CPES, Paintable wood preservative, & Borates
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Joined: 12 Feb 2009
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PostPosted: Sat May 30, 2009 4:54 pm    Post subject: CPES, Paintable wood preservative, & Borates Reply with quote

After reading the numerous posts here regarding CPES, Paintable Wood Preservative, & Borates I feel like a discussion is warranted to determine advantages & disadvantages regarding one over the other. Anyone with an opinion please respond (Especially the Master of this Realm) regarding your experiences using the above mentioned products. Below I will list my feelings regarding my thoughts and experiences.
(CPES) Clear Penetrating Epoxy Sealer- I personally have had wonderful results from this product made by Smith & Co http://www.smithandcompany.org/ . This is a 2 part mixture 1 part epoxy 1 part resin that is very similar to Liquid Wood sold by Abatron www.abatron.com , or ConServ 100 sold by www.conservepoxy.com. The pot life of CPES (Smith) is 4-6 times over Abatronís (Liquid Wood). I take that to mean it is better kinda like considering a quick dry primer over a penetrating primer which is considerable longer and better. I may be dead wrong on this point ( preference) You can find a wealth of information on this product through a reseller called the Rot Doctor www.rotdoctor.com. This is one of the best places I have been to for information surrounding CPES.
My Results
1. Eliminates loose issues with muntins, rails etc
2. Acts as a wonderful primer (although I still go overboard and use a penetrating primer)
3. If wood is weathered, rotted, porous, infected with fungus, mold, or mildew etc this product ends these wood deterioting effects
4. The manufacture claims that a borate or fungicide is not needed if this product is used and saves a step as well as time considering a Borate is not needed if warranted (Would love to get John & Jades opinion in this department).
5. Eliminates the need for a paintable wood preservative as many recommend including the Master John Leeke whom I appreciate and respect deeply for what he has done here and the movement he has helped create
6. If a wood epoxy is needed you already have a product it will bond with
This post was made because I have not heard John or many for that matter talk about this product in the way I have mentioned above or give them any endorsement regardless of Brand. My research, understanding, and experience has lead me to believe this product is the gold standard. I look forward to hearing your opinion regarding what I may be missing as I am admittedly still a student of window restoration.

As always thank you very much for all you have taught me


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PostPosted: Sun May 31, 2009 9:54 pm    Post subject: Reply with quote

Paul, thanks for starting this discussion, it will be a good one

The philosophy behind all my work and Historic HomeWorks:

>>Master of this Realm

Well, let's say Host of this Realm, or possibly Gardian of this Realm.

>>give them any endorsement

I, personally, do not give endorsements (opinions that are paid for) for products, and I seldom recommend specific products, and I hope I never slip up and tell anyone which product to use. However, I always talk and write about specific products when I actually know something about them that has proven useful in my own experience.

I DO try to understand what works and how it works and why it works. Then I can select the best method or material for a particular situation. Method and type of material or product is always far more important than any specific product.

>>this product is the gold standard

For me, I do not find, or even look, for 'gold standards' in products. 'Gold standards' are far more likely to be found in thoughtful knowledge and methods, and sometimes found in the traditional materials (wood, glass, linseed oil, granite, clay, etc.)

This is not to say that 'products' are bad.

I have been thinking (and doing) long and hard about standards lately and will be writing and speaking about standards more in the coming weeks and months.


by hammer and hand great works do stand
by pen and thought best words are wrought
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Joined: 08 Apr 2009
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Location: Indianapolis, Indiana

PostPosted: Mon Jun 01, 2009 3:10 am    Post subject: Reply with quote

Paul, I am glad to know of your experience with the CPES. But you didn't mention HOW you use it (e.g. are you saying that you completely encase a wood item with the product, or only use it on certain surfaces?). There are a variety of products that I use, and I wouldn't necessarily use some of my favorite products in certain applications. Are you saying that you prefer to use this one product in virtually all your applications?

Your raising this subject gives me the chance to once again raise the question as to whether epoxies actually "penetrate" into the wood or whether they simply fill voids. How far does this product that you like penetrate into the wood (not exactly of course, just can you see it being absorbed) and does the porosity of a given species of wood impact its ability to penetrate in your experience? What about adhesion of the paint to the penetrating epoxy...is it as good as applying the paint directly to the wood substrate...how do you get the "penetrating primer" to work after you have applied the penetrating epoxy (doesn't the epoxy prevent the primer from penetrating)?

