SS polishing level

[Hofer]

I'm going to order about 2BBL size SS304 vessels for MT/LT, Kettle and HLT. What polishing level it is supposed to be?

Thanks.

[Michael Murphy]

Im supposing your refering to the inner part since the outer is only cosmetic.

I would think the inner would be left cold rolled maybe called rolled 2B. the welded areas should be acid cleaned of any weld coloring. and perhaps smooth polished with a polish wheel. if the welder is clean, then a simple acid wash will work, not so important as the fermenters. But I have seen some pretty bad welds on ferementer extremities which made fine beer.

as for the outside, I prefer "checked" for the look and its ability to look good even when its not just cleaned.

[Moonlight]

I use the phrase "ground and polished"for the inside welds. Unless you are dealing with a regular food/beverage welder, that may not mean to them what you would like it to. A dairy tank will appear seamless, you likely don't want to pay for that. A wine tank weld is too crude for beer. This polishing of welds is where shortcuts are taken...be picky if the welder is not reputable.
The 2B finish most often refers to the luster of the sheet material.

[beertje46]

From my last quote/contract with DME:

Interior weld finish = stain removed,, polished to #4 on a regular margin

Exterior weld finish = stain removed and brightened on a regular margin.

Cladding penetrations are stain removed and brightened on a regular margin.

[Larry Horwitz]

3A 4B at least for interior welds. Exterior is cosmetic, but the cleaner the welds the easier to keep clean. I like at least stripe buffed.

[Hofer]

Thank you all for the input!
I was advised locally for 2B. 4B looks like overkill: these are just "hot side" vessels, not fermenters.
Where I could check what grit corresponds for #4 polishing?

[Larry Horwitz]

4B is only overkill if you want to scrub your stuff by hand a ton. Hot side gets just as dirty as cold side. It's your $$$.

[Hofer]

3A 4B at least for interior welds...

Could you please clarify: this 4B you recommend is for welds only?
Because I meant to order 2B polished SS plates and to polish the welds as for the proposed wording assuming that it is not polished better than the plate itself.

Thank you.

[Michael Murphy]

order it 2b, its the cheapest and it works, the welds should be polished by hand. We do this were I have fabricated equipment by taping around the weld line to get polished, and using a few differnet polishing wheels and finishing it off by scrubbing it in the same direction with a green abrasive scrubie. then take off the tabe and it looks clean and uniform. If the welder is good at what he does, then there wont be much polishing to do.

you will see the difference in the welded area and the rolled untouched areas, but as long as its clean no pits or poor welds it will be just fine.
I dont think they have a name for the level of polishing on the welds, just the finishes on the stock SS you can use.

the outside can be 2b 4b, checked, mirror, gold plated what ever you want