Preservatives: My head is spinning

[HarryH]

After reading a ton of threads on CPES, thinned epoxy, Valnor, Dr. Hook's Cure-All, etc. I am stuck for a solid, but simple suggestion as to what to brush on my pre-assembly stem and keel members to retard rot from trapped fresh water below. (No encapsulation/glass on this boat..)

Back before we apparently knew better, Cuprinol was the rage for both end grain application and obvious water traps. I read Royal Lowell and his Down East boys use(d) it liberally before stem/etc. bolt-up. Wonder if they still do...I will use all the water-shedding construction techniques at my disposal where it makes sense, but wonder if there is a fairly safe chemical help. I am looking for preservative (rot-inhibiting) qualities, not necessarily anything to make paint penetrate, flow better, etc., although whatever the preservative, it should obviously not hinder paint adhesion/longevity.

In terms of harm from toxicity, I will have a vee berth below, but will not live there...

Thanks for your reply....

_Harry

[Nicholas Carey]

Painting everything with red lead primer, expecially faying surfaces—surfaces that will be bedded against other surfaces—prior to assembly is rather traditional. Works well, too, from what I've been able to see.

George Kirby, Jr. makes a good red lead primer.

Copper Napthenate (ake "Green Death") works well, too. Here's a USDA Forest Service's Forest Products Laboratory paper on the topic —your tax dollars at work :D —entitled Fungal degradation of wood treated with metal-based preservatives: 1. Fungal tolerance (http://www.fpl.fs.fed.us/documnts/pdf1996/illma96a.pdf), by Barbara L. Illman and Terry L. Highley.

Here's the paper's abstract:
Abstract
In recent years, concerns have arisen about the leaching of heavy metals from wood treated with chromated copper arsenate (CCA), particularly because of the large amount of CCA-treated wood that will be discarded in the coming years. The long term objectives of this work are to determine the fate of copper, chromium and arsenic with the aging and potential decay of CCA-treated wood, and to develop strategies for recycling and remediation of disposed wood. In this study, we determined the ability of various decay fungi to decompose southern yellow pine wood treated with CCA or other metal-based preservatives. Isolates of Meruliporia incrassata and an isolate of Antrodia radiculosa caused the highest weight losses in CCA-treated southern yellow pine. One isolate of M. incrassata produced similar weight losses in CCA-treated and untreated southern pine after 10 weeks. Pine samples treated with very high levels of copper sulphate were decayed by M. incrassata, but the fungus was unable to decay wood treated with copper napthenate or copper-8-quinolinolate.There's a number of different copper-napthenate-based products available, I believe.

[ 08-21-2004, 11:40 PM: Message edited by: Nicholas Carey ]

[HarryH]

Thanks for the abstract and the reply, Nicholas....I am thinking copper napthenate, although I could pick up a gallon of red lead from Mr. Kirby's retail shop which is a town or two over. 5200 appeals to me as a faying compound though, since I have been impressed with its below waterline hardiness. That's another thread though..

Do you know of any copper napthenate products by name? Searched here and Googled around, and came up with a ton of reference material, but no list of products.

_Harry

[Ken Hutchins]

You asked "Do you know of any copper napthenate products by name?" Yup sure do it is Cuprinol.