Powder post beatles

[Arkyrick]

I know kiln drying kills Powder post Beatles, but when you don't have access to a kiln is there a spray that one can use to rid them?

[mddillon78]

This is what I use, it works good for me.  I mix it and put it in a one gallon sprayer.

https://amzn.to/2LtHzBv

[muggs]

You can have them fumigated just like termites. I was told it takes a lot more poison gas to kill them compared to termites. 

[SawyerTed]

I believe heat treating to 135 degrees core temperature for an hour will kill them.  I have a neighbor who built an insulated box out of rigid foam sheets around a stack of lumber.  His stack was made on the South side of a barn and the box wrapped with black plastic to take advantage of solar heating.  He inserted a jet heater in one end and was able to get 140 degrees easy.  

He used some sort of sheet metal box/baffle to create a semi-indirect air flow and used a vent on the opposite end.  

He says it worked to kill the insects.

[mredden]

Borate or any old boric acids bug killer you would use on roaches. Go to a farm supply store for borate. Boric acid will kill any insect except spiders. It's pet safe too.

Mix in a spray bottle. Spray when you wood drops under 30% moisture content. I have never abserved any stain from it

[Arkyrick]

Thanks for the great suggestions👍

[Brad_bb]

@SawyerTed What is a Jet heater?  I guess you mean a torpedo heater- kerosene or propane?  I wonder how controllable that is?

One thing to remember is that the PPB larvae are deep in the wood.  A surface spray like a borate, will likely stop adult beetles from laying eggs, but not so sure it would be totally effective against what is already there.  The borates that use an alcohol (glycol) solvent, will penetrate better than a water based.  With either one though, you will need to clean or surface the wood before a finish can be applied.  Heat is probably the most effective.  From what I've read, you need to get the wood's internal temperature up to 133 degrees F for a couple of house.  So It may take 24-48 hours at a higher temp to get the wood's internal temp up that high.  

If you don't mind what is in the wood now, but just want to prevent further larvae, one way is to put a surface finish on the wood.  Anything that seals the surface so when the adult beetle lands, it does not taste the starch of the wood, then it won't lay eggs.  It can take up to 1-2 years before the existing larvae bore out and leave, But once they do, having a surface film finish, you shouldn't have any more.

[SawyerTed]

Yes a propane torpedo heater.  Manual adjustment for around 14 hours.  It isn't a kiln, it's a poor man's solution for one or two relatively small stacks of wood.  I believe he treated somewhere around 400 board feet.  

[Don P]

I did that with a tractor trailer load of KD white pine that drove through the rain all the way from Quebec, didn't have the heart to turn him around. We rigged up a mini "kiln" in the shop and used a salamander heater to redry it. Wickedly dangerous, direct fire is a great way to burn down a shop.

A couple of things about borate. It is an alkaline salt and is applied as a solution. If you have a cell cavity full of water and outside of the cell a salty solution the salt will diffuse through the cell wall trying to equalize the concentration. Borate penetrates deeper in wood green from the saw. If the wood has dried, then, a slow drying glycol helps wet out the fiber and dries slowly helping the borate penetrate. Borate only moves in or out of the wood at or above fiber saturation point. It is not a surface treatment, when properly applied it does penetrate.

I've been reading about some interesting research that has had positive results. Borate can leach back out of wood, if it is above fiber saturation point and if there is a "sink" at lower concentration for it to diffuse into. For years researchers have experimented with various ways of fixing it within the wood so that it doesn't slowly lose borate in outdoor wet exposure. Since the late '90's they have been playing with tannin-borate mixes, both of which have been experimented with and used independently. By adding hexamine to that solution it forms a resin within the wood and is fixed enough to pass UC2 treatment, outdoor above ground. I've seen a few patents but don't see any product yet.

Railroad ties are sometimes, and more so, being treated with a combined treatment of borate and creosote. This is outdoor ground contact exposure. The process uses less creosote than previously was used in creosote alone treatment yet the ties last 4 times as long. There are papers online showing cross section samples decades after installation with curcumin applied to show borate penetration. Unlike most forms of treatment the borate has no trouble treating deep into the heartwood.