In many previous posts I discuss the use of a borate based product during the process of replacing chinking, repairing logs and have identified several other uses where borates should be used as well as methods of application.
A borate based product works well as a wood preservative — it kills mold, mildew as well insects and is very useful to have around any home – not just log homes.
I have received numerous emails and questions as to where to find ‘boric acid’ or borate-based products.Several readers have emailed saying that they found boric acid at a local at a local store but only in small amounts and at astronomical prices.
Borate based products are actually not very expensive and a little goes a long way. If you needed some in a pinch for a small project you may be can able to find a borate-based product locally but don’t just go to the local store and pick up a box of 20 Mule Team Borax. 20 Mule Team, although it contains borax, it is different than the boric acid needed.
I have placed in the side bar a link to the best source for a borate based wood preservative for your projects. They carry borate-based (PeneTreat) in the perfect sized quantities for most applications at a very attractive price.
Please follow the above link and should you wish to call them, ask for Mike Carey. He is a wealth of information. 
Tell him that Bearfort Lodge says hello.
{ 21 comments… read them below or add one }
Hello, we have a hand hewn 1837 log cabin and I am about to follow all your methods for rechinking – thank you for great advice. The whole cabin is inside another building, so non of the walls are exterior. I want to use the borate powder that you suggest that I “dust on” on. Is this powder the penetreat powder – straight from the container,and not mixed with anything?
Thanks
Karen
Hello Karen — So glad that you found the site — thanks! — Yes the powder that I dust on is Penetreat. Timbor is another brand of the powder that I use. These are borate based products that I recommend – you can use either product – I just happen to have both. When you ‘dust’ on the product — I use an empty ketchup squeeze bottle partly filled with the borate and then ‘puff’ the borate into cracks and between the logs before I chink. – You can use it straight from the container or following the directions on the side of the container of either product make a 10% solution of water and the borate and using a spray bottle or garden sprayer apply the material.
When using the powder dry — keep in mind that a little goes a very long ways. – Just a dusting will do it. when spraying — the same thing applies – just a gentle squirt of the solution – think of it like spraying a little water on a shirt before ironing – just enough to make it slightly damp. When the water dries the crystals of the borate will reform resulting in a slight white-ish residue on the log. I would only use either method between the logs before chinking.
So I’m getting ready to chink my log cabin and would like to pre-treat the logs with the Mule Team Borax Soap…..Is there a soap:water ratio? Do I use a garden sprayer or brush it on? How long do I let it dry before I start chinking?
Thanks,
Brian
Hey Brian – Well 20 Mule Team will be great for cleaning the logs but its not quite the same thing as a borate based product or material for preserving wood. — When making the solution you can start with a 10% solution following the directions on the container. I use a garden sprayer. I find it dries rather quickly as long as you are not saturating the wood – I don’t soak the wood. Its usually dry by the time I start chinking not because i’m following some rule but but the time I finshi one task and move to the next its usually dry.
So glad I found your website. It’s been 23 years since my husband and I physically built our log home. Regretably the log home company we used didn’t stress 25 years ago the preventative process needed to keep these white pine logs bug, disease and rot free. We did initially bleach and CWF for preservative purposes but the length of time for reapplication lacked. Also as with anything obviously, time, trial and error produced a better way to treat and better preservatives were formulated. Needless to say at this point in time after losing my husband I am faced with dry, cracking, bug borered and rotted places in my home. Thank God I have a carpenter son who is working hard to remedy the situation. The entire house and garage has been pressure washed, dead and rotted materials removed, all logs have been caukled. I’m feeling that at this point in time I should go with the Boric acid, Borax and glycol mixture and treat everything. My question is how much is enough??? Everything seems quite dry and I’m sure will absorb a lot, any idea?? Also do you feel Weatherall to be a superior exterior sealant over CWF. I would appreciate feedback from anyone since we are at the application stage after a lot of “nit pickey” work.
Thank you for your time and consideration.
Log home lover, Denise in MD
Hello Denise – Thanks for visiting I’m glad that you found it. I’m am sorry for your loss.
Its a tough question as to how much is enough. When using a product like Penetreat or Timbor, both borate-based wood preservatives in powder form, you will want to make at least a 10% solution following the directions on the container. You can choose to use water or you can use the environmentally friendly antifreeze – the pink stuff commonly used in boats and RVs. The propylene glycol in the antifreeze will help to pull the borate into the wood – mostly from the log ends to take advantage of the wicking action of the wood grain. However since you said that your wood is dry you could probably just use the 10% borate and water mixture. The borate will effectively kill insects and help to dry the wood. Dry wood does not rot – only wet or constantly moist wood.
