apexmateria Posted October 16, 2020 Share Posted October 16, 2020 What kind of metal are these? Cheap steel? They're around 3-4mm thick and I have 30 in my shed, they're from my grandfather (he passed away). I want to grind some or maybe even heat them to use for projects. I assume it's safe since they're rusting it means no zinc plating right? Should I strip the coating off first as a precaution? Quote Link to comment Share on other sites More sharing options...
Frazer Posted October 16, 2020 Share Posted October 16, 2020 Structural steel tube is probably just going to be mild steel. What's the OD? Chrome plating (the title) vs zinc (your question) are two different things. Either way, because of the rust, it probably has neither. "In rust we trust". However, if you want to check for yourself for galvanization dip it in some white vinegar, if it bubbles, there is a zinc coating, if not, no zinc. Chrome won't bubble either, but I don't think that is chromed. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 16, 2020 Share Posted October 16, 2020 Spark test them; quench& break test them; so far all we can say is that they are steel, (due to the rusting). Chrome in the forge makes zinc look like a multivitamin! Quote Link to comment Share on other sites More sharing options...
Frazer Posted October 16, 2020 Share Posted October 16, 2020 Not all zinc is a multivitamin, but many multivitamins contain zinc Quote Link to comment Share on other sites More sharing options...
Goods Posted October 16, 2020 Share Posted October 16, 2020 These look just like some “vintage” kitchen chair/table tubes that are chrome plated. I’m sure you’ve seen old chairs or even bumpers rusted. I’d be very careful chrome can be nasty stuff. Quote Link to comment Share on other sites More sharing options...
Anachronist58 Posted October 16, 2020 Share Posted October 16, 2020 Many thinly chrome plated items are prone to have pinhole defects. The rust blooms through these defects, making patterns typical of what we are seeing here. Proceed with caution.... Robert Taylor Quote Link to comment Share on other sites More sharing options...
apexmateria Posted October 16, 2020 Author Share Posted October 16, 2020 Thanks for the warnings, good to know! At the moment I need to cut a slot down one of the pipes with an angle grinder. Can you guys advise me how to proceed? Should I just sand off the chrome paint / plating where I want to cut? Is paint stripper / vinegar a better option? Frazer - OD = 1". Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted October 16, 2020 Share Posted October 16, 2020 Chrome is very hard, and paint strippers won't touch it. Get a respirator and slot them outside. Quote Link to comment Share on other sites More sharing options...
apexmateria Posted October 16, 2020 Author Share Posted October 16, 2020 At the moment I only have n95 masks. My respirator is this model but has no filters. Any idea what kind I need? I need it to keep me safe from refractory fiber as well since I'll be building a forge soon. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 16, 2020 Share Posted October 16, 2020 Fibers from ceramic blanket doesn't require more than a decent quality dust mask fitted correctly of course. Chrome dust or worse hexavalent chrome from being heated is much more serious, N95 isn't even in the ball park. You need to find out what cartridge your respirator uses to block metal vapors. I gave up trying to explain to supply their idea of a dust mask wouldn't work against welding and paint fumes and made them buy me a 3M White Cap 3 supplied air welding helmet, air pump and extended intake hose. I put the intake hose outside and wore that heavy beast but didn't have to breath the B A D stuff anymmore. I'm not suggesting you buy a supplied air system, just get the right thing, what you do to damage yourself now will really start to get you in your 40. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
BsnNFrnt Posted October 16, 2020 Share Posted October 16, 2020 Do a search of the American Council of Governmental Industrial Hygienist’s. This is the group the researches the chemicals used in manufacturing processes. The resource will help explain the risks. I agree with Frosty - not worth it. Unless it is Zinc, it will be highly dangerous to heat. Quote Link to comment Share on other sites More sharing options...
apexmateria Posted October 16, 2020 Author Share Posted October 16, 2020 Thanks for the help Frosty, dealing with metal vapors sounds slightly terrifying I'd prefer to avoid that https://multimedia.3m.com/mws/media/40744O/3m-respirator-cartridge-and-filter-selection-poster.pdf Is the 3M 6001i a suitable mask? Should I maybe strip off the chrome before grinding instead? I see there are some methods floating around using acids or electrolysis. Quote Link to comment Share on other sites More sharing options...
Goods Posted October 17, 2020 Share Posted October 17, 2020 Apex, if you can dissolve the chrome off, your solution will be a pretty strong toxic waste! Chrome is most dangerous in it’s hexavalent ionic state. Don’t plan on using it in a forge, worst possible situation there. Right now, the chrome is in a stable form, heating it to high temperatures will change that. Forge, plasma cutter, torch, welder, heavy grinding - all bad. Light grinding is not good either. Dust has a very high surface area and will react quickly. I can’t say for sure if the result will be hexavalent or trivalent form of ionic chrome, but you really don’t want either floating around you or others. Large chips aren’t a problem. So, hacksaws, carbide burrs, drills, etc. are fairly safe. Just clean the chips up, you don’t want them embedded in you skin. Lots of other uses... All, I’m not an expert, so if I‘m miss interpreting something just jump right in... David Quote Link to comment Share on other sites More sharing options...
apexmateria Posted October 17, 2020 Author Share Posted October 17, 2020 Even just touching the bars puts little specs of chrome onto my fingertips (because the rust is slowly flaking it off). Kind of a shame because it's so much metal that would be useful for projects, it is what it is though! Thanks guys, appreciate you helping me out. I won't grind or cut them. I'll find a safe use for them one day. Quote Link to comment Share on other sites More sharing options...
Frazer Posted October 17, 2020 Share Posted October 17, 2020 Apologies for the misleading? Perhaps just bad advise. From where I was sitting it really didn't look like chrome to me. Now that I'm looking at it again it does look more reflective in your pictures than I saw initially. My mistake. It is 1 inch tubing though so I'm sure you'll find a use for it eventually. Quote Link to comment Share on other sites More sharing options...
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