As much as I want to learn about your choice of products (and hope that you will help me learn through my questions), I do appreciate John not using his Forum to push specific products (actually admire him for resisting the temptation). There are so many applications on so many different substrates in so many different settings (environs) that having a quiver full of options seems like a wise approach.

Finish Well!
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Location: Plymouth, Indiana

PostPosted: Mon Jun 01, 2009 7:02 am    Post subject: Reply with quote

This is a very good discussion. We are very interested in correct uses of primers and paints. We have our own "standards" for prtecting and coloring of our work. We use according to what we have experienced in our relatively short business life. We also depend on the experience and advice of other experts, such as we find here on John's forum.

I can see the need for a thorough and profesional discussion (or forum) on all around standards for our industry. This industry is large enough to warrant "standards" for all of us to do our work by. John said he's been thinking and doing a lot with standards. The outcome would be less Historical sashes being abused by wrong procedures.

Many of us jumped in to the restoration field for many reasons. One product, Epoxy has allowed us to "be restorers" easily and quickly, or so it seems. Some of us are realizing that there is quite a bit more to it than just soaking rotted wood in a consildant and filling voids with epoxy.

Thanks to many here on this forum I got a wake up call. Not that we were doing bad work (I think our work is pretty good) but there's a whole other segment to restoring. Repairing wood with wood is sometimes better than repairing wood with epoxy. DUH!!

John, don't underestimate the value of this learning tool you have and I think you may be starting to relize your next level in growing this industry.

I'm here and I'm learning. I'm interested in restoring the correct way.

OK, please continue to talk about priming and painting.

Steve S
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PostPosted: Mon Jun 01, 2009 6:21 pm    Post subject: Reply with quote

I should have went over this and I am glad you brought this up. I usually cover all areas that are at least weathered(definitely all muntins & joints) of the sash with CPES. However not the top, bottom, or sides unless needed but even if this is the case I will be very careful not to seal the sash as I believe it needs to breathe.

Regarding areas which are not very weathered I use Mr. Leeke's rarely endorsed product which goes by the brand Penetrol.

The more weathered or rotted the wood the more CPES will soak into the wood (quickly) I will feed the wood the solution until it stops absorbing the product. For wood with fair to poor joints nothing is better for injecting the product than a syringe and needle (I use the one from rot doctor as it is very industrial in quality) I only insert the needle into the joint i will use the syringe to spray all around them and usually brush the rest. It's remarkable how much a severely weathered joint will absorb and I also will clamp the sash square because after the product cures you will not have anymore loose joints. Yes I said it and you read it loose joints are eliminated with this procedure unless they are in such poor shape they need replacing.

What I have not considered as well as I should have is your question of penetration...Weathered wood penetrates wonderfully however wood in great condition does not. For most purposes however historic windows that I have come across even on the interior will absorb it somewhat. John describes how borates go through all the wood uniformly and my feeling is this is not the case with CPES and in thinking this out I feel confident that it does not HOWEVER; I am of the opinion that CPES penetrates all the way to the good wood and then partially into the good wood thereby preventing any fungus issues. PROBLEM SASHES WITH FUNGUS/INSECTS NEED TO BE TREATED WITH BORATES. CPES DOES NOT TREAT NOR AM I ADVOCATING IT DOES. I am of the opinion as are many I have read that CPES prevents by impregnating the wood so as to make the food undesirable per the manufacture. CPES makes the wood resistant to insects/fungus. If you have a problem BORATES!!!!

Regarding if a penetrating primer will penetrate after using CPES. I have not had a problem with the penetrating primer. Remember to let the CPES cure according to the specs on the can. There is a temp/ time advisory on the can---the warmer the quicker the cure.

CPES is such an excellent primer that I really think that a primer coat is overkill. Much to my surprise I just looked at the manufacturer's website and they have relabeled the product under the name MultiWoodPrime for more info see http://www.smithandcompany.org/mwp/index.html

The above link also shows the penetration of CPES with dyed CPES to show its penetration so we have our answer and my gut was right.

Regarding the penetration of different species with CPES. The above link also addresses this question and states yes different levels of wood have different porosity.

