Pressure treated wood and aluminum boats

Comoxsam

Seaman Apprentice
Joined
Jul 31, 2010
Messages
49
I see this advice getting posted a lot so I thought I would start a thread as a warning to all those thinking of using pressure treated wood in (or around) their aluminum boats and trailers.

Apparently certain types of pressure treated wood contain copper which causes dissimilar metal corrosion with aluminum.

Below are some photos of the bottom of one of my boats. The boat was sitting on pressure treated wooden bunks that were covered with carpet. The carpet got wet and the chemicals leeched thru and corroded the bottom of the boat quite badly. All this damage happened in 1 year!


http://i438.photobucket.com/albums/qq107/ComoxSam/P1030707.jpg

http://i438.photobucket.com/albums/qq107/ComoxSam/P1030705.jpg

http://i438.photobucket.com/albums/qq107/ComoxSam/P1030700.jpg

http://i438.photobucket.com/albums/qq107/ComoxSam/P1030698.jpg

There are some people who have been using pressure treated wood with aluminum and haven't had any problems. I suspect it might have to do with a different type of treatment on the wood. The stuff I used had a tag right on the end saying not to use with aluminum. Unfortunately I didn't read it until it was too late.

I'm not saying never use PT wood on your boat but this is a warning about what could happen.

Hope this helps.
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,019
Re: Pressure treated wood and aluminum boats

Been discussed here hundreds of times.

The new PT wood is ACQ which is treated with a higher concentrate of copper oxides....... which is "supposed" to be safer than the old stuff which contained more arsenic.

The copper oxides are highly reactive.

PT is primarily treated against insects and fungus.

Your damage can be repaired. A few coats of gluvit epoxy on the exterior of the hull will fill in those gaps and since it is under the hull..... it will not have to be painted to prevent UV damage.
 

Comoxsam

Seaman Apprentice
Joined
Jul 31, 2010
Messages
49
Re: Pressure treated wood and aluminum boats

Been discussed here hundreds of times.

The new PT wood is ACQ which is treated with a higher concentrate of copper oxides....... which is "supposed" to be safer than the old stuff which contained more arsenic.

The copper oxides are highly reactive.

PT is primarily treated against insects and fungus.

Your damage can be repaired. A few coats of gluvit epoxy on the exterior of the hull will fill in those gaps and since it is under the hull..... it will not have to be painted to prevent UV damage.

Yep I see it is discussed a lot yet I continue to read posts where someone mentions using PT wood and everyone has to jump in with the warnings. Maybe we need an aluminum boat FAQ around here. :)

I guess I could repair my boat with some epoxy but I'm an aircraft sheet metal guy and glue doesn't seem right for some reason....
 

Bob_VT

Moderator & Unofficial iBoats Historian
Staff member
Joined
May 19, 2001
Messages
26,019
Re: Pressure treated wood and aluminum boats

I guess I could repair my boat with some epoxy but I'm an aircraft sheet metal guy and glue doesn't seem right for some reason....

Fighter jets have their skin applied with epoxy. The automobile industry uses epoxy too which will survive a crash.

The gluvit coating is good stuff...... here is a good article you might like http://www.steelheaduniversity.com/gluvit.htm
 

dozerII

Admiral
Joined
Oct 25, 2009
Messages
6,527
Re: Pressure treated wood and aluminum boats

That is pretty nasty, good thing there is lots of info on this site, as it stopped me from using pt plywood for the floor in my Starcraft.
 

Comoxsam

Seaman Apprentice
Joined
Jul 31, 2010
Messages
49
Re: Pressure treated wood and aluminum boats

Yes I feel really dumb for letting this happen. Hopefully others will be more informed.
 

RickSewall

Cadet
Joined
Jul 30, 2007
Messages
15
Re: Pressure treated wood and aluminum boats

This info in right on. I took off some pressure treated plywood and it had begun to corrode the aluminum in a few months. Good advice and do not use it.
 
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