Andrew asks about the homemade wood preservative:
Hi,
I found your post about the homemade wood treatment very informative! You mentioned at the end that you would post a recipe that didn’t use the antifreeze. Maybe I missed it, but I couldn’t find it anywhere. I’d be interested in that preservative, though… We will be building an Aspen cabin this spring, and need to give the logs a borate treatment once they’re peeled to avoid the black sapstain… I would prefer not to boil down the glycol in my kitchen, though, even though they call it “non-toxic”…. kwim?
Thanks,
Andrew
Hello Andrew –
I’ll have to go back and check — I thought I had posted that — regardless it is simply the boric acid and water –
Boric acid on its own is an anti-fungal, insecticide – however you need to get it into the wood. — The glycol acts as the carrier – Glycol will replace any moisture in the log with glycol and pull the borate in with it — this works from the ends of the logs — Glycol too is an insecticide and anti-fungal. the two in combination are very powerful. A Post on the recipe can be found here.
Mix boric acid in with water dissolve it as best you can and using a simple garden sprayer you can apply it to your logs. — You CAN use the glycol as well — the only reason that i cook it down on the stove is when Im making or stocking up on concentrate.
Since you will be using it right away –
Yeah you really don’t want to cook it down in your kitchen as it will make your kitchen smell a bit like an old garage for a while — if you were to cook it down – do it outside.
For your purposes I would just mix the boric acid with the glycol – dissolve as much of the borate as you can — and spray on your logs –
keep in mind that the mixture will penetrate best from the ends since it is from the ends that you have wicking action –
you will have – after everything dries – a light white dusting of boric acid crystals visible on the exterior of the log — I would just leave them be until you are ready are finished with the log – once you are complete with construction and ready to move in — then wipe off or brush off the residue from the logs or stain over it if you are applying a stain. I would suggest the glycol-boric mixture for the exterior only. If you are working with logs before they have been assembled then stick with just the application of boric acid without the glycol.
Boric acid, glycol or a mixture of the two are great as a preservative, insecticide and preservative however they are not going to help you on the sap stain.
removing sap is tricky. I take it your logs are somewhat fresh — good deal. Ill have to sit down and go through my files – If i remember right I had used acetone at one point then cleaned and bleached the area with a combo of cascade dishwasher soap and a thinner. — The problem with sap is that is does not easily break down but I may have a way to clean that up — I’ll have to go back in my archive files here at the lodge.
I have about 12 pounds of pine sap and pitch here so I could do a few experiments.
I’m heading out this morning to take a look at a log home of a reader that is facing some rot issues and will not be back until late Thursday evening – On Friday Ill start going through my files and see if I can find my sap blaster recipes.
I’m glad that you found the site helpful and I’ll check on that post with the other recipe I may not have properly linked or archived it.
I would love to hear more about your building project – Love to hear when people are building their own log homes – and the fact that you are getting ready to peel your logs already tells me a great deal — Fantastic.
I hope to hear from you soon
{ 15 comments… read them below or add one }
Hi there
I have a log building business in Scotland, UK and have been reading your articles on the use of Borates. We only use borates for the preservation of our logs. All logs are pre-treated with a 20% (10% Boric Acid and 10% Borax) by weight ratio with water onto our freshly processed timber whilst the moisture content is still very high. The water acts as the carrier for the borates which are then transported deep into the timber. One added benefit of the use of the borates is that they also act as a flame retardant. Once we get to the jointing stage of our logs, usually after several weeks of processing the logs (we machine round our logs) we then carry out a sealing process which can also be used on dried timber. This involves a mixture of cold pressed linseed oil and gum turpentine (the real stuff, not the petroleum imitation turpentine). We add a 2% (1% Borax and 1% Boric Acid) by weight ratio mix of the borates and apply to the timber. It takes around 24 to 48 hours to dry but gives a matt gloss finish and moisturises the timber. This mixture also helps to reduce checking of the logs whilst also carrying out its other functions as an insecticide, anti fungal and flame retardant. The oil’s main funtion is to act as the carrier for the borates to deliver them into the dry timber, and when the oil reaches a moist arear of the timber the borates are then tranferred over to the water to continue the transport process. This method is one of the most efficient of all methods of timber preservation and best of all it is non-toxic, environmentally friendly and uses totally natural raw materials. Retreatment is normally required after 10 to 12 years, although intermittent touch up is also a good thing. Points to note when calculating weights of the liquids involved is that the weights will vary depending on the liquid and their specific gravity. To help i have listed them as follows using water as the reference weight;
1 Liter water = 1 kilogram
1 Liter Linseed Oil = 0.93 kilogram
1 Liter Gum Turpentine = 0.87 kilogram
Mixing is then just a simple matter of maths
Remember never to store your raw linseed oil in sunlight otherwise it will become stand oil which is thicker and does not carry the borates as effectivley as cold pressed linseed oil. Linseed oil also darkens over time.
