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Hellbender
10-18-2002, 01:56 PM
Are there any worries about galvanic reactions if you attach SS (304 or 316 alloy) to mild steel (outdoor in the elements)? The parts will be painted after assembly, but will be in direct contact under the paint. I know totally dissimilar metals will cause problems, but didn't know about Stainless.

Thanks,
HB

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NRA Lifetime Member

mbensema
10-18-2002, 04:04 PM
According to a machine design book I have, they are only compatible when the mild steel has at least one coat of primer.

Mike

mbensema
10-19-2002, 08:26 AM
I should have also added that chart specifies steel being compatable with any metal only when primed.

Mike

trap
10-19-2002, 07:49 PM
not enough info ..... where I live no matter what you do the steel will only be around for a short time. (rust) SS lasts a little longer if marine grade and wood will only last a day or two. (termites) Will electricity be going thru it and how close is that deadly aluminum stuff?

proud to be a NRA lifer too.

jim
10-19-2002, 08:57 PM
HB, are these parts bolted or welded together?

As I learned in a basic welding course this last summer, there should be no adverse reaction as long as it is welded with stainless welding wire. Don't know why, just what I was told. If they are bolted together, I see the problem of paint cracking or not even adhering at the joint and allowing moisture to start the rusting process.

jim

Hellbender
10-20-2002, 07:26 PM
The parts will be bolted together w/ SS bolts, I even wonder about the SS bolts being threaded into the mild steel. My gut tells me it will never be a problem, but I'd to recco it to someone and then be a problem later.

On the welding....can you weld SS to mild w/o problems? Can you do this with a MIG? What wire/gas/etc?

Thanks again,
HB

[This message has been edited by Hellbender (edited 10-21-2002).]

KendallF
10-20-2002, 09:18 PM
<font face="Verdana, Arial" size="2">Originally posted by Hellbender:
The parts will be bolted together w/ SS bolts, I even wonder about the SS bolts being threaded into the mild steel. My gut tells me it will never be a problem, but I'd to recco it to someone and then be a problem later.

On the welding....can you weld SS to mild w/o problems? Can you do this with a MIG? What wire/gas/etc?

Thanks again,
HB </font>

You ought to do it with a TIG..the filler rod needs to be at least the same grade stainless as the stainless part being welded. I guess someone probably makes stainless filler wire for MIGs but I've never seen any personally. Argon shielding works fine.



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Kendall Frederick
Orange Park, FL
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chip's
10-20-2002, 10:39 PM
You can weld stainless with a mig just fine. They make (I believe 308) wire for mig's. It is sure not as clean as a tig though.
Rick

Thrud
10-24-2002, 02:28 AM
Bolting fine. Welding not. Welding bad idea. For a lasting finish on the mild steel consider a powder coat. Epoxy paints are tough but are damaged by UV (Grain rail cars are painted with this stuff - they get "chalky" looking after a time). Two or 3 part Ureathane is a good comprimise for a liquid finish. The mild steel paints (liquid) best with a hot phosphate dip or base primer - check for compatablity with your finish.