I had planned to use some aluminum angle pieces to tie down the front of
some benches I made for my deck. When I looked at the tag on the PT wood it
said "Do not use preserved wood in direct contact with aluminum".
The label says the wood is treated with Alkaline copper quaternary
compounds. Anyone know what happens if Al is used with this??
My guess is, the Al turns to a pile of white powdery gunk. The stuff is
The recommendations I've heard/read are to use stainless or, barring
that, heavily galvanized (hot-dipped?) materials.
I seem to remember a _This_Old_House_ episode where they used heavily
galvanized brackets and used a rubber sheet between the wood and the
bracket. They even went so far as to use a piece of rubber hose slipped
onto a hot-dipped galvanized lag screw to keep the screw from contacting
Great! The government makes a product that works as advertised to be taken
out production. It is replaced by something that is known to react
_unfavorably_ with accepted, cost effective, materials and practices forcing
the industry to go to extreme lengths or radically increase the cost of
doing business. All of this because people can't or won't learn to handle
materials in a safe and responsible manner. Or, more likely, some litigious
jerk found a lawyer to make a corporation pay for the jerk's mishandling of
On Thu, 04 Aug 2005 15:37:34 GMT, firstname.lastname@example.org (Lawrence
There is a non toxic alternative check out http://www.timbersil.com /
I saw it in the September TOH magazine in a one page blurb. Have not
used it but if the cost the same and you can get it, why not? Other
than silcia will eat your saw blades.
On 8 Aug 2005 10:50:45 -0700, email@example.com wrote:
Wish I knew, local lumber yard is looking at getting some at my query.
Did you try email or are you an impatient type like myself? Seems as
though they are trying to lineup "treaters" as there are only two
listed on the web site might be an opportunity to get in on the ground
Doubtful this would pertain here. Dissimilar metals as electrodes and an
electrolyte, maybe. Like the aluminum window frames and steel screws they
used on the US embassy in Cuba. Sits right at the shore in the salt air.
No? Seems like a solid state battery to me. It's treated with an
Alkaline copper compound, and then a dissimilar metal is pounded into
it as an [anode?] (I always get anode/cathode mixed up) Put it in a
little metal cylander and throw a volt meter on it, and I'd bet you'd
get a reading- not a Duracell, to be sure, but a simple battery none
It's doubtful that a plain steel screw would be used. More likely that a
galvanized steel would be used. And since zinc and aluminum have a
relatively small potential difference, it's not a big problem.
Perhaps I was unclear. I was stating fact, not speculation. The aluminum
was eaten away an inch or more in some directions. The rusty screws which
had the protection of the aluminum were in good shape. Where the aluminum
had ceased to be in contact, there was a modest pile of rust where the screw
I belive the problem here is that the wood will also retain a bit of
moisture. This moisture, along with the "Alkaline" compounds will create an
alkaline environment in contact with the aluminum. Aluminum dissolves in
alkaline solutions. That's why they tell you never to use oven cleaning
compounds on aluminum (strong alkaline solution). Understand, this won't
happen overnight, but the situation is similar to using untreated steel
angles for this job. Over time, they will both corrode.
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