Trying to figure out how to remove the enamel from a Coleman vent.I think sandblasting might do it and I have also heard of a chemical method using acid to eat the enamel. Anybody have experience with this?
Sanding cabinet with some particularly hard grains probably the only way to realistically strip enamel from a vent in any reasonable amount of time (And that's a time consuming process in itself). Acids like HCL I think can also work but it'll take until the next blue moon to strip, it'll probably end up destroying the metal before it eats away the enamel.
Besides abrasive blasting, another way to remove the porcelain enamel is by stripping it in molten, pure dry sodium hydroxide at red heat....an extremely dangerous exercise. It'd still leave the steel undamaged. Molten lye will attack and dissolve almost any kind of ceramic, porcelain enamel and glass. Another equally nasty candidate is hydrofluoric acid.
@MYN Extreme caution when heating lye molten is that it'll start reacting with whatever residual water moisture trapped in the acid as it reaches temperatures, often violently offgassing, boiling for a decent amount of time until all water is driven out. Expect alot of splashing.
Yes, molten lye is way more nasty than just hot, concentrated lye solution. You can't use a ceramic, pyrex or clay pot for that. It'd just fuse and dissolve its way out from the bottom. Pouring any water into molten lye would certainly cause a violently explosive reaction. Something that most would avoid working with. Any bodily contact with molten lye isn't that much different in effects from those caused by molten steel, despite the molten lye not being quite as hot.
The first question that comes to mind is, what is your intention once the enamel is removed? Also, how badly damaged is the enamel and is the lantern/hood a hard to find item? If its a relatively common hood, finding a replacement in better condition would probably work out much cheaper and a whole lot easier. Alternatively, if it's a rare model with a hard to find hood you might consider leaving it in its current state as the hood may easily get damaged in the process. Maybe some photos of the hood might help to show us what the problem is. Also, I'm sure you already know this but painting the hood with any sort or normal spray paint is doomed to failure. Lantern hoods experience incredibly high temperatures up into the 1000C range (1800F), way hotter than even auto engine paints can withstand. Quite a few members have tested different coatings but in the end, only electro-plating or enamelling can withstand the heat of a working pressure lantern. Hope this helps.
If you really want to remove it with an acidic chemical, then the following mixture might serve. Percentages are by weight. Mix the following:- -Ammonium bifluoride(min. 96~97% purity): 11%. -Glacial acetic acid(98-99% concentration): 14%. -Sulphuric acid(min. 98% concentration): 7%. -Water(de-ionized): 68%. I'm not cooking this up . Its actually patented. The exact details and procedure is clearly stated within the patent:-
If it is a rare piece and you want it re-enameled send it here https://www.ipe-porcelain.com/ They will do all the prep and refinish. Excellent work, but expect to wait a while as the owner does lanterns parts as a side gig and waits until he has enough to do to make it worth his time. Otherwise, as said above, buy a replacement or leave as is.