Tung Oil rather than linseed oil in the same mixtures can also be used as has been traditionally used by the Chinese for centuries in timber preservation, however one has to be careful as it is made from nuts, and should you have a visitor who suffers from nut allergies you could inadvertantly activate their allergy. As the oil is also a water barrier, your logs are protected from the rain, coupled with the borates you have a fully protected log that with care and maintenance should help keep your log home preserved for generations.
I hope this information is useful to you, and should anyone wish to contact me i can be reached on skype with the user name of rasputinscotland.
Regards
Michael Dutton
Thanks for the recipe for Boric Acid, Propylene Glycol and Borax. I heard about it from a friend but didn’t have a specific way of making and using it. I will be applying it over a post and beam structure with strawbale infill. The mix seems to address several potential problem areas such as termites, ants, fungus and fire retardance. Cheers, Eric
I HAVE A SAWMILL.I USE PINESOL IN MY WATER BOTTLE TO KEEP PINE SAP OFF MY BLADES. IT IS VERY SAFE TO USE FOR SAP CLEAN UP ON MY HANDS.
Brian – Great idea – I had not considered that — Thanks for the suggestion!
I’m a first time DIY log home builder. My logs are logdepole pine and were stacked in July 05. I had the roof on by mid-November, but not before the logs got rained on and now have have some slight darkening. For the most part, the logs are protected from sun and rain by a wrap around veranda. I’ve learned the hard way that I should have treated and protected the logs right after they were stacked but that’s water under the bridge. What approach would you recommend to take on the preservation/protection on the logs?
Hello Vickie – I am sending you an email with my phone number to talk to you about your project.
Normally I would use a wood preservative and paint it on the entire board but this really depends on the application — how are you going to use the board?
This ma sound funny but if you are going to use the board on the inside then I would take a different route than I would if using the board on the exterior.
In general you can paint it on — and thats it — but knowing how you are going to use the board may change my response — Please check your in-box for my email.
I am very interested in preservative. I have a ‘raw’ board 10 1/2″ widex 34 1/2″ long about 1/2″ : thick. How long to soak from the ends, then how long to dry? Do I just allow the board to soak standing it up in the liquid to allow the ends to wick it up or do I put it on the board like paint and allow to soak in? You can tell I know Zilch about this process but need it pronto for a house safety project. Help as much as you can, PLEASE. Your expertise will be immensely appreciated.
Hello Gary — Thanks for the information. Always good to hear from an architect.
Yes — boric acid is pretty inert stuff well to people and pets anyway.
Yes I am familiar with Timbor and happen to have a five gallon bucket of the powder in my basement. I’ll have to do some research and find out if there is any relationship of PEX to propylene — interesting
For the interior wood I would recommend about a 1:1 mix of Boric Acid and Borax dissolved in water and sprayed onto dry wood. Its pretty nontoxic to people and pets and soaks into the wood if it is dry enough. Has to be protected from water. The Borax web site seems to recommend one coat of primer and two coats of paint if used outdoors.
There is a patent from about 1982 on the web, that talks about mixing the two chemicals. Also, Borax markets a mixture under the name “Timbor”, and I looked up the code approval for the stuff a few minutes ago, and it seems to be along the same lines.
I remember an article in the journal of light construction years ago, where the guy recommended a ratio of 1:3 for the two chemicals, but couldn’t figure which was which.
By the way, I found an old book on PEX treated wood projects some time ago. I wonder if this is the same as propylene glycol? If so, it is an interesting material that even archeologists are starting to use to preserve specimins (sp?).
