Galvanized steel?

loco · Post by **loco** » Thu Mar 15, 2007 4:21 pm

Hey, the only place I've been able to get 90 degree sections of piping is a ducting company who supply only galvanized steel. Other than being galvanized, it seems to be ideal: available in 100, 125, 150 & 200mm diameter, 22guage (0.9mm) thickness and quite a tight bend.

I've not welded galvanized before, but I'm aware of the fumes it gives off, so I'll be welding and running the engine in a well ventilated area. Is there anything else I need to know about using galvanized steel?

Also, what kind of steel is usually used underneath the zinc? ie, when I come to picking up the sheet steel for the rest of the engine, what should I be looking for? Can I weld it to stainless? Is there any point since the bend seems to get the hottest in these engines?

Thanks again in advance + sorry for all the newbie questions.

Post by **Mike Everman** » Thu Mar 15, 2007 6:43 pm

The steel is carbon steel. You can weld it to stainless with 308 filler rod. I usually soak gavanized parts in vinegar for 12-24 hours to remove the plating, so you are not subject to toxic fumes when welding or running the motor.

El-Kablooey · Post by **El-Kablooey** » Thu Mar 15, 2007 8:47 pm

I read a news article not too long ago about a blacksmith who (knowing better) tossed some galvanised steel in his forge to simply burn off the zinc. About two weeks later he died from complications from metal fume fever.

Anyway, just a little reminder of how serious this can get.

Oh yeah, you need 309l filler to weld stainless to carbon steel.

metiz · Post by **metiz** » Fri Mar 16, 2007 6:24 pm

galvanised steel melts at 419.53Â°C so you'd better get everything off before running the engine or else it will burn off giving a nice toxic vapor.

Post by **Mike Everman** » Fri Mar 16, 2007 7:27 pm

El-Kablooey wrote:
Oh yeah, you need 309l filler to weld stainless to carbon steel.

Oh, yeah, I sit corrected. ;-)

Zippiot · Post by **Zippiot** » Sun Mar 18, 2007 5:54 am

The steel or the zinc melts at 419 C? Pretty sure steel melts between 2800 and 3200 F...

If you want a more dangerous/hazardous way to take off the zinc in a few seconds grab a bottle of Muratic Acid from the hardware store, wear dishwashing gloves (the big yellow ones) and do this in a ventilated area like outside. Soak a paper towel with the acid and rub it over the steel, you will see much fizzing. The zinc is gone in a few seconds at most, most galv stuff has a very thin layer on it.
Muratic Acid is about 30% HCl which reacts with zinc, and to the best of my knowledge it gives off hydrogen (the fizzing). But the acid itself is concentrated enough that it gives off fumes so outside is a must! The acid is a cement cleaner and can be found near pool supplies or paint thinners.

If you want to test the effects before you do it on your jet toss a galved nail in the acid in a pill bottle, grab 2 nails so you can do a before and after; the zinc is all gone when the fizzing stops.

metiz · Post by **metiz** » Sun Mar 18, 2007 3:40 pm

The steel or the zinc melts at 419 C? Pretty sure steel melts between 2800 and 3200 F...

with "calvenised steel melts at 419 C" I of course mean the calvenised part and not the steel itself.

Mark · Post by **Mark** » Sun Mar 18, 2007 9:41 pm

http://www.anet-dfw.com/mikefirth/techspec.htm

loco · Post by **loco** » Sat Mar 24, 2007 10:21 am

so, having made my first engine out of mild... is this thing going to deform the first time I turn up the power? It's been a great learnign experience, but I'd be gutted if it didn't run, even for a short time.

Post by **Mike Everman** » Sat Mar 24, 2007 2:48 pm

No worries! It will run a good many times, and acheive that very special color every time. I have mild steel motors I pull out and run from time to time. They were .035" wall. If you'd made it out of a tin can, it would burn through in only a few runs.

loco · Post by **loco** » Sun Mar 25, 2007 7:56 pm

Good stuff!

one last question: will I be able to weld on a regular bolt to allow me to screw in a spark plug? Are bolts made out of metal that is Ok to weld onto mild steel?

Thanks again.

mag · Post by **mag** » Sun Mar 25, 2007 8:01 pm

yes, that should work!

Zippiot · Post by **Zippiot** » Sun Mar 25, 2007 8:29 pm

Many different types of bolts, at the hardware store they should be labled. Copper or brass wont weld, zinc wont either (very shiny blueish). Your best bet is to find a galvanized bolt, since you already know how to get the zinc off of it should just leave behind an easy to weld steel type. I would stay away from Stainless Steel bolts unless you are setup to weld SS...

309 rod to weld stainelss to mild? I use a mig so I dont know...

loco · Post by **loco** » Sun Mar 25, 2007 9:53 pm

yeah I'm on MIG also, I'll buy a couple and test it on some scrab beforehand.

thanks so much, guys.

Anders Troberg · Post by **Anders Troberg** » Mon Mar 26, 2007 2:28 pm

Mike Everman wrote:The steel is carbon steel. You can weld it to stainless with 308 filler rod. I usually soak gavanized parts in vinegar for 12-24 hours to remove the plating, so you are not subject to toxic fumes when welding or running the motor.

And if you still get some fumes, you'll usually wake up in the middle of the night with a cold sweat and high fever. If that happens, drink lots of milk, and I really mean lots. Drink milk until it almost comes back up again. That'll take care of it.

I'm not saying that you should ignore basic safety and breathe the fumes, but if it happens, drink milk.

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