Major Rusting Issues In Our Building All Of A Sudden??

[Limy Sami]

No cast iron, we mainly run aluminum, copper, and some 4140. We did run a big delrin job a while back and that about killed us in here, all the gassing off of those parts was terrible. We did seem to think maybe that did something to the coolant in those two machines that ran the job. We had the customer switch to acetal after that and the nasty smell went away when we ran those parts. Could that be apart of the issue?

That'd do it, and how.

 

[boslab]

Hydrochloric is a real rust catalyst, even in a container.
The steel shelves in the chemical store in work were completely eaten, and that was an outside brick store with Louvre ventilation, none of the acid containers were open, ok there was H2So4 Hf nitric etc in there too but the worst bit was where the hydrochloric was stored
I used to park my motorcycle next to the building as it was sheltered, I swear my bike was reduced to rust faster than all the others I’ve had, powerful stuff.
I still don’t understand the exact way a sealed bottle can do that,
Water treatment plants using it for chlorination were even worse, structural steel having to be replaced.
Mark

 

[Dan from Oakland]

get rid of the acid!!! even in a closed container it will do what you have described.

 

[swarfless]

Regarding the forklift comment, I was thinking exhaust fumes if gas, battery fumes if electric, but now you mention Delrin fuming .. that & the hydrochloric acid are prime suspects.

 

[UncleFrank]

One place I worked had a plating area next to the machine shop. Once in a while the plating guys would screw up and mix something that created nitric acid gas. Overnight all the bare steel like parts, machine tables, gauge pins, tools in toolboxes, etc would have rust like your parallel, just not as bad.

 

[mhzinduction]

One place I worked had a plating area next to the machine shop. Once in a while the plating guys would screw up and mix something that created nitric acid gas. Overnight all the bare steel like parts, machine tables, gauge pins, tools in toolboxes, etc would have rust like your parallel, just not as bad.

Did you guys have a remedy to clean up the corroded items or did you pitch them? Not sure how accurate a gage pin would be if you had to polish it up to remove surface rust. We have a few pins that were out, for inspection, that have the same issue as the parallel. We figured that we would replace the ones that are trash, but if there is a trustworthy method to clean them up without changing the tolerance, that would help the pocket book.

 

[gregormarwick]

Did you guys have a remedy to clean up the corroded items or did you pitch them? Not sure how accurate a gage pin would be if you had to polish it up to remove surface rust. We have a few pins that were out, for inspection, that have the same issue as the parallel. We figured that we would replace the ones that are trash, but if there is a trustworthy method to clean them up without changing the tolerance, that would help the pocket book.

Not particularly helpful I know, but I hate the term "surface rust". All rust is surface rust, and all rusting is a subtractive process.

I like brillo pads with boiling water as the least destructive method of cleaning rust of precision surfaces, but a rusted surface is a rusted surface and the rusting can never be undone.

 

[rklopp]

Evaporust works will for removing rust without attacking the metal that remains. That's what I would use on parts that need to stay as precise as possible.

 

[UncleFrank]

Did you guys have a remedy to clean up the corroded items or did you pitch them? Not sure how accurate a gage pin would be if you had to polish it up to remove surface rust. We have a few pins that were out, for inspection, that have the same issue as the parallel. We figured that we would replace the ones that are trash, but if there is a trustworthy method to clean them up without changing the tolerance, that would help the pocket book.

Sometimes they could re-surface grind parts and save them. The rest of the precision stuff was usually toast. The machinists started putting garbage bags over their tool boxes attempting to keep out the acid fumes.

 

[mhzinduction]

Evaporust works will for removing rust without attacking the metal that remains. That's what I would use on parts that need to stay as precise as possible.

We have tried Evaporust on other items, in the past, and it tends to leave a black finish on anything it touches. Is that typical to what you have seen?

 

[rklopp]

We have tried Evaporust on other items, in the past, and it tends to leave a black finish on anything it touches. Is that typical to what you have seen?

I find the black wipes off easily.

 

[dalmatiangirl61]

We have tried Evaporust on other items, in the past, and it tends to leave a black finish on anything it touches. Is that typical to what you have seen?

I've found evaporust will blacken some metals, but not others, same batch one part is affected, other not. Scrubbing with a wire brush under hot running water will remove some of the blackness, but the part still has a grey cast. Read somewhere that Bar Keepers Friend will remove the grey, not sure if its because the abrasive, or the oxalic acid, have not tried it myself.

 

[Mechanola]

I have asked about salt in the streets because common salt is a chlorine compound, sodium chloride. Get rid of everything chlorine and or fluorine compound. Muriatic acid is your enemy.

 

[john.k]

If PVC insulation or piping is burnt it releases hydrochloric acid gas ,which wrecks everything metal in the vicinity.

 

[pcd]

Hi mhzinduction,

Did the rusting actually stop after you removed the jugs of acid?

 

[BT Fabrication]

Some coolants can contain chlorides in it, possible it could have mixed with a metal in the tank and started breaking down the coolant. Unless a battery is dying on you and off gassing from the forklift.

 

[Milacron]

We open up the bay doors when ever the weather allows, but being in Michigan, we haven't had too many chances in the last few months.

If the machine surfaces are colder than the outside air, depending on humidity, condensation will form when bay doors are open. After a period of cold weather and suddenly it's "nice outside" best to not let the outside in.

 

[PDW]

If the machine surfaces are colder than the outside air, depending on humidity, condensation will form when bay doors are open. After a period of cold weather and suddenly it's "nice outside" best to not let the outside in.

Yeah happens to me every autumn. A run of cold days then the temperature bounces back, condensation on every metal surface. These days I expect it and basically cover all surfaces with a heavy coat of oil then drop cloths over the top.

And - shit, it's autumn again....

PDW

 

[mhzinduction]

I have asked about salt in the streets because common salt is a chlorine compound, sodium chloride. Get rid of everything chlorine and or fluorine compound. Muriatic acid is your enemy.

They do not salt near us. We're set back in the woods off of a dirt road. Salt does wonders to our vehicles can't imagine it is any better on our machine tools. Thankfully they use most sand where we are.

 

[mhzinduction]

Hi mhzinduction,

Did the rusting actually stop after you removed the jugs of acid?

We polished up the parallel, pictured above, and returned it to the same place it previously was, and it has not changed appearance so far. We will leave it there for another week or so and see if anything comes about. So far it would appear that the acid in the shop may have been the culprit.