I have spoken with the owner of this company and he is a hands on guy who is willing (was with me) to speak to people who have well thought out questions. Point being, read the info on his site before calling him and asking him something you could have read as he is a busy man. www.rotdoctor.com is also a wonderful research tool that is a must read in my opinion and they resale Smith& Co products but have much more information. http://www.jamestowndistributors.com is also a good source for CPES.

I would also highly recommend the Layup and Laminating resin as a better alternative to any epoxy hands down. You can mix it with fine sawdust and get any consistency you want for whatever application. Not good if you need to handle the epoxy so in this case I would stick with the traditional epoxies in these cases. I love using it in joints that the cpes wont fix. Fixing a muntin joint is a nightmare with traditional epoxy and you cant get it completely in the joint. This product is also more flexible than any product I have found. A whole topic can be dedicated to this product.....simply amazing and no I do not work for this company lol

Maybe Jade (the other Guardian of the realm) will weigh in on this.

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PostPosted: Wed Nov 04, 2009 4:38 pm    Post subject: Wood Preservatives... Reply with quote

Hey Guys,

Thanks for all of the great info on anti-fungals/wood preservatives etc. Working in a very arid climate, I am normaly blissfully ignorant of such things as fungi growing on old windows (shocking!) However, I am now researching the proper techniques for treating new wood that is to be installed outdoors in more humid climates. Sounds like the CPES is a clear winner. Should a boractic acid treatment be used in conjuction with the epoxy? Also, has anyone heard of Woodlife Classic clear wood perservative? I haven't seen it discussed anywhere, perhaps it is a bogus product. Thanks in advance for any advise.
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PostPosted: Thu Nov 05, 2009 12:09 am    Post subject: Reply with quote


Do you have severe rot? If moderate to severe rot is present I would use a borate powder i.e. Timbor. Many if not most claim and promote Bora Care which is Termidor in a glycol base but the glycol will inhibit the ability of the CPES to penetrate and bond fibers. Rot Doctor as well as the manufacturer have and published research backing this claim. They also claim borates are over kill. I like overkill if the rot is severe enough to substantiate the time required. For most practical purposes however scraping away the rot and allowing drying time apply CPES to consolidate the remaining fibrers and allow for sufficient curing time before applying filler. CPES is based on wood resins as opposed to petroleum for its resins and are therefore the CPES is more flexible and in my opinion an unmatched product. I have tested Abatron and CPES and abatron is far lower quality product.

Regarding Woodlife Classic clear wood perservative. This I believe is a paintable water repellent. Used for exterior surfaces and can be used as such however I stick with CPES as it is far superior. If the wood is not weathered then Woodlife classic would be the route I would take as the CPES would be overkill.

After applying the CPES or water repellent, I apply a slow drying premium penetrating primer which is also overkill most of the time, I then apply 2 coats of Duration by Sherwin Williams. Duration is a premium one coat application paint due to its high resin content. Incidentaly it also carries a mildew additive. It carries a lifetime guarantee and is thicker than most paints. After this regiment is applied It will last a lifetime. I don't think you can get a better system.

This expensive procedure is for my house. I only do things above and beyond the status que. This is not practical for most budget minded home owners. You could however use this as an option in your impressive proposal to the discerning homeowners who are willing to pay for quality.


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PostPosted: Sat Nov 14, 2009 11:15 pm    Post subject: Reply with quote

I've been into cooking lately (work is a thing of the past I guess :)) and part of that has been marinating meat. I do it buy putting it in a bag and then vacuum sealing the bag. This drives the marinade into the meat. It occurred to me that with modern preservatives being available something like that could be done to windows. A person could rig up a PVC pipe or possibly a vacuum bag to a vacuum pump and put the parts and preservative in it. In a sense you would create your own treated wood albeit a lot nicer looking.

I'm not a big fan of paint. Prefer stains, even colored stains. It at least gets into the grain. As wood expands and contracts paint doesn't follow. Then you get the cracks that eventually lead to moisture getting in .
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Steve Smith

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Location: Richmond CA

PostPosted: Sat Dec 12, 2009 3:19 pm    Post subject: Reply with quote

Hello. I'm Steve Smith. Let me add some clarification to the discussion, and I can answer particular questions or refer you to on-line literature.

