Rust in my flue pan.

[lmathews]

At the beginning of the season there was what appeared to be rust spots in my flue pan along the welded joints.I have done an acid wash to clean up after the season and the spots are still there.Does anyone think that this could be bad stainless,or wrong filler wire?The pans are 3 seasons old.Should the dealers come take a look and check it out forthemseves?Just looking for some input.
Thank You Lee

[WESTVIRGINIAMAPLER]

If I paid that much for those pan as you did, I would be on CDL asap. Too much money to be rusting, but make sure that is what it is so you don't look stupid. I can't imagine it would be anything else since acid didn't clean it off.

[brookledge]

Are your pans stainless? If so what grade of stainless. If it is 403 it contains iron and can rust especially at joints. Check the pan with a magnet if it is 400 series it will attract the magnet and if it is 300 series the magnet won't hold.
Other than that I'd do what Brandon said contact the manufactuer.
Keith

[MaplePancakeMan]

I have the same problem, pans are 3 seaons old, its on the underside of the pans along the joints. I clean the creosote as best as possible and store inside during the off season. I can't figure out why they are rusting its 304 stainless.

[brookledge]

Might be worth a trip to the local welding shop and ask the question?
Keith

[lmathews]

I am a certified welder and have been working with stainless for 9 years.When I puchased the pans they were suppose to be 22ga 304 anealed stainless.A magnet does not stick.Given my background I have a little insight on the metalurgy of it.In my opinion and experiance it is rust and the dealer should do something.Just wondering that given the length of time that I have owned and used these pans,would it be feasable to contact the dealer?
Thank you all! Lee

[Brent]

I have seen the same sort of thing on stainless fittings on boats in salt water.

I would get a very thin orange stain, especially at welded joints. It drove me nuts for a while. I would clean with chemicals, wire brush, sandpaper ... it would get clean, then next trip south, it was back. Eventually I gave up.
Strange thing happened. The orange film just seemed to stabilize. Nothing ate into the seams. It didn't expand. It was just there. When I finally sold that boat after 15 or so years, the rust spots looked the same as year 1.

I think I'd raise the question with the manufacturers, but I wouldn't loose any sleep over it unless it looks like it's really eating into the seams and pitting, which I don't "think" is going to happen

[WESTVIRGINIAMAPLER]

I agree that if it is only a staining and not continuing corrosion, then not much to worry about and the manufacture will probably not do anything. I was under the impression it was actually corrosion.

[Haynes Forest Products]

When you weld stainless you have to use the right kind of gas. With that said even with the right gas if you want a nice finish on BOTH sides of the item you are welding. And at times that is hard to do if you look at a nice stainless sink the inside weld that you see is nice and clean and the underside is grey and rough that is called suggering. It is caused by oxidation from carbon entering the weld and carbon is what can make it rust. If I weld 304 stainless with 304 welding wire and use trimix gas it will rust along the weld.............becouse there is carbon in the gas and my weld is contaminated!!
Just a thought

[MaplePancakeMan]

Okay, so after reading and looking at my pans i seemed to realize a correlation. My pans were fine the first time i took them off this past season, just rust transfer stains from the rails of the arch. I then put furnace cement down to attach my rail gasket and started to burn pallets Would this cause any of this. I am leaning toward a lot of it being dis coloration but two particular seams it looks like rust. on the non welded parts of the flues there are stains that look like rust but i don't think they are.

[WF MASON]

I believe the rust is carbon comming out of the stainless at the point of the weld , welding changes the material makeup at that point and surface rust can appear.
Stainless has parameters when made and the carbon content has to fall between theses for each grade 304 , 316 ect. Sometimes the nickle content is very high and the carbon is very low in a partitular run at the factory and the 304 is close to a 316 grade, but not quite, that is a better grade of stainless. And sometimes a run can go the other way and be made on the low end of the scale. There is also 304L grade , the 'L' meaning low carbon, all the supplyers know what it is , but known I've never spoken to anyone who has ever been able to order and get any.
Gas coverage and point of weld pre/post cleaning helps with this problem.
A machinest who I respect (70 + years old) had worked in the marine industry all his life told me "Its called stain-less for a reason, becouse thats what it does, its not stain-proof."
Haynes F P is correct.

[Haynes Forest Products]

Stainless is a strange metal. If you were to burn stainless it can lose its stainless properties. If you try and use a cutting torch on it it spatters away. not a nice cut and it will rust along that cut. I do a little recycling and I run into magnetic stainless from time to time and they dont want to take it. Its found in boubble wall chimny pipe some knifes. The first Stainless was called stelite and the company that invented it is still around in Kokamo Indiana.

[Justin Turco]

We have a stainless sink in the basement that I cleaned with steelwool. Man did it start to rust after that. I believe that cleaning with a wire brush or steel wool leaves steel "in" the stainless. I wet sanded my sink with 320 to get rid of the extensive rust that was occuring. Seemed to solve the problem. Not sure if it will last. But, I think, the key is don't ever use steelwool or a wire brush even to clean soot off the bottom.