… an interior designer told me that AIA stands for Another Idiot Architect…
The bait stick sounds like a good idea — I have never used such. The glycol can be sprayed on directly this should soak into the wood. – You don’t have to make the mixture — the glycol itself will help to kill them. Dusting the area with boric acid would be a must — as the termites veture through it they will get particles of the boric acid on them and it quite frankly sucks them dry of moisture.
If you were to combine the two – the glycol and boric acid — you dont have to cook it as I do when making large batches. Mix the two together — not all of the boric acid will dissolve.
Propylene glycol is best when used in wet areas as is follows the water or moisture and replaces it and pulls the boric acid in with it. Your application is a little different. However – it may be a good way to give them a double whammy.
Dust the area well with boric acid regardless. Use the Skype and give me a shout and lets talk about this as well.
REMEMBER any time you are using the glycol – PLEASE take the necessary and seemingly unnecessary safety precautions
the wall had some old 2bys but most of it was new ones, a couple they ate completely into . and will have to be replaced . some of the old ones are riddled through the grain . they came out of the wall at the floor and into a cardboard box . thats how we found them .
do you mean to use the powered boric acid and just dust it on there .
also I thought about drilling a hole and putting a bait stick in it thats supposeto kill them. we had our house treated years ago , but I guess that it wears off over time. thanks for the advice.
jerry
Hello Jerry — This is certainly on\e step you can take — However — I would suggest that in this instance I would just use the boric acid. You can certainly use the glycol and boric acid mixture however the boric acid by itself should do the trick —
This of course depends on how eaten the wall is. Do you have any photos of the damage? — how deep have the termites gone?
I have an interier wall in the basement that the termites have ate up . Can I spray on the mixture of boric acid and rv antifreeze .Before I cover it up again.
Hello R! — Thanks for checking out the site and for your questions! — Ahhh Kentucky is so beautiful – I ‘m familiar with the Carroll and Trimble County areas. – Beautiful.
Texas is too mind you – I take it that the humidity down there is killer.
Hmm A cedar fence. Cedar is naturally resistant to rot and mildew how ever it can get a black mold on it. I would imagine that the sun ill bleach it out quickly there as well.
There are some very good products on the market – I’m surprised by such quick deterioration.
The quick answer to your question is Yes and No – With great caution:
Yes — You can use the glycol treatment – If you use it I recommend the antifreeze used in marine environments – or RV antifreeze as it is environmentally friendly and less toxic than ethylene glycol. Please stay away from Ethylene glycol. Both should be used only at your own risk.
If the fence is in proximity to a play area I would use extra caution. Is this fencing in where your 8 year old and dog play? I assume so.
The glycol can be sprayed or painted on however absorption is going to be at the ends as the fibers in the wood would pull or wick the glycol up through the fencepost. You would have very little penetration on the sides or the faces of the post.
IF you were to use it on the fence posts I personally would want to stain and seal it soon after and keep the dog, cat and your 8 year old away from it for a while.
I dont think that boric acid will really do you much good as the fence is exposed to the weather. Boric acide helps to kill off insects and mold mildew but that is best used on wood that is protected from the elements and not directly exposed to rain.
The boric acid if used can be sprayed on in a mixture with the glycol but here again you would have to protect passersby by staining and sealing the fence post.
I use the mixture or the parts individually but then again i dont have little ones running around that would have access to the areas in which I use it.
I am going to send you my information and we can have a telelphone conversation about this.
Hi. I have an odd question and thought maybe you could provide some insight. I’m from Kentucky but am living in the Houston, Texas area now. I am having a new fence made from cedar put up on my property. I have never seen the mold, mildew, and general decay of wood products (as well as others) that occurs down here. A 30 year roof lasts 12-15 down here!!! I have been told that the wood is preserved with an antifungal and antimold treatment but have seen these fences look horrible in less than a year despite this. So, I am wanting to preserve the wood myself and then stain it. Is this boric acid/glycol treatment something one could use to preserve a fence? Are there any problems with staining over it? How long would one wait between the glycol treatment and then the staining? I have an 8 year old, as well as a dog and a cat, are there any toxic or environmental considerations? Thank you in advance for your time and I appreciate any advice you can provide.
Thanks,
R