The interesting thing that Clear Penetrating Epoxy Sealer (also known as CPES, both (tm)) does, is this: It selectively wets the parts of wood where fungi have eaten abnormal porosity into wood.

Think about that for a moment.

It finds the rot.

There's simply nothing else in the marketplace that does this, and here's the proof: Go to www.woodrestoration.com. You will find there a paper that is the report of tests I did in the middle-nineties, that has time-lapse photographs, pictures taken thru a microscope and so-forth, and shows that it selectively wets the deteriorated parts of wood, whereas water selectively wets the sound parts of wood. Quite amazing...I had no idea it did that when I invented in it 1972.

There's even the entire test methodology and an open standard at that website, as I thought the market was big enough for many companies. No one else has wanted to make a product that meets that standard, so that's why I say CPES is truly a unique product.

So, there's the underlying science, and that's why I and my distributors say what they do. It turned out, even by the middle seventies, that my customers discovered it was the world's greatest primer for paint and varnish. It took me another twenty years to finally discover WHY paint lasted ten, fifteen and more years on a house. My customers told me it did, and there's a LOT of historic houses around the country that benefit, even with the paint companies forced to use lower-quality waterborne primers. There's more science behind that, too. Literature about that is available from the company website www.smithandcompany.org, and more extensive literature will be mailed on request. What I am saying here is that I discovered some basic things about the science of wood and paint and their failure mechanisms, and that's what's behind the product.

There are borates (some in glycol solutions) that dissolve in the natural water of wood, and discourage Small Life from taking up residence in the treated wood. Soluble borates can migrate by diffusion within the wood, and that is perfectly compatible with CPES and paint topcoats. Don't use the glycol-solutions, as glycols mess up a lot of things including epoxy resin systems. This has been a topic of discussion on many forums, including a long scientific post on the Wooden Boat Forum some years back.

To treat your wood with sodium borate, just buy some Tim-Bor(tm), technically disodium octaborate, and dissolve to make a few percent in water, and soak the wood with it, and then let the wood completely dry (which may take a week in warm weather) before using CPES.

There's a new borate on the market, the almost insoluble zinc borate. It's much better than sodium borate for discouraging Small Life, and does not easily migrate or wash out of wood because it *is* almost insoluble. It is actually the only environmentally friendly wood-treatment material there is, and replaces all the more dangerous wood preservatives. Zinc and boron are harmless to people and mammals, and micro-nutrients for plants. It is only insects and fungi that cannot tolerate zinc or boron. It's been known for decades, and used extensively on chipboard and oriented-strand-board, but with limited success as it never really impregnates/protects the wood. The stuff is mainly trapped in the glue, and the board manufacturers mix it in (in my opinion) so they can say they did *something*.

There has just never been a way to impregnate solid wood with this stuff until now. I invented recently a way to do this, and filed a patent on it. It is a two-step waterborne process, and you can use it (the product is called Wood Vitality(tm) and you can read more about it at www.fresher-treated.com . It leaves no color in the wood, and does not interfere with any CPES-treatment, or painting, staining or gluing process.

So, there's a few comments about wood and borates and CPES, and I hope they give a better understanding of the technology.

Steve Smith

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PostPosted: Sun Jun 02, 2013 11:19 pm    Post subject: Reply with quote

impact1839 wrote:

After applying the CPES or water repellent, I apply a slow drying premium penetrating primer which is also overkill most of the time, I then apply 2 coats of Duration by Sherwin Williams. Duration is a premium one coat application paint due to its high resin content. Incidentaly it also carries a mildew additive. It carries a lifetime guarantee and is thicker than most paints. After this regiment is applied It will last a lifetime. I don't think you can get a better system.

This expensive procedure is for my house. I only do things above and beyond the status que. This is not practical for most budget minded home owners. You could however use this as an option in your impressive proposal to the discerning homeowners who are willing to pay for quality.


I know this is an old thread.


I'm planning on installing a decorative fence this summer. Somewhere around 36" to 42" high, roughly 70 linear feet.

The plan was to pre treat all the wood with CPES in my garage, and prime and paint everything before cutting and putting it all together.

Are you still using two coats of oil primer with the CPES?

If there is a step I can avoid, I'd like to do that. But if the primer is needed, then I wouldn't skip it. I want this fence to look good for a long while.
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