that today, rarely do you see good stuff and when it is its usually by the farmer who bothered to seek a little training not a contractor. Thing is a lot of skills are being lost and one of them certainly seems to be welding and fabrication out on farms and such. Perhaps its because you can no longer make a lot of farm stuff for the price of imports few people to do it = higher quotes? I must admit I don't find that and am fully aware if I price anything too high it will often end up in the hands of a guy who "can do a bit"

 

[Rocketman]

I think the skills are easily available it's probably just price driving out the skill in certain areas.

Put it this way all the brewery equipment fabricators around Burton-on-Trent wouldn't be doing such things.

 

[Kent]

I think the skills are easily available it's probably just price driving out the skill in certain areas.

Put it this way all the brewery equipment fabricators around Burton-on-Trent wouldn't be doing such things.

The new boom area " micro brewery stuff". No honestly what I am saying is and I can only speak about my own locality high quality TIG work is available because of the aerospace here and production MIG etc. But out on the farms and construction sites outdoors skills are not as available as they were (rates of pay for advertised jobs reflect this) 20 years back good TIG lads were wanted all over for catering equipment manufacture and rates were high as a result outside mucky steel guys were ten a penny and didn't get paid that great as a result. I came back to it from other things and noticed that straight off

 

[Rocketman]

Well it's always been massive in the Burton area. Big brewery town for donkey's of years. The engineering HNC I did back in the 90's in Burton even had a stainless steel half unit on it just because of the local businesses. We had quite a lot of designers for the brewery fabrication companies on our HNC - probably as much as half the class.

 

[Bill Edwards]

Thing is a lot of skills are being lost and one of them certainly seems to be welding and fabrication out on farms and such. Perhaps its because you can no longer make a lot of farm stuff for the price of imports few people to do it = higher quotes? I must admit I don't find that and am fully aware if I price anything too high it will often end up in the hands of a guy who "can do a bit"

I have made a few gates for a farm I work on, because they needed to be a certain size.

But for another job the farmer went and bought a decent quantity of ready built ones where they didn't need to be made to fit.
Why?
Because even if I made a jig for that size it would still have cost as much in my time (never mind the metal and consumables) as they cost, and they're galvanised.

 

[dan.taylor.1]

Yeah I agree with gates and repeat production stuff, but some of the welding and fab work I've seen on new machinery is terrible, in fact one of our sheds has some suspect welds and it's from a VERY big manufacturer in the north of England!

 

[Gavin_d]

I would tell them to get there **** down here and sort it. You paid for a defective product and they are asking you to sort it!

 

[Kent]

Yeah I agree with gates and repeat production stuff, but some of the welding and fab work I've seen on new machinery is terrible, in fact one of our sheds has some suspect welds and it's from a VERY big manufacturer in the north of England!

very big manufacturer with lots of cheap low skilled labour working on a time bonus no doubt.

 

[Kent]

I have made a few gates for a farm I work on, because they needed to be a certain size.

But for another job the farmer went and bought a decent quantity of ready built ones where they didn't need to be made to fit.
Why?
Because even if I made a jig for that size it would still have cost as much in my time (never mind the metal and consumables) as they cost, and they're galvanised.

I was asked if I could make better Lambing pen gates because a client keeps busting them. He was paying something under £30 for them I think ( it was about my guess on stuff and galv anyhow) so I told him yes but the electric, materials, galvanising and consumables will cost me that before I get anything for the labour so it will cost far more. Imported in bulk, staff paid about £1 a day and still the importer is likely to be making a goodly amount, you cant change that and frankly who wants to bust a gut making a load of cheap gates day in day out if you could.
You know though gates are like anything else cheap is not always economy. I have currently fallen into cataloguing the old smithy made field gates round my area many are 200 yrs old I recon, not an electric weld in sight and some of the younger ones made prior to ww1 are actually still functioning (no galv back then). Heck of a low whole of life cost isn't it. Yesterday I got so fed up of lifting someone else's modern tube / galv 5 bar wide gate I spent an hour sorting it, still not great just better and I bet its not 10 yrs old !

 

[Rob55]

I would tell them to get there **** down here and sort it. You paid for a defective product and they are asking you to sort it!

Don't worry not paid for yet. Difficulty is they were made in England and are now in N.Ireland. But you are right, I am not going to be the one who sorts it out.

 

[dan.taylor.1]

Yeah I put an hour into fettling one of ours that's as old as I am and about three times as heavy as a modern galved equivalent! I reckon it'll outlast my dad on the farm!!