Power-washing is never a good idea as you are introducing water at high pressure – water is the enemy of logs. Having done that through you can try the borate and glycol mix at the log ends and a water glycol mix other places. Use only on the exterior.
After application there may be a white film that appears on your logs simply because the crystals of the borate have dried and reformed. you can either simply brush that off or leave it be. Or you could use the borate and mix that in a 10% with your stain. You could stain right over the borate application as well.
I use Weatherall products around here for stain and finish – I have had great success with their products and find them to be superior to others.
Please let me know how your project is coming along.
I was delighted to find your site via a patient. We don’t have a log home but we do have a home constructed from an eclectic collection of salvaged 1870 heart pine doors; porch post salvaged from the Lottie Moon home where they foolishy torn off a back balcony rather than resotoring it; and flooring, v groove paneling milled and stored in a dry area for over 60 years. We used a commercial version of your “home brew” borax treatment that was very effective but costly. We have another large stack of wood that we want to use upstairs on the walls that would have cost a great deal to treat. Thanks to you I can start treating this summer. Almost finished with the house? Are you ever finished? No.
Linda –
Well I’m glad that you found the site as well. Wow sounds like a wonderful project — Feel free to send photos. I hope that you find other useful information here at the lodge.
Why are you pretending this stuff is hard to get? You can just buy a box or a bag of borax at any decent hardware store or garden center.
Holy cow! SEVENTY bucks for a bucket of borax solution? who in the world buys this stuff?
I don’t pretend this is hard to get but you have to make sure tht the product you are getting is the right stuff. You can certainly use 20 Mule Team Borax — go for it – I use it myself for cleaning purposes however its not quite the same thing as the borate used in insecticide.
Both Timbor and Penetreat contain borate in the correct form. Certainly there are other resources but make sure you know what you are getting.
Hello Monique — I am sorry for the inconvenience — Here at Bearfort Lodge — I have a major computer melt down and it has taken until Mid October to resolve. Almost all my files and information were frozen and unreachable– Im glad that you were able to find the materials that you were seeking. — I am in the final stages of recovering all of my files and will respond as quickly as possilbe
Boric acid can be bought at the dollar store. It is $2 for a pound bottle. It is roach powder.
Also, boric acid is the main ingrediant in borax soap.
You bet – the base ingredient for many insecticides is a borate – a form of boric acid. Yes although you are correct that there is borax in 20 Mule Team Borax it is different from the borate in either insecticide or wood preservatives such as Penetreat or Timbor.
20 Mule Team is great for cleaning and can be used in other applications its chemical structure is slightly different.
Hi There, I sent emails to, and left phone messages for the company you suugested for Boric Acid. They did not return either. I am glad now, as the local farm feed store was able to order me in a 50 lb bag of boric acid for $49.95. That is a lot less than the website you have here, plus I didn;t have to pay shipping on top!!!
Hello Monique — Hmmm I’m not sure why your calls or emails would have gone unanswered. I’ll have to get in touch with Mike. Regarding your find at the feed store – Fantastic! There are all sorts of resources to find that which you seek. Great find.
Hello NewLogger — Im glad that you find the website helpful. Boric acid — or more appropriately a product such as the Penetreat which is borate-based will help in the prevention on mold growth a well as insect infestation. A stain and seal of the exterior is recommended — I use a product called Weatherall – it is a water-based stain and seal in one.
thank you for your website it is very informative. We recently purchased a log hone, built 25 years ago and found some rotting logs, much to our dismay, that the inspectors didnt find. We are wondering if we can use boric acid as a compete all over the house protector. We plan on replacing the rotten logs, have it re-chinked and then use a protectant on the whole house. Can we do that with the boric acid or do we use a wood sealer and if so, what wood sealer do you recommend.? Thanks!
Log Cabin Adventures –
Thanks for visiting Bearfort Lodge – Yeah this stuff is killer for insects.
WOW – Ive been checking out your website – With your permission Id like to place a link to your site.
I am so glad I read this article because I have been trying to remember for some time what it was my parents used to kill ants when I was a child. It was boric acid! I kept thinking of borax but somehow felt that was wrong (though I love it for cleaning!). Now maybe we can take care of a persistent ant problem we have experienced both here and at our cabin. Thanks!
Hello Chauncey – Thanks for visiting Bearfort Lodge. YES PeneTreat is borate-based. Just follow the link.
PeneTreat can be used mixed with water (follow the directions) as well as using it in dry form. As you may have read on many of my previous posts, I use it dry to dust areas before chinking.
This is excellent stuff — it is a dry powder that comes in a 3 1/2 gallon bucket and a 5 gallon bucket.
Hello. THANK YOU for the great info.
I’m confused about one thing. Is the link to PeneTreat the source mentioned for boric acid?
Chauncey
{ 1 trackback }