Galvanized vs. Stainless
stephenr
| Posted in General Questions on
I am going to shoot off raw spruce with a coil siding nailer for my siding. Its more cost effective to shoot galvanized than stainless, by a lot. I am told hot dipped is better than electro. I don’t want the galvanized to rust and bleed down my siding. Advice?
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Replies
Electro galv has a lot less coating thickness than hot dipped (HDG).
The tannins in some woods like cedar can cause rusting of HDG nails, but not sure how spruce compares with tannin content. If you're concerned about exposed HDG rusting/streaking eventually, stainless is the only way to completely eliminate that risk.
Thanks Chris. Unless someone knows that spruce and HDG together won't cause bleeding, I will have to cough up for stainless.
It's hard to say for sure that hot dipped galvanized will be safe over time. Some things degrade the zinc coating, and it is just a coating. For underground stuff, as long as there is zinc on the underlying metal, it will protect any exposed areas. I'm not sure if that applies to fasteners though, so it might be if the zinc coating has any thin spots that erode away first, rust might start on the underlying metal and then you'll get streaks.
If you'll have exposed fasteners and you're really concerned, I'd spend the money for stainless nails and play it safe. Rust streaks tend to soak into the wood if the wood isn't sealed, and then you have a problem with no simple solution if you do end up having a problem down the road.
BTW, electro galvanized is nothing like HDG. Absolutely avoid electro galvanized for outdoor stuff.
Bill
You can try the new wood nails (lignoloc nails). No corrosion worries there. Only 5x the cost of stainless + the special gun.
Hopefully that gives some perspective that the stainless nail cost isn't as bad comparatively.
Jamie
Thanks! interesting stuff.
The traditional nail for white cedar shingles was a 4D galvanized box nail, and before that a plain steel square nail. Neither tended to create stains except for directly around the nail, even on coastal homes. I still recommend stainless steel nails for clients' projects near the coast, but otherwise I use galvanized. Inland, such as on my own house, I'm fine with electro-plated, but if you're close to the coast I'd go for hot-dipped to be safe. (Sorry, I keep forgetting where you are in Maine.)
Michael--
Where I am by the coast local code requires stainless for cedar shingles. My personal experience is that when the nails are covered by another course of shingles they basically last forever, I've pulled off shingles that may have been 100 years old and the plain steel square nails were fine. However, if the head is exposed -- either because the shingle is face nailed, or the nail falls on a gap in the covering course -- even hot-dipped nails will start rusting rather quickly and the head will fall off and then the shingle comes loose.
Salt spray in coastal areas is nasty stuff for metals. Aluminum antennas usually have to be sprayed with what is basically a clear coat for protection. Steel fares very poorly. REAL hot dipper galvanized fastners (the dull gray ones, not shiny) may hold up OK, but not as well as stainless.
I can't say for certain in this exact application, but if it were me, I'd spend the money on stainless and not worry about it. I just don't like to take chances where the savings are relatively small, and the potential for messing up something hard to fix is there.
Bill
DC, that's interesting that it's in the code there. I agree that if the nailhead is exposed than it's a different situation. Good shingling technique does not put the nails within 1/2" of being exposed, but that rule is sometimes broken of course.
Serious question: Have you considered Copper, Aluminum, or another non-ferrous metal altogether? Ends the potential for corrosion and discolouring, but yes, you might have to change your workflow (to manually hammer them in?)
While I am always offended to pay hundreds of bucks for a box of nails, as a percentage of the cost of the project...I don't know if spruce is 100 year siding, so maybe SS is overkill, but in the scheme of things not that much money
Great replies, thanks. I have a fair bit of carpenters thumb, which is exasperated by hand nailing and impact driving (time to switch trades? ). A coil nailer with a vibrational glove seems the best way to get the siding nailed off in this case. I am in Waldoboro on the coast. Ther salt air puts a surface rust on everything. I keeo a can of silicone on the ready. Glad we have stainless.
I like the Bostitch siding coil nailer. For spots where it won't fit, like under a gable overhang I like a palm nailer. Between the two I rarely use a hammer.
The drawback of stainless nails is the magnet in the palm nailer won't hold them.